Technical-Report-For-The-Eradication

Cover illustrations: Mainland Antigua from Maiden Island West. Credit Sophia Steele – Fauna & Flora International

THE OPINIONS OF THE AUTHORS DO NOT NECESSARILY REFLECT THE OPINIONS OF THE PARTNER ORGANISATIONS OF THE OFFSHORE ISLANDS CONSERVATION PROGRAMME. PUBLISHED BY Offshore Islands Conservation Programme St. John’s, Antigua

RECOMMENDED CITATION

Lawrence, S.N., Bell, E.A., Challenger, S.C. & Steele, Sophia (2019) Technical Report for the Eradication of Black Rats Rattus rattus from Maiden Island West, Antigua. Report for the Offshore Islands Conservation Programme, St John’s, Antigua and Barbuda.

The award-winning Offshore Islands Conservation Programme (OICP) was established in 1995 as the Antiguan Racer Conservation Project, and operates under a partnership between the Government of Antigua and Barbuda, Environmental Awareness Group, Durrell Wildlife Conservation Trust and Fauna & Flora International. This partnership is working towards the Vision of healthy, functioning coastal ecosystems that are sustainably managed for the conservation of native wildlife and for the benefit of local people. Our activities include environmental education, endangered species management, invasive species control, habitat restoration, research and monitoring, and strengthening local governance and management capacity.

This study was co-funded by the U.S. Fish & Wildlife Service under the Neotropical Migratory Bird Conservation Act Program, Project #F17AP00667 - Improving and Conserving Critical Bird Habitat on Antigua & Barbuda’s Offshore Islands, and the Global Environment Facility Grant - Preventing the COSTS of IAS in Barbados and the OECS.

Contact details: Ms Natalya Lawrence, Project Coordinator, Offshore Islands Conservation Programme, Environmental Awareness Group, P. O. Box 2103, St John’s, Antigua, West Indies. www.eagantigua.org; Email: [email protected]

ii 1. Executive Summary

Since 1995, the Offshore Islands Conservation Programme (OICP) has eradicated harmful alien invasive mammals from 15 offshore islands around Antigua. This has resulted in visible improvements in habitat quality and significantly boosted the populations of rare and endemic reptiles, birds, invertebrates and plants (Daltry et al., 2014).

This is the Technical Report following the operation to eradicate black rats Rattus rattus from Maiden Island West (1.21 hectares) in accordance with the methods recommended in the Operational Plan and Feasibility Study Report produced for the island. Maiden Island West is a part of the globally recognised Important Bird & Biodiversity Area (IBA – AG006) and Offshore Islands Key Biodiversity Area, and lies 0.72 km off the southwestern coast of Antigua.

The operation was administered by partner organisations of the OICP, particularly by the Environmental Awareness Group and the OICP Coordinator Natalya Lawrence during the fieldwork stage of the operation. The eradication was facilitated by Elizabeth Bell but was completed under the leadership of Natalya Lawrence. The eradication was completed with a steady team of local and regional volunteers from the Boys’ Brigade of Antigua and Barbuda, volunteers and interns from the Department of Environment, volunteers from the Community Development Division and from the Environmental Awareness Group. The owners of Maiden Island West, the Hall Family, were also crucial to the success of the eradication, providing transportation, shelter, and facilities for the eradication team as well as participating in the execution of the eradication.

Equipment and all necessary approvals were in place by 27th June, and the field work began on 30th June, 2018. The eradication operation was officially completed by 17th August, 2018. At the end of the operation, all equipment and material were removed from the island leaving 13 lockable permanent bait stations in place, with a maximum separation of 30m between stations.

During the eradication operations, several stations were consistently attacked by hermit crabs. The bait poses no threat to the crabs. Although there was concern that the crabs would get to the bait and consume it all before the rats could, trail cameras showed that the rats were easily able to access and help themselves to the bait. Other non-target species, including ants, cockroaches and mould, had much less impact on bait take.

There was no evidence of non-target species being affected by the bait or subjected to secondary poisoning throughout the operation. One dead juvenile black-crowned night heron was collected and a necropsy was done. Results showed no signs of secondary poisoning. After consultation with Elizabeth Bell, it was determined that the bird could have died from natural causes.

The intensive monitoring phase of the operation suggested that all rats had been eradicated from Maiden Island West.

The long-term monitoring will be undertaken by the Hall Family on a monthly basis.

3 There were several sightings of mongooses on the mainland (Seaforth area) close to the island. However, no mongooses have ever been detected on the island (either historically or presently) and the distance needed to be swum by a mongoose to reach the island would be very unattractive to these animals. Nevertheless, it would be wise to have a biosecurity protocol for mongooses in place in the event that they are inadvertently transported to the island.

In summary:

1. The eradication of black rats from Maiden Island West was a ground-based operation using bait stations and Klerat brodifacoum grain-based wax blocks that was completed by August, 2018. 2. The eradication of rats from Maiden Island appears to be successful. 3. In line with common international practice, Maiden Island West can only be officially declared rat- free if no further signs are detected within 2 years of eradication. 4. Bait station interference from hermit crabs was high. 5. There was no evidence that non-target species were affected or subjected to secondary poisoning throughout the operation. 6. Ecological monitoring of seabirds, land birds, reptiles and vegetation should be initiated and continued to document the effects of the eradications on the native flora and fauna. 7. Only with constant vigilance and an ongoing commitment from all OICP staff and the Hall Family to prevent, detect and respond to any incursions will the overall goal of the operation be achieved.

