(BLOOMINGTON) - The crows have returned to their favorite winter vacation spot.
Thousands of the big, black birds - visitors from colder climes - have been using areas just south of downtown Bloomington as a communal nighttime roost for several winters.
The Herald-Times reports that without a formal census, it is impossible to know the number of crows in the local murder or whether the number has grown in recent years.
Winter crow roosts are an ancient phenomenon, but the birds have adapted to a modern lifestyle. They seem to prefer well-lit urban areas with large trees, surrounded by agricultural areas where they can disperse to forage during the day in places like Bloomington and Terre Haute.
Dozens of cities across the country host winter crow roosts. Terre Haute was a locale for years before Bloomington's crow popularity was recognized.
Indiana State University students conducted a crow census in Terre Haute in the winter of 1996, tallying 10,000 crows; in 1999, 30,000; and most recently, in the winter of 2005, they counted 58,000. In 2009, Terre Haute established a committee to develop a management plan, including a volunteer-staffed crow patrol trained to use pyrotechnics and bright lights to prevent the murder from roosting.
The city has also established "tolerance zones," places it hopes the crows will move to when they have been shooed out of zero-tolerance areas.
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