Beach-Nesting Birds Within Corner Inlet

BEACH-NESTING BIRDS WITHIN CORNER INLET

Monitoring of beach-nesting shorebird and seabird breeding success in Corner Inlet to assess the health of the RAMSAR site

September 2019 – March 2020

By Amy Adams and Grainne Maguire, Beach-nesting Birds Program, BirdLife Australia

Snake Island (Grainne Maguire).

Executive Summary Beach-nesting birds (BNB) are a suite of birds including resident shorebirds and migratory seabirds, that are largely dependent on coastal habitats for breeding. Many beach-nesting bird species have experienced population declines, local extinctions and a contraction in range. Despite the highly threatened nature of beach-nesting birds and their habitat, little emphasis has been placed on their conservation and management in Australia. The Corner Inlet barrier islands offer a unique opportunity to monitor these beach-nesting shorebirds and seabirds during the breeding season where it is predicted that the local populations would experience higher rates of breeding success than the well-monitored but highly disturbed mainland sites.

Three of the barrier islands (Snake, Clonmel, Boxbank) within Corner Inlet were surveyed on eight separate occasions between September 2019 and February 2020 with the aim to inform the Ramsar site’s Limit of Acceptable Change monitoring regime as well as to document the distribution and breeding success of beach-nesting bird species. Additionally, Dream Island was surveyed three times during the same survey period to search for evidence of nesting terns. Threat assessments were carried out at active nest sites and where appropriate, remote cameras were set to assist in identifying nest fates.

In total, 283 Hooded Plover, 331 Red-capped Plover, 1,139 Pied Oystercatcher and 16 Sooty Oystercatchers were counted throughout the breeding season, with numbers varying each month. There were consistent sightings of pairs of breeding Hooded Plovers and Pied Oystercatchers on what we were able to estimate as 19 Hooded Plover and 59 Pied Oystercatcher territories across the three main barrier islands. There were no Hooded Plover fledglings produced across the three islands despite at least 42 nesting attempts by 19 pairs. Of the known 132 Pied Oystercatcher breeding attempts by 59 pairs, only one chick is known to have fledged. We detected five Caspian Tern and three Fairy Tern colonies on Clonmel Island. A small Fairy Tern colony and a single Little Tern nest were also detected on Dream Island. The Caspian Terns successfully hatched and fledged chicks although final numbers of fledglings are not clear due to the logistical challenge of capturing fledging of chicks of varying age within a narrow window of time.

While there were challenges in accessing the islands, a wealth of data was collected to inform our understanding of the health of this system for breeding shorebirds and seabirds. Foxes were detected on Snake and Dream Islands, and evidence of fox predation was detected by remote cameras set on two Pied Oystercatcher nests on Snake Island. Ravens and Silver Gulls were the most common source of nest failure for a range of species on the islands, as well as tidal inundation of nests. Several recommendations are made regarding improving future monitoring and mitigating key threats to beach-nesting birds within the barrier islands to improve breeding success outcomes.

Snake Island (Grainne Maguire). 2

Introduction Beach-nesting birds (BNB) are a suite of birds including resident shorebirds and migratory seabirds, that are largely dependent on coastal habitats for breeding. Shorebirds nesting along the southern coastline of Australia and Victoria in particular, include the Hooded Plover (Thinornis cucullatus), Australian Pied Oystercatcher (Haematopus longirostris), Sooty Oystercatcher (Haematopus fuliginosus) and Red-capped Plover (Charadrius ruficapillus). Beach-nesting seabirds that breed in Victoria, Australia, include Caspian Terns (Hydroprogne caspia), Crested Terns (Thalasseus bergii), Fairy Terns (Sternula nereis) and Little Terns (Sternula albifrons).

Beach-nesting birds lay their eggs on beaches, in a simple scrape above the high-tide mark, sand spits, dunes or rocky shores, where sand, shell or rock provides an ideal substrate for their well camouflaged, stone coloured eggs. This camouflage serves to protect the eggs from native predators, and the colouration of their chicks also closely matches the coastal environment. Beach- nesting shorebirds are territorial, occupying discrete sections of coast with suitable nesting habitat and food to support the pair plus chicks. Red-capped Plovers can be less territorial, nesting semi- colonially in small groups. Beach-nesting shorebirds predominantly feed on invertebrates on the sand surface, under wrack, on rock platforms and in the soft wet sand. When their eggs hatch, the precocial (i.e. relatively mature and mobile from the moment of hatching) chicks move about with the parents, either being fed for the first few weeks as is the case for Oystercatchers, or foraging for themselves from the moment of hatching, as for the Plover species. Beach-nesting seabirds on the other hand, typically nest colonially, as they benefit from safety in numbers while one or both of the pair are out at sea foraging.

Birds that nest on beaches experience one of the harshest struggles of any bird to successfully produce young (Maguire 2008). Prior to human settlement, high tides, storms and native predators, such as gulls, ravens and birds of prey, were the main threats shaping breeding success outcomes for these birds. Since European settlement, reproduction rates have been dramatically impacted by a range of new threats added to the coastal environment including: destruction and modification of habitat, introduced predators such as foxes and cats, increases in native predator populations (such as gulls and ravens) related to urbanisation, and human recreation (and their companion canines, horses and vehicles) on beaches that results in crushing of eggs and chicks, or lethal disturbance during incubation and chick rearing phases (Maguire 2008; Maguire et al. 2014). The features that adapt beach-nesting birds to their environment become detrimental to their breeding success where human recreation occurs: the location of nests, camouflage of the eggs and young, the long incubation and brood rearing phases, and the passive nature of nest and brood defence (with the exception of terns that swoop approaching people), all make them highly susceptible to breeding failure.

Many beach-nesting bird species have experienced population declines, local extinctions and a contraction in range. Hooded Plovers and Fairy Terns are both listed as threatened species under the Federal Environment Protection and Biodiversity Conservation (EPBC) Act 1999.

Despite the highly threatened nature of beach-nesting birds and their habitat, little emphasis has been placed on their conservation and management in Australia. There has been a bias in research and conservation efforts towards migratory shorebirds in comparison to resident species (Weston

2007), even though a greater number of resident species have a threatened status (Milton et al. 2005). Beach-nesting shorebirds and seabirds can be excellent indicators of coastal health, providing coastal managers with insight into the threats present within the coastal environment, and a measure of the effectiveness of investment in threat mitigation (Schlacher et al. 2014). They are therefore an important group of birds for coastal managers to focus their efforts.

Study aims

Nooramunga Marine & Coastal Park is one of four significant parks located within the Corner Inlet Ramsar Site. It covers approximately 30,000 ha between Port Welshpool and McLoughlins Beach and consists of a complex series of coastal habitats, islands, intertidal flats and subtidal marine environments. Of significance is a series of barrier sand islands that protect the inner islands from the open coast, namely Snake Island, Clonmel Island, Boxbank Island and Dream Island.

The Hooded Plover, an iconic coastal species, has been the focus of BirdLife Australia’s Beach- nesting bird project since 2006. The species is listed as threatened both at the state and national level. Increasing the breeding success has been essential in halting the decline in Hooded Plover numbers experienced in Victoria. The Corner Inlet barrier islands contain important breeding areas for this threatened species as well as for other beach-nesting shorebirds including Red-capped Plovers and Pied Oystercatchers, and for seabirds including Crested Terns, Caspian Terns and occasionally Fairy Terns.

Given the relatively pristine habitat within the Corner Inlet barrier islands, there is a unique opportunity to add to our knowledge of the breeding success rates of these species in habitats with low human visitation compared to the well-monitored, mainland beaches that experience moderate to high levels of human (dog, horse and even vehicle) visitation.

The Corner Inlet barrier islands offer a unique opportunity to monitor these beach-nesting shorebirds and seabirds which would be predicted to experience higher rates of breeding success than the well-monitored mainland, due to the infrequent human use of the islands and thus presumably only natural, pre-European colonisation, threat levels. Little is known about the range and intensity of threats impacting beach-nesting shorebird and seabird breeding success within the barrier islands. Predators and weeds may be having greater influence on the breeding outcomes for this population of birds, but that remains largely unknown. Identifying the sources of nest failure and tracking threats at breeding sites through the breeding season, would also enable us to formulate targeted threat mitigation actions for sites to improve future success. The islands have the potential to act as a refuge for these birds and a source of recruitment for mainland populations given the lower predicted recreational threat base.

Under Ramsar site obligations, the critical processes and services (CPS’s) identified at the time of listing must be intermittently assessed against Limits of Acceptable Change (LAC’s). The below Limits of Acceptable Change monitoring requirements have been outlined for Waterbird (beach-nesting shorebird and seabird) Breeding:

Limit of Acceptable Change (LAC) Spatial / temporal scale of measurements

Nesting of the following species recorded in at least 50% of years: Recommended baseline Australian Fairy Tern monitoring program should Australian Pied Oystercatcher comprise a minimum of two Caspian Tern annual sampling periods Crested Tern separated by at least one year Hooded Plover (and within a five-year period).

To date, there has been no dedicated study of the breeding success of beach-nesting shorebirds and seabirds in Corner Inlet. The only surveys to have been completed in Corner Inlet include BirdLife Australia’s biennial count surveys, opportunistic sightings by rangers when doing fox baiting or observers during Shorebirds 2020 counts conducted from boats, records of tern nesting colony sizes by the VWSG when conducting banding trips of chicks and BirdLife Australia’s pilot study which carried out repeated visits to the barrier islands during the summer of 2018 (Maguire & Ekanayake 2018).

The specific aims of this study are to inform the above LAC monitoring regime as well as to document the breeding success of beach-nesting species in this unique island system by: 1. Surveying the three most important barrier islands in Corner Inlet (Snake, Clonmel, Boxbank) across the breeding season (September-February) to map the distribution of breeding beach-nesting shorebirds and seabirds. In the 2018 pilot study, Dream Island was identified as having lower densities of breeding shorebirds than the other three islands, but it is historically known to be a preferred Crested tern nesting site. Therefore, Dream Island would be surveyed in the peak months of breeding to search for any evidence of tern nesting. 2. To identify consistent locations of breeding birds to estimate the number of territories on each island in a given breeding season, as well as map any tern nesting sites; 3. To follow the progress of any nests or chick sightings to document fates of nesting attempts and overall rates of success for each of the focal species of beach-nesting birds (a minimum of eight to nine repeated surveys during September to February is required to meet this aim); 4. Where suitable, set remote cameras on active nests to assist in identifying nest fates, and; 5. Carry out threat assessments at each site where nesting or chicks are observed.

Snake Island (Grainne Maguire). 5

Methods Three of the islands within Corner Inlet were repeatedly visited – Snake Island, Clonmel Island, and Boxbank Island. These were deemed of highest value for the main species of interest (Hooded Plover, Pied Oystercatcher and tern species). These islands were surveyed on eight separate occasions (original aim was to survey nine times, but Table 1 highlights the significant challenges encountered) between September 2019 and February 2020 by a team of highly experienced, beach- nesting bird observers. Dream Island was surveyed less frequently (three surveys) during the same survey period, mainly to search for any evidence of nesting terns, which can be unpredictable in their choice of nesting location. Table 1 summarises survey effort, teams and boat transportation.

Table 1. The dates, team composition and boat provider for each survey period. Green highlighting indicates successful trips, while orange highlighting represents planned trips that were cancelled (see notes column).

Survey Date Island Observers Boat provider Notes # 23/09/2019 Boxbank Parks Victoria Cancelled - storm 23/09/2019 Clonmel Parks Victoria Cancelled - storm 24/09/2019 Snake Parks Victoria Cancelled - storm Renee Mead, Bridget Survey 7/10/2019 Boxbank Nicholson, Daniel Lees, Lindall Parks Victoria 1 Kidd Meg Cullen, Lucinda Plowman, 7/10/2019 Clonmel Parks Victoria Sonia Sanchez, Chris Willocks Grainne Maguire, Kasun 22/10/2019 Snake Kraken Ekanayake Cancelled - swell 8/10/2019 Snake conditions 21/10/2019 Boxbank Glenn Ehmke, Renee Mead Kraken Survey Grainne Maguire, Kasun 2 21/10/2019 Clonmel Kraken Ekanayake, Leo Berzins 2/11/2019- Snake Grainne Maguire, Phil Barrett Kraken 3/11/2019 18/11/2019 Boxbank Renee Mead, Lindall Kidd Parks Victoria Grainne Maguire, Daniel Lees, Survey 18/11/2019 Clonmel Parks Victoria 3 Laura Tan Grainne Maguire, Daniel Lees, 19/11/2019 Snake Parks Victoria Lindall Kidd, Renee Mead 7/12/2019- Snake Jon Fallaw, Bec Hayward Kraken 8/12/2019 Survey 10/12/2019 Boxbank Lindall Kidd, Sharon Woodend Parks Victoria 4 Kasun Ekanayake, Tegan 10/12/2019 Clonmel Douglas, Shani Blyth, Bridget Parks Victoria Nicolson 13/12/2019- Snake Grainne Maguire, Phil Barrett Kraken 15/12/2019 17/12/2019 Boxbank Renee Mead, Laura Rhodes Parks Victoria Survey Kasun Ekanayake, Andrew 5 17/12/2019 Clonmel Hunter, Alan Willcocks, Chris Parks Victoria Willocks 17/12/2019 Dream Brownen Baird, Sally Leonard Parks Victoria

