|
Winter Crow Roost in Terre Haute, IN |
|
About WVAS
Monthly Meetings Field Trips Christmas Bird Count Spring Bird Count Winter Crow Roost Chimney Swift Migration The Natural Yard Recycling in TH Clean Air Terre Haute Spider Quiz .......... WVAS Home Join Audubon Indiana Audubon Society TREES Inc.
|
In spring and summer, the Common Crow (Corvus brachyrhynchos) flies about in small groups composed of a breeding pair and their nonbreeding young. In late fall through winter, crows gather together nightly in large communal roosts, with birds numbering in the hundreds to thousands. Crows are thought to return to the same winter roost spot each night, with some flying to the roost from as far as 50 miles away. They typically fly to the roost along certain established flight lines, and often stop along the way at sub-roosts or staging areas before making their way to the primary roost. In the past few years, the winter crow roost in Terre Haute has averaged 35,000 - 55,000 birds. On November 27, 2006, the undergraduate ecology class at Indiana State University, led by Dr. Peter Scott, counted the crows as they flew into the city, with a total estimate of 58,000 birds. Why do they roost in the city? Dr. Kevin McGowan, an ornithologist at Cornell University and an expert on crows, has observed that cities like Terre Haute with large crow populations are typically surrounded by farmland, particularly cornfields, which provide food for the birds throughout the year. Most of the crows that spend the night in Terre Haute move back out into the countryside during the day to feed. During the day, some crows can be observed on city lawns feeding on acorns, others visit bird feeders for peanuts and cracked corn, and a troublesome few can be seen feeding at open dumpsters and uncovered garbage cans. Please cover all garbage cans and dumpsters! The crows roost in the city from December to March, which is the same time as the crow hunting season (late) in Indiana (Indiana's 2006-2007 Hunting Season). So, crows may be coming into the city to avoid hunters. Crows are the only Indiana "game" animal with no daily limit. Some business owners have complained of bird droppings on their roof or sidewalk. How to keep crows from perching on roofs? One humane bird control product is to string a thin wire along ledges or across roofs so that birds cannot perch on either the wire or the ledge/roof. As an alternative to killing crows, we propose studying where they are coming from, which may shed light on why they are here and how to manage them. Dr. McGowan has observed that crows migrate south during the winter, so most of the crows in Terre Haute are probably not local. A birdbanding study is needed to determine where these birds are coming from. We have experienced bird-banders in central Indiana who would be willing to assist us with this project. Another alternative, more controversial, is to create a winter roost sanctuary. WVAS was one of the sponsors of a successful CrowFest in January 2007, highlighting the issues concerning this common urban problem. We will help sponsor another CrowFest in winter 2008/2009.
This page last modified 5/26/08 |