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.


A what?? of wagtails

BY Karen Hunt

birdlife.com

What do you call a group of willie wagtails?

Its one of those questions in search of an answer but beware, past attempts to collectively name birds have left more cases of misleading information than a Dodgy Brothers ad.

Take owls for example. Being a mostly solitary bird, its unlikely they would ever form a parliament. And having seen a couple of parliaments in my time, I have to say the reputed wisdom and dignity of the owl is very much in abeyance.

Crows are rarely murderous, although definitely malicious, and I’ve never seen them muster. Choughs don’t clatter, eagles never convocate and robins are rarely a riot. I have trouble imagining a hill of sand-pipers. or a wisp of snipe even though I held a Lathams Snipe once and it WAS pretty small.

On the other hand, a peep of chickens sounds just right. As does a pandemonium of parrots, a screech of gulls and a murmuration of starlings. And having once raised Guinea fowl, I can attest that a confusion of guinea fowl is just that.

A pretence of bitterns could I guess be explained by the birds constant disguise as a reed but please explain – what is a twack of ducks? My dictionary has twack meaning to strike something hard with the back of the middle finger and although my experience with ducks is not extensive, their lack of a middle finger seems to render that explanation a tad ridiculous.

So what to call my Willie Wagtails?

It has to be a word that encapsulates their perkiness, their cheerful fearlessness and air of joie de vie combined with their sartorial splendor, a classic tuxedo jacket and slim line trews. The word must do justice to the constantly flicking tail, which seems to have go than the Eveready battery bloke.

So, how about a waggle of willies?

Works for me.

Highway construction postponed for migratory birds in Xinjiang

Source: Xinhua| 2019-07-14 11:27:04|Editor: Yurou

ebird.org

URUMQI, July 14 (Xinhua) — The construction of a highway in northwest China’s Xinjiang Uygur Autonomous Region has been postponed to protect migratory birds.

In mid-June, workers found a large number of birds building nests and hatching in the cracks of the rocks laid on the roadbed of a section of Barkol-Hami highway. The birds Sturnus roseus, commonly known as rosy starling, are natural enemies of locusts. Xinjiang has set up nests in mountainous areas and grasslands to attract the birds to combat a destructive plague of locusts in recent years.

“A large number of starlings have settled in Hami thanks to artificial nests and related publicity activities. In most parts of the Hami grassland we can prevent locust plague without using pesticides,” said Li Zhanwu, head of the locust and rat plague control station in the city of Hami.

“We decided to suspend construction until the baby birds are hatched and leave the nests,” said Li Zhigang, one of the project managers.

The construction company also set up more than 20 warning signs in the site where birds are abundant. Construction of the postponed road section was scheduled to be completed in mid-July. But now it may be delayed by about one and a half months.

The 76.5-km Barkol-Hami Highway is an important transportation project in eastern Xinjiang.