Monthly Archives: July 2017

Researchers in Cambodia find nest of rare riverine bird

(Physorg 20 July 2017)

Wildlife researchers in Cambodia have found a breeding location for the masked finfoot, one of the world’s most endangered birds, raising hopes of its continuing survival.

The New York-based Wildlife Conservation Society said Thursday its scientists, along with conservationists from Cambodia’s Environment Ministry and residents along the Memay river in the Kulen Promtep Wildlife Sanctuary, discovered the only confirmed breeding location in Cambodia for the very rare species.

The International Union for Conservation of Nature has placed the bird on its red list of globally endangered species because its worldwide population of less than 1,000 is declining at an alarming rate. It is found only in Bangladesh, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Singapore, Thailand and Vietnam.

Poaching and cutting down the trees where the bird lives are causing the population decline, said Eng Mengey, a communications officer at the Wildlife Conservation Society.

The Kulen Promtep Wildlife Sanctuary is one of several in Cambodia’s Preah Vihear province that are home to many endangered bird species, including the critically endangered giant ibis and white-shouldered ibis, the Wildlife Conservation Society said.

“This finding provides further evidence that the Northern Plains of Cambodia is an important biodiversity hotspot and critical area for conserving breeding habitat for globally threatened water birds,” Alistair Mould, a technical adviser for the society, said in a statement.

Read more at: https://phys.org/news/2017-07-cambodia-rare-riverine-bird.html#jCp

Rural structures pose greater relative threat to birds than urban ones

 

Bird_mortality_chart.jpg
(Peter Kelley 21 July 2017)

About one billion birds are killed every year when they unwittingly fly into human-made objects such as buildings with reflective windows. Such collisions are the largest unintended human cause of bird deaths worldwide—and they are a serious concern for conservationists.

A new paper published in June in the journal Biological Conservation finds that, as one might suspect, smaller buildings cause fewer bird deaths than do bigger buildings. But the research team of about 60—including three co-authors with the University of Washington—also found that larger buildings in rural areas pose a greater threat to birds than if those same-sized buildings were located in an urban area.

Lead author of the paper is Stephen B. Hager, professor of biology at Augustana College in Rock Island, Illinois. Co-author Karen Dyson, an urban design and planning doctoral candidate in the UW College of Built Environments helped collect bird-collision data and assisted in editing the paper, along with UW alumni Anqi Chen and Carolyn Foster.

The research team monitored 300 buildings of varying size and environmental surroundings for bird mortality at 40 college and university campuses in North America in the autumn of 2014. This included six buildings on the UW’s Seattle campus. They designed a standardized monitoring protocol so that the field crews documented bird mortality uniformly. In all, they documented 324 bird carcasses of 41 species. At each site, somewhere between zero and 34 birds met their feathery demise.

“Consistent with previous studies, we found that building size had a strong positive effect on bird-window collision mortality,” Hager and team wrote in a statement about the continent-wide research. “But the strength of the effect on mortality depended on regional urbanization.”

Why is that? The researchers think it might be related to how birds select habitats during migration, and differences in bird behavior between urban and rural populations. For example, they write, forest-adapted birds often select rural habitats with lots of open space and fairly few impervious surfaces over more urban areas.

Lighting patterns may also play a part, they reason. Lights from large, low-rise buildings in rural areas may act to attract migrating birds in what the team dubbed a “large-scale beacon effect,” where this effect may be “more diluted among large buildings in urban areas.”

Another theory is that urban birds may actually learn from “non-fatal” collisions and gain “new anti-collision behaviors” that help them avoid colliding with windows in urban areas. Previous research, they note, “suggests that the relatively large brain size in birds makes them primed for learning.”

The results suggest, the authors write, that measures taken to prevent bird collisions “should be prioritized at large buildings in regions of low urbanization throughout North America.”

Tiny songbird won’t be silenced

(Joann Adkins 14 July 2017)

On a quiet, 30-acre property near West Palm Beach, Fla., 19 Florida grasshopper sparrows are starting to sing.

