Category Archives: birds

Mountain plover not warranted for endangered species listing

Nesting mountain plover (Photo/Fritz Knopf)

Here’s some food for thought.

The mountain plover’s populations now range around 20,000 birds left in the world. Across the globe, a very different creature, the saiga antelope, only boasts about 40,000. One of these animals is globally listed as critically endangered, and one was found not qualified for federal endangered species status. Any guesses?

Today, the U.S. Fish and Wildlife Service, after a review of the current scientific and commercial information found mountain plover not warranted for listing, citing threats to its habitat as less significant than previously thought.

Mountain plovers are a small ground-nesting bird that rely on short-grass prairies and shrub-steppe environments in the American West for breeding habitat. Land use and habitat loss have been a primary suspect in the disappearance of the plover, an animal so good at hiding, that science is just now starting to get a better idea of how many are left. Recent research shows that rather than being pushed out by agriculture, mountain plovers are actually using farmland as a refuge during nesting season.

I want to take this as good news, but with short-grass prairie and steppe disappearing, swallowed up by energy development and overgrazing, active cropland does not sound like the most stable of refuges for a bird of small numbers, stature and a master of camouflage.  My hope is that not being listed will help avoid animosity of the animal by landowners, and perhaps even foster pride and care of the plover so that farmers will not have to contend with being the harbor of an endangered species.

Saiga Antelope, numbers around 40,000, critically endangered and rightfully so.

How many of an animal is left is not necessarily determinant of whether a species should be protected. Many factors go into the decision. But one has to wonder, what makes a population of 20,000 birds so much more stable than 40,000 of another species?


Naked Penguins

Naked featherless African Penguin by Nola Parsons

Feather-loss disorder has also been observed in African penguins, which inhabit the coast and offshore islands of South Africa. (Photo/Nola Parsons)

Penguins already endure their fair share of image problems. They’re a bit pudgy around the middle (not that there’s anything wrong with that). They have wings, but can’t fly, and a beach strut that’s really more of an awkward waddle. Now these tuxedoed birds can add bald to that list.

In a somewhat alarming twist of fate, penguins are being born featherless, and scientists don’t know why.

The phenomenon first emerged in 2006 when researchers observed featherless black-footed (AKA African) penguin chicks at a rehabilitation center in Cape Town, South Africa. That year about 59 percent of penguin chicks at the South African Foundation for the Conservation of Coastal Birds lost their feathers, followed by 97 percent in 2007. Meanwhile, researchers with the Wildlife Conservation Society and University of Washington in Argentina also observed featherless Magellanic penguins in the wild.

In both cases, the featherless chicks grew at slower rates than their downy counterparts, most likely because they had to expend more energy to regulate their body temperature, said the researchers in a press release. The goose-fleshed penguins also had a tendency to spend more time in the sun, compared to feathered penguins. Many of these vulnerable chicks died during the study.

A researcher holds a featherless Magellanic penguin chick.

A researcher holds a featherless Magellanic penguin chick. (Photo/Jeffrey Smith)

So far, scientists don’t yet know what’s causing what looks like the avian version of mange. Disease, thyroid disorder, genetics and nutrient deficiencies could all be potential culprits, they say.

On a slightly more positive note, it does look like chicks that survive do eventually grow feathers. Researchers are working furiously to figure out what’s causing the trouble.

“We need to learn how to stop the spread of feather-loss disorder, as penguins already have problems with oil pollution and climate variation,” said P. Dee Boersma, one of the study authors in a press release. “It’s important to keep disease from being added to the list of threats they face.”

Scientific Journal:

Waterbirds

Study Authors and Affiliations:

Olivia J. Kane, Jeffrey R. Smith, and P. Dee Boersma of the Wildlife Conservation Society and the University of Washington; Nola J. Parsons and Vanessa Strauss of the South African Foundation for the Conservation of Coastal Birds; and Pablo Garcia-Borboroglu and Cecilia Villanueva of Centro Nacional Patagónico

Contact:

John Delaney, jdelaney@wcs.org, 718-220-3275, Wildlife Conservation Society


Gangster Birds of the Kalahari Desert

A drongo in the Kalahari. (Photo/Andy Radford, University of Bristol)

Drongos, African Kalahari Desert birds with a penchant for thievery, are taking a turn towards the avian equivalent of organized crime, a new study finds.

The victims in this case, pied babblers, have long contended with the risk of drongos popping in to make off with the babblers’ hard-earned insect prey. Now it seems a set of behaviors have evolved that are taking this interaction from a purely parasitic relationship to one of more mutual benefit. Researchers found that the drongos form protection squads for foraging babblers, keeping an eye out for trouble and strong-arming danger when it arrives.

“Like any good gangster,” says Andrew Radford, a scientist with the University of Bristol who led the research team, “as well as lying and stealing, the drongos also provide protection by mobbing aerial predators and giving true alarm calls on some occasions.”