Survey Date Island Observers Boat provider Notes # 5/1/2020 Boxbank Renee Mead, Neil Shelley Kraken Grainne Maguire, Laura 5/1/2020 Clonmel Kraken Rhodes, Mark Lethlean 5/1/2020 Dream Jon Fallaw, Bec Hayward Kraken Survey 6/01/2020- Cancelled - low air Snake Kraken 6 7/01/2020 quality 17/01/2020- Snake Kraken Cancelled - storm 18/01/2020 25/01/2020- Snake Grainne Maguire, Phil Barrett Kraken 26/01/2020 Cancelled – changed 16/01/2020 Boxbank Kraken boat operator availability Cancelled – changed 16/01/2020 Clonmel Kraken boat operator availability Cancelled - changed boat 16/01/2020 Dream Kraken Survey operator availability 7 2/2/2020 Boxbank Renee Mead, Julie Riley Kraken

Grainne Maguire, Andrew 2/2/2020 Clonmel Hunter, Stuart Inchley, Cara Kraken Schulz 16/02/2020- Cancelled – boat broke Snake 18/02/2020 down Kraken, Boat broke down after 16/02/2020 Boxbank Renee Mead, Tanya Cowell Jono Stevenson dropping observers on return island Kraken, Boat broke down after 16/02/2020 Clonmel Kasun Ekanayake, Leo Berzins Jono Stevenson dropping observers on Survey return island 8 Kraken, Boat broke down after 16/02/2020 Dream Jon Fallaw, Bec Hayward Jono Stevenson dropping observers on return island 19/02/2020- Grainne Maguire, Laura Snake Parks Victoria 20/02/2020 Rhodes Volunteer boat Survey Clonmel 12/03/2020 Lindall Kidd (shorebirds 9 partial count)

Boat pick-up from Snake Island (Grainne Maguire). 7

Figures 1-4 show the areas surveyed during each of the eight survey periods. We targeted ocean beach habitat and the expansive spits/sandflats at both ends of each island as these represent the optimal habitat for beach-nesting species. It is likely that Pied Oystercatchers and Red-capped Plovers use the inner, lower energy habitat for nesting but to a lesser degree. On Snake Island, we decided to concentrate surveying efforts between Bentleigh Point and the far eastern spit, after the pilot study (2018) revealed the majority of nesting Hooded Plover and Pied Oystercatcher pairs are concentrated in this stretch.

Surveys were carried out approximately four weeks apart, which is the maximum frequency to allow for nest or chick fates to be followed from one visit to the next to determine an outcome. Hooded Plovers and Pied Oystercatchers have an egg phase of approximately 28 and 26 days respectively, and a chick phase of 35 to 49 days respectively, and are capable of multiple attempts in a season which spans from August to late March. Terns colonially and synchronously nest. They can re-nest in a given season, with some nesting extending in to the late summer. However, cancellation of trips due to a combination of boat availability, tide heights, storms and poor air quality due to the bushfires meant that some survey periods were smaller or larger than the targeted four weeks (see Table 1).

Ahead of each survey, the team of observers would be emailed the instructions and job safety analysis, and the night before each survey, the team would go over the aims, procedures and how to fill out the data sheets. From survey two onwards, teams would also be made aware of the locations of any nest or chick sightings from previous surveys.

During each survey, a team of two observers for each of Snake, Boxbank and Dream Islands, and four for Clonmel Island, would walk at a slow, consistent pace spread out along the beach/spit to ensure that the entire area from the water’s edge to dune or sand flat was searched. If the area was particularly wide (e.g. spits) and the team only consisted of two people, they would cover one half of the area at a time, being careful not to displace or double count any birds. Due to logistics on some trips (e.g. pinch points on Snake Island, lack of boat access to the eastern end of Dream Island), some islands had to be traversed up and back. The return surveys were not included in the analyses. However, if additional nesting information was discovered on a return survey, this detail was added to the original observation and included. Binoculars and spotting scopes were used to scan ahead for evidence of nesting or chicks, before birds could detect the approaching observers. The table of previously found or suspected nests and chicks would be consulted, and the GPS used to track to that location to assess if the nest/chicks were still active.

Hooded Plovers, Snake Island (remote camera image). 8

Figure 1. Extent of survey coverage (repeated over seven visits) on Snake Island.

Figure 2. Extent of survey coverage (repeated over eight visits) on Clonmel Island.

Figure 3. Extent of survey coverage (repeated over eight visits) on Boxbank Island.

Figure 4. Extent of survey coverage (repeated over three visits) on Dream Island.

We recorded every observation of our target species (Hooded Plovers, Red-capped Plovers, Pied Oystercatchers, Sooty Oystercatchers, Crested Terns, Caspian Terns, Fairy Terns and Little Terns) regardless of whether these were breeding or non-breeding. Where time permitted, a migratory shorebirds survey was also carried out.

For those observations that involved confirmed or suspected breeding, we would record the following:

1. Evidence of breeding or nesting behaviour including stage of the breeding cycle (scrape, courting/mating, nest with eggs, chicks, fledged, failed), and the egg or chick number observed. 2. A snapshot threat assessment encompassing a 100 m radius around the sighting including tracks/prints. In addition, a description of the composition (percentage cover) of the vegetation present on the foredune/primary dune. 3. For every nest found, standardised photos of the nest and nesting habitat, and a GPS reading of the nest’s location. 4. For every nest of a Hooded Plover, Red-capped Plover or Pied Oystercatcher, floating eggs to estimate laying date. 5. For a subset of nests (any species), remote cameras would be set and left in situ until the next visit. Cameras would only be set on nests where: 1) the beach was wide enough and the camera was unlikely to be flooded/inundated, and 2) the nest was at least 1 km from the nearest camera in either direction.

Detailed instructions for photographing nests, floating eggs and setting remote cameras were provided to trained participants and they were given a set of data sheets for egg float and nest camera set details, as well as for additional fields about tern colonies. The bulk of observations, nesting data and threat data were entered directly in to the Beach-nesting Birds program section within Birdata via the mobile phone app.

Beach surveys, nest monitoring and remote camera monitoring of nests was carried out under Department of Environment, Land, Water and Planning Wildlife Act and National Parks Act permit numbers 10009068 (Oystercatcher and tern species) and 10008428 (Hooded Plovers). Banding of Hooded Plovers was carried out under permit number 10009067.

Results Beach-nesting bird sightings and distribution Table 2 presents the average number of each of the beach-nesting shorebird and seabird species sighted. Table 3 presents the total numbers of Hooded Plovers, Red-capped Plovers and Pied Oystercatchers and it is evident that numbers fluctuated between the seven survey periods where all three main islands were consistently surveyed. Snake Island had an average of 17 Hooded Plovers sighted across the season, but this fluctuated to as few as nine at the end of the breeding season and a maximum count of 26 sighted at the start of the season. Clonmel also had variable numbers of Hooded Plovers across the season, with as few as seven and as many as 25, but an average of 13. Pied Oystercatcher numbers were largest on Boxbank Island, particularly at the start and end of the

breeding season, but during the season were more stable and representative of the breeding population. It is apparent that the breeding Pied Oystercatchers move off Clonmel at the end of the season and are likely accounting for greater numbers seen on Boxbank at that time. This suggests foraging habitat is most ideal on Boxbank and when birds aren’t breeding, they will opt to flock on the most productive island. Sooty Oystercatcher numbers were typically stable across all survey periods (Table 3).

The total numbers of the tern species also fluctuated between the seven survey periods and were the highest during December and January with numbers then decreasing on subsequent visits for each species (Table 3). These fluctuations suggest post-breeding movements are occurring in and out of the island system.

Figures 5-8 shows the distribution of beach-nesting shorebirds and Figures 9-12 shows the distribution of seabirds for each island across all surveys. With the exception of Snake Island, it is evident that the spits on the islands attract the greatest densities of birds compared to the ocean- facing interiors of the islands.

Table 2. Average number of adult beach-nesting bird species sighted for the three main barrier islands visited for seven trips where all islands were surveyed.

Species Adults

Hooded Plover 35.4

Red-capped Plover 39.7

Pied Oystercatcher 138

Sooty Oystercatcher 2.1

Caspian Tern 33.4

Crested Tern 53.4

Fairy Tern 8.9

Little Tern 32.9

A Hooded Plover nest (left) and a Pied Oystercatcher nest (right) on Snake Island (photos: Grainne Maguire).

Figure 5. Distribution of beach-nesting shorebirds on Snake Island over the seven surveys.

Figure 6. Distribution of beach-nesting shorebirds on Clonmel Island over the eight surveys.

Figure 7. Distribution of beach-nesting shorebirds on Boxbank Island over the eight surveys.

Figure 8. Distribution of beach-nesting shorebirds on Dream Island over the three surveys.

Figure 9. Distribution of seabirds on Snake Island over the seven surveys.

Figure 10. Distribution of seabirds on Clonmel Island over the eight surveys.

Figure 11. Distribution of seabirds on Boxbank Island over the eight surveys.

Figure 12. Distribution of seabirds on Dream Island over the three surveys.

Table 3. The number of beach-nesting bird species (adults and juveniles) observed on the four Corner Inlet islands during the eight survey periods.

BOXBANK CLONMEL DREAM SNAKE TOTAL Species Survey period Adults Juvs Adults Juvs Adults Juvs Adults Juvs Adults Juvs Hooded Plover Trip 1 - October 0 0 18 0 - - 26 0 44 0 Hooded Plover Trip 2 – October (early November Snake only) 5 0 7 0 - - 17 0 29 0 Hooded Plover Trip 3 - November 4 0 13 0 - - 12 0 29 0 Hooded Plover Trip 4 - December 6 0 24 0 - - 16 0 46 0 Hooded Plover Trip 5 - December 5 0 15 0 4 0 15 0 39 0 Hooded Plover Trip 6 - January 3 0 11 0 7 0 25 0 46 0 Hooded Plover Trip 7 - February 2 0 11 0 - - - - 13 0 Hooded Plover Trip 8 - February 7 0 10 1 11 0 9 0 37 1 Red-capped Plover Trip 1 - October 5 0 14 0 - - 6 0 25 0 Red-capped Plover Trip 2 – October (early November Snake only) 3 0 23 0 - - 7 0 33 0 Red-capped Plover Trip 3 - November 6 0 20 0 - - 6 0 32 0 Red-capped Plover Trip 4 - December 11 0 25 0 - - 8 0 44 0 Red-capped Plover Trip 5 - December 6 0 23 0 18 0 6 0 53 0 Red-capped Plover Trip 6 - January 15 0 12 0 14 0 9 1 50 1 Red-capped Plover Trip 7 - February 5 0 10 0 - - - - 15 0 Red-capped Plover Trip 8 - February 60 0 10 0 6 0 3 0 79 0 Pied Oystercatcher Trip 1 - October 134 0 50 0 - - 20 0 204 0 Pied Oystercatcher Trip 2 – October (early November Snake only) 24 1 58 0 - - 62 0 144 1 Pied Oystercatcher Trip 3 - November 22 0 56 0 - - 19 0 97 0 Pied Oystercatcher Trip 4 - December 39 0 79 0 - - 35 0 153 0 Pied Oystercatcher Trip 5 - December 31 0 59 0 21 0 24 0 135 0 Pied Oystercatcher Trip 6 - January 24 0 45 0 12 0 38 0 119 0 Pied Oystercatcher Trip 7 - February 118 0 14 0 - - - - 132 0 Pied Oystercatcher Trip 8 - February 102 0 18 0 8 0 27 0 155 0

BOXBANK CLONMEL DREAM SNAKE TOTAL Species Survey period Adults Juvs Adults Juvs Adults Juvs Adults Juvs Adults Juvs Sooty Oystercatcher Trip 1 - October 0 0 3 0 - - 2 0 5 0 Sooty Oystercatcher Trip 2 – October (early November Snake only) 0 0 0 0 - - 1 0 1 0 Sooty Oystercatcher Trip 3 - November 0 0 0 0 - - 1 0 1 0 Sooty Oystercatcher Trip 4 - December 0 0 1 0 - - 0 0 1 0 Sooty Oystercatcher Trip 5 - December 0 0 0 0 0 0 0 0 0 0 Sooty Oystercatcher Trip 6 - January 0 0 1 0 0 0 1 0 2 0 Sooty Oystercatcher Trip 7 - February 1 0 0 0 - - - - 1 0 Sooty Oystercatcher Trip 8 - February 1 0 2 0 0 0 2 0 5 0 Caspian Tern Trip 1 - October 3 0 6 0 - - 7 0 16 0 Caspian Tern Trip 2 – October (early November Snake only) 3 0 1 0 - - 1 0 5 0 Caspian Tern Trip 3 - November 1 0 5 0 - - 1 0 7 0 Caspian Tern Trip 4 - December 4 0 37 0 - - 6 0 47 0 Caspian Tern Trip 5 - December 2 0 38 0 6 0 3 0 49 0 Caspian Tern Trip 6 - January 0 0 85 0 4 0 1 0 90 0 Caspian Tern Trip 7 - February 3 0 58 0 - - - - 61 0 Caspian Tern Trip 8 - February 1 0 29 0 0 0 0 0 30 0 Caspian Tern Trip 9 - March* - - 15 5 - - - - 15 5 Crested Tern Trip 1 - October 14 0 0 0 - - 0 0 14 0 Crested Tern Trip 2 – October (early November Snake only) 0 0 0 0 - - 20 0 20 0 Crested Tern Trip 3 - November 24 0 4 0 - - 0 0 28 0 Crested Tern Trip 4 - December 0 0 18 0 - - 0 0 18 0 Crested Tern Trip 5 - December 23 0 0 0 2 0 0 0 25 0 Crested Tern Trip 6 - January 0 0 54 0 0 0 111 0 165 0 Crested Tern Trip 7 - February 14 0 0 0 - - - - 14 0 Crested Tern Trip 8 - February 0 0 56 0 12 0 50 0 118 0

BOXBANK CLONMEL DREAM SNAKE TOTAL Species Survey period Adults Juvs Adults Juvs Adults Juvs Adults Juvs Adults Juvs Fairy Tern Trip 1 - October 18 0 0 0 - - 0 0 18 0 Fairy Tern Trip 2 – October (early November Snake only) 0 0 4 0 - - 6 0 10 0 Fairy Tern Trip 3 - November 2 0 8 0 - - 0 0 10 0 Fairy Tern Trip 4 - December 0 0 2 0 - - 0 0 2 0 Fairy Tern Trip 5 - December 0 0 12 0 0 0 0 0 12 0 Fairy Tern Trip 6 - January 0 0 10 0 11 0 0 0 21 0 Fairy Tern Trip 7 - February 0 0 11 0 - - - - 11 0 Fairy Tern Trip 8 - February 0 0 0 0 4 0 0 0 4 0 Little Tern Trip 1 - October 0 0 0 0 - - 0 0 0 0 Little Tern Trip 2 – October (early November Snake only) 0 0 0 0 - - 0 0 0 0 Little Tern Trip 3 - November 0 0 0 0 - - 0 0 0 0 Little Tern Trip 4 - December 0 0 0 0 - - 5 0 5 0 Little Tern Trip 5 - December 100 0 0 0 3 0 2 0 105 0 Little Tern Trip 6 - January 0 0 2 0 2 0 0 0 4 0 Little Tern Trip 7 - February 0 0 14 0 - - - - 14 0 Little Tern Trip 8 - February 0 0 121 0 0 0 0 0 121 0 *Visit to colony location only

Left to right (Snake Island): An adult Hooded Plover (Grainne Maguire); A Pied Oystercatcher pair on a nest; A Red-capped Plover flying away from its two egg nest.

