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New Zealand robin populations have been found to lose their fear of rats after only one generation in a predator-free environment, raising questions about the reintroduction of birds from island sanctuaries to the mainland.

Researchers Ian Jamieson and Karin Ludwig from Otago University compared robins on Stewart Island, where Norway rats are common, with birds on Ulva Island, where rats were eradicated in 1996.

The birds on Ulva are descendants of birds from the Stewart Island population, and Ulva does have native predators – the flightless weka and a native owl.

A report on the research, published in Animal Behaviour, said the Stewart Island robins were more agitated than the Ulva birds in the presence of a rat model, and were more hesitant about approaching mealworm food, which they tended to collect one at a time.

Many of the robins on Ulva appeared to show little fear or recognition of the model rat and were much less agitated and more likely to consume all five mealworms in a shorter time, despite the nearby model rat.

Vigilance and antipredator behaviour were costly for the birds, as they needed to be traded off against other activities, such as feeding or resting, the report said.

New Zealand robins appeared to possess proper antipredator behaviours, such as mobbing and alarm calling, but needed to learn to recognise a mammalian predator as a specific threat.

If experience were important to develop predator recognition, then isolation for just one generation would have a significant effect on the performance of a population. That seemed to be the case for Stewart Island robins reintroduced to rat-free Ulva, the report said.

“These results raise the question of whether established populations on island sanctuaries are appropriate sources for harvesting for reintroductions back to the mainland.”

While predator-naïve birds might be more likely to forage in the presence of a potential threat, as long as some individuals survived an initial attack that incident might be enough to restore predator recognition capabilities.

Original story on stuff.co.nz

Press Release – Department of Conservation
A Hector’s dolphin – the world’s smallest and rarest marine dolphin – was spotted in Wellington harbour yesterday after last being seen in 2009.

The dolphin was sighted at Mahanga Bay yesterday afternoon by a member of the public, who reported the sighting to DOC today. They said that the dolphin had “spent about five minutes zooming under and around the boat (with the engine in neutral) before disappearing”. A spectator on shore reported seeing two dolphins, but only one animal was seen from the boat.

The first live record of a Hector’s dolphin in Wellington Harbour was in January 2009. Several sightings of the dolphin were made during the summer and autumn of 2009, with photo and video evidence taken, but there have been no further sightings in the harbour until now. There have been several sightings of possibly the same animal around the Kapiti coast last year.

full press release on scoop.co.nz

Tuesday, 8 November 2011, 10:52 am
Press Release: Department of Conservation

First wild kakī chick to hatch this season raises hope

The first wild kakī/black stilt chick has emerged from its shell and raises hope after a disappointing start to the 2011 breeding season.

“With the hatching of this wild chick it is now starting to feel like the breeding season is underway. It has been a very late start. The first wild eggs would normally be hatching in October,” explained Liz Brown, DOC Aviculturist.

“We are also down on the number of eggs we are incubating this year at our Captive Breeding Centre in Twizel. We have 30 eggs currently incubating compared with a consistent tally of around 60 eggs over previous seasons,” states Liz.

“The captive birds have been laying later than normal both in Twizel and at Isaacs Wildlife Trust in Christchurch.”

A decline in nesting behaviour seems to be a general trend amongst all braided river birds this year. The region experienced snow in mid October which caused desertion of some nests. This was then followed by floods shortly after which delays re-nesting.

Every spring, native river birds flock to braided rivers to breed.

“From early September until late January those out enjoying braided rivers are asked to be considerate of our fragile nesting birds,” says Liz.

“They nest on the ground and can be very hard to see, especially from a 4WD vehicle. It is better for the birds welfare if you walk to your favourite angling spot rather than drive.”

“Birds that are swooping, circling or calling loudly probably have nests nearby. Move away so that they can return to their nests and look after their chicks.”

The wild egg was collected by Department of Conservation rangers from a pair of adult kakī nesting on braided river gravels. It has taken 25 days to hatch. More eggs collected from the wild are expected to hatch within a few days.

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Background information

Kakī/Black Stilts are one of the rarest waders in the world. Threat classification is nationally critical.

Kakī were once common throughout New Zealand, now mostly found in Mackenzie/Waitaki basins

Other riverbed birds migrate in winter, kakī will stay in the braided rivers of Canterbury/North Otago high country and forage for food

Main threat to the population is predation by feral cats, stoats, weasels and ferrets. Hedgehogs will eat eggs.

Wild population was reduced to only 23 birds in 1981. In August 2011 the wild population was approx 170 birds.

Six adult breeding pairs are held in captivity. Four pairs are held in Twizel at the Captive Breeding Centre. Two pairs are held in Christchurch at the Isaacs Wildlife Trust.

http://www.doc.govt.nz/kaki

Bird of the year 2011

 

http://www.birdoftheyear.org.nz/

Wednesday, 17 August 2011, 9:48 am
Press Release: Department of Conservation

Dead kea dumped at Arthur’s Pass were shot

Preliminary autopsy results from five dead kea dumped near Arthur’s Pass have confirmed that the birds were shot.

The initial pathology report from Massey University said evidence pointed to the use of an air-rifle and a shotgun to kill the five kea.

DOC Field Centre Supervisor, Chris Stewart, said, “We are appalled by this sort of behaviour and we have referred the matter to the NZ Police.”

“Kea are endangered and their wild population could be as low as 1000 birds,” said Stewart.

The full report will not be available until later this week but the initial results will assist the Police and DOC with their ongoing enquiries.

“The results also showed that all five animals were young and healthy and could have gone on to contribute to future generations of the species”

Under the Wildlife Act, it is a criminal offence to kill kea. Offenders could face a $100,000 fine or six months in prison.

The birds were found piled up on a picnic table at Klondyke Corner in Arthur’s Pass on Monday morning last week. Anyone who was in the area around Klondyke Corner over the weekend of 6-7 August are asked to ring the NZ Police, the 0800 DOCHOTline – 0800 36 24 68 or the Arthur’s Pass Field Centre.

The incident occurred in the same week that a dead kea was dumped on the driveway of a DOC staff member on the West Coast. Early indications are that this bird was also shot and this case has been referred to the Police.

Desperately cold wild fantails have made a nest of a South Canterbury home as the polar storm sweeping the country takes a huge toll on our birdlife.

Experts expect millions of birds to die as a result of the polar blast covering the country.

For Doug Sail in Hunter, 40 kilometres south of Timaru, the warmth of his dryer drew in three frozen fantails and he unwittingly saved their lives.

“I noticed them flying around the back door trying to get in. Occasionally they tried to fly in through the window and hit the glass.

“I needed to let the room air out and when I left the door open, all of a sudden there they were – three of them.”

He said the chilly birds made themselves quite at home and remained for about five hours.

“You couldn’t shoo them out, they wouldn’t go out through the open door.”

They were so determined to stay that when he shut the door to get them out, the birds simply found another way in.

“They flew in through the open toilet window. Then, thinking they were just cold, we decided to leave them”

As the creatures huddled together for warmth, Doug and his wife Emily Gilbert took photos and videos.

“It’s something I’ve never seen before. I was surprised at how tame they were.

“When my wife was taking a video clip of them, one of them landed on her camera while she was filming.”

Video and Full story on stuff.co.nz

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