These tiny songbirds bask in the breezes that flow through their custom enclosure. They know the nesting season is near. Named for their song, which resembles the sounds of grasshoppers, the sparrows are blissfully unaware that they are among the last of their kind. These birds share the property with a motley crew of endangered wildlife. There are the east African bongo antelopes, living far from the poachers and habitat destruction that have pushed their species to the brink of extinction. Golden lion tamarins can be seen across the way, part of a 40-year breeding program that has helped restore the species in the forests of Brazil. Large birds and tiny primates make up the rest of the residents of the property. They are part of a broad initiative in the Tropical Conservation Institute (TCI), a collaboration between FIU and the Rare Species Conservatory Foundation (RSCF).

The Florida grasshopper sparrows are the newest addition to the RSCF property. Less than 60 breeding pairs remain in the wild today, according to Karl Miller with the Florida Fish and Wildlife Conservation Commission. Some say it could be fewer than 25. At about an ounce, the bird’s tiny size makes it difficult to find. Their cryptic coloring of brown feathers with flecks of gray works like camouflage. They’re also very elusive, so keeping tabs on them is difficult. Yet, scientists know it is one of the most imperiled birds on the planet. FIU conservationist Paul Reillo is more blunt.

“This bird is going to go extinct in the wild. There’s no question about that.”

Reillo is the director of TCI and founder of RSCF. For 35 years, the biologist has fought to save species through field-based conservation and, when necessary, captive-breeding programs. The team of researchers that make up TCI is working across the world to protect and restore populations of birds, land animals and marine species. The institute has received core funding support from the Batchelor Foundation to help sustain its programs. Nearly every species the researchers are working with are fighting for survival. Many are winning.

In the 1980s, populations of the red-browed Amazon parrot were falling to desperately low numbers. The species, with its distinctive green feathers and striking red crown, appeared to be headed for extinction, nothing more than a footnote in the history of the planet’s biodiversity. Reillo and the RSCF team gave captive breeding a try.

They started with 11 birds. Today, nearly 30 years later, the red-brow’s numbers have grown to nearly 100 in captivity, and are making a comeback in the wild. Reillo thinks the same could happen for the Florida grasshopper sparrow.

“It’s a species on life support,” he said. “We need to pull out all the stops this year. There is definitely optimism around here, but this bird is facing its end. It’s scary.”

The Florida grasshopper sparrow has been listed as an endangered species since 1986. It is not a migratory bird and historically was only known to nest in the dry prairie grasses of central and southern Florida. As much as 90 percent of the sparrow’s natural habitat has been developed, and today there is only one area left in the wild where the sparrows are known to reside—a swath of land not far from Walt Disney World. The sparrow population in that area has experienced a brutal decline in the past five years.

In 2015, seven young hatchlings, some abandoned and the rest from nests expected to fail, were put into the care of Reillo and his team—the first time the species was brought into captivity. Reillo was expecting a slow start, but the captive clutch shocked everyone when two birds mated and produced four hatchlings in the first year. The team had little time to celebrate because, soon after, heavy rains flooded the prairie. State and federal wildlife officials recovered as many eggs as they could and brought those to Reillo for incubation and rearing.

“This little bird is doing everything to stay on planet Earth, but the odds are against it,” Reillo said. “We have problems on every front. Financial. Disease. Habitat.”

When asked if the Florida grasshopper sparrow can elude extinction, Reillo doesn’t have an answer. But with so few left on the planet, he says captive breeding is the difference between this bird being here and not.

Sandra Sneckenberger, an endangered species recovery biologist with the U.S. Fish and Wildlife Service, says the Florida grasshopper sparrow is a tough species to take on. Few were willing to be involved in a captive breeding program, she said, but federal officials knew Reillo and his team could give the sparrow a fighting chance.