4 2. Table of Contents

1. Executive Summary ...... 3 2. Table of Contents ...... 5 3. Acknowledgements ...... 6 4. Introduction ...... 7 4.1 Purpose and Scope of the Technical Report ...... 7 4.2 Implementing Agency and Sponsors ...... 7 4.3 Context for Maiden Island West’s Restoration ...... 7 5. The Reasons for the Maiden Island West Rat Eradication ...... 8 6. Project Site and Target Species ...... 9 9 6.1 Maiden Island West ...... 9 6.2 Black Rats ...... 10 7. Eradication Preparation, Implementation and Monitoring ...... 12 7.1 Summary of Activities for Phase 1 of the Eradication ...... 12 7.2 Summary of Phase 2 of Maiden Island West Eradication ...... 17 8. Crab Interference ...... 21 9. Problems Encountered ...... 22 10. Recommendations ...... 22 11. Conclusions ...... 22 12. References ...... 24 13. Appendix ...... 26 13.1 Eradication Schedule ...... 26 13.2 Biosecurity Checklist for Hall Family ...... 30 13.3 Bird Species Observed...... 33

5 3. Acknowledgements

This work was supported by the Offshore Islands Conservation Programme (OICP) with financial support from U.S. Fish & Wildlife Service and the Global Environment Facility.

Thanks are expressed to the Department of Environment for providing technical support and field assistance.

Many thanks to Elizabeth Bell (Wildlife Management International Ltd. – WMIL) for guiding this eradication.

The team is grateful to the Hall Family (owners of Maiden Island West) for their keen involvement and support during the implementation of this eradication. Gratitude is also expressed for them providing daily on-time transportation to the island and for accommodating the team by opening up their cottage to the team.

To Ms Sarah Havery, many thanks for providing training, guidelines, reports and recommendations to guide future eradications.

Finally, thanks are expressed to all the volunteers: Ms Gita Gardner, Daniel Perreira, Ruleo Camacho, Nathan Wilson, Grantley Edwards, Members of the Boys’ Brigade, Sophia Punnett-Steele, Shanna Challenger, Andelle Trotman, Michael Hall, Vernon Hall, Archie Hall, Ella Hall, Adrian Hall, Robert Hall and J.D. Hall.

6 4. Introduction

4.1 Purpose and Scope of the Technical Report

This document provides an account of the operation to eradicate black rats Rattus rattus from Maiden Island West, a 1.21ha island off the Southwest coast of Antigua.

Readers are advised to refer to the Maiden Island West Eradication Feasibility Report (Lawrence et al., 2018) to more fully understand the reasoning behind the choices of methods for this eradication. It should be taken into account that an adaptive management approach was used; therefore any deviations from the Operational Plan (Lawrence et al., 2018) were only made to aid the success of the operation, and involved discussions between the team leader and the eradication advisor.

4.2 Implementing Agency and Sponsors

The eradication of rats from Maiden Island West forms part of the Offshore Islands Conservation Programme (OICP), which was founded in 1995 under the name of the Antiguan Racer Conservation Project. Focusing on the offshore islands of Antigua the OICP is a landscape-wide programme with the vision of “healthy, functioning coastal ecosystems that are sustainably managed for the conservation of native wildlife and for the benefit of local people” (Daltry et al., 2014).

The Environmental Awareness Group (EAG) is the main coordinating body for the OICP and was the main agency responsible for the eradication of rats the Island. The operation was principally funded by the U.S. Fish & Wildlife Service’s Neotropical Migratory Bird Conservation Act (USFWS-NMBCA) and The Global Environment Facility’s Preventing the Costs of IAS in Barbados and the OECS, but with significant additional in-kind support from the EAG and its partners.

The OICP is co-managed by the EAG, Government of Antigua and Barbuda, Fauna & Flora International (FFI) and Durrell Wildlife Conservation Trust (Durrell). This eradication also benefited from technical advice from Wildlife Management International Ltd, which was contracted by EAG on behalf of this programme.

4.3 Context for Maiden Island West’s Restoration

The removal of invasive species is a key component of the OICP’s strategy (Daltry et al., 2014). Current achievements of the OICP include the eradication of black rats from 15 uninhabited offshore islands.

Removing invasive species has proven to be remarkably beneficial for Antigua’s flora and fauna, including the native bird species, the reptile communities (including the Critically Endangered Antiguan racer Alsophis antiguae) and for the composition of the flora (Lawrence et al. 2013).

7 5. The Reasons for the Maiden Island West Rat Eradication

Maiden West Island forms part of the Offshore Islands of Antigua Important Bird Area (AG006), a nationally and internationally recognised location for seabirds (Prosper et al. 2008). It also forms part of the globally designated Offshore Islands Key Biodiversity Area (Wege et al. 2009). Black rats are implicated in the decline of lizard, bird, invertebrate and plant populations on the island. Eradicating rats will make resident wildlife populations more secure and create the opportunity for birds and other species to re- colonise the islands.

In detail, the reasons to remove black rats from these islands are:

• To conserve and enhance the regionally and internationally important breeding seabird populations present in the Offshore Islands Important Bird Area, facilitate re-colonization of Maiden Island by other native seabird and land species in the future, and provide a secure staging post for migrants.

