All posts by bird-nerd

Aotearoa’s most endangered birds receive three new man-made nesting sites

https://www.tvnz.co.nz/one

Workers on a mission to protect the Tara iti
Workers on a mission to protect the Tara iti Source: 1 NEWS

New Zealand’s most endangered bird, the fairy tern, will receive a boost to their breeding season following the creation of three new man-made shell nesting sites in Waipu, north of Auckland.

It was reported earlier this year that around 40 of the native birds, otherwise known as tara it, were initially thought to be left. But an additional chick hatched in late December and then another two were born on New Year’s Day.

The shell patch breeding sites is said to create safer places for the Tara iti to nest, protecting them from tidal inundation and sand blow.

These shell patches will contain 130 tonnes of locally sourced shell, transported by helicopter into the new and safer sites.

“Other than predator control, habitat enhancement is the most important action that can be taken to ensure the tara iti’s survival,” said Linda Guzik of Shorebirds Trust.

Fairy terns can’t be bred in captivity because they’re very particular about their nests. They can be found near beaches in Northland’s Waipu, Mangawhai and north Auckland’s Pakiri.

“In past we’ve had nests impacted from high winds, which means the parent birds can’t find their eggs, and king tides washing the nests away,” Tara Iti Recovery Group leader Troy Makan said in a statement. “The new sites will be placed in the rear of the dunes, providing more protection for the chicks and their parents.” 


Meet the ‘Hercules parrot’ from prehistoric New Zealand — the biggest ever discovered

Trevor H. Worthy, The Conversation

Heracles inexpectatus on the forest floor, with three small wrens foraging at its feet. Picture: Dr. Brian Choo, Flinders University.Source:Supplied

Say hello to Heracles inexpectatus, a parrot the size of a human child.

But don’t worry, you won’t meet one face-to-face.

Our new discovery lived around 20 million years ago in what is now New Zealand — adding to the islands’ rich and storied collection of remarkable bird species.

Heracles was truly a giant among birds, The Conversationreports.

It was about one metre long, stood 80-90cm tall, and weighed about 7kg. That makes it about the same size as a dodo, and far bigger than its modern-day cousin, the kākāpō. Unsurprisingly, given its heft, it was likely also flightless.

We discovered Heracles in the St Bathans Fauna, a collection of 20 million-year-old fossils from Central Otago.

Over the past 20 years, our research has discovered around 40 species from the St Bathans Fauna, including a wealth of fascinating prehistoric bird remains. These include eggshell and fragments of moa ancestors, a tiny kiwi, many ducks, a couple of pigeons, flightless rails, hawks and eagles, shorebirds, songbirds, and several small parrot species. Crocodilians, turtles, bats and even rare land mammals complete this eclectic group.

Heracles now reveals that another avian giant existed in this fauna. For the first and only time since, a giant parrot occupied the herbivore/omnivore niche on a forest floor.

emarkably, the fragments of bone that allowed us to discover this giant parrot had sat on a shelf since 2008, patiently waiting for their turn to be described. We had known that St Bathans also contains eagle fossils of similar size, so the Heracles fossils were put on the eagle pile while we waited to find some more fossils that might tell us more.

But upon pulling them out and looking more closely, it was immediately clear that these were not eagle bones, so we started trying to work out what they were. Parrots were not on our radar at first, purely because these bones were far larger than those of any known parrot. But after a while the bones told their story — they were of a parrot, and nothing else was remotely similar. Moreover, they were in some ways fairly similar to the kākāpō.

And so Heracles inexpectatus was born, the name derived from Greek mythology.

So what was a giant parrot doing in ancient New Zealand? What did it eat? Could it have had a taste for meat, as the kea still does? These mountain parrots prey on the chicks of burrowing petrels and are notorious for attacking sheep.

But in New Zealand 20 million years ago there were no sheep, and in fact no large mammals at all. Probably, like most parrots, Heracles ate plants. Its size meant no fruit was too big, no nut too tough to crack. And the botanical evidence shows that it lived in a rich and diverse subtropical forest, where cycads, palms, casuarinas and up to 60 species of laurels thrived.

All these plants would have provided a rich bounty for this large parrot. But we warrant that it likely still snacked on moa occasionally, as kea still did more recently, when they got mired in swamps.