Evidence of breeding Breeding activity varied between the beach-nesting shorebird species on the four surveyed islands, with Pied Oystercatchers exhibiting the most breeding activity overall. Snake Island is of highest value to breeding Hooded Plovers, while Clonmel is of highest value to breeding Pied Oystercatchers. Boxbank and Snake Islands also supported large numbers of breeding Pied Oystercatcher pairs. A small number of active tern colonies were detected through the breeding season on Clonmel and Dream Islands. The large Crested Tern colony/colonies usually occurring within Corner Inlet did not appear during the 2019-20 breeding season. Figures 13-16 map the distribution of breeding activity for both the beach-nesting shorebird and seabird species.

Left to right/top to bottom: Hooded Plover scrape, Snake Island (Jon Fallaw); Pied Oystercatcher scrape, Boxbank Island (Renee Mead); Pied Oystercatcher scrape, Snake Island (Jon Fallaw); Pied Oystercatcher chick, Clonmel Island (Laura Tan); Pied Oystercatcher chick with camera set, Snake Island (Jon Fallaw); Floating a Pied Oystercatcher egg, Clonmel Island (Jon Fallaw).

Figure 13. Breeding events observed during the seven survey periods on Snake Island.

Figure 14. Breeding events observed during the eight survey periods on Clonmel Island.

Figure 15. Breeding events observed during the eight survey periods on Boxbank Island.

Figure 16. Breeding events observed during the three survey periods on Dream Island.

Hooded Plover Figures 17-19 represent the breeding territories on each of the three main islands, derived from repeated observations of pairs over the 2019-20 breeding season. There appear to be six Hooded Plover territories on Clonmel Island and three on Boxbank (with a fourth occurring late in the season). The same number of territories were detected on these islands during the 2018 summer pilot study. Nine territories were detected on Snake Island, the same as in the pilot study, but note, these were detected over a smaller survey area. It is suspected that two additional pairs were detected this season. Four territories were detected on Dream Island in the pilot study (Maguire & Ekanayake, 2018), however this island was not surveyed frequently enough in the 2019-20 breeding season to detect nesting activity.

Table 4 summarises all of the Hooded Plover breeding activity observed including nest fates across all islands during the 2019-20 breeding season. In total, seven nests with eggs were located on Snake Island and two on Boxbank (Table 4). Of these, only one nest on Snake Island successfully hatched chicks. However, it is likely that these chicks did not fledge as the chicks were not sighted past a young age and the pair had re-nested before the approximate fledging date. No nests with eggs were located on Clonmel island, but at least one pair was repeatedly seen leading and acting as though nesting on the western spit. There was one observation of a Hooded Plover juvenile (estimated as a 2-month old fledgling) on Clonmel Island in February, but this is suspected to have come from another area as the timing did not match the suspected nest. Juveniles are known to disperse widely post-fledging and Clonmel is a popular flocking site. In the pilot study over the 2018 summer, flocks of juveniles using Clonmel were common, with up to five juveniles seen in a single flock.

On Snake Island, pairs 4 and 5 (purple and red, Figure 18) swapped partners (as one individual was flagged) throughout the breeding season and these adjacent territories were fluid throughout the season. There was a lot of movement and aggression between the birds along this stretch of the beach between Big Hole access and Bentleigh Point.

In total, eight nests had eggs floated to estimate lay and hatch dates (Table 4; Figure 20). Lay dates ranged from 05/10/2019 to 25/01/2020 (Table 4). This method is valuable for areas being infrequently surveyed as it allows observers to time their next visit to confirm hatching success.

Four Hooded Plover nests had remote cameras set. A raven predated the eggs five days after they were laid (based on egg float) for two nests. Two chicks hatched from another nest which also has an abandoned egg, while the fate of the remaining nest was not captured on camera as a raven knocked the camera over two days after it was set and the nest was no longer in view. A fox also visited the same nest area the day after the raven was observed.

Figure 20. Hooded Plover egg float/days to hatching (from Mead 2012).

Left to Right: Hooded Plover nest on Snake Island, 25/01/20; Hooded Plover nest that successfully hatched on Snake Island (near bait station 22), 03/11/19 (photos: Grainne Maguire).

Figure 17. Hooded Plover breeding territories on Boxbank Island. Each colour represents a cluster of breeding attempts for a predicted territorial pair. Grey circles represent non-breeding observations. The green star represents a pair late in the season.

Figure 18. Hooded Plover breeding territories on Snake Island. Each colour represents a cluster of breeding attempts for a predicted territorial pair. Grey circles represent non-breeding observations.

Snake Island, Glenn Ehmke

Figure 19. Hooded Plover breeding territories on Clonmel Island. Each colour represents a cluster of breeding attempts for a predicted territorial pair. Grey circles represent non-breeding observations.

Table 4: Summary of Hooded Plover breeding activity and nest fates across all four surveyed islands. Each individual nesting attempt has its own ID which is a concatenation of the island, pair and nesting attempt.

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Island Status Habitat Camera Evidence Fate date Notes nest # found egg stage date date chick Fate fate Birds/nest not Prior to Boxbank B1/1 05/01/20 NE Spit 1 1 05/01/20 06/02/20 N SF sighted on next trip 02/02/20

Boxbank B2/1 10/12/19 SN Leading

Boxbank B2/2 16/02/20 SN Leading

Leading; Boxbank B3/1 10/12/19 SN scrape phase Boxbank B3/1 17/12/19 NE Spit 1 2 14/12/19 15/01/20 N Egg 3 days old Birds/nest not Prior to Boxbank B3/1 05/01/20 NE Spit 2 7, 7 14/12/19 15/01/20 N SF Eggs 17 days old sighted on next trip 02/02/20

Boxbank B4/1 16/02/20 SN Leading

Clonmel C1/1 10/12/19 SN Calling Clonmel C1/2 05/01/20 SN Clonmel C1/3 02/02/20 SN Leading Birds/nest not Prior to Clonmel C2/1 07/10/19 S Beach N SF sighted on next trip 21/10/19 Clonmel C3/1 10/12/19 SN Birds/nest not Prior to Clonmel C3/2 05/01/20 S Beach N SF sighted on next trip 02/02/20 Clonmel C4/1 18/11/19 SN Calling Clonmel C4/2 10/12/19 SN Clonmel C4/3 17/12/19 SN Leading Clonmel C5/1 10/12/19 SN

Birds/nest not Prior to Clonmel C6/1 17/12/19 S Beach N SF sighted on next trip 05/01/20

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Island Status Habitat Camera Evidence Fate date Notes nest # found egg stage date date chick Fate fate Snake S1/1 22/10/19 SN

Snake S2/1 22/10/19 S Beach N CF Inundated 03/11/19 Birds/nest not Prior to Snake S2/2 25/01/20 NE Beach 3 N SF Leading sighted on next trip 17/01/20 Found an avian Birds/nest not Prior to Snake S3/1 22/10/19 S Beach N SF depredated egg sighted on next trip 02/11/19 on 02/11/19 Eggs rolled out of Snake S3/2 19/11/19 NE Beach 2 1, 1 19/11/19 17/12/19 N CF 19/11/19 nest Raven knocks camera over Nest gone (raven (16/12/19): nest Snake S3/3 14/12/19 NE Dune 3 Y CF and fox both in 25/01/20 out of view. vicinity of nest) Fox present 17/12/19 Deer prints within 1 Snake S4/1 22/10/19 NE Dune 2 1, 1 22/10/19 19/11/19 N CF 03/11/19 m of nest Leading. Yellow Snake S4/2 19/11/19 SN 42 courting Birds/nest not Prior to Snake S4/3 14/12/19 S Beach N SF sighted on next trip 25/01/20 Snake S4/4 25/01/20 NE Beach 2 2, 2 22/01/20 19/02/20 Y CF Raven predation 27/01/20 Eggs 3 days old Prior to Snake S5/1 22/10/19 S Dune N CF Inundated 03/11/19 Birds/nest not Prior to Snake S5/2 03/11/19 S Dune N SF Leading sighted on next trip 19/11/19 New scrape Prior to Snake S5/3 14/12/19 S Dune N SF Calling detected next trip 25/01/20 Birds/nest not Prior to Snake S5/4 25/01/20 S Dune N SF sighted on next trip 06/01/20 Snake S6/1 22/10/19 SN

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Island Status Habitat Camera Evidence Fate date Notes nest # found egg stage date date chick Fate fate Leading at another Prior to Snake S6/2 03/11/19 S Beach N SF location 19/11/19 Snake S6/3 19/11/19 SN Leading at another Prior to Snake S6/4 08/12/19 S Beach N SF location 14/12/19 Snake S6/5 14/12/19 SN Snake S6/6 25/01/20 SN Snake S7/1 22/10/19 NE Dune 3 1, 1, 1 22/10/19 19/11/19 Y Snake S7/1 03/11/19 NE Dune 3 5, 5, 5 22/10/19 19/11/19 Y Snake S7/1 19/11/19 NE Dune 3 Y Chicks sighted; Nest: presence of new 22/11/19; One egg Snake S7/1 08/12/19 C 2 Y CH SF nest Chicks: Prior abandoned 14/12/19 Re-nested in Prior to Snake S7/2 14/12/19 S Beach N SF different location 24/01/20 2 ravens predate Eggs 0 days old Snake S7/3 25/01/20 NE Dune 2 1, 1 25/01/20 22/02/20 Y CF 30/01/20 nest (just laid) Birds/nest not Prior to Snake S8/1 19/11/19 S Spit N SF sighted on next trip 07/12/19 Birds/nest not Prior to Snake S8/2 26/01/20 S Spit N SF sighted on next trip 17/01/19 Egg found stone Prior to Snake S9/1 22/10/19 NE Spit 2 7, 7 05/10/19 30/10/19 N CF cold 02/11/19 C = Chicks sighted; NE = Nest with eggs; S = Scrape (no eggs); SN =Suspect nest; CF = Confirmed fail; CH = Confirmed hatch; SF = Suspect fail

Pied Oystercatcher There appear to be 17 Pied Oystercatcher territories on Snake Island, 23 on Clonmel and 19 on Boxbank. The number of territories should be treated with caution however, as they represent our best estimate of numbers of pairs using each area. Breeding territories on the spits were particularly hard to delineate due to the number of adult birds nesting in close proximity to one another. Figures 21-23 represent the estimated breeding territories on each of the three main islands, derived from repeated observations of pairs over the breeding season.

In total, 18 nests with eggs were detected on Snake Island, 29 on Clonmel, 15 on Boxbank and one on Dream Island. Of these nests, four hatched on Snake and one hatched on Clonmel. There were also cases of suspected chicks on Snake (one nest), Clonmel (two nests) and Boxbank (one nest) where the adult birds were highly vocal, territorial and flying overhead. Time did not permit us to wait out of sight for chicks to come out of hiding. All other nests had suspected or confirmed failures at the egg stage. Of the nests that hatched, only one successfully fledged a chick in January (Snake Island). One juvenile Pied Oystercatcher was observed in October on Boxbank Island. The juvenile was observed with one adult from breeding pair four (orange circles, Figure 21) while it had an active nest.

In total, 47 nests had eggs floated to estimate lay and hatch dates (Appendix 1). Lay dates ranged from 01/10/2019 to 02/01/2020 (Appendix 1). Thirteen of these nests had remote cameras set. The fates of these camera monitored nests included predation by foxes (two nests on Snake Island); predation by Silver Gulls (one nest); predation by ravens (two nests); one nest had the eggs moved around by a raven but which did not predate them but which likely failed as the pair made a new nest; chicks hatched from two nests on Clonmel Island but the chicks were only caught on camera for one day and two days respectively; a chick was observed from another of the monitored nests on Snake Island but the camera was not operational at time of hatching; and the outcome of the remaining four nests were not captured on the cameras but all were suspected to have failed (Appendix 1).