The species presents unique challenges for scientists. The bird’s size makes it difficult to handle and nearly impossible to examine. No long-term captive-breeding program exists for similar sparrow species, so the team has no template to follow. Little is known about their immunity or to what diseases they are susceptible. Scientists often recover remains of animals to investigate cause of death and determine if populations suffer from parasitic diseases, bacterial infections or other illnesses. But just as their size and secretive nature make them difficult to locate while alive, it’s nearly impossible to find the bodies of Florida grasshopper sparrows when they die. Since first being placed into captivity, a few were discovered to be carriers of a disease from the wild population.

Read more

Clever crows can plan for the future like humans do

Clever crows can plan for the future like humans do

(Markus Boeckle And Professor Nicky Clayton 14 July 2017)

This contrasts with all of the previous studies in future planning, which have focused on naturally occurring behaviour. For example, we know that California scrub jays cache their food according to their future needs. And that bonobos, chimpanzees and orangutans select, transport and save appropriate tools for future needs.

General intelligence

These studies have shown that animals can plan for the future – but they left an important question open for debate. Are animals only able to plan to use abilities that have evolved to give them a specific advantage, or can they flexibly and intelligently apply planning behaviour across various actions? Most critics would say the former, as the animals were tested in naturally occurring behaviours.

But the new research provides the first compelling evidence that animal species can plan for the future using behaviour that doesn’t typically occur in nature. This supports the view that at least some cognitive abilities in animals don’t evolve just in response to specific problems. Instead, it suggests that animals can apply these behaviours flexibly across problems in a similar way to humans.

It seems that, in corvids and apes, intelligence is not a system to solve a predefined set of problems (dedicated intelligence) but rather a computational system to improvise new solutions (improvisational intelligence). But it is still unclear what this cognitive system exactly is and how it evolved.

What’s needed now is neuro-biological evidence of general intelligence in animals. We also need to investigate how flexible and improvisational behaviour evolved. Then we might be able to see how crows’ ability to plan for the future fits in with their broader cognitive powers.

Humans aren’t as unique as we used to think. Not, at least when it comes to making plans for the future. Scientists originally thought humans were the only animals that made plans but, over the past decade, studies on non-human primates and the crow family have challenged this perspective.

For example, we’ve seen that these animals are able to store tools for later use, cache food in places where it will be needed the most, and hide pieces of the sort of food they know will be running low in the future.

In all these studies, the animals had to consider what to do, where to do it and when to prepare for certain specific future events. The latest research shows that ravens can indeed anticipate the “what, where and when” of a future event on the basis of previous experiences. But unlike the previous studies, this work tested the birds in behaviour they don’t normally show in the wild. This provides evidence that they have a much more general ability to plan for the future than previously thought.

Food hoarding is common in members of the crow family (corvids) because they often eat from perishable animal carcasses, which provide lots of food but are only available for a short amount of time. To create a suitable cache of food they need to work out what to store, where to put it and when to do so.

The new study, published in the journal Science, tested the birds outside this naturally occurring behaviour, which may have evolved specifically because it gives crows a survival advantage. Some crow species are known to naturally use tools to retrieve food. So the researchers tested whether the birds could store and retrieve a tool so they could get at their food after a gap of 17 hours – something we wouldn’t expect them to do naturally. The scientists didn’t give the birds a chance to learn this behaviour first but they were still able to instantly select the tool out of a number of unnecessary items.

In another experiment, the researchers taught ravens to select a token from a number of items that they could then exchange for food. Again, the birds then showed that they could plan for the future using this new behaviour. They were able to store this token and then retrieve and use it when they were offered the chance to exchange it for food 17 hours later.

This contrasts with all of the previous studies in future planning, which have focused on naturally occurring behaviour. For example, we know that California scrub jays cache their food according to their future needs. And that bonobos, chimpanzees and orangutans select, transport and save appropriate tools for future needs.

General intelligence

These studies have shown that animals can plan for the future – but they left an important question open for debate. Are animals only able to plan to use abilities that have evolved to give them a specific advantage, or can they flexibly and intelligently apply planning behaviour across various actions? Most critics would say the former, as the animals were tested in naturally occurring behaviours.

But the new research provides the first compelling evidence that animal species can plan for the future using behaviour that doesn’t typically occur in nature. This supports the view that at least some cognitive abilities in animals don’t evolve just in response to specific problems. Instead, it suggests that animals can apply these behaviours flexibly across problems in a similar way to humans.