• To conserve and enable the recovery of endemic and globally threatened lizard species on the island, and potentially create opportunities for some species to be reintroduced (e.g. the Critically Endangered Antiguan racer may potentially be returned to Maiden Island (pending approval from homeowners).

• To facilitate the recovery and regeneration of rare and endemic native plants and invertebrate species.

• To act on the strategic goals of the National Biodiversity Strategic Action Plan.

• To deliver on national commitments to the Convention on Biological Diversity (e.g. Article 8(h) requires the control or eradication on alien species that threaten ecosystems, habitats or species).

• To deliver on national commitments to the St George’s Declaration of Principles for Environmental Sustainability in the Organisation of Eastern Caribbean States (e.g. adoption of measures to eradicate invasive alien organisms).

• To show ongoing pro-active conservation in Antigua & Barbuda, and create new opportunities for environmental education.

• To protect marine environment under the Marine Areas (Preservation and Enhancement) Act.

8 6. Project Site and Target Species

6.1 Maiden Island West

Maiden Island West (17° 05’ N; 61° 53’ W) is on the Western coast of Antigua (Figure 1). It lies in Five Islands Harbour in the parish of Saint Mary, approximately 725 metres, at the closest point, from the mainland. Maiden Island is approximately 1.21ha in size. The island is mostly unoccupied with one dwelling place, seasonally used by the owners.

Access onto the island is via a small shallow beach. At low tide, the island can be circumnavigated by foot. However, there does not appear to be any other suitable landing sites on the island.

The soil on the island is very fertile, and the vegetation is quite lush. The island is vegetated with a number of thick areas of scrub; generally described as offshore island dry forest consisting of Pisonia subcordata, Canella winterana, Melocactus intortus, Jacquinia arborea making up the canopy and undergrowth containing Pithecellobium unguiscati and Agave karatto, (Lindsay & Horwith 1997).Introduced vegetation includes limes Citrus aurantium, lemons, Citrus maxima, most likely planted by the homeowners. Additional vegetation surveys will be conducted by vegetation specialist, Carolyn Thomas.

Like many islands in Antigua, Maiden Island West has a tropical dry climate with low rainfall (< 1,000 mm per year). The wet season, which overlaps with the hurricane season, extends from August to November.

As one of the offshore islands of Antigua, Maiden Island West makes up a part of the Offshore Islands Important Bird Area (AG006), which was designated mainly because of its significant seabird populations (Prosper et al. 2008). Surveys in January 2018 and again in June 2018 revealed nesting seabirds and wetland birds including Black-Crowned Night Herons Nycticorax nycticorax (listed as a vagrant in Birds of the West Indies, Raffaele et al). Various landbirds have been recorded including Antillean crested hummingbirds Orthorhyncus cristatus, green-throated caribs Eulampis holosericeus, bananaquits Coereba flaveola, zenaida dove Zenaida aurita and Lesser Antillean bullfinch Loxigilla noctis (Natalya Lawrence, pers. obs. 2018). Caribbean brown pelicans Pelecanus occidentalis occidentalis and Magnificent Frigate Birds Fregata magnificens forage around the island, but it is not known whether they breed there.

Maiden Island West is also part of the internationally-recognised Offshore Islands Key Biodiversity Area, designated mainly because of its globally threatened reptiles (Wege et al. 2009).Though an established rat population existed on the island, three species of reptiles have been observed: the endemic spotted anole Anolis leachi, the regionally endemic Watts’ anole Anolis wattsi and the endemic Antigua Ground Dragon Pholidoscelis griswoldi. These lizards were quite easily observed across the island (Natalya Lawrence, pers. obs. 2018). Critically Endangered Antiguan racers may have inhabited this island in the past but are now absent. The island does not appear to provide suitable habitat for nesting sea turtles.

9 Hermit crabs Coenobita clypeatus are present in moderate numbers, and large purplish land crabs, Gecarcinidae family were also observed in the night. The only mammals recorded there prior to their eradication were the non-native black rats Rattus rattus.

Figure 1 Maiden Island West, Antigua

Maiden Island West is privately owned by the Hall Family. There is one dwelling structure permanently installed on the island. This is seasonally used by the family and is well maintained. The entire family is keen to conserve the island’s biodiversity and happy to have had the invasive mammals permanently removed.

6.2 Black Rats

Originally from India, black rats Rattus rattus are now found throughout the world. They are smaller than the brown rat R. norvegicus (which also occurs on mainland Antigua, especially in urban areas), and have a slender body, long scaly tail, large ears and dark hairy feet (King 1990, Novak 1999). Black rats can grow up to 230 mm in length and have an average weight of 225g, but can weigh up to 300g (Cunningham & Moor 1993). There are three colour phases; rattus (black back and dark grey belly), alexandrinus (brown back and pale grey belly) and frugivorus (brown back and white or cream belly). The variation in proportion of colour morphs can vary depending on the location, although frugivorus is usually the most common colour phase (Cunningham & Moor 1993, King 1990).

10 Males are larger than females, and when mature have prominent scrotum at the base of the tail (King 1990, Novak 1999). Usually only breeding females have visible nipples (King 1990, Novak 1999). Black rats have excellent smell, touch, taste and hearing sense (King 1990). Black rats are omnivorous (but can also be specialist) feeders, taking advantage of any potential food source and will often cache food (King 1990, Nowak 1999). When on the ground, black rats prefer to eat food under cover; but in the trees rats will feed on any available flat surface (King 1990).

