Outdoor cats wreak havoc with birds

Every four years, ornithologists from Canada to Mexico gather for the North American Ornithological Conference, which was just held in Washington, D.C. There were 2,000 attendees, of which 20, or 1% of the entire conference, were current or former William & Mary students.

Several research topics dominated the conference, the theme of which was "Bringing Science and Conservation Together."

A very active research area is the devastating effect of outdoor cats on birds. One speaker declared that after a decade of effort on the subject, no further research is necessary. The data show that over a billion birds a year are killed by cats in North America. One interesting new finding based on "kitty-cam" studies is that only 1 in 5 birds killed by a cat is ever brought home. This is why most people are certain that their fluffy angel doesn't kill many birds.

Unfortunately, like creationists and climate change deniers, owners of outdoor cats don't care about actual data and justify their irresponsible behavior on the claim that other sources of mortality make the impact of cats irrelevant. In fact, cat predation is the single biggest direct human cause of songbird mortality – worse than pesticide poisoning, collisions with windows, towers, turbines and cars combined. The data are clear: Outdoor cats are devastating wild songbirds. Convincing the public to do something about the cat predation problem is a conservation policy challenge of major proportions, but it's no longer an issue requiring research.

Another hot research area at the conference was the effect of noise pollution on birds. Because birds communicate by using complex songs and calls, sounds from engines that are of the same pitch as bird vocalizations can make communication difficult. Male birds will sing at a higher pitch when in the presence of constant traffic noise, but there are limits to such accommodation. Constant loud noises such as those produced during fracking or other energy extraction may be especially devastating to prairie birds that communicate across vast, formerly quiet spaces. On the flip side, targeted noise that encourages birds to leave, because they cannot hear each other or their predators, may be useful when trying to keep birds from colliding with wind turbines or airplanes, as presented by William & Mary researchers at the conference.

Finally, the technological revolution in miniaturizing data collectors has resulted in a deluge of studies tracking birds during their migrations. Everything we thought we knew about how birds find their way, fuel their journeys, and spend their time is going to be revised based on studies tracking birds with satellite or cell-tower based devices.

The next North American Ornithology Conference is in 2020 in Puerto Rico. Hopefully we will hear talks about successful intervention programs with outdoor cat owners, the noise pollution experts will be declaring that no more research is necessary, and we'll be outfitting birds with transmitters that can turn off wind turbines or trigger warning systems as they approach dangerous collisions.

Cristol teaches in the Biology Department at the College of William and Mary and can be contacted at dacris@wm.edu. To discover local birding opportunities visit http://williamsburgbirdclub.org/

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