Crows darken the Ann Arbor skies. Discuss.



Crows are somewhat challenging to count accurately. Because they congregate in large flocks, the ability to accurately measure how many of them there are in an area depends on area birders' knowledge of where they are likely to gather. Dea Armstrong, the City of Ann Arbor ornithologist with the Natural Area Preservation unit, noted that any individual year bird count should not be considered as an exact measure, but rather that population trends should be looked at over a number of years.


Miller described his encounter with the birds around 2 a.m. one night when he and a friend were walking through the Diag. “As we were walking there, we were talking about the crows, and how terrifying they are," he said. "We were looking around to make sure they weren’t there, and of course they were, in four or five trees.” Miller said once they saw the crows, he and his friend started running, trying to avoid being defecated on.


The American crow (Corvus brachyrynchos) can be found all over the country in flocks containing up to hundreds of thousands of birds, said Cynthia Parr, U-M zoology researcher. Flocking in such large numbers may help the crows locate additional food sources and help with breeding. But why Ann Arbor?


A man walking his dog on a trail near the Amtrak station Dec. 26 found 15 dead crows and two that were dying, authorities said. A necropsy on the dead crows was performed at Michigan State University. Although the results aren't in yet, poison is suspected, said Dan Sheill, a special agent with the Ann Arbor office of the U.S. Fish and Wildlife Service.