A Pied Oystercatcher chasing off a raven from its two egg nest, Clonmel Island.

Left to right/top to bottom: Pied Oystercatcher nest Clonmel Island, 18/11/19; Pied Oystercatcher nest Clonmel Island, 18/11/19; Pied Oystercatcher one egg nest Snake Island, mid-December; Pied Oystercatcher two egg nest Clonmel Island, 17/12/19; A recently hatched Pied Oystercatcher chick Clonmel Island, 27/11/19; Pied Oystercatcher chick Snake Island, 14/12/19 (photos: Grainne Maguire).

A Pied Oystercatcher fledgling detected by a remote camera on Snake Island in January 2020 (date on camera is incorrect).

Figure 21. Pied Oystercatcher breeding territories on Boxbank Island. Each colour represents a cluster of breeding attempts for a predicted territorial pair.

Figure 22. Pied Oystercatcher breeding territories on Snake Island. Each colour represents a cluster of breeding attempts for a predicted territorial pair.

Figure 23. Pied Oystercatcher breeding territories on Clonmel Island. Each colour represents a cluster of breeding attempts for a predicted territorial pair.

Red-capped Plovers Over the course of the breeding season, eight Red-capped Plover nests were detected (one on Snake, one on Dream and six on Clonmel) between 21/10/2019 and 05/01/2020, while there were 31 observations of suspected breeding (Figures 24-27). Eggs were floated from five of the nests with lay dates ranging from 18/11/2019 to 24/12/2019 (Table 5; Figure 28). Chicks were suspected to be present on Dream Island on the 05/01/2020 and 16/02/2020 trips. One chick was observed on Clonmel Island on the 21/10/2019. It is suspected that all chicks failed. A camera was set on a Red- capped Plover nest on Snake Island. It appears that this nest was abandoned with adults only detected in two photos (the day after the camera was set) and the eggs were found buried and rotten on the following trip. Time was not invested in monitoring Red-capped Plovers intensively due to time constraints in locating nests of these, the most cryptic, of the beach-nesting species, and because they were not the focus of the project.

Figure 28. Red-capped Plover egg float/days to hatching (from Ekanayake 2011).

Left to right: Red-capped Plover nest, Clonmel Island; Red-Capped Plover nest, Snake Island (photos: Grainne Maguire).

Table 5: Egg float data for Red-capped Plover nests detected on Clonmel Island. Date Nest # Float Est. lay Est. hatch Fate Pair Fate Evidence Notes found habitat Egg stage date date date Eggs gone C1 18/11/19 Dune 1 0 18/11/19 19/12/19 SF 10/12/19 next trip

Eggs gone C2 18/11/19 Dune 2 1, 1 18/11/19 16/12/19 SF 10/12/19 next trip

Eggs gone Eggs 11 C3 17/12/19 Dune 2 5, 5 06/12/19 03/01/20 SF 05/01/20 next trip days old

Eggs gone C4 05/01/20 Beach 1 5 24/12/19 21/01/20 SF 02/02/20 next trip

Eggs gone Two C5 05/01/20 Beach 2 8, 5 Suspect 1 egg unviable SF 02/02/20 next trip females

A one egg Pied Oystercatcher nest lower left, then Red-capped Plover prints to the right leading to a nest in among the salt bush (see insert), Clonmel Island (photos: Grainne Maguire).

Figure 24. Red-capped Plover breeding activity on Boxbank Island over the seven surveys.

Figure 25. Red-capped Plover breeding activity on Snake Island over the seven surveys.

Figure 26. Red-capped Plover breeding activity on Clonmel Island over the eight surveys.

Figure 27. Red-capped Plover breeding activity on Dream Island over the three surveys.

Terns There were a few cases of tern breeding detected on Clonmel and Dream Islands (Table 6; Figures 28-29). A colony of Caspian Terns on Clonmel were first detected on the 10/12/2019 with the colony having eight nests and 11 eggs present, as well as evidence of egg predation and remaining eggs getting buried (Table 6). A single nest with two eggs was also observed approximately 150 m southeast from the active colony and a camera was set-up to monitor the fate of the nest. By the 17/12/2019, the active colony had failed and a colony had been established by the single nest with the camera, including a pair nesting between the camera and the original nesting pair the camera was monitoring! By January, 81 adult birds were observed within the colony and the first chicks were observed on the 02/02/2020. Given the age of chicks on the next visit, where many runners were present, we did not approach the camera to retrieve it or change the SD card and batteries. The risk of runners dispersing from the colony and aggression from the colony was too high. When the camera was retrieved in March after the colony had completely departed from the location, five juveniles were observed within the colony indicating there had been successful breeding from within the colony. Another failed colony containing at least 12 nests with egg shells was detected on Clonmel on the south western spit but was never observed as an active colony. Three other single nest attempts were also observed throughout the season on the south western spit. Fairy Terns displayed breeding behaviours on Clonmel and Dream Islands. Four adults were observed in the vicinity of a scrape on Dream Island in January. It is suspected that this was a failed nesting attempt (Table 6). Three separate colonies were observed on Clonmel Island from November to January, but all colonies were suspected to have failed (Table 6). A camera was not set on the Fairy Tern colony on the eastern spit on Clonmel due to the presence of Silver Gulls nearby and the risks being too high to disturb the colony. One active Little Tern nest was detected on Dream Island in December but is suspected to have failed (Table 6).

Location of a Fairy Tern colony on the eastern spit, Clonmel Island (Grainne Maguire).

Top to bottom, left to right: Fairy Tern scrape, Dream Island taken through a scope (Jon Fallaw); close up of a Fairy Tern on a nest taken through a scope, Clonmel Island, 05/01/20 (Grainne Maguire); Caspian Tern colony from a distance, Clonmel Island, then close up at egg stage (left) and at chick stage (right); Camouflage at its best, a Caspian Tern chick up close (Grainne Maguire).

Top to bottom, left to right: Remote camera set-up on a single Caspian Tern nest on Clonmel Island approximately 150 m from a colony; the following trip another pair had nested between the camera and the original nest with a colony forming at this site; an indication of the number of pairs nesting within the colony (approximately 32 in total), proximity to one another and different nesting stages (note chick from original nest); A fluffy Caspian Tern chick from the second nesting pair and incubating adults in the background; Adult with fish to feed chick from the second pair; Chick and adult from the second pair and a fledgling about to be fed by a parent to the right.

Figure 28. Tern breeding activity on Clonmel Island over the eight surveys.

Figure 29. Tern breeding activity on Dream Island over the three surveys.

Table 6. Summary of tern breeding activity and nest fates across all four surveyed islands. Each individual nesting attempt has its own ID which is a concatenation of the island, pair and nesting attempt.

Colony Date # # # # # # Island Species Status Habitat Camera Fate Evidence Fate date Notes # found adults scrape nests eggs chicks juveniles Some eggs 5x1 egg nests, 3x2 Colony predated. egg nests; 4 Clonmel CT C/CT/1 10/12/19 CN Dune 15 3 8 11 CF gone by Remaining eggs predated eggs 17/12/19 getting buried. (unknown predator). Two egg nest on its Clonmel CT C/CT/2 10/12/19 N Beach 2 2 Y own. Colony increased from a single nest to 4x1 egg nests; 2x2 egg nests; Calling, aerial displays, Clonmel CT C/CT/2 17/12/19 CN Beach 28 20 6 8 Y courtship feeding, scrape making, incubating, dive- bombing. Silver Gulls close to colony. Clonmel CT C/CT/2 05/01/20 CN Beach 81 Y Chicks 1/3 adult size Clonmel CT C/CT/2 02/02/20 CNC Spit 54 8 Y and fluffy. Chicks 1/2 adult Clonmel CT C/CT/2 16/02/20 CNC Beach 28 4 28 Y size, mix down and feathers. Original nest no longer active Chicks and (02/02/20). Colony Not Clonmel CT C/CT/2 12/03/20 J 15 Not surveyed 5 Y CH juveniles still active with known present chicks. SD cards full 04/02/20.

Colony Date # # # # # # Island Species Status Habitat Camera Fate Evidence Fate date Notes # found adults scrape nests eggs chicks juveniles Calling, aerial displays, incubating, dive-bombing, Clonmel CT C/CT/3 05/01/20 N Dune 0 1 flying, resting. Eggs floated. Single nest 80 m away from colony. Predated colony: 12 Colony not destroyed nests Prior to Clonmel CT C/CT/4 05/01/20 CN Dune 0 SF located next with egg shells. 05/01/20 visit Never observed active colony.

Colony not Prior to Adults calling. Clonmel CT C/CT/5 10/12/19 SN Spit 1 SF located next 17/12/19 Single nest. visit

Colony not Adults territorial and Prior to Clonmel CT C/CT/5 05/01/20 SN Beach 2 SF located next aggressive. Single 02/02/20 visit nest. Only 2 adults present, no Prior to Clonmel FT C/FT/1 18/11/19 S Spit 4 10 SF breeding 10/12/19 behaviours Colony has Prior to 1x2 egg nests; 1x1 Clonmel FT C/FT/2 17/12/19 CN Beach 10 10 2 3 SF moved 17/12/19 egg nest. locations Colony not Prior to Likely same colony Clonmel FT C/FT/3 05/01/20 CN Spit 8 SF located next 02/02/20 as C/FT/2. visit Colony not Prior to Dream FT D/FT/1 05/01/20 S Spit 4 SF located next 16/02/20 visit Dream Nest gone, no Prior to LT D/LT/1 17/12/19 N Spit 3 1 SF breeding One bird incubating. 05/01/20 behaviours CT = Caspian Tern; FT = Fairy Tern; LT = Little Tern; CN = Colony with nests; CNC = Colony with nests and chicks; J = Juveniles; N = Nest with eggs; S = Scrape (no eggs); SN = Suspect nest; CF = Confirmed fail; SF = Suspect fail.

Flagged sightings Leg flags/bands were observed on four different species: Hooded Plovers, Pied Oystercatchers, Caspian Terns and Little Terns during the survey period. Sixty complete flag/band details were observed with two of these only being detected through the camera data. There were another 79 occassions where incomplete leg flag/band details were recorded. Four adult Hooded Plovers were banded on Snake Island in November. Table 7 presents the origin of the banded birds where a full flag reading was possible.

Top to bottom, left to right: Pied Oystercatcher PM Yellow with nest on Clonmel Island; Pied Oystercatcher MU Yellow with eggs on Clonmel Island (partner is unbanded); Pied Oystercatcher 4Y Yellow circles MU Yellow’s nest; Pied Oystercatcher 6P Yellow visits MU Yellow’s nest two days after 4Y Yellow. Metal banded Caspian Tern on a nest, Clonmel Island; Caspian Tern K6 Orange within the Clonmel Island colony.

Table 7. Flagged birds sighted during the breeding season and details on origin/date of banding.

Island Date Species # Ad Flags Origin White (Left) Banded in Victoria. Master colour (right) missing. Blue (Left) Banded in Victoria. Master colour (right) missing. Boxbank 07/10/19 PO 4 Red (Left) Banded in Victoria. Master colour (right) missing. Metal only (Right) Unknown. Boxbank 07/10/19 PO 4 BH Yellow (Right) Banded 14/08/2010, Corner Inlet. 2 years old when banded. Clonmel 07/10/19 PO 2 MD? Yellow (Left) Banded in Corner Inlet. Boxbank 07/10/19 PO 2 C7? Yellow (Right) Banded in Corner Inlet. Clonmel 07/10/19 PO 4 Yellow (Right) Banded in Victoria. Clonmel 07/10/19 PO 2 Yellow engraved flag (Right) Banded in Victoria. 4Y Yellow (Right) Banded 21/06/2008, Corner Inlet. 3+ years old when banded. 112 Yellow (Right) Banded 03/07/2016, Corner Inlet. 4+ years old when banded. PR Yellow (Right) Banded 24/06/2013, Corner Inlet. 3 years old when banded. TH Yellow (Right) Banded 28/06/2014, Corner Inlet. 4 years old when banded. Boxbank 07/10/19 PO 93 108 Yellow (Right)* Banded 02/07/2016, Corner Inlet. 1 year old when banded. AB Yellow (Right) Banded 06/07/2008, Corner Inlet. 1 year old when banded. TC Yellow (Right) Banded 28/06/2014, Corner Inlet. 1 year old when banded. Yellow x2 Banded in Victoria. Metal only (Left) Unknown. Clonmel 07/10/19 PO 4 Unknown band (Left) Unknown. Boxbank 07/10/19 PO 7 Flag unknown Unknown. Clonmel 07/10/19 PO 2 Possible band Left leg Unknown. Boxbank 21/10/19 PO 3 Yellow (Right) Banded in Victoria. Boxbank 21/10/19 PO 2 45 Yellow (Right) Banded 25/06/2009, Corner Inlet. 4+ years old when banded. Boxbank 21/10/19 PO 1 Yellow (Right) Banded in Victoria. Clonmel 21/10/19 PO 2 Yellow (Right) Banded in Victoria. Boxbank 21/10/19 PO 2 47 Yellow (Right) Banded 25/06/2009, Corner Inlet. 4+ years old when banded. Boxbank 21/10/19 PO 2 6Z Yellow (Right) Banded 05/07/2008, Corner Inlet. Not aged.