That means pied babblers can spend less time watching for predators and more time looking for prey. The relationship is not without its caveats. Drongos still aim to take advantage of babblers, crying wolf to scare the babblers and grab the insects. The babblers likely put up with it, the researchers say, because the benefit of not having to worry about predators outweighs the cost of the drongos’ antics.

The research, which is a collaboration with the Universities of Bristol, Cambridge and Cape Town, is published online in the current issue of Evolution.

Andy Radford (University of Bristol) and a pied babbler in the Kalahari. (Photo/Matthew Bell, University of Cambridge)

A pied babbler in the Kalahari. (Photo/Andy Radford, University of Bristol)


Could a proposed EU ban on discarding bycatch threaten seabirds?

Northern gannet picture taken at bird colony of Helgoland, North sea, German Bight, May 2002. (Photo/ Michael Haferkamp)

You know the scene. A commercial fisherman hoists a net roiling with flip-flopping fish. Clouds of seabirds swarm and fill the air with a greedy squawking, their beaks hungry for unwanted catch.

That raucous chorus may get a little quieter soon as birds are forced to seek their feast elsewhere. In a move aimed at curbing the devastating environmental consequences tied to commercial fishing, the European Union looks to consider new restrictions that would ban the discard of unwanted fish. The rule could be a win for fisheries conservation, but in a twist of good intentions, could also risks endangering the gannet, a seabird that thrives on bycatch tossed overboard.

Fisheries have dealt more than one blow to seabird populations as birds compete for resources or risk becoming ensnared in equipment. One of the few successful species, the gannet, has adapted to exploit the leftovers of commercial fisheries, swooping in on fish and other creatures thrown aside and left behind.

Dr. Keith Hamer, a researcher with Leeds’ Faculty of Biological Sciences is leading a team of researchers that will study the gannet and assess the possible consequences of imparting a ban on discarding unwanted catch. “Although discards should be stopped to protect marine biodiversity, research is needed on the impact of a ban, so policy makers can understand the best way to implement it,” said Hamer in a press release.

The study will especially look to better understand how gannets rely on bycatch for raising chicks. Past research indicates that breeding pairs may prefer different menus with some birds relying mostly on discards from fishing boats and others seeking out sand eels or diving for mackerel and herring. “We think gannets have different aptitudes and specialities and for some, that skill might be finding and following fishing boats,” said Hamer.

So if gannets feel like they’re being watched, they’re not so far off. Researchers plan to catch and tag breeding pairs from 12 colonies throughout the United Kingdom. Hamer along with scientists Stephen Votier of the Marine Biology & Ecology Research Centre at the University of Plymouth, and Stuart Bearhop, with the University of Exeter, will keep tabs on the birds’ locations, diving patterns, diet and nests.

“Although the long-term benefits of a ban will be positive, we need to accurately predict short-term impacts as well,” said Hamer. “If gannets have specialised to the extent we believe, rather than cut off a crucial food source overnight, a gradual phasing in of the ban would allow them time to retrain to find food elsewhere.”

Hopefully this thinking ahead will help prevent a new conservation crisis from cropping up even as the EU takes steps to solve another.


Dosed: Livestock scavenging vultures consume cocktail of veterinary drugs

A griffon vulture soars through canyons of the Douro River in Portugal. (Photo/Morgan E. Heim)

Griffon, their name conjures images of legend and mythology, but in the skies above Spain and Portugal, thousands of real life griffon vultures survey the earth looking for their next meal. And to a griffon, nothing says “yummy” quite like a fresh pile of pork carcasses – well, maybe sheep.

Don’t knock it. They are one of nature’s best cleaner-uppers. But it turns out that griffon vultures and at least two other vulture species are ingesting something not on their carrion menu, drugs and lots of them.

Vulture numbers have soared in Europe since the 1980s, thanks in part to the common practice of carcass dumping of dead livestock, also called muladares, which provide vultures with a ready and reliable supply of chow. But in cattle, drugs abound. And lunch at a muladar promises a chemical cocktail of veterinary medicine as well as protein.

A griffon vulture soars in the skies above the Douro River in northeastern Portugal. (Photo/Morgan E. Heim)

A new study by Guillermo Blanco with Museo Nacional de Ciencias Naturales in Madrid showed that the proportion of vulture nestlings testing positive for antibiotics rose from 0 percent in 2001 to 70 percent in 2006, and now scientists are seeing a triple threat. Blanco found griffon, Egyptian and cinereous vultures, contained combinations of antibiotics, anti-parasitics and non-steroid anti-inflammatory drugs, such as aspirin, in their system, a never before seen combination in a wild animal, according to the researchers.

Scientists are still studying what this chemical cocktail could spell for the vulture, and the three species did show variance in the amounts and types of drugs found in their systems, possibly due to the differences in how they feed. But Blanco and his colleagues do mention possible reasons for why and how the drugs are building up in the birds’ bodies.

