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Monitoring birds

Update on what birds the eradication team have been monitoring

Written by Stephen Horn – Project Manager

Members of the Antipodes Mouse Eradication project have been working to document native flora and fauna both before and after the application of rodent bait to eradicate mice to better understand the impact that mice have had on these endemic and native communities. The information gathered will complement baseline studies started in 1996 to document the changes of these communities in response to the absence of mice if the eradication has been successful.

Monitoring of ground-bird populations has been conducted using distance sampling techniques “before” and “after” the eradication attempt. Mice are competitors for seed and invertebrate resources that ground-birds rely on. Mice are also believed to prey on nestlings and or eggs of some ground and sea bird species. Distance sampling methodology for native ground birds is accomplished by traversing the island along pre-established transects observing the visual presence of four endemic ground bird taxa: Antipodes Island Parakeet (Cyanoramphus unicolor), Reischeck’s parakeet (Cyanoramphus hochstetteri) Antipodes Island Snipe (Coenocorypha aucklandica meinertzhagenae) and Antipodes Island Pipit (Anthus novaeseelandiae steindachneri) which are endemic subspecies. The monitoring team cover a variety of terrain while conducting the transects; from relatively flat tundra-like moss and lichen dominated plateau to literally swimming through head height grasses, sedge and ferns on hillsides and lower wetland areas. At the beginning of each transect, environmental conditions are recorded as the conditions have an effect on the frequency of encounters particularly when it is too windy. Some days bring blue clear skies and light winds (rare) and others windy conditions with scattered hailstorms and rain!

Pipit catching

Pipit catching

Ann Pipit catching

Ann Pipit catching

Antipodes pipit

Antipodes pipit

Snipe Encounter

Snipe are cryptic creatures. Encounters with them are relatively rare on the Antipodes compared with other Subantarctic Islands, such as Adams Island in the Auckland Islands Group and Campbell Island where no rodent pests exist. Every snipe seen is recorded against the person hours spent in the field. Snipe are expected to increase in abundance on Antipodes Island with the removal of mice and the affect of their activities. The encounter rate of snipe will complement monitoring started in 2012 and will continue as part of the post-eradication monitoring activities.

Pipits

Twenty five Antipodes Island pipits were captured and banded for short-term identification with plastic bands of varying colour combinations within the vicinity of the Hut Cove, Reef Point, Anchorage Bay and Stella Bay, near the field camp. A daily route is walked through this area and sightings recorded in order to track survival before and after the application of bait. The results provide an understanding of the short term impacts of baiting on the pipit population as some pipits were found to feed on the bait during winter trials in 2013. Preliminary results have identified some banded pipits that have disappeared since baiting. However, observations remain frequent and transects along coastal strongholds show good numbers of pipits are present, which is a reassuring result. Sustainable populations also exist on the offshore islands which weren’t baited where we were confident mice were not present (Bollons Island and the Windward Islands) providing the required insurance in case losses were higher than expected.

Banding Albatross Chicks

Monitoring for the endemic Antipodean wandering albatross (Diomedea antipodensis) has been undertaken on an almost annual basis since 1994 to track survival, productivity, recruitment and on a more extensive basis, the extent of this bird’s feeding grounds. The team here has contributed to this work by assessing the chick survival in the study area. We have also done work to utilise helicopter based aerial photography paired with GIS in an attempt to conduct a population census as Antipodean albatross chicks are present and being fed over the winter, easily visible on nest mounds from the air. The only other seabird breeding over winter is the Grey petrel. Young albatross chicks in a study area on the North Plains have also been banded for identification prior to them fledging late in the year, allowing their survival to be tracked over the years.

Watch this space for the teams monitoring of insects and vegetation…

Monitoring to detect mice

The Antipodes eradication team have been busy monitoring

Written by Stephen Horn – Project Manager


Tracking tunnels for detecting mice have been deployed on Antipodes Island as well on the offshore islands including Bollons, Leeward and Windward Islands. Each device station contains a tracking card and a bait positioned in the middle of the card. As mice move into the tunnel they walk across a black ink pad to access the bait, leaving their signature footprint on either end of the card confirming their presence and depending on number of tracks, giving some indication of the density of the population.

Finlay setting up biosecurity network

Mouse tracking tunnel

Mouse tracking tunnel

Following the bait application to eradicate mice, 15 tracking tunnels were placed around the field camp and coastal areas around the Hut Cove and Anchorage Bay and also at an elevated plateau site on the North Plains.

The tracking tunnels were monitored daily when possible on Antipodes Island and when the weather was conducive to access the offshore islands. None of the offshore island monitoring stations showed the presence of mice.