Black rats are major predators of land and seabirds, invertebrates, lizards and native mammals, and are voracious consumers of vegetation, seeds and fruit. They have caused the extinction of a number of plant species, particularly those on isolated offshore islands (Atkinson 1985, Bell 1978, Imber 1985, King 1990). Although natural food is a high proportion of black rat diet, human products (stores, vegetables and crops) are also targeted (King 1990).

Black rats are very agile and skilful climbers, and live both in trees and on the ground (King 1990). They are unwilling swimmers, but have been recorded swimming between islands up to 750 m apart (King 1990).

Black rats do not often burrow, preferring to nest in trees, under thick vegetation or in rock tumbles or crevices (King 1990, Nowak 1999). Despite this, tracks and runs are common in areas of black rat activity (King 1990). Black rats are usually associated with forests or vegetated areas, but can live in a range of habitats from barren ground, coasts, grassland to lush forest as well as human dwellings, buildings and farms (King 1990, Nowak 1999).

In natural habitat, black rats do not live in colonies, preferring to disperse throughout the available area (King 1990). However in urban areas, a small number of adult females and one dominant male will live together in a territory that will be aggressively defended against other rats (King 1990). Home range for black rats can vary from 0.1 ha to 1 ha in all types of habitats; this depends on food availability and habitat quality (Moors 1985, King 1990). Males have larger home ranges than females, which stay close to breeding sites; but this may vary depending on habitat quality, food availability, predation pressure and other factors (King 1990, Nowak 1999).

Black rats construct nests out of various items including newspaper and cardboard, but they are usually made from vegetation (twigs and leaves) and feathers, with new material added regularly (King 1990, Nowak 1999). They can breed throughout the year, but this generally depends on food availability and habitat (King 1990, Nowak 1999). Gestation is between 20 and 22 days and litter size varies from 3 to 10 young (usually 5-6); the average annual production can be up to 40 young per year (King 1990, Nowak 1999). The young are weaned when they are between 21 and 28 days old (about 40 g) and can be sexually mature at three months old (King 1990, Nowak 1999). Black rats usually live between 12 and 18 months in the wild, with females generally living longer than males (Daniel 1972, King 1990).

Black rats are mainly nocturnal and generally shy; however this depends on habitat, predation pressure, hierarchy, disturbance and food availability (King 1990). They explore all areas and objects within their home range, but can be cautious regarding new or strange objects within this area (King 1990).

Black rats are commonly infested with fleas and mites as well as being known carriers of several diseases that endanger people, including leptospirosis and salmonellosis (King 1990).

11 It is likely that black rats were accidentally introduced to Maiden Island sometime after the 17th century when rats were first recorded in the Caribbean region (Campbell 1991, Long 2003). No house mice Mus musculus were recorded on the island during feasibility studies or the eradication.

7. Eradication Preparation, Implementation and Monitoring

7.1 Summary of Activities for Phase 1 of the Eradication

27th June, 2018

The Data Management Unit of the Department of Environment (DoE) provided EAG with a GPS unit on Maiden Island West with a calibrated 30m grid across the island. This grid would aid in the upcoming track-cutting that would need to take place before bait was laid on the island.

30th June, 2018

Two shifts of teams from the Boys Brigade of Antigua & Barbuda along with members of the EAG began clearing overgrown trails as well as cutting minor paths on Maiden, using the grid provided by the DoE. The first team left Jolly Harbour at 7 am. Nathan Wilson and Natalya Lawrence from the EAG marked out the first trail to be cleaned up while the Boys’ Brigade had a light breakfast. Trail clearing began at 8:45 and concluded at 10:45. This team cleared most of the trail. After having lunch, team two finished clearing the second trail begun by team one and that work ended at 2:30 pm. Team two and the members from EAG returned to the mainland an hour ahead of schedule.

An area to the rear (west) of the island was left to be cleared but by then, the dust and the heat made work difficult, added to the fact that there were some fledging herons that we wanted to give a little more time to mature.

Figure 2 Trail Clearing for eradication of black rats. Courtesy Natalya Lawrence EAG-OICP

12 05th July, 2018

Natalya Lawrence and Elizabeth (Biz) Bell, Invasive Species Specialist (Wildlife Management International Ltd./(WMIL) met with property owner, Mr Michael Hall, to discuss upcoming eradication work and the possibility of reintroducing snakes to the island at a later date. That decision must be made by the entire Hall Family.

07th July, 2018

A team of volunteers returned to Maiden Island from Jolly Harbour. They left at 7 am, transported by Mr. Michael Hall. The team comprised of Natalya Lawrence, coordinator; Nathan Wilson, EAG staff; Ruleo Camacho, Marine Biologist, DoE; Carolyn Thomas, Plant Biologist; Biz Bell, invasive species specialist. Ruleo, Natalya and Nathan completed the trail-clearing at the back of the island while Carolyn conducted a plant survey (will be made available to the Hall Family), and Biz inspected the island in general and then the lines that had been cut on this and the previous weekend. Ruleo, who discovered a pygmy gecko, sent photos off to renowned herpetologist, Dr Jenny Daltry of Fauna & Flora International (who had visited Maiden Island in May with Natalya). She later confirmed that it was a local endemic species but extremely hard to find. The work was completed by 9:30 am and the team left shortly thereafter.

