Effects of Urbanization on Bird Populations in the Canadian Central Arctic

Аннотация

Development of the Hamlet of Baker Lake (Qamani'tuaq) in the central Canadian Arctic during the 1950s was typical of the local urbanization that has occurred in Arctic regions during the latter half of the 20th century. The effects of urbanization on bird populations were examined by comparing populations before and after 1950, comparing populations in anthropogenic ecosystems with natural ones, and recording the presence or absence of exotic species usually associated with human dwellings and settlements. Of a total 60 local species, 21 had not been reported prior to 1950. Most of these were waterfowl, shorebirds, and gulls, all species that benefited from the presence of sewage lagoons and a refuse dump, or were associated with building sites (American robin). Semipalmated plovers were associated with gravel pits and gravel roadsides, whereas semipalmated sandpipers, Lapland longspurs, horned larks, Savannah sparrows, and white-crowned sparrows were most abundant in town. Vagrants from south of the tree line have been reported from the study site. It is hypothesized that climatic amelioration in association with the development of urban ecosystems may have encouraged migration overshoots in these species. These vagrants may be the early colonizers that eventually result in breeding range extensions, as has been observed in several waterfowl species, American robins, and white-throated sparrows. Twelve apparent species losses have occurred since 1950, but these are likely due to general scarcity or lack of observers rather than reduced abundance. No exotic "city" species, such as rock doves, European starlings, or house sparrows, have been recorded in Baker Lake. It is not anticipated that these species would become established or survive at Baker Lake in the near future, because of its isolation and severe winters.