First reported in a NY Times article, a new study in the Journal of Ornithology reports that cats are responsible for the death of many gray catbirds in Washington D.C.. Seeking to calculate the fraction of bird deaths attributed to cats, researchers at the Smithsonian Institution and Towson University placed radio transmitters on baby catbirds. According to their results, they found that close to 80 percent of the birds had been killed by predators; cats were responsible for 40 percent of those deaths. Emphasizing the importance of addressing cat predation, The American Bird Conservancy estimates that pets and feral cats kill nearly 500 million birds each year. Still, more danger lurks for birds in places cats cannot reach.
According to the United States Fish and Wildlife Service, wind turbines kill nearly 450 thousand birds each year; this number is expected to increase dramatically as demand for wind farms are met. Let’s face it – birds have a knack for colliding with human-made objects, crashing full speed ahead into freshly cleaned windows and stealthy power lines. Why do birds fail to avoid structures of impending doom?
Recently published in the International Journal of Avian Science, this new study helps us better understand the world through the lens of a bird. Professor Martin from Binghamton University explains in Science Daily the complexities of a bird in motion -“When in flight, birds may turn their heads to look down, either with the binocular field or with the lateral part of an eye’s visual field,” said Martin. “Such behaviour results in certain species being at least temporarily blind in the direction of travel.” In addition, the researcher explains that birds detects movement, rather than spatial detail, and are restricted to only a few flight speeds, making it difficult for them to stop in time. When rain or lights further cloud visual information, it becomes increasingly harder for a bird to navigate the sullen skies.
If we want to reduce bird collisions, keeping the cats inside and leaving the windows dirty may not be enough. The study reminds us that humans see the world differently than their co-animalia-inhabitants; we must account for such sensory variation to develop and deploy effective efforts of conservation.