Figure 3 Pygmy Gecko found on Maiden Island Courtesy Natalya Lawrence EAG-OICP

09th July, 2018

Biz and Natalya visited the EAG shed to gather material and equipment for the eradication.

10th July – 11th July.

On 10th July, Natalya and Biz arrived at Maiden Island, transported by the Hall Family (Vernon, Adrian, Archie and Ella) from Seaforth Beach. They settled into the cottage then began setting bait points along the trails cut. Two points were set at each station, one in a bottle (to prevent crabs from getting to the bait) and one simply wired on to a tree. Two blocks of bait were wired at each point, with a total of 4 blocks of bait at each station. The stations were labelled A1 to A11 and three trail cameras were armed

13 at A1, A6 and A10. This exercise ended at 7:15pm and the team returned to the cottage. They then armed the final trail camera on the verandah of the house.

On 11th July, 8:55 am, Natalya and Biz reviewed all the stations for activity. Most of the 11 stations had rat activity but there was also evidence of crab and ant uptake at some of the stations. The bait was reviewed but not changed at that moment. At A7, the bottle and its bait were completely gone and this was most likely the work of a land crab. This exercise was completed by 9:40 and the camera from the verandah was taken to bait station A8 as all the bait blocks from the two points were totally consumed. There were also rat droppings with flecks of colour in them, indicating that rats had consumed the bait.

A bird count was taken at the end of this exercise.

At 10:30 am, the team wired bait points along the coast of the island: B1-B11. In some cases, only one point was wired (B5 & B6). There is an area where particular caution must be taken, near the south west corner of the island. This baiting exercise ended at 11:25 am.

Following this, Biz and Natalya studied the bait points on the GPS Unit and saw a negligible gap which they closed, creating A8A, just after and above A8. It was less than 30 m, but the habitat looked suitable for rats.

Figure 4 Map Showing Bait Points A1-11 and B1-11 – Courtesy Elizabeth Bell WMIL-OICP

At 14:15 pm, Natalya and Biz went along the ‘A’ track and changed/replenished all bait as needed at the various bait points. A bottle was also added to station A6 and replaced at station A7. Station A8A was not checked as it had been baited only a few hours before.

Biz swapped memory cards for new ones in all the trail cameras and armed them for use overnight.

14 Figure 5 Bait wired to a tree, consumed by rats – Credit Natalya Lawrence OICP-EAG

Figure 6 Rat consuming bait – Trail Camera, Station A6

15 Figure 7 Rat at bait point – Trail Camera, Station A6

All the chewed bait was collected and properly disposed of.

The gear was packed up and stored, and the team left the island at 5:30, transported by Vernon, Adrian, Archie and Ella Hall, back to Seaforth, and then to the Hall farm for final drop off.

16 7.2 Summary of Phase 2 of Maiden Island West Eradication

Activity Results Comments Plans for the Future

Any comments on the activity, e.g. Completed, What activities how successful (or not) has it been? What are future plans? (e.g. no Why? If partially completed, what has Part complete, change to plan, additions to plan, were planned to take place during been done? this month? added detail to plan) No action taken, etc. What still needs to be done?

When no rat sign was detected on A biosecurity plan will be developed 01st August, bait points were  Baiting and shared with the Hall family so Baiting took place until 30th July, removed, leaving only non-toxic that the island is routinely monitored 2018. monitoring points and sub-points. for rats and an incursion can be These were on the top of the island swiftly dealt with. and around the coast.

To monitor for the presence of rats tracking tunnels, trail cameras and flavoured wax were installed across Chocolate flavoured plastic cubes the top of the island and around the were placed in permanent bait boxes coast. across the island as crabs would enter  Monitoring bait boxes and consume bait. The Monitoring took place until 17th cubes are another method of August, 2018. detecting rat presence and last longer Tracking tunnels have ink pads which than flavoured wax. As such, these show prints of any animal that would will be a permanent fixture in the bait have walked through the tunnel. boxes.

17 Activity Results Comments Plans for the Future

Any comments on the activity, e.g. What activities Completed, how successful (or not) has it been? What are future plans? (e.g. no Part complete, Why? If partially completed, what has change to plan, additions to plan, were planned to take place during been done? added detail to plan) this month? No action taken, etc. What still needs to be done?

The cameras were set to capture movement near the monitoring points.

The flavoured wax was used as non- toxic bait. The three flavours were chocolate, aniseed and peanut. This was to give a variety of options just in case there was a fussy rat. Peanut flavoured wax was a favourite with crabs and ants and had to be mounted higher than the other two flavours.

12 stations have been installed across the island and stocked with bait and  Permanent bait station chocolate flavoured plastic cubes These stations must be checked and across the top of the island. replenished every 4 weeks. This is to installation Completed. quickly detect any incursions of rats so that it may be swiftly dealt with. The positions of the stations have been GPS marked.

18 Activity Results Comments Plans for the Future

A dead juvenile black-crowned night heron was collected from Maiden Island and Shanna Challenger performed a necropsy on 31st July. The bird did not die as a result of poisoning from bait placed on the island. Elizabeth Bell of Wildlife  Bird Necropsy International opined that it is natural for some of the the juvenile birds to None Completed die off naturally each nesting period and it could have been as a result of starvation.