Island Date Species # Ad Flags Origin NB Yellow (Right) Banded 07/02/2013, Corner Inlet. 2+ years old when banded. Clonmel 21/10/19 PO 2 Metal only (Right) Unknown. Banded 26/04/13, French Island. Originally colour banded as a 1 year old 08/04/01 in S8 White (Right)ꝉ Clonmel 21/10/19 PO 2 Westernport Bay. J5 Yellow (Right) Banded 26/06/2005, Corner Inlet. 3+ years old when banded. Boxbank 21/10/19 PO 2 YK Yellow (Right) Banded 16/06/2015, Corner Inlet. 4+ years old when banded. Clonmel 21/10/19 PO 3 Flag unknown Unknown. Snake 22/10/19 HP 2 42 Yellow (Left) Fledged 28/03/2017. Banded 20/04/2017 Anzac West, Phillip Island. Male. Orange engraved flag Snake 22/10/19 PO 2 Banded on Phillip Island. (Right) Snake 22/10/19 PO 2 Yellow (Right) Banded in Victoria. Clonmel 23/10/19 PO 1 PM Yellow (Right) Banded 23/06/13, Corner Inlet. 1 year old when banded. (camera) Snake 03/11/19 HP 2 42 Yellow (Left) Fledged 28/03/2017. Banded 20/04/2017 Anzac West, Phillip Island. Male. Orange engraved flag Snake 03/11/19 PO 1 Banded on Phillip Island. (Right) Snake 03/11/19 PO 22 Yellow engraved flag (Right) Banded in Victoria. Snake 03/11/19 PO 2 Flag unknown Unknown. 3W Yellow (Right) Banded 21/06/2008, Corner Inlet. 3+ years old when banded. Boxbank 18/11/19 PO 3 HN Yellow (Right) Banded 20/06/2012, Corner Inlet. 1 year old when banded. Clonmel 18/11/19 PO 1 Metal Unknown. Clonmel 18/11/19 PO 1 Metal only (Left) Unknown. Clonmel 18/11/19 PO 2 Metal only (Right) Unknown. Clonmel 18/11/19 PO 2 N7 Red (Right) Banded 17/05/2011, Westernport Bay. 1 year old when banded. Metal only (Left) Unknown. Boxbank 18/11/19 PO 2 B4 Red (Right) Banded in Westernport Bay Red/white/green ring (Left), Boxbank 18/11/19 PO 2 Banded pre-2007, Victoria. Combination has lost rings. Metal (Right) Clonmel 18/11/19 PO 2 9L Yellow (Right) Barry Beach, Corner Inlet, 13/08/2006, 4 years old when banded. Clonmel 18/11/19 PO 4 6P Yellow (Right) Banded 22/06/2008, Corner Inlet. 1 year old when banded.

Island Date Species # Ad Flags Origin Boxbank 18/11/19 PO 2 YK Yellow (Right) Banded 16/06/2015, Corner Inlet. 4+ years old when banded. Clonmel 18/11/19 PO 2 MU Yellow (Right) Banded 05/08/2012, Corner Inlet. 2 years old when banded. NB Yellow (Right) Banded 07/02/2013, Corner Inlet. 2+ years old when banded. Clonmel 18/11/19 PO 3 Metal only (Right) Unknown. Clonmel 18/11/19 PO 2 VR Yellow (Right) Banded 12/08/2014, Corner Inlet. 2 years old when banded. Snake 19/11/19 HP 2 42 Yellow (Left) Fledged 28/03/2017. Banded 20/04/2017 Anzac West, Phillip Island. Male. Snake 19/11/19 PO 1 YC Yellow (Right) Banded 16/06/2015, Corner Inlet. 4+ years old when banded. Snake 20/11/19 HP 1 CN White (Right) Banded as an adult on this date. Snake 20/11/19 HP 1 PB White (Right) Banded as an adult on this date. Snake 20/11/19 HP 1 SN White (Right) Banded as an adult on this date. Snake 20/11/19 HP 1 BS White (Right) Banded as an adult on this date. PB White (Right) Banded 20/11/2019 as an adult on Snake Island. Snake 08/12/19 HP 4 SN White (Right) Banded 20/11/2019 as an adult on Snake Island. 42 Yellow (Left) Fledged 28/03/2017. Banded 20/04/2017 Anzac West, Phillip Island. Male. Snake 08/12/19 CT 3 Metal only (Left) Unknown. Likely Victoria. Snake 08/12/19 PO 1 54 Red (Right) Banded 03/07/2012, Westernport Bay. 4+ years old when banded. Light Green/White Left, Snake 08/12/19 PO 2 Banded pre-2007, Victoria. Combination has lost rings. Metal Right Snake 08/12/19 PO 2 9V Yellow (Right) Banded 05/07/2008, Corner Inlet. Not aged. Boxbank 10/12/19 PO 3 BH Yellow (Right) Banded 14/08/2010, Corner Inlet. 2 years old when banded. Clonmel 10/12/19 PO 6 JS Yellow (Right) Banded 19/06/2012 off Mann's Beach, Corner Inlet. 4+ years old when banded. Metal only (Right) Unknown. Clonmel 10/12/19 PO 2 NB Yellow (Right) Banded 07/02/2013, Corner Inlet. 2+ years old when banded. Clonmel 10/12/19 PO 2 VD Yellow (Right) Banded 12/08/2014, Corner Inlet. 2 years old when banded. Clonmel 10/12/19 PO 3 X5 Yellow (Right) Banded 23/07/2005, Corner Inlet. 2 years old when banded. Boxbank 10/12/19 PO 1 Yellow engraved flag (Right) Banded in Victoria. JS Yellow (Right) Banded 19/06/2012 off Mann's Beach, Corner Inlet. 4+ years old when banded. Clonmel 10/12/19 PO 2 5B Yellow (Right) Banded 26/06/2006, Corner Inlet. 3+ years old when banded. Clonmel 10/12/19 PO 2 Flag unknown Unknown.

Island Date Species # Ad Flags Origin Clonmel 10/12/19 PO 6 Flag unknown x2 Unknown. Clonmel 11/12/2019 CT 2 Orange K6 (Right) Banded 11/01/16, Corner Inlet as a chick. (camera) Snake 14/12/19 HP 3 White engraved flag (Right) Unknown. Assume one of the 4 birds banded in November. Snake 14/12/19 HP 2 42 Yellow (Left) Fledged 28/03/2017. Banded 20/04/2017 Anzac West, Phillip Island. Male. Snake 14/12/19 PO 2 54 Red (Right) Banded 03/07/2012, Westernport Bay. 4+ years old when banded. Snake 14/12/19 PO 3 Yellow engraved flag (Right) Banded in Victoria. Dream 17/12/19 CT 2 Metal only (Left) Unknown. Likely Victoria. Dream 17/12/19 CT 2 Metal only (Left) Unknown. Likely Victoria. Orange (Right), Metal only Boxbank 17/12/19 LT 100 Banded in Victoria. (Left) 5B Yellow (Right) Banded 26/06/2006, Corner Inlet. 3+ years old when banded. Clonmel 17/12/19 PO 2 JS Yellow (Right) Banded 19/06/2012 off Mann's Beach, Corner Inlet. 4+ years old when banded. Clonmel 17/12/19 PO 3 J5 Yellow (Right) Banded 26/06/2005, Corner Inlet. 3+ years old when banded. NB Yellow (Right) Banded 07/02/2013, Corner Inlet. 2+ years old when banded. Clonmel 17/12/19 PO 2 Metal only (Right) Unknown. Dream 17/12/19 PO 1 Red Banded in Westernport Bay Red/White (Left), Metal Boxbank 17/12/19 PO 2 Banded pre-2007, Victoria. Combination has lost rings. (Right) Clonmel 17/12/19 PO 2 Yellow (Right) Banded in Victoria. Clonmel 17/12/19 PO 2 Yellow (Right) Banded in Victoria. Clonmel 17/12/19 PO 2 VD Yellow (Right) Banded 12/08/2014, Corner Inlet. 2 years old when banded. Clonmel 17/12/19 PO 2 X5 Yellow (Right) Banded 23/07/2005, Corner Inlet. 2 years old when banded. Dream 17/12/19 PO 2 6B Yellow (Right) Banded 12/07/2006, Corner Inlet. 1 year old when banded. Dream 17/12/19 PO 2 Yellow (Right) Banded in Victoria. Dream 17/12/19 PO 3 Yellow (Right) Banded in Victoria. Boxbank 17/12/19 PO 2 SP Yellow (Right) Banded 23/06/2014, Corner Inlet. 3 years old when banded. Boxbank 17/12/19 PO 2 BP Yellow (Right) Banded 14/08/2010, Corner Inlet. 2 years old when banded. Dream 17/12/19 PO 2 Yellow (Right) Banded in Victoria. Dream 17/12/19 PO 1 Yellow (Right) Banded in Victoria.

Island Date Species # Ad Flags Origin Clonmel 17/12/19 PO 4 MU Yellow (Right) Banded 05/08/2012, Corner Inlet. 2 years old when banded. Boxbank 17/12/19 PO 3 XJ Yellow (Right) Banded 30/01/2015, Corner Inlet. 4+ years old when banded. Clonmel 05/01/20 PO 2 Yellow Banded in Victoria. N7 Red (Right) Banded 17/05/2011, Westernport Bay. 1 year old when banded. Clonmel 05/01/20 PO 12 118 Yellow (Right) Banded 05/07/2016, Corner Inlet. 2 years old when banded. White/Light green Left, Banded pre-2007, Corner Inlet. Combination has lost rings. Dream 05/01/20 PO 2 Green/metal Right Red (Right) engraved black Banded on Phillip Island. Clonmel 05/01/20 PO 2 LE Yellow (Right) Banded 22/06/2012, Corner Inlet. 1 year old when banded. Boxbank 05/01/20 PO 2 Yellow (Right) Banded in Victoria. Clonmel 05/01/20 PO 2 VD Yellow (Right) Banded 12/08/2014, Corner Inlet. 2 years old when banded. Clonmel 05/01/20 PO 2 MU Yellow (Right) Banded 05/08/2012, Corner Inlet. 2 years old when banded. 3 White engraved flag (Right) Unknown. Assume one of the 4 birds banded in November. Snake 25/01/20 HP 1 42 Yellow (Left) Fledged 28/03/2017. Banded 20/04/2017 Anzac West, Phillip Island. Male. Snake 25/01/20 PO 2 54 Red (Right) Banded 03/07/2012, Westernport Bay. 4+ years old when banded. Snake 25/01/20 PO 2 Yellow (Right) Banded in Victoria. TE Yellow (Right) Banded 28/06/2014, Corner Inlet. 4 years old when banded. UM Yellow (Right) Banded 12/08/2014, Corner Inlet. 2 years old when banded. Orange (Right) Banded on Phillip Island. Boxbank 02/02/20 PO 108 '4-' (likely 40) Yellow (Right) Banded in Corner Inlet. ET? Yellow (Right) Banded in Corner Inlet. Yellow x10 Banded in Victoria. 47 Yellow (Right) Banded 25/06/2009, Corner Inlet. 4+ years old when banded. Boxbank 02/02/20 PO 2 KT Yellow (Right) Banded 21/06/2012, Corner Inlet. 4+ years old when banded. Boxbank 02/02/20 PO 5 Yellow (Right) x2 Banded in Victoria. Clonmel 02/02/20 PO 2 Yellow (Right) Banded in Victoria. Clonmel 02/02/20 PO 2 Yellow (Right) Banded in Victoria. Clonmel 02/02/20 PO 3 J5 Yellow (Right) Banded 26/06/2005, Corner Inlet. 3+ years old when banded. Clonmel 16/02/20 PO 3 Yellow (Right) Banded in Victoria.

Island Date Species # Ad Flags Origin BC Yellow (Right)¥ Banded 14/08/2010, Corner Inlet. 2 years old when banded. Black/white (Left), Metal Banded pre-2007, Victoria. Combination has lost rings. Right Boxbank 16/02/20 PO 95 6Z Yellow (Right) Banded 05/07/2008, Corner Inlet. Not aged. Orange (Right) Banded on Phillip Island. Yellow (Right) x10 Banded in Victoria. KK Yellow (Right) Banded 21/06/12, Corner Inlet. 4+ years old when banded. Clonmel 16/02/20 PO 3 JP Yellow (Right) Banded 19/06/2012, Corner Inlet. 4+ years old when banded. Metal only (Right) Unknown. Clonmel 16/02/20 PO 2 N8 Yellow (Right) Banded 02/08/2003, Corner Inlet. 3+ years old when banded. Boxbank 16/02/20 PO 2 Yellow (Right) Banded in Victoria. BS White (Right) Banded 20/11/2019 as an adult on Snake Island. Snake 19/02/20 HP 2 42 Yellow (Left) Fledged 28/03/2017. Banded 20/04/2017 Anzac West, Phillip Island. Male. CT = Caspian Tern; LT = Little Tern; HP = Hooded Plover; PO = Pied Oystercatcher *Misidentified as White in the field but this combination does not exist; ꝉMisidentified as Yellow in the field but this combination does not exist; ¥Misreported as left leg.

Left to right: An adult Hooded Plover being flagged (SN White) on Snake Island, November 2019 (photos: Grainne Maguire).

Remote camera monitoring of nesting attempts Faunatech Snap remote cameras (with wide angle lens) were deployed on 19 nests to follow the nest fate (Table 8). Of these, 19 successfully worked and were retrieved. Two cameras on Boxbank Island were not retrieved: one went missing and the other was buried by sand. SD cards were swapped on cameras at two locations: the Caspian Tern colony on Clonmel and a Hooded Plover nest on Snake (Table 8). Cameras were operational for between 3-35 days, with four instances of the SD cards being full or batteries dying before cameras were retrieved (Table 8).