Trevor H. Worthy is an Associate Professor and leading vertebrate palaeontologist at Flinders University. Continue the conversation | trevor.worthy@flinders.edu.au

This article originally appeared in The Conversation and is republished here with permission

Young birds dedicate specialized brain cells to learning new songs

By Chrissy Sexton Earth.com staff writer

In a groundbreaking new study, experts at Columbia University have pinpointed what happens in the brain of a young songbird as it learns a new tune. The findings demonstrate the extraordinary flexibility of the developing brain.

The auditory cortex, which is the neural region that processes sounds, is similar in both birds and mammals. Therefore, the findings may help to explain why it is so easy for children to pick up on their native language, yet adults tend to struggle to learn a language that they were not exposed to early in life. 

“The language sounds we learn as infants shape the way we hear for the rest of our lives, and the vocal sounds that songbirds hear while young may have the same effect,” said study senior author Dr. Sarah M.N. Woolley. “By mapping these birds’ auditory systems as they learn their songs, we hope to decipher the mechanisms that guide our own capacity to learn speech.”

The zebra finch is the most commonly studied songbird species. A young male zebra finch listens and imitates a song performed by his father during the first three months of life.

“When first learning to sing, the juvenile’s song is unstructured, similar to the way a human baby babbles before producing words,” said study first author Dr. Jordan Moore. “But by the time the bird nears adulthood, it reproduces the more complex aspects of its father’s song. We were interested in what is happening in the brain during this song learning period.”

The analysis was focused on neurons in the auditory cortex. While monitoring this neural activity, the researchers played recordings of songs to zebra finches and long-tailed finches. Next, they played synthetic sounds that were designed to match certain acoustic features of the birdsongs.

The experiment enabled the team to identify a neural circuit in the auditory cortex where the responses of the brain cells become specialized for the songs that the birds learn.

“After identifying this circuit, we wanted to understand its flexibility,” explained Dr. Woolley. “How does this circuit change over time as the bird learns and matures? And how do these changes integrate the bird’s biology and its experience with the song its tutor sings?”

To investigate, the researchers placed eggs from the two finch species in the nests of a third songbird species, the Bengalese finch. The team could then assess whether the young birds learned the songs of their adoptive fathers.

Among the young songbirds that were introduced to foster fathers, the auditory neurons showed specialized tuning for the acoustic features of Bengalese finch song. This confirms that the selectivity of the early birdsong is not simply shaped by the bird species, but by what the young bird learned to sing.

The study is published in the journal Nature Neuroscience.


Wind turbines ‘an extinction threat’ for birds

MATTHEW DENHOLM THE AUSTRALIAN

The critically endangered Swift Parrot. Picture: Norm Oorloff
The critically endangered Swift Parrot. Picture: Norm Oorloff

Regulators should consider the cumulative impacts of wind farms on birds before approving new turbines, or risk driving species to ­extinction, a prominent conservation ecologist warns.

Jamie Kirkpatrick, from the University of Tasmania, yesterday said federal and state environmental assessments typically ­examined the impact on threatened species of single projects only. “This is really a failure of the process because one swift parrot here or one eagle there is not of great moment, but when you have it repeated and repeated you soon get to a critical level,” Professor Kirkpatrick said.

In Tasmania, 10 new wind farms are proposed or under construction, adding to a number of existing major turbine sites, three of which have killed at least 37 eagles since 2002. There are fears the wind farm boom will push endangered species such as the Tasmanian wedge-tailed eagle, swift parrot and orange-bellied parrot closer to extinction.

Professor Kirkpatrick urged the federal and state governments to ensure assessment of the new projects considered the wider impact of similar developments on bird populations.

Wind farms are typically ­approved on the condition proponents take measures to mitigate or offset expected impacts on local threatened bird species.

Professor Kirkpatrick said this did not address the bigger picture of wind farm impacts: “The individual small impacts of each one is theoretically bearable but when you consider the cumulative ­impact, they are not. It’s only when you start adding them up and look at the overall fecundity of that species that it starts to become ­really concerning.”

Tasmanian Environment Minister Peter Gutwein defended the adequacy of existing state ­assessments: “Large-scale wind farm developments are subject to rigorous assessments and environmental approvals, with the ­opportunity for public submissions. The government has complete confidence in the ability of the independent Environment Protection Agency to assess any major wind farm proposals.”