The results of the necropsy were shared with the Hall family.

 Stocking bait boxes with bait With no indication of rats being on These stations must be checked and and non-toxic, chocolate- the island, the monitoring material replenished every 4 weeks. This is to Completed was removed and bait boxes were flavoured cubes quickly detect any incursions of rats stocked with toxic bait and not toxic- so that it may be swiftly dealt with. chocolate wax cubes.

19 Activity Results Comments Plans for the Future

 Data collection: Bird and These data should be collected at least twice per year. Bird and lizad lizard Ongoing None data were collected during the eradication period.

On 17th August, the team stocked On leaving the island, it was noted permanent bait stations with bait and that one temporary monitoring point still had flagging tape. This was  Removal of all eradication removed flagging tape, and Completed temporary monitoring points from located on the western end of the material and equipment the entire island. island and was pointed out to Mr Vernon Hall who would have a family member remove it at a later date.

20 8. Crab Interference

Crabs consumed large quantities of the Klerat© bait throughout the operation. The main concern was to ensure the availability of bait for the rats, notably in the important stage when the rat bait take had dropped rapidly and it was vital to remove the last few individuals. Most of the bait was wired through bottles to deter crabs and bait points were shifted in order to confuse the crabs. Further, trail cameras were used at stations of high crab interference to monitor for the presence of rats.

Figure 8 An example of high hermit crab interference with the bait on Pelican Island (Photograph: Vanessa Coldwell [Havery, 2014]).

21 9. Problems Encountered

During this operation, no major problems were encountered. The project team had the full support of its partners as well as the Hall Family who participated in the eradication, and provided all the transport needed to and from the island.

There was need to reschedule at least once because of tropical cyclone activity. The eradication was done during the Atlantic Hurricane Season which runs from 01 June to 30 November every year.

10. Recommendations

1. The Hall Family has agreed to manage the biosecurity of the island on a monthly basis and will be supported by the team at the Environmental Awareness Group. Because the island is frequently visited by the family, and at times by seamen and yachties, it is recommended that a protocol be put in place to reduce risks of introducing Invasive Alien Species, and an action plan to deal with such an eventuality. 2. During the monitoring phase, at times it was difficult to differentiate between rat teeth marks and crab clawings. In those instances, the use of lit magnifying glasses was an indispensable tool to draw the final conclusion. It is recommended that magnifying glasses fitted with lights be a permanent part of biosecurity monitoring in the future.

11. Conclusions

The operation on Maiden Island West has shown that total eradication of rats is possible due to the support of dedicated volunteers, OICP partners and the Hall Family.

At this stage the results suggest rats have been successfully eradicated from the island, although this should be confirmed in August 2020.

Apart from hermit crabs, no other non-target species were a significant problem in terms of bait interference. No non-target species were subjected to secondary poisoning throughout the operation.

Twelve permanent bait stations were installed Maiden Island West in the same position as the temporary A-Stations. These permanent stations will now form a part of long-term biosecurity measures on the island.

22 The eradication of introduced invasive species has become an internationally important tool in island conservation, with significant long-term benefits from relatively short-term investments. The eradication of black rats from Maiden Island West will have significant benefits to birds, lizards, and invertebrate populations and the vegetation composition is likely to change (Lawrence et al., 2013).

For Maiden Island West to remain rat-free, a constant vigilance and an ongoing commitment will be required from the Hall Family and the OICP team to detect and respond to any incursions.