The tracking tunnels around the coast fell away to zero tracking approximately 10 days after the first bait application. We continued to track mice until close to the completion of the second bait application around the field camp before tracking went to zero and bait take from the trays around the infrastructure stopped.

Mice are almost impossible to detect at low density and much of Antipodes Island is steep and inaccessible so these results are not sufficient to say if the eradication attempt was successful but provide interesting data about the period required for mice to succumb. Rodent detection dogs and monitoring tools will be used on site in 2018, two potential mouse breeding seasons after the eradication attempt. This gives sufficient time for any remaining mice to have bred to detectable levels if the eradication was not successful. If no mice are detected at that stage we can be confident they have been eradicated.

Many of the monitoring tools have been set up as part of a long term biosecurity network to be checked upon the arrival of any visitors to help protect against the risk of any future incursion.

Bird and insect monitoring have also been a big focus for the team. Watch this space for these updates from the island.

Pizza nights

Stephen Horn updates us on simple pleasures of life on Antipodes

29 July 2016

Friday night is pizza night and our reference for keeping track of which day of the week it is. Chef Pete Kirkman brought with him two tiles that he skillfully cut to size to fit our diesel oven which have become ideal pizza stones. The next step was riveting a second shelf into the oven in order to cook two at a time and Pizza night was born.

 
The setup produced perfectly cooked bases matched only by Pete’s mouth-watering toppings. Team favourites include chicken and apricot, smoked salmon and of course chorizo and bacon. Not satisfied with the limited implements available, Jamie Doube (team Doctor and budding pizza engineer) added authenticity to the scene by creating a pizza paddle for inserting and retrieving the creations from the oven and a never fail pizza slicer out of an offcut of chimney flue.

Friday night Antipodes Island

Friday night Antipodes Island

It’s hard to imagine a better way to spend a Friday evening as semolina flour coats the table, bases spin through the air and pizzas are delivered two by two, hot from the oven to the table and politely cut into the smallest of pieces enabling everyone a taste as they are heartily devoured. Mamma Mia!

 

Antipodes two parakeets

Introducing the Antipodes Island parakeet and the  Reischek’s parakeet

Written by Finlay Cox on Antipodes Island

Antipodes Island Parakeet

Cyanoramphus unicolor

The Antipodes Island Parakeet is endemic to the Antipodes Islands. It is common throughout the Antipodes Islands, particularly in areas of tall dense tussocks and sedges on slopes and along streams. The population is estimated to be approximately 2000-3000 birds, less abundant than the other endemic parakeet – Reischek’s parakeet.

The Antipodes Island parakeet has one of the most unlikely back stories of any New Zealand bird. It was named by the artist, illustrator and poet Edward Lear (1812-1888). Lear’s first publication, at the age of 19, was Illustrations of the Family of Psittacidae, or Parrots. In this volume, Lear illustrated and named the green parrot that was held at the London Zoo. No-one knew where the bird had come from, and it was another 55 years before Captain Fairchild of the New Zealand government steamer Stella solved the riddle, discovering that Lear’s ‘Platycercus unicolor Uniform Parakeet’ came from Antipodes Island!

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Antipodes Island parakeet. Photo by F.Cox

The largest and most robust of all the Cyanoramphus parakeets (approx 130 g), the Antipodes Island parakeet has uniformly green plumage that lacks the crown colouration typical of the rest of the genus. It has a very large bill and broad, rounded wings. They are inquisitive and often attracted to human activity. As seen in Pete the cook’s photo.

They display strong seasonal and interannual dietary preferences for leaves and seeds supplemented seasonally with flowers, seeds, berries, carrion and flesh from grey-backed storm petrels. Invertebrates are a minor component of the diet. The birds forage extensively on the ground.

Interestingly – as seen in the video, carrion makes up part of their diet. The Antipodes parakeets partially fill the scavenging niche – taking advantage of leftover protein on carcasses of petrels hunted by skua and dead penguins amongst the many colonies on the island.

Reference

Greene, T.C.; Miskelly, C.M. 2013. Antipodes Island parakeet. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz

Reischek’s Parakeet

Cyanoramphus hochstetteri

Reischek’s parakeet is endemic to the Antipodes Islands. It is common throughout the Antipodes Islands, particularly in more open areas and coastal fringes close to penguin colonies. The population is estimated to be approximately 4000-5000 birds.

They are named after Austrian ornithologist and taxidermist Andreas Reischek, the first scientist to visit the Antipodes Islands. He was a passenger on the Stella and called in to Antipodes Island in February 1888.

