This article is part of the Feathered Fridays series, a spotlight on different bird species found at your airports or aerodrome spaces.
Image: Sam Lievense
Risk Level: High Risk
Overview
The house crow goes by many names, Indian, greynecked, Ceylon or Colombo, all referring to the same species. House crows look like other species of crows with their medium size, black feet/beak, and glossy-black plumage; however, differentiated by their greyish-colored collar. They are frequently spotted in groups called “murders” and roost communally in large numbers. They can be easily heard by their loud and harsh, “kaa kaa kaa”.
Range
House crows are native and widespread in India and other south Asian countries like Maldives. Because they are an intelligent and adaptable species, they have been introduced and are now invasive in Singapore, Malaysia, and parts of East Africa.
Behavior
House crows are vocal birds that roost in large numbers in urban areas, gardens, scrublands, and mangroves. Crows are some of the smartest birds in the animal kingdom, this intelligence can make them quite pesky and at times aggressive. They can be aggressive birds during fledging season, May through June, when their young learn to fly. Crows have the ability to recognize faces, so if one were to encroach on their territory, they will remember you and hold a grudge.
House crows are omnivores that frequently raid crops, from harvest fruits like mango, guava, and figs to grains like wheats and corns. These birds are not picky eaters, eating everything from stolen fresh fruit from a market to carrion and trash from a landfill.
Impact of Airfields
House crows flocking in large numbers can be a problem for airports. Because house crows are so intelligent, dispersal methods can be tricker and more time consuming than with other birds. Acoustical deterrent systems can be an effective way to disperse large groups of crows. Playing a recording of a distressed crow at different times of the day for multiple consecutive days can help prevent the return of said crows.
House crows are attracted to trash, it is important to keep control areas like airports litter-free and trash bins covered. Because they gather where easy food is available, leaving trash bags outside is a bad idea. They can easily tear open a trash bag to fest, attracting more crows and possibly other unwanted species. Airports should uphold strict “no eating or drinking” rules when airside/on the runway. It is important to take simple, yet effective crow-proofing trash bin measures; this includes using securely tight fitting lids, preferably secured with bungee cord or elastic strip.
Crows do not like shiny objects. For backyard DIY crow deterrents, hanging shiny objects like CDs or aluminum plates often work. The crows think anything shiny is some sort of dangerous weapon. On a larger scale like airports, the hanging of iridescent tapes and lines can be a successful deterrent. Note that because they have a high intelligence, iridescent tapes will only work temporarily. Rotating the tapes and lines every week/month across different runways at different points is a more effective deterrent for these smart birds.
Identifying which species of birds in general can help determine a species management program and to implement relevant actions that can prevent and reduce wildlife strikes in airports.
Comments