Of the cameras that worked, we could determine the nest fate from 13 cameras. Chicks were observed on camera from four nests (21%; two Pied Oystercatcher nests, one Hooded Plover nest and the Caspian Tern colony; Table 8). A further Pied Oystercatcher nest hatched but the chicks weren’t captured on camera due to a full SD card. The outcomes of these chicks were not observed on camera, however, based on subsquent surveys it is suspected that none of these chicks fledged. Of the nests that failed, 21% failed due to raven predation, 11% due to fox predation, 5% due to Silver Gull predation; 5% due to abandonment and 32% are suspected to have failed but the outcome was not captured on camera (Table 8).

Clockwise: A remote camera buried in the sand on Snake Island (Grainne Maguire); A White-bellied Sea-eagle perched on the fallen tree where a camera was set to monitor a Pied Oystercatcher nest on Clonmel Island; A range of species, including the incubating Pied Oystercatcher (right) and after nest failure (left) captured by the same camera.

Table 8. Summary of the remote cameras set to monitor the nest fates of beach-nesting birds over the breeding season on the three main islands.

Date # days # trigger events Island Species # images Nest fate Fate date Notes Deployed Retrieved operational Raven Gull Magpie Fox Deer People Other Swapped cameras 07/10/19; 21/10/19; Unknown. Prior 21/10, second Boxbank PO 3 23,106 0 0 0 0 0 0 21/10/19 missing Suspect fail. 18/11/19 camera went missing Unknown. Prior Boxbank PO 21/10/19 Missing ------Camera buried Suspect fail. 18/11/19 Outcome not caught on Unknown. Prior to Clonmel PO 21/10/19 18/11/19 4 20,367 0 1 0 0 0 0 camera; SD card Suspect fail. 18/11/19 full/batteries dead Second egg Raven (abandoned) Clonmel PO 21/10/19 18/11/19 29 9,975 8 0 0 0 0 0 Mouse: 2 24/10/19 predation taken by raven 28/10/19 First sighted: 03/12/19 Clonmel PO 18/11/19 10/12/19 25 5,073 0 0 0 0 0 0 Chicks hatch Last sighted: 04/12/19 First sighted: Kangaroo: 27/11/19 Clonmel PO 18/11/19 10/12/19 25 19,167 17 43 0 0 0 0 Chicks hatch 37 Last sighted: 29/11/19 Silver Gull predation Clonmel PO 10/12/19 22/12/19 13 38,823 0 188 0 0 0 0 (one egg); 17/12/19 fate 2nd egg unknown Cameras Chicks + Clonmel CT 10/12/19 12/03/20 23* 79,116 0 1,286 0 0 0 0 Unknown swapped; Four SD juveniles cards Raven moved Unknown. eggs within nest Suspect fail Prior to Clonmel PO 17/12/19 05/01/20 3 20,262 107 0 0 0 0 0 (19/12/19); SD (new nest 05/01/20 card full/batteries next trip). dead

Date # days # trigger events Island Species # images Nest fate Fate date Notes Deployed Retrieved operational Raven Gull Magpie Fox Deer People Other Outcome not Unknown. caught on Suspect fail Prior to Clonmel PO 17/12/19 05/01/20 3 22,776 0 0 0 0 0 0 camera; SD card (new nest 05/01/20 full/batteries next trip). dead Camera half Fox Snake PO 22/10/19 03/11/19 8 19,092 0 0 0 122 0 0 25/10/19 buried when predation retrieved Chicks First sighted: hatched; 22/11/19 Changed SD cards Snake HP 22/10/19 19/02/20 35 28,571 12 0 18 9 8 0 one egg Last sighted: twice abandoned 22/11/19 Raven Snake PO 03/11/19 19/11/19 13* 4,080 9 0 0 2 0 0 08/11/19 predation Fox Snake PO 19/11/19 08/12/19 20 5,010 9 0 13 0 0 9 03/12/19 predation Outcome not Chick caught on hatched Sighted: Snake PO 19/11/19 08/12/19 4 23,133 0 0 0 0 0 0 camera; SD card (determined 08/12/19 full/batteries by survey) dead Raven knocked Unknown. Prior to camera over Snake HP 14/12/19 25/01/20 9 882 125 0 0 1 0 0 Suspect fail. 25/01/20 which was buried when retrieved. Adults appear to Snake RCP 14/12/19 25/01/20 7 22,007 0 0 0 0 0 0 16/12/19 abandon nest Raven Snake HP 25/01/20 19/02/20 26 2,659 136 5 51 0 0 0 27/01/20 predation Raven Two ravens Snake HP 25/01/20 19/02/20 26 16,106 105 1 12 3 25 0 30/01/2020 predation present *Minimum number of days based on day/night cycle as camera malfunctioned creating an incorrect time stamp on photos HP = Hooded Plover; PO = Pied Oystercatcher; RCP = Red-capped Plover

One camera set on a Pied Oystercatcher nest on Clonmel Island had an expansive view of the spit, and captured many different shorebird and seabird species including flocks of Sanderling, Bar-tailed Godwit, stints, Little Terns, Hooded Plovers, and even a White-bellied Sea-eagle that perched on the fallen tree where the camera was mounted. The camera also captured lots of behaviours of the nesting Pied Oystercatchers over three weeks including a partner swap mid incubation (detected via the leg bands). The nest was eventually predated by a Forest Raven which took one of the two eggs in the clutch. The nest site was then inundated. The pair then began scraping a few meters from the original nest site.

The journey of a Pied Oystercatcher pair on Clonmel Island. Top to bottom, left to right: Pair with a two egg nest (Blue band and unbanded); aggression between pair and two other Pied Oystercatchers including PM Yellow; PM Yellow has replaced Blue banded bird at the nest; an approaching high tide; tidal inundation of the nest area (egg was predated by a raven prior to inundation); the beginning of a new scrape by PM Yellow.

Threat summary

When possible, an assessment of the threat environment was made for each observation of a breeding beach-nesting bird species. Seventy-three threat assessments were made on Snake Island, 91 on Clonmel, 114 on Boxbank and 26 on Dream Island. Threat frequencies have been calculated for each of the four surveyed islands (Table 9). People were the most frequently recorded threat on Dream Island followed by Pacific Gulls (Table 9), although note, far fewer assessments were made for this island due to fewer visits. Pacific and Silver Gulls were the most frequently recorded threats on Clonmel and Boxbank Islands, while deer was the most common threat observed on Snake Island (Table 9).

Table 9. The number of threat assessments recorded (in brackets) on each island and the proportion of visits where each threat type was present.

Threat type Snake (n=73) Clonmel (n=91) Boxbank (n=114) Dream (n=26) People 4.11% 2.20% 0.00% 46.15% Vehicles 4.11% 0.00% 0.00% 0.00% Foxes 27.40% 0.00% 0.00% 15.38% Horses 1.37% 0.00% 0.00% 0.00% Deer 31.51% 5.49% 0.00% 0.00% Magpies 5.48% 0.00% 0.00% 7.69% Ravens 23.29% 7.69% 8.77% 0.00% Pacific Gulls 8.22% 17.58% 24.56% 42.31% Silver Gulls 8.22% 29.67% 36.84% 7.69% Rats 1.37% 3.30% 0.00% 0.00% Birds of Prey 2.74% 1.10% 6.14% 0.00%

Appendix 2 reveals the islands and number of occasions where human, rat, deer, horse and fox prints were detected. Human prints were present on all islands except Boxbank Island. No dog or cat prints were detected in any surveys. However, dogs were captured on a remote camera set to monitor foxes on Dream Island in February. Evidence of foxes was detected on Snake and Dream Islands, however Snake Island appeared to have a higher density of prints that were more widespread across the island.

Horses were only detected on one trip on Snake island (25/01/20) and unfortunately, they were along a long stretch of the upper beach and behind within the dune swale, both locations where the birds usually nest. A group of horse riders were also captured on a remote camera set to monitor foxes on Snake Island in February. Deer and rats were detected on Snake and Clonmel Islands (Table 9). Deer are noted to be eating all the native plants in the dune system which poses a risk as is killing those stabilising plants while the deer do not appear to be eating the weed species. On each of the four occasions that rat prints were detected, these were associated with an observation of a nesting shorebird species (Pied Oystercatcher and Red-capped Plover).

Top to bottom, left to right: Dogs caught on remote camera; Dream Island; A group of horse riders caught on camera, Snake Island; Horse prints along the upper beach (left) and in the dune swale (right), Snake Island; Deer having a devastating impact on native vegetation, Snake Island (photos: Grainne Maguire).

Appendix 3 reveals the islands and number of occasions where avian predators were detected. Ravens were detected on three of the islands and some flocks of over 50 individuals were regularly sighted on Clonmel and Boxbank Islands. There tended to be particular parts of the islands used by ravens, for example adjacent to the vegetated interior on Clonmel. On Snake Island, ravens were common across most of the island. Ravens were detected at nine of the 19 camera monitored nests throughout the breeding season.

Magpies were detected on Snake and Dream Islands and were detected by remote cameras near the vicinity of two Hooded Plover and one Pied Oystercatcher nest on Snake Island. Magpie prints were also detected next to a Pied Oystercatcher scrape on Snake Island. Pacific Gulls were sighted on all four islands, with the largest flock occurring on Boxbank (13 individuals). Silver Gulls were sighted on all four islands, with the largest flock (40 birds) being observed on Snake Island. Flocks of over 20 individuals were also observed on Boxbank on multiple occasions. Silver Gulls are known to nest in a large colony on Boxbank Island during late spring. There were six occasions (three on Clonmel, two on Snake and one on Boxbank) where eggs were not floated due to the nearby presence of Silver Gulls. It was also noted that individual Silver Gulls sat on the edge of the Caspian Tern colony on Clonmel Island, taking advantage of any movement or disturbance within the colony to try to approach nests/chicks. The remote camera detected Silver Gulls at this tern colony 1,286 times over a 23-day period. Silver Gulls were also observed harassing nesting Fairy Terns on Clonmel Island, preventing the deployment of a remote camera on the colony. Birds of prey (Swamp Harriers and White-bellied Sea-eagles) were detected on Snake, Clonmel and Boxbank Islands. Nesting Pied Oystercatchers would leave the nest to chase off raptors from the area, often alerting observers to the presence of a nest due to their alarm calls. The fresh remains of a Pied Oystercatcher were found on Snake Island during one survey, with many raptor prints around the carcass.

Avian predator prints surrounding a dead Pied Oystercatcher, Snake Island (photos: Grainne Maguire).

Threats caught on remote camera. Top to bottom, left to right: Foxes (Snake Island); Ravens (Clonmel Island); Silver Gulls (Clonmel Island); Deer in vicinity of Hooded Plover nests (Snake Island).

The frequency of detection of particular weed species was also assessed for each island as part of the threat assessment (Table 10). Marram Grass (Ammophila Arenaria) had the highest frequency of detection for Snake and Clonmel. Marram Grass and Sea-wheat Grass (Thinopyrum junceiforme) had the same frequency of detection on Boxbank Island (Table 10). Sea Spurge (Euphorbia paralias) was the most commonly detected weed species on Dream Island being detected in 31% of observations (Table 10).

Table 10. The number of threat assessments recorded (in brackets) on each island and the proportion of visits where each weed species was present.

Species Snake (n=73) Clonmel (n=91) Boxbank (n=114) Dream (n=26)

Marram Grass 72.60% 16.30% 0.88% 11.54%

Sea Rocket 0.00% 5.43% 0.00% 0.00%

Pyp Grass 0.00% 0.00% 0.00% 0.00%

Sea Spurge 16.44% 9.89% 0.00% 30.77%

Beach Daisy 0.00% 0.00% 0.00% 0.00%

Sea Wheat Grass 28.77% 13.19% 0.88% 3.85%

Marram grass is an invasive coastal grass that is known to impact the suitability of habitat for beach- nesting species such as the Hooded Plover, resulting in a loss of dune and foredune habitat for nesting and in cliffing of the dune face when tides are high (Cousens et al. 2013). This appears to be the dominant vegetation on three of the islands which is a concern given the invasive nature of this grass and its impact on habitat availability. The islands are believed to be a pristine system, however, they are dominated by coastal weed species.

Eroding dune faces on Snake Island in February (photos: Grainne Maguire).

While beach litter was not formally recorded, the survey teams regularly encountered litter on the islands and in particular balloon debris which was the most abundant on Snake and Clonmel Islands. A bottle with a message was found on Clonmel that had been released from 90 mile beach.

Clockwise: Balloons were a common feature in the Corner Inlet environment, often found on the beach or in the dunes; Some of the litter collected within a few kilometres on Snake Island (photos: Grainne Maguire).

Habitat photos

Habitat on Snake Island (photos: Grainne Maguire and Jon Fallaw).

Habitat on Clonmel Island (photos: Grainne Maguire).

Habitat on Boxbank Island (photos: Renee Mead and Dan Lees).

Habitat on Dream Island (photos: Grainne Maguire).

Recommendations All monitored species, except the Crested Terns, bred during the 2019/20 season. However, the breeding attempts do not signal breeding success which was incredibly poor, with only a single Caspian Tern colony successfully fledging chicks and one Pied Oystercatcher pair fledging a single chick. This trend of birds attempting to breed but not successfully producing any young could be an indication that the area is a ‘sink’ if it continues in future seasons. Future monitoring of breeding success of birds within the area is therefore critical to informing the LAC and determining whether the area is a sink, or if this was just a very poor breeding season.

