Swallow Nests:A Challenge for Facility Managers

  • Published
  • By Wildlife Biologist,Herman Griese
  • 3rd Civil Engineer Squadron
ELMENDORF AIR FORCE BASE, Alaska --  We are on the verge of spring, and with spring come the swarms of migrant birds to Alaska. Among the 200 plus returning bird species are swallows. Swallows are small "song birds" that are very agile flyers enabling them to catch insects in flight. While touted by Alaskans as mosquito eaters, they prefer larger insects available during daylight hours. 

Though beneficial for insect control swallows pose a Bird and Aircraft Strike Hazard. Despite their small size, striking a swallow can create aircraft damage. They can also build nests in aircraft intakes. Their droppings dirty equipments and facilities and pose a potential health risk. These annoyances result from their habit of nesting on buildings. Thus 3rd Wing BASH Reduction Program Instructions, 92-212, requires facility managers to make facilities unattractive for nesting. How to do that relates to the nesting habit of the two species common on Elmendorf the violet-green swallows, and the cliff swallows. 

The violet-green swallow is a hole-nester. It arrives in early May and will seek any hole, horizontal pipe, or anything similar in which to build its nest. The swallow gets its name from the violet and green iridescence of the feathers on its back. Their white face, breast, belly and rump separate them from other swallow species.
Ensuring a building has no potential nesting sites for violet-green swallows can be accomplished by covering any holes, horizontal vents or pipes with hardware mesh. Nest materials include grasses and feathers that should be removed before blocking a vent or pipe. 

Cliff swallows, the proverbial 'swallows of Capistrano', arrive late May or early June. Cliff swallows are "mud dobbers" that construct mud nests under eaves of buildings, especially hangars. They are gregarious nesters often constructing nests that attach to their neighbor's nest. A cliff swallow' s plumage shows a mix of orange, blue, gray and tan. 

Cliff swallows' mud nests should be washed away as their construction is initiated. A high pressure water stream is usually adequate. Eliminating local sources of mud can also slow the construction process. Nests can and should be removed before eggs are laid indicated by the size of the nest opening. Most all birds, eggs and nestlings are protected by the Migratory Bird Treaty Act, and that includes swallows. Once eggs are laid nest removal should cease by the facility manager. 

USDA Wildlife Services is contracted by the 3rd Wing to keep Elmendorf aircraft safe from birds around the airfield. They are permitted by US Fish and Wildlife Service to haze and sometimes kill serious offenders. However, Wildlife Services is not contracted to remove swallow nests and to eliminate attractive nest sites. That is the responsibility of the facility manager. 

Swallows are very persistent while building nests, therefore nest removal should be a daily task until they give up and move on to another area. Their nesting period is May through mid July. 

Resolving this Elmendorf Bird Aircraft Strike Hazard risk is a team effort, and several professionals are available to aid facility managers. The Natural Resources Element of 3rdCES Asset Management is responsible for securing federal permits to take or haze migratory birds, and they can provide advice on resolving nesting bird issues. They can be reached at 552-0200. Pest Management Shop of 3rd CES Operations Flight can provide assistance in bird-proofing facilities. USDA Wildlife Services, continually vigilant within the BEZ, will be contacting facility managers as soon as they observe swallow nests being initiated. And, you, the airmen, officers and workers here on Elmendorf -if you observe swallows around a building in the BEZ contact 552-BIRD. 

The time to swallow-proof your buildings is now, before your vent is plugged with nesting materials. Have a plan to check your facility daily for nesting activities. And have a plan to wash off those mud nests as soon as the swallows start gathering. 

A reminder to all Elmendorf employees annual BASH training is required and accessible at: https://portal.elmendorf.af.mil/Training/default.aspx