Vultures typically split mealtimes between muladares and “vulture restaurants,” scavenging from the carcasses of free-ranging livestock. Drugs abound in both food sources, but reside in much greater concentrations and types in the bodies of farm-raised cattle – farm-raised livestock require more drugs due to their compact living quarters. Recent European Union regulations aimed at curbing the spread of mad cow disease made it illegal to abandon carcasses of free-roaming cattle in the countryside. As an unintended consequence of the rule, this practice eliminated one key source of food for the vulture, concentrating food in the veterinary drug-laden muladares. The regulation has also been reputed to be a probable contributor to the vulture’s decline since 2003.

Side-effects could include increased disease, due to exposure to immuno-suppressants, changing delicate bacterial communities in the vulture’s system and a rise of infection or transmission at feeding sites.

One remedy would be to allow for carcass abandonment to resume according to the study. “There is no evidence of BSE [mad cow] transmission risk due to the abandonment of unstabled livestock carcasses in the countryside,” wrote the study authors. “Therefore, this traditional practice in the Mediterranean regions should be legally permitted in order to increase availability, dispersion and quality of food for scavengers.”

You can read more about Blanco and his colleagues’ findings in the December 2009 issue of the journal Animal Conservation.


The high fidelity of alligator love

Two American Alligators (Photo/Matthew Field)

Two American Alligators (Photo/Matthew Field)

Oh alligator love, it’s not as fickle as you might think. Get on a gator’s good side and you may just have found a friend for life, if you’re another alligator of course.

In a study that combines field science with molecular biology, researchers from the Savannah River Ecology Laboratory found that alligators were surprisingly loyal partners and akin to birds in their mating habits. The discovery offers new insights into evolutionary links and behavior of crocodilians, birds and dinosaurs – and certainly, at least where one science writer is concerned, proving there is a lot more going on behind those alligator eyes than a cold reptilian stare.

Researchers trapped and re-trapped alligators at Louisiana’s Rockefeller Wildlife Refuge, 76,000 acres of alligator dream real estate bordering the Gulf of Mexico. “Given how incredibly open and dense the alligator population is at RWR, we didn’t expect to find fidelity,” said researcher Stacey Lance. “I don’t think any of us expected that the same pair of alligators that bred together in 1997 would still be breeding together in 2005 and may still be producing nests together to this day.”

Crocodilians have already proven to be more invested in the care of their offspring than most other reptiles, actively nurturing young and defending nests. Crocodiles are even known as considerate egg-layers. As a female drops the egg, she will blindly catch it with a hind leg before it hits the ground and gently place it in the nest. But up until now alligators were thought to be polygamous, mating with several different partners and leading to many fathers for a single nest.

After ten years of following alligators at the refuge, scientists Lance, Travis Glenn, Ruth Elsey and Tracey Tuberville discovered that 70 percent of female alligators stick with who they like. Even if they have multiple partners, the same bachelors get picked year after year, regardless of whether females encounter a new slew of potential suitors.

The study marks the first time fidelity has been observed in any crocodilian species. “In this study, by combining molecular techniques with field studies, we were able to figure something out about a species that we never would have known otherwise,” said Lance. “Hopefully future studies will also lead to some unexpected and equally fascinating results.”

Results of the study were published in the October 7 issue of Molecular Ecology.


Saving the white-shouldered ibis and a way of life in rural Cambodia

Only about 500 of the birds remain in the world,  making the white-shouldered ibis a creature that flirts dangerously

A white-shouldered ibis in Cambodia. Human impact on this critically endangered bird can be beneficial rather than destructive, and could even save it from extinction. (Photo/Hugh Wright)

A white-shouldered ibis in Cambodia. Human impact on this critically endangered bird can be beneficial rather than destructive, and could even save it from extinction. (Photo/Hugh Wright)

with extinction. The once common bird’s number is not up just yet however, as the ibis’ saving grace may lie in their relationship with small-scale farmers of Cambodia, a partnership likely to help save both the bird and a traditional way of life in Southeast Asia.

A new study published in the journal Animal Conservation highlights the work of the University of East Anglia and BirdLife International as they look at the benefits of traditional small-scale farming to survival of the critically endangered white-shouldered ibis.  Farming and cattle grazing create ideal forage land for the birds and opens a clean line of sight for spotting predators and prey. These findings draw attention to the friendlier side of human impacts. But plans for large-scale development in western Siem Pang, Cambodia, threaten both the farmer’s way of life and the ibis’ last hope for survival.

Scientists, conservation groups and the Cambodian government are currently looking at ways to mediate impacts. “The Forestry Administration in Cambodia is supportive of a proposal to make the area a protected forest,” said Hugh Wright, lead author of the study, in a press release “and we believe that this – along with the continuation of local farming methods practiced for generation after generation – will be crucial in saving this once common species from extinction.”

To find out more about the plight of the white-shouldered ibis, check out BirdLife International.


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