Starlings are frequently considered pests because of the damage they
cause, especially to agriculture and in urban roosts. This publication
provides facts about starlings and methods to control their damage in agriculture.
|Figure 1. Adult European starling (Sturnus vulgaris).|
Foods - Starlings eat various foods, including fruits and seeds of both wild and cultivated varieties. Insects, especially white grubs in lawns or pastures, and other invertebrates total about half the diet overall, and are especially important during the spring breeding season. Starlings also eat livestock rations and food found in garbage during the winter.
Movements - Although not always migratory, some will migrate
up to several hundred miles. Others may remain in the same general area
throughout the year. Outside the breeding season, starlings feed and roost
in flocks. Each day, they may fly 15 to 30 or more miles from roosting
to feeding sites. During winter, they roost in dense vegetation, such as
coniferous trees, or in urban structures, farm buildings, and other areas
protected from wind and weather. Some of these roosting areas are occupied
by wintering starlings year after year.
. . .
As trends move toward urban and rural sustainable landscapes, starlings
and other birds may become more important in biological and integrated
pest control systems.
Structures. Where starlings are a problem inside buildings or other structures, close all openings larger than one inch so they cannot enter (Figure 2). This is a permanent solution to problems inside the structure. Heavy plastic (PVC, polyvinyl chloride) or rubber strips hung in open doorways of farm buildings have been successful in keeping birds out, while allowing people, machinery, or livestock to enter (Figure 2). One installation approach is to hang 10-inch wide strips with about 2-inch gaps between them. Such strips might also protect feed bunkers. Where birds are roosting on a ledge, place a board or metal covering over the ledge at a 450 angle (Figure 3). Porcupine wires (metal protectors) are also available for preventing roosting on ledges or roof beams, and netting placed under roof beams will prevent roosting on the beams (Figure 4). Netting is also useful around buildings for covering window or other openings.
Fruit Crops. Netting is useful for covering fruit crops such as cherries or grapes to prevent bird damage, and studies show it to be a cost-effective method of protecting higher-value grapes in commercial vineyards. For wine grapes harvested one time per season, tractor-mounted rollers can facilitate installation and removal of netting draped directly over vines. Some New York vineyards have used this method for 5 years with the original netting still in good condition. For table grapes harvested by hand several times per year, a frame can be used to hold the netting above the vines so it doesnt interfere with the frequent harvests. A practical tip: if protecting the total vineyard is impractical, protect varieties that receive the most damage: those that ripen early or are otherwise highly attractive to birds (e.g. small, dark, sweet grapes).
|Figure 2. Bird-proof buildings to permanently eliminate bird problems inside.||Figure 3. A board or metal covering over a ledge at a 45° angle (a) or porcupine wires (b) can be used to prevent roosting and nesting.||Figure 4. Netting can be used for excluding birds from building rafters and from fruit trees.|
Cultural Methods and Habitat Modification
Starlings are attracted to livestock operations by the food or water available to them, especially during winter when the weather is cold and food scarce. Some livestock operations are more attractive to starlings than others. Operations with large quantities of feed always available, especially when located near a starling roost, are the most likely to have damage problems. Farm management practices are important in long-term starling control. These practices limit food and water available to starlings, thus making the livestock environment less attractive. The following practices used singly, or preferably in combination, will reduce feed losses and the chances of disease transmission as well as the cost and labor of conventional control measures:
Use bird-proof facilities
to store grain.
|Bird-proof livestock feeders such as these flip-top pig feeders limit starling access to the feed and reduce starling interaction with livestock.|
|Figure 6. Lower the water level in livestock waterers so starlings cannot reach it when perching on the edge. At the same time, keep the water level high enough that they cannot stand in it.|
|Propane exploders frighten starlings from many damage situations by producing a loud report at pre-determined intervals. For best results, exploders should be elevated above vegetation and the location and report interval changed regularly. Although these have been used successfully at some cattle feedlots, the loud noise may frighten some livestock.|
Frightening is effective in dispersing starlings from roosts, small-scale fruit crops, and some other troublesome situations. It is useful around livestock operations that have warm climates year-round, and where major concentrations of wintering starlings exist. In the mid to northern states, starlings concentrate at livestock facilities primarily during cold winter months when snow covers natural food sources.
Frightening devices include recorded distress or alarm calls, gas-operated exploders, battery-operated alarms, pyrotechnics (e.g. shellcrackers, bird bombs), lights (for roosting sites at night), bright objects, and other noise makers. Beating on tin sheets or barrels with clubs also scares birds. Some novel visual frightening devices with potential effectiveness are eye-spot balloons, hawk kites, and mylar reflective tape. Ultrasonic (high frequency, above 20 kHz) sounds do not frighten starlings and most other birds because, like humans, they do not hear these sounds.
Harassing birds, throughout the evening as they land, can be effective in dispersing bird roosts if done for three to four consecutive evenings or until birds no longer return. Spraying birds with water from a hose or from sprinklers mounted in the roost trees has helped in some situations. A combination of several scare techniques used together works better than a single technique used alone. Varying the location, intensity, and types of scare devices improves their effectiveness.
Two additional tips for successful frightening efforts: 1 ) begin
early before birds form a strong attachment to the site and 2) be persistent
until the problem is solved.
. . .
The wide-ranging movements of starlings, the time necessary to maintain and manage traps, and the number of starlings that can be captured compared to the total number in an area, often make trapping an impractical control method. ...
Shooting is more effective as a dispersal technique than as a way to reduce starling numbers. The number of starlings that can be killed by shooting is small in relation to the numbers of starlings usually involved in pest situations. ...
Toxicants - Starlicide Complete
Starlicide Complete (0.1% 3-chloro p-toluidine hydrochloride) is registered
for controlling starlings and blackbirds around livestock and poultry operations.
It is toxic to other types of birds in differing amounts....
Acknowledgements: We thank R. M. Timm for his participation
in an earlier version of this guide, M. E. Tobin and G.R. White for technical
advice, and M. M. Beck, R. M. Case, B.U. Constantine, L. E. Germer, J.
A. Gosey, D. F. Mott, D. E. Reese, and A. R. Stickley for manuscript reviews.
Art: Renee Lanik, UNL Graphic Designer.
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¹ Use of trade names does not imply endorsemnent.
. . .
Printed in Cooperation with the North Central Educational Materials Project.
Issued in furtherance of Cooperative Extension work, Acts of Congress of May 8 and June 30 1914, in cooperation with the U.S. Department of Agriculture and Cooperative Extension Services of Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota and Wisconsin. Kenneth R. Bolen, Director, Cooperative Extension, University of Nebraska, Lincoln, NE 68583.