Breeding attempts commonly failed at the egg stage. The season was impacted by poor and unstable weather conditions which shifted sand significantly on the islands and inundated areas. However, threats from predators were also a dominant feature on the islands, with ravens, Silver Gulls and foxes demonstrating the biggest impact. In addition, deer posed a trampling threat as well as impacting native vegetation of habitat value to the birds. Humans and dogs were also detected on occasions, and while this was rare, a single dog or group camping for the day could have a devastating impact to the birds, particularly as this occurred more commonly on spits, where the highest density of nesting birds occur.

The following recommendations are made to assist in mitigating key threats to beach-nesting birds detected on the Corner Inlet barrier islands:

• Fox control is carried out on Snake and Dream Islands, which includes trialling alternative types of control in addition to baiting which does not appear to be impacting the foxes using key breeding sites on Snake Island

• Ensure Clonmel and Boxbank Islands continue to be fox free

• Explore non-lethal methods of controlling raven and Silver Gull predation

• Regular liaison at start of each season with key stakeholder groups, such as Parks Victoria and the Cattleman’s Association, using the islands to ensure best practice beach use is understood. This could be an opportunity to establish the best means of communicating locations of active breeding sites so that visiting stakeholders are aware of areas to be cautious in.

• Improved awareness among locals and boaties of the value of the barrier islands to beach- nesting birds, including ways to avoid doing harm. Some suggested ideas for outreach include a targeted waterproof resource for boat users to keep in the boat to assist with identifying birds and knowing their sensitivities; presence at local events; targeted events at boat ramps during peak launching periods. This includes warning people that dogs are not permitted on the barrier islands.

• Protection of important native dune vegetation from foraging deer, e.g. Hairy Spinifex dunes on Snake Island

• Targeted control of weeds on some breeding sites where habitat is limited or reduced due to tidal impacts

In addition to the above recommendations around mitigating identified threats, it is also important to adapt monitoring on the islands to improve the ease of collecting, accessing and interpreting data. The following recommendations are made to improve monitoring and evaluation outcomes:

• Recording types of litter encountered as part of the threat assessments

• Assigning an individual GPS unit to each island where sightings are saved and thus easily accessed on each subsequent visit

• Improved labelling of individual breeding attempts so that fates are more easily recorded during subsequent follow up visits

• Better camouflage of remote nest cameras to avoid raven interest

A Caspian Tern chick and adults, Clonmel Island (remote camera image).

Acknowledgements This study was funded by The Department of Environment, Land, Water and Planning via the West Gippsland Catchment Management Authority (WGCMA). We would like to thank Tanya Cowell at WGCMA for all her assistance and support. We would also like to thank Parks Victoria for their advice, support and assistance with boat transportation and vehicle and accommodation on Snake Island during several trips, in particular Steve Voros and Brian Martin. Special thanks to Jonathon Stevenson for rescuing us from the islands when the boat that took us out broke down! We would like to thank the Cattleman’s Association for their support and use of the hut area.

An enormous thank you to the observers who volunteered to take part in the surveys: Phil Barrett, Leo Berzins, Jon Fallaw, Bec Hayward, Lindall Kidd, Laura Rhodes, Julie Riley, Andrew Hunter, Cara Schulz, Stuart Inchley, Laura Tan, Neil Shelley, Mark Lethlean, Tanya Cowell, Bridget Nicholson, Glenn Ehmke, Lucinda Plowman, Chris Willocks, Allan Willocks, Bronwen Baird, Sally Leonard, Sharon Woodend, Tegan Douglas, Shani Blyth. Thanks to staff from the Beach-nesting Birds team for participating in repeated surveys: Renee Mead, Daniel Lees, Kasun Ekanayake, Grainne Maguire, Sonia Sanchez and Meg Cullen.

We also would like to thank Tony and Sheryl from Kraken Tours for their fantastic service, especially for braving the cold and blasting rain as we headed out on some trips!

References Cousens, R., Kennedy, D., Maguire, G. and Williams, K. (2013). Just how bad are coastal weeds? Assessing the geo-eco-psycho-socio-economic impacts. Rural Industries Research and Development Corporation (RIRDC) Publication No. 13/032, Canberra, Australia.

Maguire, G. S. (2008). A practical guide to managing beach-nesting birds in Australia. Birds Australia, Melbourne, Australia.

Maguire, G., Cullen, M. and Mead, R. (2014). Managing the Hooded Plover in Victoria: A site by site assessment of threats and prioritisation of management investment on Parks Victoria managed land. Report to Parks Victoria. BirdLife Australia, Carlton, Victoria.

Maguire, G. and Ekanayake, K. (2018). Beach-nesting birds within Corner Inlet: A pilot study in to the feasibility of monitoring breeding success of shorebirds and seabirds in Corner Inlet January – March 2018. Report to West Gippsland Catchment Management Authority. BirdLife Australia, Carlton, Victoria.

Milton, D., Minton, C. and Gosbell, K. (2005). Are populations of migratory shorebirds in the East Asian Australasian Flyway at risk of decline? International Wader Studies 17: 153-157.

Schlacher, T.A., Schoeman, D.S., Jones, A.R., Dugan, J.E., Hubbard, D.M., Defeo, O., Peterson, C.H., Weston, M.A., Maslo, B., Olds, A.D., Scapini, F., Nel, R., Harris, L.R., Lucrezi, S., Lastra, M., Huijbers, C.M. and Connolly, R.M. (2014). Metrics to assess ecological condition, change, and impacts in sandy beach ecosystems. Journal of Environmental Management 144: 322-335.

Weston, M. A. (2007). Are we neglecting the non-migratory shorebirds of the east Asian Australasian flyway? Stilt 50: 215-223.

Appendix 1: Summary of Pied Oystercatcher breeding activity and nest fates across all four surveyed islands. Each individual nesting attempt has its own ID which is a concatenation of the island, pair and nesting attempt.

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Boxbank B1/1 07/10/19 NE Spit/ 1 1 07/10/19 03/11/19 N SF Birds/nest not sighted Prior to Estuary on next trip 21/10/19

Boxbank B1/2 10/12/19 NE Dune 1 4 01/12/19 25/12/19 N SF New nest in different Prior to location on next trip 17/12/19 Boxbank B1/3 17/12/19 SN Boxbank B1/3 05/01/20 NE Spit 1 8 21/12/19 09/01/20 N CF Silver Gull predation 05/01/20 Boxbank B1/4 02/02/20 SN Boxbank B1/5 16/02/20 SN Boxbank B2/1 07/10/19 NE Dune 2 2, 3 01/10/19 25/10/19 Y Swapped cameras

Boxbank B2/1 21/10/19 NE Dune 2 Y SF Birds/nest not sighted Prior to Camera went on next trip 18/11/19 missing

Boxbank B3/1 07/10/19 S Beach N SF Birds/nest not sighted Prior to on next trip 21/10/19

Boxbank B3/2 17/12/19 S Beach N SF Birds/nest not sighted Prior to on next trip 05/01/20

Boxbank B4/1 21/10/19 NE Beach 3 3, 3, 3 15/10/19 09/11/19 N CF Adults located near a Prior to failed nest on next trip 18/11/19

Boxbank B4/2 17/12/19 S Beach N SF Pair leading at another Prior to location 05/01/20

Boxbank B4/3 05/01/20 SN Boxbank B5/1 07/10/19 SN Boxbank B5/2 10/12/19 SN Boxbank B6/1 10/12/19 S Dune N SF Birds/nest not sighted Prior to on next trip 17/12/19

Boxbank B7/1 10/12/19 NE Beach 3 N CF Eggs found smashed Prior to 10/12/19 Boxbank B7/2 10/12/19 SN

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Boxbank B8/1 21/10/19 NE Beach 1 1 21/10/19 17/11/19 N CF Adults located near a Prior to failed 1 egg nest on 18/11/19 next trip

Boxbank B8/2 10/12/19 NE N CF Avian depredated eggs Prior to 10/12/19 Boxbank B8/3 10/12/19 SN Boxbank B9/1 17/12/19 NE Beach 2 N SF Birds/nest not sighted Prior to Eggs not on next trip 05/01/20 floated due to gull presence Boxbank B10/1 10/12/19 NE Beach N CF Avian predation Prior to (smashed eggs) 10/12/19 Boxbank B10/2 10/12/19 SN Boxbank B10/2 17/12/19 SC SH SF Lots of footprints 17/12/19; Adults leading around nest indicated 05/01/20 hatching; no evidence of chicks on next trip Boxbank B11/1 07/10/19 SN Boxbank B12/1 21/10/19 SN Boxbank B13/1 07/10/19 SN Boxbank B13/2 18/11/19 NE Beach 1 5 06/11/19 01/12/19 N SF Pair leading at another Prior to location 10/12/19 Boxbank B13/3 10/12/19 SN Boxbank B13/4 05/01/20 SN Boxbank B14/1 21/10/19 SN Boxbank B14/2 18/11/19 SN Boxbank B14/3 17/12/19 SN Boxbank B15/1 21/10/19 S Spit N Boxbank B15/1 18/11/19 NE Spit 1 8 28/10/19 22/11/19 N SF Birds/nest not sighted Prior to on next trip 10/12/19

Boxbank B15/2 17/12/19 S Spit N SF Birds/nest not sighted Prior to on next trip 05/01/20 Boxbank B16/1 07/10/19 SN Boxbank B16/1 21/10/19 NE Spit 1 4 12/10/19 06/11/19 N CF Silver Gull predation 21/10/19

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Boxbank B16/2 10/12/19 SN Boxbank B16/3 17/12/19 S Spit N SF Birds/nest not sighted Prior to on next trip 05/01/20 Boxbank B17/1 05/01/20 SN Boxbank B18/1 21/10/19 NE Beach 2 N SF Birds/nest not sighted Prior to on next trip 18/11/19

Boxbank B19/1 07/10/19 S Beach N SF New nest in different Prior to location on next trip 21/10/19

Boxbank B19/2 21/10/19 NE Beach 2 1, 1 21/10/19 17/11/19 Y SF Birds/nest not sighted Prior to Camera buried on next trip 18/11/19 Clonmel C1/1 18/11/19 NE Dune 2 1, 1 18/11/19 13/12/19 N Clonmel C1/1 10/12/19 NE Dune 2 N SF New scrape in different Prior to location on next trip 17/12/19

Clonmel C1/2 17/12/19 S Spit N SF Nest not sighted on Prior to next trip 05/01/20

Clonmel C1/3 05/01/20 SN SF Nest not sighted on Prior to next trip; birds not 02/02/20 displaying breeding behaviours

Clonmel C2/1 21/10/19 SN Clonmel C2/1 18/11/19 NE Dune 2 N SF Eggs gone; New nest in Prior to Eggs not different location on 10/12/19 floated due to next trip gull presence

Clonmel C2/2 10/12/19 S Spit N SF Nest not sighted on Prior to next trip; birds not 17/12/19 displaying breeding behaviours

Clonmel C3/1 21/10/19 NE Dune 2 1, 1 21/10/19 15/11/19 Y SF New egg on next trip Prior to Outcome not 18/11/19 on camera: SD card full Clonmel C3/2 18/11/19 NE Dune 1 1 18/11/19 15/12/19 N SF New scrape detected Prior to on next trip 10/12/19

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Clonmel C3/3 10/12/19 S Beach N SF Nest not sighted on Prior to trip next trip 17/12/19

Clonmel C4/1 21/10/19 SN

Clonmel C4/2 10/12/19 S Spit N SF Birds/nest not sighted Prior to on next trip 17/12/19

Clonmel C5/1 05/01/20 SN

Clonmel C6/1 21/10/19 SN

Clonmel C6/2 18/11/19 NE Beach 2 5, 5 06/11/19 01/12/19 1 Y CH SF Chicks sighted on 03/12/19; Chick hatched camera; not seen on 04/12/19 ~03/12/19 camera after 04/12 or on next trip

Clonmel C7/1 21/10/19 S Beach N SF Birds/nest not sighted Prior to on next trip 18/11/19 Clonmel C7/2 17/12/19 SN Clonmel C8/1 07/10/19 S Beach N SF Birds/nest not sighted Prior to on next trip 21/10/19 Clonmel C9/1 21/10/19 NE Beach 1 4 12/10/19 06/11/19 N

Clonmel C9/1 18/11/19 C 1 N CH SF Chicks sighted on 18/11/19; Chick 1/3 adult camera; not seen on prior to size and fluffy next trip 10/12/19

Clonmel C10/1 21/10/19 SN

Clonmel C10/2 18/11/19 SN

Clonmel C10/3 10/12/19 SN

Clonmel C10/4 05/01/20 NE Beach 2 3, 3 30/12/19 24/01/20 N SF Birds/nest not sighted Prior to on next trip 02/02/20

Clonmel C11/1 21/10/19 S Beach N SF New nest in different Prior to location on next trip 18/11/19

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Clonmel C11/2 18/11/19 NE Beach 1 8 28/10/19 22/11/19 1 Y CH CF Chick last sighted 27/11/19; Chick ~two 29/11/19, nest appears 29/11/19 days old when abandoned 09/12/19 last sighted

Clonmel C11/3 17/12/19 NE Beach 2 2, 2 30/11/19 25/12/19 Y CF Observed nest failed; Prior to Raven moved new nest at different 05/01/20 eggs within location nest 19/12/19 (eggs remained in nest) Clonmel C11/4 05/01/20 NE Beach 2 2, 2 02/01/20 27/01/20 N SF Birds/nest not sighted Prior to on next trip 02/02/20

Clonmel C12/1 18/11/19 S Dune N SF New nest in different Prior to location on next trip 10/12/19 Clonmel C12/2 10/12/19 NE Dune 2 N Clonmel C12/2 17/12/19 NE Dune 2 4, 4 08/12/19 02/01/20 Y CF New nest in different Prior to Eggs 8.5 days location on next trip 05/01/20 old; Outcome not on camera: SD card full

