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Effects of urbanization on bird populations in the Canadian Central Arctic.

Article Excerpt
ABSTRACT. 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 th e 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.

Key words: birds, Nunavut, Northwest Territories, Baker Lake, urbanization, Arctic

RESUME. Au cours des annees 1950, l'amenagement du hameau de Baker Lake (Qamani'tuaq) dans le centre de l'Arctique canadien etait typique de l'urbanisation locale qui a eu cours dans les regions arctiques durant la derniere moitie du [XX.sup.e] siecle. On a etudie les repercussions de l'urbanisation sur les populations d'oiseaux en comparant des populations avant et apres 1950, en comparant des populations au sein d'ecosystemes anthropiques avec celles d'ecosystemes naturels, et en consignant la presence ou l'absence d'especes exotiques associees aux habitations et aux etablissements humains. Sur un total de 60 especes locales, 21 n'avaient pas ete rapportees avant 1950. Celles-ci etaient composees pour la plupart de sauvagine, d'oiseaux de rivage et de mouettes, especes qui beneficiaient toutes de la presence d'etangs d'eaux usees et d'une decharge, ou qui etaient associees avec des chantiers de construction (merle d'Amerique). Les pluviers semipalmes etaient associes aux gravieres et aux bords de routes en gravier, alors que les becasseaux semipalmes, les bruants lapons, les alouettes hausse-col, les bruants des pres et les bruants a couronne blanche se concentraient dans la ville. On a mentionne la presence sur le site de l'etude d'oiseaux egares venus du sud de la limite des arbres. On emet l'hypothese que le rechauffement climatique joint a l'expansion d'ecosystemes urbains pourrait avoir favorise chez ces especes le prolongement migratoire. Ces oiseaux egares pourraient etre les premiers a coloniser une region qui finit par devenir une extension de leur territoire de reproduction, comme on a pu l'observer chez diverses especes de sauvagine ainsi que chez le merle d'Amerique et le bruant a gorge blanche. Depuis 1950, il semble s'etre produit une perte pour douze especes, mais cela est probablement du a une penurie generale d'observateurs plutot qu'a une diminution de population. A Baker Lake, on n'a enregistre aucune espece exotique [much less than]des villes[much greater than], telles que le pigeon biset, l 'etourneau sansonnet ou le moineau domestique. On ne s'attend pas a ce que ces especes s'etablissent ou survivent a Baker Lake dans un futur proche, en raison de l'isolation du lieu et de la rigueur de l'hiver.

Mots cles: oiseaux, Nunavut, Territoires du Nord-Ouest, Baker Lake, urbanisation, Arctique

Traduit pour la revue Arctic par Nesida Loyer.

INTRODUCTION

Human communities increased throughout the Arctic during the second half of the 20th century. Local urbanization of tundra landscapes has had a major and continuing impact on local avian populations, but there have been no...

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