23 12. References

Bell, E.A. (2012) Dog Island Restoration Project: the Eradication of Black Rats (Rattus rattus) from Dog Island, Anguilla. Unpublished technical report prepared for Anguilla National Trust, Department of Environment, Government of Anguilla and Fauna & Flora International. Bell, E.A. & Daltry, J.C. (2013) Feasibility Studies for the Eradication of Black Rats Rattus rattus and Small Asian Mongooses Herpestes javanicus from Pelican Island and Smith Island, Antigua. Report from Wildlife Management International Ltd and Fauna & Flora International to the Offshore Islands Conservation Programme, St John’s, Antigua and Barbuda. CEPF Grant 60933 (2012) Pest Management Plan - Offshore Islands Conservation Programme: Maintaining Rat-Free Islands for the Benefit of Antigua’s Biodiversity and People. Environmental Awareness Group Inc., Antigua and Barbuda. Daltry, J.C. (2000) The Second Rat Eradication on Praslin Island, Saint Lucia: August –September, 2000. Unpublished report to the Saint Lucia Forest and Lands Department and the Durrell Wildlife Conservation Trust. Daltry, J.C. Bell, E.A., Lawrence, S.N. & Havery, S.J. (2014) Operational Plan for the Eradication of Black Rats Rattus rattus and Small Asian Mongooses Herpestes javanicus from Pelican and Codrington Islands, Antigua. Report from Fauna & Flora International, Wildlife Management International Ltd and Environmental Awareness Group to the Offshore Islands Conservation Programme, St John’s, Antigua and Barbuda. Day, M. & Daltry, J. (1996) Rat eradication to conserve the Antiguan racer. Aliens, 3, 14-15. Havery, S.J., Read, S., Coldwell, V., Chan, C., Renny, W. & Nether, E. (2014) Personal Observations throughout the Operation to eradicate black rats and small Asian mongooses from Pelican and Codrington Islands. Havery, S.J., (2014) Technical report for the Eradication of Black Rats Rattus rattus and and Small Asian Mongooses Herpestes javanicus from Pelican, Codrington and unnamed Islands, Antigua. Report to the Offshore Islands Conservation Programme, St John’s, Antigua and Barbuda. Howald, G., Donlan, C.J., Galvan, J.P., Russell, J.C., Parkes, J., Samaniego, A., Wang, Y., Veitch, D., Genovesi, P., Pascal, M., Saunders, A. & Tershey, B. (2007) Invasive rodent eradication on islands. Conservation Biology, 21, 1258- 1268. Jones, H.P., Tershy, B.R., Zavaleta, E.S., Croll, D.A., Keitt, B.S., Finkelstein, M.E. & Howald, G.R. (2008) Review of the global severity of the effects of invasive rats on seabirds. Conservation Biology, 22, 16-26. Lawrence, N., James, K., Otto, A., Ross, T.N. & Daltry, J.C. (2013) Is eradicating rats worth it? Impacts observed on Antigua’s offshore islands. Program and Abstracts: Society for the Conservation and Study of Caribbean Birds, 19th Regional Meeting, July 26-31. Georgetown, Grenada. Pain, D.J., Brooke, M.D., Finnie, J.K. & Jackson, A. (2000) Effects of brodifacoum on the land crabs of Ascension Island. Journal of Wildlife Management, 64, 380-387. Raffaelle, H., Wiley, J., Garrido, O., Keith, A. & Raffaelle, J. (2003) Birds of the West Indies. A & C Black Publishers Ltd. London, UK. Ross, T. & Tallarico, S. (2010) Antigua Offshore Island Seabird Surveys, June 2010. A report to the Offshore Islands Conservation Programme, Environmental Awareness Group and Fauna & Flora International.

24 Ross, T. (2011) Seabird, Land Bird and Lizard Surveys on Antigua’s Offshore Islands, May–June, 2011. A report to the Environmental Awareness Group, St John’s, Antigua. Towns, D.R. & Broome, K.G. (2003) From small Maria to massive Campbell: forty years of rat eradications from New Zealand islands. New Zealand Journal of Zoology, 30, 377-398. Varnham, K. & Daltry, J.C. (2012) Operational Plan for the Emergency Eradication of Green Island. Unpublished technical plan to the Mill Reef Club and partners of the Offshore Islands Conservation Programme. Varnham, K. & Daltry, J.C. (2006) Eradication of Invasive Black Rats (Rattus rattus) from Green and York Islands, Antigua: June-July, 2006. Unpublished technical report to the Mill Reef Club and partners of the Antiguan Racer Conservation Project.

25 13. Appendix

13.1 Eradication Schedule

◄ Jun 2018 July 2018 Aug 2018 ►

Sun Mon Tue Wed Thu Fri Sat 1 2 3 4 5 6 7 Pre-eradication Trip: Transport: Michael Hall (2 trips) Day Trip: 700 – 1000hrs Field Workers : Biz, Ruleo, Natalya, Carolyn, Nathan Tasks:Finish trails, plant survey, reconnaissance.

8 9 10 11 12 13 14 Put all the equipment Start of eradication: Baiting (Check 1): Baiting (Check 2): Baiting (Check 3): Baiting (Check 4): together Set up bait points Tasks:Check ‘A’Bait points, Day Trip – 1600-1800hrs Day Trip – 1600-1800hrs EXTRA BAIT PUT OUT install ‘B’ Bait points and Set up camera traps Transport: Vernon, Archie Transport: Vernon, Archie Transport: Michael, Archie map them Hall Hall Hall Transport: Vernon, Adrian, Ella, Archie Hall Transport: Vernon, Adrian, Ella, Archie Hall Day Trip – 8 am – 9 am Monitors: Biz, Natalya Monitors: Biz, Gita, Monitors: Biz, Natalya Monitors: Biz, Grantley, Monitors: Biz, Natalya Grantley, Natalya Tasks:Set ‘A’ Bait points Tasks:Check Bait points, Andelle, Natalya Tasks:Check Bait points, and map them Leave afternoon: 17:00 Tasks:Check Bait points, change SD Cards change SD Cards Sleep overnight change SD Cards

◄ Jun 2018 July 2018 Aug 2018 ►

Sun Mon Tue Wed Thu Fri Sat 15 16 17 18 19 20 21 Baiting (Check 5): Baiting (Check 6): Baiting (Check 7): Baiting (Check 8): Baiting (Check 9): Baiting (Check 10): Day Trip – 1600-1800hrs Day Trip – 1600-1800hrs Depart Mainland 4pm Put out monitoring Monitoring (Check 1): Monitoring (Check 2): With 2 additional volunteers With 2 additional volunteers Sleep overnight Install Permanent Bait Stations Install Permanent Bait EXTRA BAIT PUT OUT Transport: Vernon, Archie Transport: Vernon Hall Transport: Robert Hall posts Stations DAY TRIP: approximately 8 Hall Transport: J.D. Hall Day Trip – 1600-1800hrs am – 10 am Monitors: Biz, Grantley, Monitors: Biz, Grantley, Transport: Vernon Hall, Ella Transport: Michael Hall

