Prevention of Roosting Birds
Trees on our property are a wonderful thing, they provide shade and give us privacy, even help to block the Kansas winds and attract birds. Unfortunately they can attract troublesome birds and if they attract enough of them they might even decide that your tree or trees will become their home. If this happens what if anything can be done? Fortunately the problem can usually be resolved, but not without some effort.
After nesting, blackbirds and starlings begin forming flocks and roosts. Roosts are sometimes formed by late June, but most are established in July. Because flocks prefer deciduous trees, the prevalence of deciduous shade trees in urban and suburban areas makes these sites attractive. Thousands of blackbirds may occupy several blocks of suitable trees in summer roosts. Birds abandon deciduous tree roosts when the leaves drop in the fall.
Community organization may be necessary when using scaring devices to disperse large summer roosts in suburban neighborhoods. If a summer roost has formed in the same neighborhood for several years, make plans in the spring or early summer before the birds arrive, because they are more easily dispersed before becoming accustomed to a site. Here are the steps to take: 1) Consult neighbors to see if they agree on the problem. 2) Contact local authorities to let them know of your plans, since a lot of noise will be made, and to find out if there are any city regulations that you would need to be aware of. 3) Obtain necessary equipment: a portable CD player and CD of blackbird distress call, pistol launchers with whistle bombs (check with city first), and/or portable air horn, and any other items to make noise in order to frighten the birds. 4) Organize enough responsible help. 5) Schedule activities for at least three and possibly five or more consecutive evenings. 6) Begin dispersal activities about one-half hour before dark, or as soon as the birds begin settling into the roost; continue until dark.
When the birds first arrive, they may perch in nearby trees and fly around without settling. This activity is referred to as staging and may go on for 15 to 30 minutes before the birds actually roost. When the birds appear to be roosting, begin playing distress calls, loudly and intermittently at first, and then continuously as most of the birds are entering. The player and distress calls should be moved to various locations within the roost every few minutes if the roost consists of several trees throughout the block. Shooters should use pistol launchers to fire over the tops of the roost trees. Whistle bombs fired into the incoming flocks will help turn them back. Continue using distress calls and scaring devices as long as birds are entering the roost. After dark, cease activity because birds remaining will not leave, and efforts are useless.
Be persistent and follow-up on successive evenings. In large roosts or where roosts are well established, the first evening may appear to be unsuccessful. Scaring may have to be continued for 4 or 5 days before the birds abandon the area. With small roosts or where birds are less established, scaring may disperse flocks the first night but should be continued for several more evenings to prevent them from returning.
Where dispersed flocks go is unpredictable. They may join flights of birds going to other roosts or may set up a new one. Once birds have been moved, they are usually more responsive to dispersal from another site.
Federal and state regulations protect blackbirds and other migratory birds. A federal permit is required to take, possess or transport migratory birds for depredation control purposes. But no permit is required to scare or herd these birds. A standing order exists for blackbirds, cowbirds, grackles, crows, and magpies. No federal permit is required and control measures-including lethal methods-may be taken when these species are found “committing or about to commit depredation,” or when they “constitute a health hazard or other nuisance.”
If you have any further questions or need the information on ordering the distress CD contact your local County Extension Office. The whistle bombs are considered a pyrotechnic and permission from the city will be necessary.