Federal Environment Minister Sussan Ley said the impact of wind farms on threatened species was already a “key factor” in assessment: “A proposed wind farm development is not considered in isolation. In regions where there are a number of wind farms, existing levels of impact on threatened bird species may be considered.

“When a nationally listed bird species is in small numbers nationally, or its distribution or habitat is limited, or if the habitat has particular importance for the species, wind farm activity could have a significant impact, and this is taken into account.”

Last month, The Weekend Australian revealed Woolnorth Wind Farm Holdings’ two sites in the state’s northwest had recorded three eagle deaths in the past few months. It was also ­revealed the company’s wider operations, including a third wind farm in the state’s northeast, had combined recorded the deaths of 32 wedge-tailed eagles and five white-bellied sea eagles since the first site began operating in 2002-04.

desperately seeking Stipiturus

Karen Hunt

Tom Hunt

They’re determined, these volunteers.

Why else would they slog , day after day, through kilometers of spiky, hummocky grasslands in the dry heat of the Victorian mallee, searching for a tiny bundle of feathers with an absurdly flamboyant tail?

Well, to find it, for one thing. And to count it, for another.

Because no one is sure how many of these tiny birds, the mysterious Mallee Emu Wren, Stipiturus mallee, remain in the lonely, semi-arid shrub lands that make up the Wyperfield, Murray-Sunset and Hattah Kulkyne National Parks in Victoria’s north west.

PhD student Simon Verdon from La Trobe University, leader of this somewhat masochistic band, wants to find out. He’s on a mission to do the most comprehensive survey of the Mallee Emu Wren in years, if not ever.

It’s not going to be easy. The emu wren is tiny, about the size of a golf ball, not counting a tail that’s almost twice as long again as its body, and which more strongly resembles filament-y emu feathers than the tightly controlled rear appendages of other wrens . Males sport a sky blue head and frontal bib but apart from that, they are the same colour as the dry spikes of Triodia grass in which they hide.

And that’s the rub – the birds like to hide in the middle of the almost impenetrable clumps of what’s aptly described as porcupine grass. What they eat, where they go, and what they are doing when they get there are also mysteries, but that’s a story for another day.

In the spring, when the counting begins, the males are more visible, flaunting their blue bibs, sashaying through the topmost spikes of the Triodia, tails erect. But only briefly, dropping into the all encompassing spikes at the drop of a volunteer’s hat. And the females remain as elusive as ever.

So the volunteer army, some 35 strong, tough, determined and indefatigable, venture into the wilderness, day after day, searching, and listening, and searching some more.

And reporting back to the man who counts.

West Nile virus lingers longer in birds exposed to light pollution

Banner image of a house sparrow courtesy of the University of South Florida.

by Mongabay.com on 29 July 2019

Light pollution could lead to more infections with West Nile virus by increasing the amount of time that small songbirds hold on to the virus, according to a new study.

“The findings may be the first indication that light pollution can affect the spread of zoonotic diseases,” Meredith Kernbach, a doctoral student in global health at the University of South Florida and lead author of the study, said in a statement. Kernbach and her colleagues published their findings in the journal Proceedings of the Royal Society B: Biological Sciences on July 24.

Scientists already know that exposure to artificial light can affect animal biology, including our own, interfering with immune system functioning, metabolism and behavior.

“Many hosts and vectors use light cues to coordinate daily and seasonal rhythms,” Kernbach said. “[D]isruption of these rhythms by light exposure at night could affect immune responses, generating the effects we see here.”

She and her colleagues wondered whether artificial light might influence the way the birds’ bodies react to the virus that causes West Nile fever. Symptoms, when they do appear, are typically similar to those of the flu in humans, and in rare cases can be fatal.

Research has shown that songbirds like house sparrows (Passer domesticus) carry West Nile virus, along with other diseases. They’re also frequent visitors to towns and cities, where light pollution abounds and where there are dense human populations to which they can hand off the virus through successive bites by the same mosquito.

To test their hypothesis, the team kept two groups of wild house sparrows under different lighting conditions. The control group experienced 12 hours of light and 12 hours of darkness each day for up to three weeks. The second group of birds was kept in an area with 12 hours of light as well, but then the researchers exposed them to 12 hours of dim light meant to mimic the nighttime street and building lights of an urban environment. In the midst of the light exposure experiments, Kernbach and her colleagues inoculated the birds with West Nile virus.