The Reischek’s parakeet is smaller than the uniformly green Antipodes Island Parakeet. It looks very similar to other ‘red-crowned’ parakeets of NZ mainland. But appearances can be deceiving, genetic studies show that crown colour is not a good indicator of parakeet relationships, as the orange-fronted parakeet may be the closest relative of Reischek’s parakeet.

Reischek’s Parakeet. Photo by F.Cox

Reischek’s Parakeet. Photo by F.Cox

Consumption of leaves, flowers, berries and seeds from 14 plant species has been recorded. Invertebrates are a minor component of the diet. Reischek’s parakeets occasionally scavenge from corpses of petrels and albatrosses, but not as frequently as Antipodes Island parakeets. Reischek’s parakeets forage extensively on the ground and in winter search for insects amongst the penguin guano when penguin colonies are empty.

Flock of Reischek’s Parakeet. Photo by F.Cox

Flock of Reischek’s Parakeet. Photo by F.Cox

Reference

Greene, T.C. 2013. Reischek’s parakeet. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz

Antipodean Albatross

Introducing the Antipodean Albatross

Written by Finlay Cox on Antipodes Island

Diomedea antipodensis

The Antipodean albatross is a large albatross with a wing span of 3 metres. There are two subspecies that breed almost exclusively on the Auckland and Antipodes Islands. The Antipodes Island subspecies (D. a. antipodensis) breeds almost entirely on Antipodes Island. They forage over the continental shelf edge and deep water from south of West Australia to the coast of Chile. Foraging as far north as 27°S, and as far south as 72°S.

Antipodean albatross are large albatross with pink bills and plumage that varies in colour from black and white to chocolate brown depending on sex and age.

About 3700 pairs breed on Antipodes Island. Since successful breeders only nest every second year the total population of breeding birds is about twice as large.

Albatross adult. Photo by F. Cox

Albatross adult. Photo by F. Cox

Their food source includes squid, fish and discards from boats. This habit of following boats and taking bait from hooks has led to large numbers being killed in long-line fisheries. This probably led to a dramatic decline in numbers in the 70s and 80s which slowed with the demise of the southern bluefin tuna fishery and improvements in bird by-catch avoidance techniques.

Between 2005 and 2007 populations and breeding success at both the Auckland and Antipodes Islands dramatically declined, possible explanations could include by-catch in a new swordfish fishery, and or changing ocean conditions associated with global warming.

 

Albatross chick. Photo by F.Cox

Albatross chick. Photo by F.Cox

Antipodean albatross lay a single egg between December and February and take a whole year to hatch the egg and raise the chick. Both members of the pair incubate the egg and care for the young, taking shifts of up to 3 weeks while incubating.

Antipodean albatross are masters of low-energy flying, exploiting small updrafts created by wind and waves and rarely flapping their wings. They cover large distances at high speed to find sparsely distributed prey.  Their squid and fish diet is mostly scavenged, either taken from the surface or from shallow plunge dives. They are long-lived and don’t start breeding until they are between 7 to perhaps 20 years old and have an elaborate courtship lasting several years which initially involves a characteristic singing and dancing display. They form enduring pairs that mostly last until one of the pair dies.

Reference

Elliott. G.P.; Walker, K.J. 2013. Antipodean albatross. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz

 

 

Boat on the way!

 

Norfolk Guardian preparing to depart. Photo by C. Nanning

Norfolk Guardian preparing to depart. Photo by C. Nanning

 

Update from Stephen Horn – Project Manager

27 July 2016

Direct from a freight run to Norfolk Island, the Norfolk Guardian docked in Auckland on the 25th July in preparation for its next voyage to the Antipodes Islands to retrieve the mouse eradication team. The NZ Navy have been supporting the project by accommodating the vessel at Devonport where we used divers to check the hull for any unwanted marine organism that may pose a biosecurity risk to the Subantarctic marine environment.

Auckland DOC ranger Carol Nanning and the famous rodent detection dog team of Pai and Piri also visited the ship to check for any sign of rodents or insects and to reset the biosecurity monitoring tools on-board.

The sniff team inside the Norfolk Guardian. Photo by C. Nanning

Pai and Piri at the dock. Photo by C. Nanning

All clear! Photo by C. Nanning

All clear! Photo by C. Nanning

The dogs worked around the ship, sniffing their way through the various compartments before giving the vessel the all clear.

The detection tools on-board will be checked again upon arrival at the Antipodes.