It seems that, in corvids and apes, intelligence is not a system to solve a predefined set of problems (dedicated intelligence) but rather a computational system to improvise new solutions (improvisational intelligence). But it is still unclear what this cognitive system exactly is and how it evolved.

What’s needed now is neuro-biological evidence of general intelligence in animals. We also need to investigate how flexible and improvisational behaviour evolved. Then we might be able to see how crows’ ability to plan for the future fits in with their broader cognitive powers.

Are Australia’s native pigeons sitting ducks?

(Andrew Peters, Charles Sturt University 13 July 2017)

The word “pigeon” evokes thoughts of gentle cooing, fluttering in rafters, and poo-encrusted statues. The species responsible for the encrustation is deeply familiar to us, having ridden waves of European expansionism to inhabit every continent, including Australia. First domesticated thousands of years ago, urban pigeons have turned feral again.

Less familiar are the native species that are not your stereotypical pigeons: a posse of pointy-headed crested pigeons in a suburban park, or a flock of topknot pigeons feeding in a camphor laurel.

Australia and its neighbouring islands are the global epicentre of pigeon and dove (or “columbid”) diversity with the highest density of different columbids – an impressive 134 species – found in the region. Twenty-two of these native species are found in Australia alone, in just about every habitat.

These native species play an important role in ecosystem functioning: they forage for and disperse seeds, concentrate nutrients in the environment, and are a source of food for predators. Fruit doves for example, are zealous fruitarians, and the region’s tropical rainforests depend on them for tree diversity. Where fruit-doves have disappeared in the South Pacific, numerous plant species have lost an effective dispersal mechanism.

The future of Australia’s native pigeons however, may depend on our domestic pigeons. Australia’s domestic pigeon population—both feral and captive – is large and interconnected by frequent local and interstate movements. Pigeon racing, for example, involves releasing captive birds hundreds of kilometres from their homes only so they may find their way back. While most birds do navigate home, up to 20% will not return, of which some will join feral pigeon populations. Birds are also traded across the country and illegally from overseas. These movements, together with poor biosecurity practices, mean that captive pigeons can and do mingle with feral domestic pigeons.

Read more

How migrating birds ‘run a marathon,’ burning muscles and organs in long flights

How migrating birds 'run a marathon,' burning muscles and organs in long flights

(Physorg, University of Massachusetts Amherst 12 July 2017)

Migrating birds complete long non-stop flights of many hours for songbirds and days for some shorebirds to reach breeding or wintering grounds. During such flights a bird’s metabolic rate is very high, fueled by stored fat, but also by burning the protein in musc

les and organs in a process that is not well understood, says eco-physiologist Alexander Gerson at the University of Massachusetts Amherst.

Now he has received a three-year, $756,000 National Science Foundation grant to thoroughly investigate the consequences and mechanisms of this phenomenon, which sometimes leads to dramatic reductions in migrating birds’ muscle mass and organs but may not result in significant loss of function.

As he explains, “There is evidence that some birds see a 20 percent reduction in muscle mass and up to 50 percent mass losses in the liver, intestine, kidneys and other organs except the brain and lungs. In one of the longest flights documented in this hemisphere, the blackpoll warbler during migration flies 22 hours over water, where they absolutely cannot stop. When you run a marathon like that, you either run out of fuel or water, but these birds can produce both by metabolizing their muscle and organ tissues.”

He adds, “We’re interested in what happens during flight, where the energy comes from, and how they maintain water balance. Water is produced from metabolism, and breaking down protein yields the most. But what happens when you lose 20 percent of your pectoralis muscles? Do you lose function or just size? These are a few of our questions.”

Gerson says this study will use two ultra-specialized tools not available to most researchers: a field-portable quantitative magnetic resonance imaging (QMRI) machine, and a wind tunnel specifically designed to study long duration flight in birds, one of just three in world, located at the Advanced Facility for Avian Research at Western University in London, Ontario.