Beginning two days after exposure to the virus, the team measured the amount of the virus in the blood of each bird. They all had comparable levels of the virus after four days, but six days in, the birds being exposed to the nighttime lights had significantly higher levels of West Nile virus in their blood than the control group.

The researchers also created a statistical model demonstrating that the lingering viral load in light-pollution-exposed sparrows could increase the chances of an outbreak of West Nile fever by 41 percent.

Earlier research had shown that higher levels of the stress hormone corticosterone made another species of birds more enticing to hungry mosquitos, and the scientists did notice a slight bump in this compound in the birds exposed to the dim night lights. But that alone didn’t explain the persistence of West Nile virus in the animals’ blood samples, pointing to the need for more research. The stress that light induces could have other effects, for example, on the secretion of the hormone melatonin, that could affect bird behavior, the authors write.

In the meantime, the team suggests that motion-sensitive lights might diminish exposure to light pollution and that lights could be turned off at night when the transmission of West Nile virus is particularly high.

Banner image of a house sparrow courtesy of the University of South Florida. 

Citation:

Kernbach, M. E., Newhouse, D. J., Miller, J. M., Hall, R. J., Gibbons, J., Oberstaller, J., … Martin, L. B. (2019). Light pollution increases West Nile virus competence of a ubiquitous passerine reservoir species. Proceedings of the Royal Society B: Biological Sciences286(1907), 20191051. doi:10.1098/rspb.2019.1051

Birds with darker wing feathers have increased flight efficiency

By Chrissy Sexton Earth.com staff writer

New research from Ghent University in Belgium has revealed that the color of a bird’s wings plays an important role in flight efficiency. The study suggests that darker wing feathers give birds an aerodynamic advantage.

The experts set out to analyze how the color of bird feathers may affect wing temperature, and whether darker wings may heat up faster than lighter wings under solar radiation.

Using thermal imaging, the researchers examined the surface temperature changes in the feathers of two live osprey with increased solar radiation. 

In addition, the team experimentally heated different colored wings in a wind tunnel and measured wing temperatures during flight. Osprey, gannet, and back-blacked gull wings were exposed to various realistic wind speeds.

The team discovered that dark feathers not only warm up the wings but also the surrounding air, which increases air flow. According to the study, a common wing pattern consisting of white feathers at the body and black feathers at the wing tips seems to help lift the wings. 

“Even under simulated flight conditions, darker wings consistently became hotter than pale wings. In white wings with black tips, the temperature differential produced convective currents towards the darker wing tips that could lead to an increase in lift,” wrote the study authors. 

The darker feathers were found to heat up much more than light feathers. “We found temperature differences of about 9 degrees between black and white,” study lead author Svana Rogalla told New Scientist. “We would even find these temperature differences in the same wing.”

The study is published in the Journal of the Royal Society Interface.

Richard Hill’s mission to save south-west’s endangered red-tailed black cockatoo

Picture: Bob McPherson

Richard Hill shifted to Casterton 21 years ago with his family to study the region’s endangered red-tailed black cockatoo, and he’s never looked back. As a senior biodiversity officer with the Department of Environment, Land, Water and Planning (DELWP), his mission is to preserve the unique bird.

“It’s been a 21-year project looking at and understanding the cockatoo, how rare it is and what the causes of their decline are,” Mr Hill said. “My aim is to stop it from going extinct.

“This area has a really small population of about 1500 and it’s in decline. It’s quite endangered in small parts of south-west Victoria and South Australia. 

“They’re a very unique sub-species only found in this small part of south-west Victoria.”

He is part of a larger recovery team for the cockatoo. 


“There are lots of people working trying to help the cockatoo. DELWP and what I do is a small part of that,” he said. 

A major part of his work here is helping with the annual count, organised by Birdlife Australia, where willing and able volunteers head out in fleets of vehicles to track the birds and monitor their population numbers.

“The count involves up to 80 vehicles and is all done by volunteers. I’ve been doing that for 21 years,” he said.  “We try and find where the birds are and how many there are, that produces a ballpark figure – it’s not completely accurate because it’s very hard to count them in flocks. “That can happen over 20 nights but it’s the best information we have.”