Clonmel C12/3 05/01/20 NE Beach 1 N SF Birds/nest not sighted Prior to Eggs not on next trip 02/02/20 floated due to gull presence Clonmel C13/1 18/11/19 NE Spit 1 3 12/11/19 07/12/19 N Clonmel C13/1 10/12/19 NE Dune 2 5, 5 23/11/19 18/12/19 N Clonmel C13/1 17/12/19 NE Dune 2 N SF Nest not sighted on Prior to Eggs not next trip; birds not 05/01/20 floated as displaying breeding processed a behaviours week ago

Clonmel C14/1 21/10/19 NE Spit 2 4, 4 12/10/19 06/11/19 Y CF Raven predation 1 egg, 24/10/19 other egg likely (raven); abandoned (tidal 25/10/19 inundation) - later (abandoned); taken by a raven. 28/10/19 (raven)

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Clonmel C14/2 17/12/19 NE Dune 2 4, 4 08/12/19 02/01/20 N SF Birds/nest not sighted Prior to Eggs 8.5 days on next trip 05/01/20 old

Clonmel C15/1 21/10/19 SN Clonmel C15/2 17/12/19 S Beach N SF Birds/nest not sighted Prior to on next trip 05/01/20

Clonmel C16/1 21/10/19 NE Spit 2 3, 3 15/10/19 09/11/19 N SF New nest in different Prior to location on next trip 15/11/19

Clonmel C16/2 18/11/19 NE Dune 1 2 15/11/19 10/12/19 N SF New nest in different Prior to location on next trip 10/12/19

Clonmel C16/3 10/12/19 NE Beach 2 N Eggs not floated due to gull presence

Clonmel C16/3 17/12/19 NE Beach 2 5, 5 06/12/19 31/12/19 N SF Birds/nest not sighted Prior to Eggs 11 days on next trip 05/01/20 old

Clonmel C17/1 21/10/19 NE Spit 2 5, 5 09/10/19 03/11/19 N SF Nest not sighted on Prior to next trip; birds not 18/11/19 displaying breeding behaviours

Clonmel C17/2 17/12/19 NE Beach 1 1 17/12/19 13/01/20 N CF Egg found predated on Prior to Egg 0 days old next trip 05/01/20 (just laid) Clonmel C18/1 21/10/19 NE Dune 1 1 21/10/19 17/11/20 N Clonmel C18/2 18/11/19 NE Estuary 2 4, 4 09/11/19 04/12/19 N Clonmel C18/2 10/12/19 NE Dune 2 8, 8 19/11/19 14/12/19 N Clonmel C18/2 17/12/19 NE Dune 2 5, 3 Suspect eggs unviable N CF Egg float result Prior to suggests abandonment 17/12/19

Clonmel C18/3 05/01/20 S Spit N SF Possibly abandoned Prior to due to raven footprint 05/01/20 by scrape Clonmel C19/1 18/11/19 SN N

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Clonmel C19/1 10/12/19 SC N SH SF Well used scrape 10/12/19; indicating possible prior to hatching; no chicks 17/12/19 sighted on next trip

Clonmel C19/2 05/01/20 S Spit N SF Birds/nest not sighted Prior to on next trip 02/02/20

Clonmel C20/1 21/10/19 NE Spit 1 N CF Buried nest Prior to 21/10/19

Clonmel C20/2 21/10/19 NE Spit 2 3, 4 14/10/19 08/11/19 N SF Birds/nest not sighted Prior to on next trip 18/11/19 Clonmel C20/3 10/12/19 NE Blowout 2 8, 5 Suspect 1 egg unviable Y Clonmel C20/3 17/12/19 NE Beach 2 Y CF Silver Gull predation (1 17/12/19 egg); unknown fate other egg Clonmel C21/1 21/10/19 SN Clonmel C21/2 10/12/19 NE Dune 2 5, 4 26/11/19 21/12/19 N Clonmel C21/2 17/12/19 NE Dune 2 8, 8 26/11/19 21/12/19 N Clonmel C21/2 05/01/20 SC Spit N SH Suspect chicks 05/01/20 Clonmel C22/1 18/11/19 NE Spit 2 2, 3 15/11/19 10/12/19 N SF Birds/nest not sighted Prior to on next trip 10/12/19

Clonmel C22/2 05/01/20 NE Spit 2 N SF Birds/nest not sighted Prior to on next trip 02/02/20

Clonmel C23/1 10/12/19 NE Dune 1 4 10/01/19 26/12/19 N SF Birds/nest not sighted Prior to on next trip 17/12/19

Dream D1/1 05/01/20 NE Dune 1 4 27/12/19 20/01/20 N SF Birds/nest not sighted Prior to Egg 8.5 days on next trip 16/02/20 old

Snake S1/1 22/10/19 S Beach N SF New nest in different Prior to location on next trip 03/11/19

Snake S1/2 03/11/19 S Beach N SF Birds/nest not sighted Prior to on next trip 19/11/19 Snake S1/3 14/12/19 S Dune N Snake S1/3 25/01/20 SC N SH Observational data 25/01/20

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Snake S2/1 22/10/19 S Dune N SF New nest in different Prior to location on next trip 03/11/19 Snake S2/2 03/11/19 NE Beach 2 N Snake S2/2 14/12/19 C Not N CH SF Parents behaviour 08/12/19; Chick hiding observed indicates chick prior to 25/01/20

Snake S3/1 22/10/19 S Dune N SF Raven prints leading 22/10/19 into scrape Snake S3/2 03/11/19 S Beach N Snake S3/2 19/11/19 NE Dune 2 3, 4 10/11/19 05/12/19 N Snake S3/2 25/01/20 C 1 N CH F Chicks sighted flying 25/01/20 Chick adult size and flying Snake S4/1 03/11/19 S Dune N SF Birds/nest not sighted Prior to on next trip 19/11/19

Snake S4/2 08/12/19 S Beach N SF New nest in different Prior to location on next trip 14/12/19

Snake S4/3 14/12/19 NE Beach 2 N SF Birds/nest not sighted Prior to on next trip 25/01/20

Snake S5/1 22/10/19 S Dune N SF New nest in different Prior to location on next trip 03/11/19

Snake S5/2 03/11/19 NE Beach 1 1 03/11/19 01/12/19 N SF New nest in different Prior to location on next trip 19/11/19

Snake S5/3 19/11/19 S Dune N SF Birds/nest not sighted Prior to on next trip 07/12/19

Snake S5/4 14/12/19 NE Dune 1 N SF Birds/nest not sighted Prior to on next trip 25/01/20

Snake S6/1 19/11/19 NE Beach 2 4, 4 10/11/19 05/12/19 N SF Birds/nest not sighted Prior to on next trip 07/12/19 Snake S6/2 14/12/19 SN Snake S7/1 22/10/19 S Dune N SF New nest in different Prior to location on next trip 02/11/19

Snake S7/2 02/11/19 NE Dune 1 1 02/11/19 29/11/19 N CF Observational - nest Prior to gone 19/11/19

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Snake S7/3 13/12/19 NE Dune 1 N CF Found predated egg 13/12/19 Snake S8/1 22/10/19 NE Spit 1 N SF New nest in different Prior to Eggs not location on next trip 02/11/19 floated due to gull presence Snake S8/2 02/11/19 S Dune N SF New nest in different Prior to location on next trip 19/11/19

Snake S8/3 19/11/19 NE Dune 1 N SF Birds/nest not sighted Prior to Eggs not on next trip 15/12/19 floated due to gull presence Snake S8/4 15/12/19 S Dune N SF Birds/nest not sighted Prior to on next trip 25/01/20 Snake S9/1 22/10/19 NE Beach 1 8 01/10/19 26/10/19 N SF Snake S9/2 19/11/19 NE Dune 1 5 07/11/19 02/12/19 Y Snake S9/2 08/12/19 C 1 Y CH SF Chick sighted Prior to Chick 1/3 adult 13/12/19 size and fluffy; Outcome not on camera: SD card full Snake S10/1 22/10/19 NE Beach 2 3, 3 16/10/19 10/11/19 Y CF Fox predation 25/10/19 Snake S10/2 19/11/19 NE Spit 2 2, 2 16/11/19 11/12/19 N Snake S10/2 26/01/20 C 1 N CH SF Chick sighted 26/01/20; Chick 2/3 adult prior to size 06/01/20 Snake S11/1 22/10/19 S Spit N SF New nest in different Prior to location on next trip 03/11/19

Snake S11/2 03/11/19 S Spit N SF New scrape detected Prior to on next trip 19/11/19 Snake S11/3 19/11/19 NE Spit 1 0 19/11/19 14/12/19 N Snake S11/3 14/12/19 C 1 N CH SF Chick sighted but then 14/12/19; Chick 1/3 adult not sighted on next trip prior to size and fluffy 25/01/20 Snake S12/1 22/10/19 NE Dune 2 2, 2 19/10/19 13/11/19 N CF Observation - nest Prior to failed 02/11/19

Snake S12/2 19/11/19 NE Spit 2 1, 1 19/11/19 14/12/19 Y CF Fox predation 03/12/19

Pair/ Date # Float Est. lay Est. hatch # Nest Chick Fate date Island Status Habitat Camera Evidence Notes nest # found Egg stage date date Chick Fate fate (nest; chick) Snake S12/3 08/12/19 S Beach N SF Birds/nest not sighted Prior to on next trip 13/12/19

Snake S13/1 22/10/19 S Spit N SF Birds/nest not sighted Prior to on next trip 02/11/19

Snake S14/1 25/01/20 SN

Snake S15/1 22/10/19 S Beach N SF New scrape detected Prior to on next trip 03/11/19

Snake S15/2 03/11/19 NE Beach 2 Y CF Raven predation 08/11/19

Snake S16/1 22/10/19 S Dune N

Snake S16/2 14/12/19 SN

Snake S17/1 22/10/19 SN

NE = Nest with eggs; S = Scrape (no eggs); SN = Suspect nest; SC = Suspect chicks; C = Chicks sighted; CF = Confirmed fail; CH = Confirmed hatch; F = Fledged; SF = Suspect fail; SH = Suspect hatch

Left to right (Snake Island): Pied Oystercatcher pair with nest; Pied Oystercatcher nest; depredated Pied Oystercatcher egg (photos: Grainne Maguire).

Appendix 2. Prints detected on the four islands and the number of beach-nesting bird occupied sites where these were detected during each trip.

Print type Island Trip Observations detected Clonmel 6 1 Clonmel 7 1 Dream 5 10 People Dream 6 2 Snake 1 2 Snake 2 1 Clonmel 3 2 Rat Clonmel 5 1 Snake 5 1 Clonmel 2 1 Clonmel 6 4 Snake 1 2 Snake 2 7 Deer Snake 3 2 Snake 4 5 Snake 5 3 Snake 6 2 Snake 8 2 Horse Snake 6 1 Dream 5 4 Snake 1 7 Snake 2 3 Fox Snake 3 1 Snake 4 5 Snake 6 3 Snake 8 1

Left: Rat prints on Clonmel Island (Grainne Maguire). Above: Fox prints on Snake Island. Prints on each dune hump on Rat prints, Clonmel island the spit indicates that the fox has learnt to search these favoured nesting locations (photos: Grainne Maguire).

Appendix 3. Avian predators detected on the four islands and the number of beach-nesting bird occupied sites where these were detected during each trip.

Prints detected Island Trip Observations detected Total observed Boxbank 1 2 2 Boxbank 2 1 1 Boxbank 3 2 6 Boxbank 4 2 2 Boxbank 5 1 Only prints observed Boxbank 7 1 50 Boxbank 8 1 1 Clonmel 2 1 2 Clonmel 3 1 1 Ravens Clonmel 5 1 52 Clonmel 6 3 25 Clonmel 8 1 2 Snake 1 7 2 Snake 2 1 2 Snake 3 2 2 Snake 4 1 1 Snake 5 1 2 Snake 6 2 3 Snake 8 3 19 Snake 1 1 1 Snake 2 1 2 Magpies Snake 3 1 1 Snake 4 1 2 Dream 5 2 4 Boxbank 1 7 33 Boxbank 2 2 8 Boxbank 3 3 14* Boxbank 5 5 20 Boxbank 6 2 3 Boxbank 7 3 19 Boxbank 8 6 9 Clonmel 1 7 11 Clonmel 2 1 1 Pacific Gulls Clonmel 3 1 1 Clonmel 4 1 1 Clonmel 5 1 2 Clonmel 6 5 5 Dream 5 11 63 Snake 1 2 3 Snake 3 2 2 Snake 4 1 1 Snake 8 1 1

Prints detected Island Trip Observations detected Total observed Boxbank 1 8 13 Boxbank 2 5 17 Boxbank 3 3 Unspecified count Boxbank 4 5 Unspecified count Boxbank 5 13 83 Boxbank 6 3 4 Boxbank 7 4 73 Boxbank 8 1 3 Clonmel 1 7 16 Clonmel 2 2 2 Silver Gulls Clonmel 3 2 26 Clonmel 4 2 3 Clonmel 5 5 7 Clonmel 6 9 14* Dream 5 1 2 Dream 6 1 Unspecified count Snake 1 2 2 Snake 3 1 1 Snake 4 2 41 Snake 8 1 1 Boxbank 1 2 2 Swamp Harriers Clonmel 2 1 1 Snake 1 1 1 White-bellied Boxbank 1 5 5 Sea-eagle Snake 2 1 1 *Minimum count (some observations didn't specify numbers)