Monitors: Biz, Grantley, Andelle, Natalya Andelle, Natalya Leave at 1700 Hall Monitors: Biz, Andelle, Andelle, Natalya Monitors: Biz, Natalya Leave Lunch-time Natalya ***Dead rats seen Natalya’s 10th wedding Tasks:Check Bait points, Tasks:Check Bait points, Monitors: Biz, Sophie, Tasks:Check Bait points and anniversary ☺ change SD Cards Tasks:Check Bait points, change SD Cards Andelle, Natalya monitoring stations, change change SD Cards Tasks:Check Bait points, Tasks:Check Bait points and SD Cards change SD Cards monitoring stations, change SD Cards 22 23 24 25 26 27 28 Biz Leaves Baiting (Check 11): Baiting (Check 12): Baiting (Check 13): (American Airlines 14.49 hr) Monitoring (Check 3): Monitoring (Check 4): Monitoring (Check 5): DAY TRIP: 1600 – 1800 hrs DAY TRIP: 1600 – 1800 hrs DAY TRIP: 1600 – 1800 hrs Transport: Vernon Hall Transport: Vernon Hall Transport: Robert Hall Monitors: Natalya, Monitors: Gita, Natalya, Monitors: Gita, Natalya, Grantley, Andelle Grantley, Andelle Grantley, Andelle Tasks:Check Bait points and Tasks:Check Bait points and Tasks:Check Bait points and monitoring stations, change monitoring stations, change monitoring stations, change SD Cards SD Cards SD Cards, install Permanent Bait Stations

27 ◄ Jun 2018 July 2018 Aug 2018 ►

Sun Mon Tue Wed Thu Fri Sat 29 30 31 Baiting (Check 14): Juvenile Black-Crowned Night heron necropsy Monitoring (Check 6): performed. Results shared DAY TRIP: 1600 – 1800 hrs with Hall Family Transport: Robert Hall Monitors: Natalya, Grantley, Andelle Tasks:Check Bait points and monitoring stations, change SD Cards, install Permanent Bait Stations ***Dead Juvenile night heron collected, baby tortoise found

◄ Jul 2018 August 2018 Sep 2018 ►

Sun Mon Tue Wed Thu Fri Sat 1 2 3 4 Baiting (Check 15)- Final if no rats seen on Friday Baiting (Check 16): Only if rat sign observed Monitoring (Check 7): Monitoring (Check 8): DAY TRIP: 1600 hrs DAY TRIP: 1600 hrs Transport: Vernon Hall Transport: Vernon Hall Monitors: Andelle, Natalya Monitors: Grantley, Andelle, Natalya, Daniel Tasks: check tree bait points, install final bait station, Tasks: Remove bait points, fill bait stations, check monitoring, set tracking tunnels check monitoring, check tracking tunnels, take cameras

◄ Jul 2018 August 2018 Sep 2018 ►

Sun Mon Tue Wed Thu Fri Sat 5 6 7 8 9 10 11 Baiting (Check 17): Only if rat sign observed Baiting (Check 18): Only if rat sign observed Monitoring (Check 9): Monitoring (Check 10): DAY TRIP: 1600 hrs DAY TRIP: 1600 hrs Transport: Transport: Monitors: Andelle, Sophie, Natalya Monitors: Grantley, Andelle, Natalya, Daniel Tasks:check monitoring, check tracking tunnels Tasks:check monitoring, check tracking tunnels 12 13 14 15 16 17 18 END OF ERADICATION Monitoring (Check 11): DAY TRIP: 1600 hrs Transport: Monitors: Tasks: Remove all equipment from cottage, remove flagging tape, wires, monitoring, tracking tunnels. 19 20 21 22 23 24 25

26 27 28 29 30 31

29 13.2 Biosecurity Checklist for Hall Family

32 13.3 Bird Species Observed

Nesting Local Name Latin Name Observers Confirmed N/Y

Antillean Crested Orthorhyncus cristatus NL, SC, SS N Hummingbird

Bananaquit Coereba flaveola NL, SC, SS, BB N

Black-Crowned Night Heron Nycticorax nycticorax NL, SC, SS, BB, JD Y

Caribbean Brown Pelican Pelecanus occidentalis NL, SC, SS, BB N occidentalis

Gray Kingbird Tyrannus dominicensis NL, SC, SS, BB N

Great Egret Ardea alba NL, SC, SS N

Green Heron Butorides virescens NL Y

Green-Throated Carib Eulampis holosericeus NL, SC, SS, BB N

Laughing Gull Leucophaeus atricilla NL, SC, SS, BB, JD Y

Lesser Antillean Bullfinch Loxigilla noctis NL, SC, SS, BB N

Little Blue Heron Egretta caerulea NL, SC, SS, BB, JD Y

Magnificent Frigate Bird Fregata magnificens NL, SC, SS, BB, JD N

Osprey Pandion haliaetus NL, SC, SS, BB N

Royal Tern Thalasseus maximus NL, SC, SS, BB N

Sandwich Tern Thalasseus sandvicensis NL, SC, SS N

Zenaida Dove Zenaida aurita NL, SC, SS, BB N

BB- Elizabeth Bell NL – Natalya Lawrence

GE- Grantley Edwards SC – Shanna Challenger

JD- Jenny Daltry SS – Sophia Steele