SOUTH KAIPARA LAKES SURVEY AND DABCHICK CENSUS FOR 25TH APRIL 2019 COMPILED BY DENISE POYNER – JANUARY 2020 It’s a bit late. However, I’m in the head space to write up the 2019 report for the Dabchick Census completed on 25th April 2019. 38 volunteers 819 wetland birds 36 grebes Waioneke school A puzzle or two Health & Safety children attend again Update on activities Bird Atlas It’s important, I believe, to maintain a sense of what the survey is about and what it entails. This is a scientific survey where at least some insight into the process is provided in each report. The survey was started in 1969. It is run by the Ornithological Society of New Zealand (aka Birds New Zealand), and is particular to the Auckland region of this organisation. The survey is held annually on only one day of the year being 25th April. We do this regardless of the weather. Volunteers who come along are placed in groups with a knowledgeable birding person to help identity the birds they are seeing. At the end of the count we enjoy a barbecue hosted by a local South Head resident and South Kaipara Landcare (SKL). The volunteer group is a mix of SKL members, Birds NZ members, South Head residents and interested parties. As we have sixteen active sites with water in them, it is great to have a good number of volunteers. On the day we had 38 volunteers attend. This is a great number to have along to help with the count. We have twenty-five sites in our records. Nine lakes are classified as dry. They are mostly situated in the southern area of the dune lakes system. The dry sites are affected by the water uptake of Woodhill Forest. All lakes remain on our list to visit. The count covers three things. Firstly, we are counting New Zealand dabchicks and their close relative the Australasian little grebe. We are looking for adults and juveniles of each of these species. Secondly, we count other wetland birds such as all species of shags, white-faced heron, Australasian bittern, black swan, Canada geese and feral geese, a variety of ducks, Australasian shoveller, teal and New Zealand scaup. Finally, we also make note of the presence of any other bird that is related to the wetland area such as pukeko, Australasian harrier, stilts, terns, oystercatchers, and common passerine. Statistics are generally meaningless unless there is a scientific test supporting research. On the other hand, it is interesting to see how populations of a species can change over time. As this is a New Zealand dabchick census, and we count its close relative the Australasian little grebe, I’d like to show you the count from 2013 to 2019 for these two birds. 2013 2014 2015 2016 2017 2018 2019 19 13 14 28 31 33 36 Here’s an update on the graph I placed in the 2018 report. South Kaipara Lakes Survey - Count of Dabchick 2013 -2019 40 35 30 25 20 15 Number 10 5 0 2013 2014 2015 2016 2017 2018 2019 Year Back around 2001-2006 the count was around, or over, 100 birds. We saw a big decrease to 53 birds in 2007 and a continuing decrease since then. Countering that though, and while not back to past numbers in the population, it is heartening to see an increase in grebes across 2016 to 2019. Decreases in bird population is a concern. What’s doing that? Several factors can be considered – rainfall, food availability due to habitat changes, pest control or lack thereof, external disturbance such as boats, jet skiers and water skiers, and water quality. External disturbance is an important factor due to the species nesting in a pile of aquatic vegetation on the waterway. (Szabo, 2017). In the seven years, 2013 to 2019, the overall count of birds takes a bit of a ride. Sometimes it has been around 1000 birds, sometimes well over that at around 1300 birds, and sometimes well under that at 700-850 birds. Mostly though the ups and downs are about the number of water fowl we count. Species like paradise shelduck, grey duck, mallard, and mallard x grey duck show fluctuations over time. Other significant changes over the seven year period of 2013 to 2019 include: a decline in little black shag; a decline in little shag; Canada geese show a lumpy ride across the seven years; an up and down year on year affect on paradise shelduck; a big drop in mallard x grey duck from 2018 to 2019, but otherwise an average, expectable count for 2019; a good year for Australasian shoveler earlier on, but down to 14 individuals in 2019. Generally, most species bobble along as determined by habitat conditions. Pest control is a big factor in the survival of any species. I am aware South Kaipara Landcare actively engages in pest control activities. Over time this is sure to have good effect on populations of