The experimental series will look at body fat, lean mass and water content in one larger species, Swainson’s thrush, and one smaller, the yellow-rumped warbler, in the field and in wild birds flying in the climate-controlled wind tunnel. There, researchers can manipulate such factors as humidity and temperature to study the amount of water lost to respiration. This is relevant to climate change, Gerson notes, because flying in warmer air means more protein and water loss.

His research team will also look at water-loss rates in non-flight conditions, at rest, and look for differences among migrants and non-migrants. Further, Gerson and colleagues will conduct metabolic phenotyping and use transcriptomics to explore molecular mechanisms of protein breakdown and regeneration with UMass Amherst molecular biologists Courtney Babbitt and Larry Schwartz.

Gerson intends to engage many undergraduate and graduate students from diverse backgrounds in the research, training them in a range of cutting-edge techniques applicable to many science, technology, engineering and mathematics (STEM) fields. They will in turn develop and implement science communication and outreach programs for middle school students in a local low-income school district yet to be determined.

At the end of three years, Gerson says, “We hope to better understand the influence of climate on flight metabolism and have a better understanding of functional consequences of protein breakdown, which has the potential to be exciting because they burn a lot of muscles and don’t seem to show any dramatic functional loss. It may shed some really new light on questions that have been around for quite some time.”

Nesting in cavities protects birds from predators—to a point

Nesting in cavities protects birds from predators -- to a point
(Physorg 12 June 2017; Photo M. Arndt)

Nesting in cavities provides birds with some protection from predators—but it isn’t foolproof. A new study from The Auk: Ornithological Advances explores how Poland’s cavity-nesting Marsh Tits deal with predator attacks and finds that while tactics such as small entrances and solid walls do help, adaptations like this can only take the birds so far.

Wrocław University’s Tomasz Wesołowski has spent nearly thirty years monitoring Marsh Tit nest cavities in Poland’s Białowieża Forest, comparing nests that are destroyed with nests that are attacked but survive. He has found that a nest’s chance of survival depends on the predator’s technique—broods are least likely to survive (10%) when the predator manages to get into the cavity through the existing entrance, more likely (29%) when the predator uses its paws or beak to pluck out the nest contents, and most likely to survive (39%) when the predator tries to enlarge the opening or make a new one. Tits’ antipredator tactics vary in their effectiveness depending on the predator; attacks by Great Spotted Woodpeckers were successful only 60% of the time, while forest dormice were 100% successful.

The results show that despite the constant pressure of natural selection, Marsh Tits can only improve their antipredator tactics so much—there are limits to adaptation. Small, narrow entrances don’t work against small predators and are only effective when combined with cavity walls made of solid (not decomposing) wood; nests that were deep in a cavity, out of reach of the entrance, are safest, but birds seldom place their nests that way, suggesting that cavities that are too deep may cause other problems for Marsh Tit parents.

The Białowieża Forest, one of the last remaining tracts of old-growth forest in Europe, is an ideal place to study cavity-nesting birds, full of cavities of every size and shape for Marsh Tits to choose from. However, the fieldwork was not without its difficulties. “The Białowieża Forest still contains fragments of primeval origin,” says Wesołowski. “The work is challenging, as the old-growth stands are very tall. Marsh Tits breed at very low densities, and on average one has to search five to seven hectares of this forest to find a single breeding cavity. It requires much patience and determination.”

“To understand the evolution of nesting behaviors, many ornithologists attempt to quantify the trade-offs that birds face in warding off nest predators. Usually we do this by comparing nests that fail versus nests that succeed, but that approach is limited because we can’t tease apart the multiple factors, including chance, that contributed to making a nest successful,” according to Kristina Cockle of the National Scientific and Technical Research Council of Argentina (CONICET), an ornithologist not involved with the study who has worked extensively on nest cavities. “The new study by Wesołowski compares, instead, nests that were depredated to nests that were attacked but survived. With this approach, the author was able to identify the physical attributes of tree cavities that foiled a suite of nest attackers from woodpeckers to dormice.”