On-going biosecurity for visiting vessels and people is paramount to protect the biodiversity values of offshore islands and the work we have done here on the Antipodes. It is wonderful to have people like Carol and dogs like Pai and Piri involved. 

The Norfolk Guardian left port last night at 6pm and are now on their way to Antipodes. We look forward to seeing the Norfolk Guardian and her crew here again soon.

Cheers Stephen

Check out Pai and Piri on Facebook

Read about the previous trip of the Norfolk Guardian to the Antipodes.

 

 

Update from the Antipodes

The mouse eradication team

Antipodes Mouse Eradication Team

Update from Stephen Horn – Project Manager

25 July 2016

The Evohe arrived on Saturday night and offloaded John Henderson, Cullum Boleyn and Ray Bellringer to help with the deconstruction of our camp and the hangar structure.

We fare-welled team members Jamie Doube and Keith Springer back to Dunedin yesterday.

We took advantage of a calm day yesterday to retrieve our monitoring gear from the offshore islands and pull in the radio repeater we had on Mt Galloway. The swell was still  4 -5 m from the north.

The Norfolk Guardian is due to arrive next Sunday or Monday – so will be up to the weather after that. We need at least 2 good days to load the vessel. The Evohe will also be returning to transport the rest of the team back to New Zealand mainland.

Everything is coming to a close quite quickly now. All going well we may be departing the island late next week. Team doing well – we were treated to some fresh fruit last night with some of the supplies that came ashore.

Cheers Stephen

 

Hut from the sea. Photo by F.Cox

Hut from the sea. Photo by F.Cox

Hut site.

Hut site.

 

Antipodes Snipe

Introducing the Antipodes snipe

Written by Finlay Cox on Antipodes Island

The Subantarctic snipe species includes both the first New Zealand snipe to be discovered, and the most recent. The Auckland Island subspecies was discovered on Enderby Island in November 1840 during the Erebus & Terror expedition. The Campbell Island subspecies was not known to exist before a chance discovery on sheer-sided 20 ha Jacquemart Island in 1997. Following the eradication of rats on Campbell Island in 2001, this critically endangered snipe naturally recolonised the main island, completing a remarkable story of discovery and recovery within less than a decade.

Antipodes Snipe Anchorage Bay. Photo by F.Cox

Antipodes Snipe Anchorage Bay. Photo by F.Cox

Subantarctic snipe have long bills and legs and are longer than other New Zealand snipe species. The three subspecies differ slightly in size and markings Antipodes Island snipe are darker than Auckland Island birds above, and their plumage is more yellow than all other populations. Their diet includes soil-dwelling invertebrates obtained by probing below the surface.

Miskelly, C.M. 2013. Subantarctic snipe. In Miskelly, C.M. (ed.) New Zealand Birds Online. www.nzbirdsonline.org.nz

See more great video from the Antipodes team Million Dollar Mouse video channel

Find out more about the Antipodes Snipe

 

Storm on Antipodes

Update from Stephen Horn – Project Manager

17 July 2016

The northerly hit us with some force, on the 14th July, seriously testing the security of the tents. I got up in the night to check mine and got saturated as water from the waves crashing against the nearby cliffs was thrown in the air and hurled across camp. The severe weather continued all day. I have to admit that my tent needed some stabilising. Fin was going to film it been blown around but then thought it would be a poor reflection on the DOC team’s ability to pitch a tent! I took that to heart so with some help from the doctor, and in the driving salt water it was secured with a veritable spider web of guy ropes reaching out for the earth in every direction. Keith Springer had already experienced his tent being blown away in a gust a couple of weeks before. He went to bed one night and was mystified to find an empty campsite. In the darkness there was no sign of his shelter so he bunked down beside a couple of scrub bars in Keith Hawkin’s palace and managed to locate the tent along with his sleeping bag and gear bags in the morning across the creek. The guy ropes had ripped at the fly. 

Back to the present the angry seas were frothing out to 100 m offshore. Once again we had disconnected the roof water feeding into the tanks to avoid the salt contaminating our supplies. The rain gauge near the hut quickly filled with salt water. It’s the sort of day you can imagine that birds are blown away to populate new islands. It was an impressive display and many took the opportunity to survey the sight from the hillside. A check was made of the load site and items re-secured. Back at camp water was mopped out of some of the tents near the frontier of the campsite. The elements has shaken the satellite dish knocking our connection out of alignment, taking our communications capabilities back to the basic level of the first couple of weeks. Oh well. The savings in data usage have allowed us some wriggle room to watch the rugby this weekend. Every cloud has a silver lining. 

Cheers

Stephen