Category Archives: International News

White-tailed eagles return to southern Britain after 240 years

Patrick Barkham The Guardian

A white-tailed eagle, Britain’s largest bird of prey.
 A white-tailed eagle, Britain’s largest bird of prey. Photograph: Mike Crutch/Forestry England/PA

White-tailed eagles are gracing the skies of southern Britain for the first time in 240 years after six eaglets were released on the Isle of Wight.

The huge birds, which are fitted with satellite tags, are expected to disperse along the south coast of England in a scheme backed by the environment secretary, Theresa Villiers, who welcomed the return of the “majestic” species.

It is hoped Britain’s largest bird of prey will eventually breed in the wild and mirror the success of the reintroduction scheme in Scotland.

The birds, which grow to have a wingspan of up to 8ft (2.4 metres) and are also known as sea eagles, were persecuted to extinction across Britain by the start of the 20th century. It took several decades after chicks from Norway were returned to Scotland in the 1970s before the birds bred and expanded their range. There are now 130 breeding pairs across Scotland, and the six young Isle of Wight birds were taken from Scotland under special licence.

“This release is a great opportunity for the Isle of Wight to expand its ecotourism market, creating wealth and jobs in the local economy,” Villiers said.

The Scottish reintroduction, which centred on the Isle of Mull, was found to have bolstered the local economy by up to £5m a year.

In the five-year reintroduction programme led by Forestry England and the Roy Dennis Wildlife Foundation, up to 60 white-tailed eagles will eventually be released. At first they will be offered food at feeding stations to encourage them to settle along the south coast.

Roy Dennis, founder of the foundation, said: “I have spent much of my life working on the reintroduction of these amazing birds and so watching them take to the skies of the Isle of Wight has been a truly special moment.

“Establishing a population of white-tailed eagles in the south of England will link and support emerging populations of these birds in the Netherlands, France and Ireland, with the aim of restoring the species to the southern half of Europe.”

Tony Juniper, the chair of Natural England, which is licensing the trial, said: “The return of these spectacular birds to England is a real landmark for conservation. I very much hope that it will also provide a practical demonstration of the fact that we can actually reverse the historic decline of our depleted natural environment.

“It will also show how helping the recovery of our wildlife can be done at the same time as bringing benefits for people, in this case by offering a boost to the local economy through wildlife tourism.”

Moves to reintroduce white-tailed eagles into East Anglia 10 years ago were defeated by opposition from local farmers, who feared the birds would terrorise young pigs and take lambs.

The Isle of Wight was chosen as the location to reintroduce the species because its quieter coasts, cliffs and woodlands provide potential nesting and resting sites, while the Solent and surrounding estuaries offer plenty of food, with fish such as grey mullet and water birds forming the bulk of the eagles’ diet.

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.


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.

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.