Pest Profile: Birds

Kristen Stevens, BCE

We don’t often think of birds as pests, and, indeed, most of them are not. However, there are some birds that can pose public health and damage concerns in addition to being a nuisance. They carry all number of different food-borne illnesses such as salmonellosis, histoplasmosis, campylobacteriosis and some others. Some birds like to roost and nest on or under the eaves of buildings. This is a problem because they can not only damage the surface on which they are nesting but also leave unsightly messes in those areas from urinating and/or defecating. Common pest birds that fit this description are pigeons, sparrows and starlings.

Pigeons are commonly found in both urban and rural areas. Scavenging for food left behind by people, they typically frequent parks and sidewalks. They use city bridges and buildings as roosting and nesting sites and will often inhabit farmyards, livestock facilities, grain elevators and feed mills. Pigeons have gray bodies with a whitish rump, two black bars on the secondary wing feathers, a broad black band on the tail and red feet. Their average weight is about 10-13 oz, and the average length is 11”. Movement of pigeon flocks can be extensive and involves habits such as roosting, nesting and feeding. Some flocks travel distances as great as 5 miles between feeding and nesting sites. Pigeons are typically creatures of habit and will consistently nest in the same location. However, if they are driven from an area, they will find another place to rest and will continue on as if they were never disturbed.

Sparrows are another species of bird pest. It is considered one of the most common urban birds, and most people consider it to be a nuisance. It is identified by its small, stocky appearance. The upper parts are reddish brown streaked with black, and the under parts are gray. The female and immature birds lack any distinctive markings, but the male has a black throat, a gray crown and a chestnut-colored nape. Flocks of sparrows can be an incredible nuisance. In rural areas they can be particularly destructive around poultry and other livestock operations because they will consume and contaminate livestock feed. Sparrows commonly nest in and around buildings.

The final pest bird species is the starling. Like pigeons, they are a pest in both urban and rural environments. Similar to pigeons and sparrows, they travel in flocks and nest in cavities on the ledges of buildings in rural areas. In cities and suburban areas they will nest and roost in buildings, parks and residential trees. They also tend to make their homes in commercial structures such as lighted signs, marquees and billboards. The vocalizations of starlings at roost sites and the filth they produce are extremely annoying to neighboring residents and building owners. When these birds aggregate in trees in large numbers, the accumulation of feces on and around the tree will eventually kill the tree.

These are just three examples of bird species that are typically a nuisance, but there are several other species that cause problems, although they typically fall beyond the scope of urban pest management situations. While many birds are beautiful and fun to watch, there are also many that are pests. So, the next time you’re bird watching, be on the lookout for a pest or a bystander!

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