Displaying items by tag: American Bird Conservancy

 

(Washington, D.C., April 18, 2013) A new study from British scientists has documented for the first time, significant new impacts to birds from outdoor cats, reporting that even brief appearances of cats near avian nest sites leads to at least a doubling in lethal nest predation of eggs and young birds by third-party animals, as well as behavioral changes in parent birds that lead to an approximately 33 percent reduction in the amount of food brought to nestlings following a predation threat.

The study was peer-reviewed and published in the Journal of Applied Ecology (January 30, 2013). The study was led by Karl Evans of the Department of Animal and Plant Sciences, University of Sheffield in collaboration with his PhD student Colin Bonnington and Kevin Gaston of the Environment and Sustainability Institute, University of Exeter.

The study was carried out by observing 47 blackbird nests in 2010 and 49 nests in 2011 in Sheffield, England, during the breeding season from March to August and compared nest dynamics following presentation of a taxidermist-prepared cat, a predatory grey squirrel, and a rabbit. The crucial finding is that the natural response of parenting birds to the appearance of predators – alarm calling and nest defense – dramatically affects rates of bird nest predation by third-party animals thusly alerted to the nest, as well as much lower feeding rates of young birds for prolonged periods following the threat of predation by cats.

The domestic cat model consistently prompted significantly higher alarm calling rates than either the rabbit or the squirrel. “Logistical models of nest fate demonstrated that the probability of nest predation within 24 hours of model exposure increased with the amount of parental nest defense,” the study said. Predation by third-party animals during chick incubation was highest following presentation of the cat model (23 percent of nests) followed by the grey squirrel (5 percent) and the rabbit (0 percent). At the young chick stage, predation was 13 percent for the cat model and zero for the other two models. At the old chick stage, there was no predation owing to the ability of the young birds to escape on their own.

Even more concerning is the fact that the study found no evidence that parental feeding rates returned to normal even after the cat model had been removed for lengthy periods of time such as even up to 90 minutes later. Further, there was no evidence that the parents at any time compensated for the reduced feeding rate, by bringing more food at a later time.

“Reduced food delivery, even over short time periods, can adversely influence chick condition and reproductive success and over longer time periods can promote smaller clutches,” the study said.

The study said that the behavioral changes in birds caused by the appearance of cats “….may have considerable implications for (bird) population and community dynamics” and suggests that “…the impacts of sub lethal effects on avian prey populations are frequently greater than those arising from lethal effects…..”

The study concludes that whilst cats housed indoors require more care and attention from their owners the most effective management option is thus to house cats permanently indoors. About half of cat owners in North America do this to prevent cats having road traffic accidents or being injured in fights with other cats.

“Here we have yet another peer-reviewed study that documents additional, serious impacts to bird populations that previously have not been fully appreciated. Feral and outdoor cats are simply devastating populations of birds and other wildlife,” said Clare Nielsen, Director of Communications for American Bird Conservancy, one of the leading bird conservation organizations in the U.S.

The new study follows the release in January, 2013, of a new, widely-reported, peer-reviewed study by scientists from two of the world’s leading science and wildlife organizations – the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service (FWS) – which found that bird and mammal mortality caused by outdoor cats in the United States is much higher than has been widely reported, with annual bird mortality now estimated to be 1.4 to 3.7 billion and mammal mortality likely 6.9 – 20.7 billion individuals.

That study’s estimate of bird mortality far exceeds any previously estimated U.S. figure for cats. In fact, this magnitude of mortality may exceed all other direct sources of anthropogenic bird and mammal mortality combined. Other bird mortality sources include collisions with windows, buildings, communication towers, and vehicles, as well as pesticide poisoning.

The study estimated that the median number of birds killed by cats annually is 2.4 billion and the median number of mammals killed is 12.3 billion. About 69 percent of the bird mortality from cat predation and 89 percent of the mammal mortality was from un-owned, or feral, cats.

Free-ranging cats on islands have caused or contributed to 33 (14 percent) of the modern bird, mammal, and reptile extinctions recorded by the International Union for Conservation of Nature Red List of Threatened Species.

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American Bird Conservancy (ABC) is a 501(c)(3) not-for-profit membership organization whose mission is to conserve native birds and their habitats throughout the Americas. ABC acts by safeguarding the rarest species, conserving and restoring habitats, and reducing threats, while building capacity in the bird conservation movement.

(Washington, D.C., March 27, 2013) American Bird Conservancy, bowing to a tidal wave of public opinion, has declared the Peep (Marshmallicious delicious) to be this year’s Easter bird of the week, and has further announced it is to be split into four bird species. The reselection of 2011’s choice was based on popular opinion. “I couldn’t fight it any longer. The time has come – it was a no brainer for me,” ABC President George Fenwick said.

Up until now, scientists have recognized only the familiar “yellow” form of peep as a full species; but there is currently support in the ornithological community for granting separate species status to the blue, teal, pink, and purple forms, currently considered color morphs. “There simply isn’t any evidence that these forms interbreed,” said ABC senior scientist Dr. David Wiedenfeld. “While they can often be found roosting in the same box, the fact is that nobody has ever seen an intermediate bird between the color morphs,” he added.The presence of occasional orange and other colored birds in the population may represent occasional aberrant individuals, but any new taxonomic changes will require further study.”

In naming the Peep as Bird of The Week for a second time, ABC also raised eyebrows again. “We’ve never had a repeat Bird of the Week. That was a tough decision and I know some will disagree but if the Grammy Awards and Saturday Night Live can have repeat hosts, we thought we could break tradition as well. Some will point out that Bird of the Week is a bigger deal and needs to stand firm on tradition, but I say the Peep has been a real giver and it’s time for us to give back and return the favors from decades of springtime giving. It’s just the right thing to do.”

Peeps typically make their appearance in the springtime, with numbers peaking in April. Despite their ubiquitous distribution and social nature, their migratory paths, wintering, and breeding areas are little known.

During their breeding season, Peeps can easily be found in suburban backyard habitats, where they lay clutches of colorful eggs in nests of brightly-colored plastic grasses. Adult and immature peeps can be quickly located by their sweet calls and neon plumage.

Although Peeps are heavily consumed, their populations appear to quickly rebound in subsequent years and therefore they are not a species of conservation concern. Enjoy this popular harbinger of spring!

Asked about the possibility of a three-peat, Fenwick was noncommittal: “Well, we’ve never shied away from controversy. Naming the Peep Bird of the Week in 2011 caused quite an uproar – almost crashed our website. This decision will probably cause another firestorm – I probably won’t answer my phone for a week. But who knows, anything is possible. We’ll take the pulse when the next time comes.”

See ABC's Bird of the Week profile for this species!

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American Bird Conservancy (ABC) is a 501(c)(3) not-for-profit membership organization whose mission is to conserve native birds and their habitats throughout the Americas. ABC acts by safeguarding the rarest species, conserving and restoring habitats, and reducing threats, while building capacity in the bird conservation movement.

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