birds. An actively engaged landowner doing pest control has killed 380 pests since he started. The list of pests includes: hedgehogs, rats, stoats, possums, ferrets and feral cats. The next section is facts about the New Zealand Dabchick. I have reviewed current information, amended references where necessary and included a bit more detail as a result. Short facts about New Zealand Dabchick Scientific name: Order: Podicipediformes Family: Podicipedidae Genus and species: Poliocephalus rufopectus They have been around a long time. G R Gray named them in 1843. (Szabo, 2017) Other names: In Maori, they are called several names. Those names appear to be localised. For example, in the Hokianga they are called taihoropi. In the Waikato, they are known as taratimoho. Other names are weweia and totokipio and New Zealand Grebe. (Szabo, 2017) Description A small to medium sized bird belonging to the grebe family. They are diving birds. Long necked. Can change their buoyancy. Brown-black in colour with a rufous red breast (in breeding season) and yellow eye. White under- feathers including end of the tail. Thick olive-green legs with lobed feet. Feet are yellow on the inner side and edges. Short black bill. (Szabo, 2017) About 29cm in length and 250 grams in weight. (Wikipedia, 2017) Population, Population and Conservation status: conservation Origin: Endemic (Szabo, 2017) status, threats, Number: 1900 – 2000 individuals. (Szabo, 2017) location, and Conservation Status: Near threatened (Wikipedia, 2019). Recovering behaviour. (Szabo, 2017) Threats: Predation, water quality, loss of natural habitat caused by wetland drainage, and increased disturbance such as boat usage, jet skiing and water skiing are all threats. Nests are affected by disturbance. Location: The species inhabits freshwater lakes and ponds on the volcanic plateau, Rotorua lakes area, Northland, Hawkes Bay and Wairarapa. The species could be found in the South Island during the 1800’s and 1900’s. It became extinct as a breeding species in the 1940’s. The good news is a breeding pair was located near Takaka in 2012, and a pair have bred near Blenheim in 2015. They favour shallow water with dense vegetation on small freshwater lakes and pond, sand dune lakes and lagoons, and larger inland lakes with shallow, sheltered inlets up to the size of Lake Taupo. They will live at sea level and up to 740m altitude. (Szabo, 2017) For 2019, the strongholds for the species were: Marie Neverman Reserve, Lake Kereta. Behaviour: The species can change its buoyancy by changing the angle its feathers are held against its body. They can be aggressive toward intruders. The behaviour is displayed as: head being lowered forward, neck and back arched, half raised wings, short rushes or low pattering flight towards an intruder. Appeasement displays include: head bobbing up and down, side to side and back and forth. They dive as a last resort to escape. They will turn “stern- on and raise and fluff up the rear feathers to display a white “owl-face” pattern on each side of the tail feathers. This is thought to be a territorial behaviour that conveys mild alarm when threatened. They fly at night. They can cross large bodies of water such as Cook Strait. Genetically they are a super-species to the hoary-headed grebe of Australia and appear to be related to the Rollandia of South America. (Szabo, 2017) Breeding: All year round with territorial displays in June-July and egg laying in the August to February period. Nests are made of aquatic material about 1m deep in construction. They will also build nests in a cave. Courtship involves: preening, rearing, head turning and shaking, and ritualised displays of diving and pattering. The species is monogamous. Lay 2-3 bluish eggs that become stained brown in the nest. Incubation is over 22 or 23 days. Chicks are born with irregular black-brown horizontal stripes on a white background. They have a bright red bill with black markings. Chicks are reared over 70 days. They ride on the parents back for the first week, and mostly over the second and third week until they are too big to do so in the fourth week. (Szabo, 2017). Chicks are capable of moving around straight after hatching (precocial). They are flightless for the first few weeks but are capable of swimming and diving. (Wikipedia, 2019) Food: Aquatic invertebrates such as insects and larvae, fish and crayfish, shellfish, leeches. (Szabo, 2017) Waioneke School A small group of Waioneke School children attended again. A message from Claire Bennett the day after the count gave thanks to Ian and Trina (Birds New Zealand – Auckland Branch) for the great educational activity the children had.