Habitats of small mammals at Whiteshell Nuclear Research Establishment

Technical Report · Sat Dec 01 04:00:00 EST 1973

OSTI ID:4939455

Iverson, S L; Turner, B N

The small mammals in the area around the Whiteshell Nuclear Research Establishment in southeastern Manitoba were sampled by approximately 110,000 snap- trap nights in a 5 year period. Habitats trapped were divided into major types on the basis of the tree species present, and occurrences of the different species of shrubs and herbs in each habitat type were noted. The major habitats were mixed deciduous, aspen, ash, mixed coniferous, The small mammal component of the mixed deciduous forest was dominated by Peromyscus maniculatus and Clethrionomys gapperi but all of the other species included in this study were also present. In both aspen and ash forests, Microtus pennsylvanicus and C. gapperi were the most numerous species, with Sorex arcticus reaching its greatest abundance in the latter. In the open field, M. pennsylvanicus was most abundant, followed by Zapus hudsonius, C. gapperi, M. pennsylvanicus and Sorex cinereus were the most numerous mammals in the black spruce bog community, and also extended into the black spruce forest. All of the species studied, except Napaeozapus insignis and S. arcticus, were present in the mixed coniferous forest. S. arcticus and S. cinereus, although captured in habitats ranging from heavy forest to open field, appeared to be most numerous in young forests and other intermediate habitats. Blarina brevicauda was most numerous in older forests. P. maniculatus and N. insignis were most common in the mixed deciduous forest, but P. maniculatus occurred more frequently than N. insignis in the younger forests. P. maniculatus showed a significant positive relationship with large tree diameter and low percentages of ground cover. C. gapperi was captured in highest numbers in the mixed deciduous and coniferous forests, but was also found in the other types of forest in greater numbers than P. maniculaius. M. pennsylvanicus and Zapus hudsonius were most common in the open field, but both species were present in the forests. Analysis of data from stations in the forest where M. pennsylvanicus was captured showed that this vole was most common in areas structurally most similar to open field, that is, areas with small trees and more ground cover. Most of the species were captured in a greater range of habithts than has been generally reported. This mav be due to gene flow between eastern and western subspecies, the physical proximity of the different habitats, and more thorough sampling including long-term intensive snap-trapping. (auth)

• Research Organization: Atomic Energy of Canada Ltd., Pinawa, Manitoba. Whiteshell Nuclear Research Establishment
• Sponsoring Organization: Sponsor not identified
• NSA Number: NSA-29-029395
• OSTI ID: 4939455
• Report Number(s): AECL--3956
• Country of Publication: Canada
• Language: English

Related Subjects

CANADA
CONIFERS
DISTRIBUTION
ECOLOGY
ENVIRONMENT
FORESTS
HERBS
MAMMALS
N44500* --Environmental & Earth Sciences--Site Surveys
REACTOR SITES
SAMPLING
SHRUBS
TREES
WR-1 REACTOR