He said the red-tailed black cockatoos were disappearing at high rates. 

“The bird is in decline, and now we’re trying to find out why,” he said. “The rate of decline has steepened in the last five years and we really need to work out if there’s something new we have missed. “We understand their food sources are declining and we are planting lots of trees to arrest that decline. “There might be other things affecting the birds, so we are about to launch new studies into what causes breeding success and how to help them in the wild.”

Annual count: Dick Cooper searching for red-tailed black cockatoos in an old redgum tree near Casterton with Richard Hill in 2001. Picture: Sandy Scheltema

 Annual count: Dick Cooper searching for red-tailed black cockatoos in an old redgum tree near Casterton with Richard Hill in 2001. Picture: Sandy Scheltema

Mr Hill suspects climate change is a large contributing factor to the decline of the species.

“Climate change really is the elephant in the room for this species because it depends on the eucalyptus trees,” he said. They get seeds of a couple of species of eucalypt and their flowering appears to be linked with rainfall. Climate change may be causing them to produce less feed, we have to try and diagnose it because they are critical resources. We need to look at the ecology and find out what’s going on.”

Birds have always been Mr Hill’s passion.

“Birds are my thing, I did my masters on owls on Christmas Island and I’ve been studying birds for most of my working life,” he said.

Mr Hill and his team are looking for volunteers for the next annual count.

“The annual count takes place at the start of May and we’re always looking for people to help with that,” he said. “We’re also looking for private properties to plant more trees for the birds to feed and nest.”

Those interested are asked to contact the Birdlife coordinator on 1800 262 062.

Endangered: The red-tailed black cockatoo. Picture: Richard Hill

 Endangered: The red-tailed black cockatoo. Picture: Richard Hill

and in further orange-fronted parakeet news

from Toi Toi Wines release

This endemic bird is still critically endangered, and was once thought to be extinct. But a few birds were found in the valleys of Canterbury’s Arthurs Pass, and now with the efforts of DOC, Forest and Bird, Christchurch Helicopters and Toi Toi Wine, they are now recovering.

But they are not out of the woods yet, as during mega mast seeding events populations of rats and stoats also multiply, and once the seeds disappear, they then turn their attention to the fledgling birds.

The Isaac Conservation and Wildlife Trust has played a crucial role in rearing captive-bred birds for release into the wild.

This year, 62 birds from the Trust, Orana Wildlife Park and Auckland Zoo have been released into the south branch of the Hurunui Valley.

Extensive trapping of stoats and rats in the valley has meant this is a good year to release the birds.  In the wild the birds are extremely difficult to monitor, so radio transmitters have been attached to the birds to track where they go in the valley. They will be monitored for about 54 days or until the transmitters cease to operate.

This bird was nearly extinct. Now, its population could double thanks to an ‘epic’ breeding season

By Leah Asmelash and Brian Ries, CNN

from CNN

The orange-fronted parakeet is one of the rarest birds in New Zealand, but its population may have doubled after an “epic” season of mating.Staff with the nation’s Department of Conservation say they found at least 150 orange-fronted parakeets have been born this season alone. They discovered 31 new wild parakeet nests — three times the number of nests in recent years.The new births have the potential to double the current population, said Minister of Conservation Eugenie Sage in a statement. And the lovemaking could continue for several more months, as beech trees in the region continue to have one of their largest mast seasons in over 40 years.

Mast is the botanical name for nuts, seeds, buds, or fruits that are produced by trees and shrubs and eaten by wildlife.”There has been so much seed on the beech trees, the birds just keep on breeding, with some parakeet pairs onto their fifth clutch of eggs,” Sage said. “This year’s epic breeding provides a much-needed boost to the kākāriki karaka population.”Without such a large beech mast, the birds typically only have just one or two clutches of eggs.

There are currently less than 300 orange-fronted parakeets in existence

The orange-fronted parakeet was once thought to be extinct, but was rediscovered in 1993. The current population is thought to be anywhere between 100 and 300 birds, which is why this mating season is so significant.Conservation efforts in the country have helped increase the population, with organizations breeding the birds and then releasing them into the wild.The birds aren’t the only ones benefiting from the higher beech mast. The increase in seeds also means more rats, stoats and feral cats — all of which pose risks to the bird. Sage said the department’s next steps are to focus on protecting the birds from the rising number of predators.