ARCTIC Ecological Distribution of Small Mammals in the De Long Mountains of Northwestern Alaska

• Main Author: Richard J Douglass
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; toundra; Tundra; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.533.7385; http://pubs.aina.ucalgary.ca/arctic/Arctic37-2-148.pdf

ABSTRACT. The ecological distribution of small mammals (< 200 g) was studied in the foothill tundra of the De Long Mountains in northwestern Alaska. Three species of shrews and five species of microtine rodents were trapped on 15 live-trapping grids during 1978 and 1979. Emphasis was placed on the three most abundant microtine species (Clerhrionomys rurilus, Microtus oeconomus and M. gregalis). During late summer up to six species of small mammals were captured per habitat type which ranged from wet meadow through mesic shrubland to dry ridges. Following snowmelt most habitats contained only a single species and some contained none. Only four habitat types were continuously occupied by small mammals during both summers. Species diversity was variable among habitats. Most species of small mammals were captured on eight or fewer of the 15 trapping grids. Only Clerhrionomys rurilus was captured on all grids. The number of habitats occupied by Clerhrionomys rurilus increased from 4 to 14 as population densities increased. The number of habitats occupied by the other species seemed to be independent of population density. Average population densities for the microtines were low (< 15.ha- I) and, for each species, varied according to habitat type. Only Clerhrionomys rurilus populations demonstrated marked intra-annual fluctuations (3.ha- I to 37,ha- I). Key words: rodents, habitat, Alaska, populations, Clerhrionomys ncrilus, Microtus oeconomus, Microrus gregulis RESUME. La distribution tcologique de petits mammiferes (200 g) fut Btudiee dans la toundra des contraforts des montagnes De Lung uans le nord-ouest de I’Alaska. Trois espbces de musaraignes et cinq esp&ces de rongeurs microtines furent captures dans des grilles A pikges a recipient en 1978 et 1979. L’etude porta surtout sur les trois espkces praominantes de microtin6s (Clethrionomys rurilus, Microtus oeconomus et M. gregalis).