Body Weights of Adult and Juvenile Northern Pocket Gophers, Thomomys talpoides, in Central Alberta Alfalfa Fields

In an effort to recognize adults from juveniles in late summer and early fall, carcasses of Northern Pocket Gophers (Thomomys talpoides) captured from April to October 1994 in a pure alfalfa (Medicago spp.) field in Camrose and a mixed alfalfa-orchard grass (Dactylis glomerata)-dandelion (Taraxacum spp.) field in Lacombe, in central Alberta were analyzed. Mean weights of adult males and females were significantly (P < 0.05) larger than those of juveniles with near-adult body sizes in late summer and early fall. On the basis of the limits of 95% confidence intervals for individual values in Camrose and Lacombe, live-captured males weighing < 130 g could be classified as juveniles; those that are > 180 g would be adults. Males weighing between 130 and 180 g could be either juveniles or adults. Live-captured females weighing < 110 g would likely be juveniles. With larger animals, the pubic symphysis should be used to distinguish young females from adults. Given the variability of body weight in Northern Pocket Gophers, it is suggested that criteria for aging based on weight be derived for local populations in specific habitat types. On average, Northern Pocket Gopher males and females from Camrose were significantly (P < 0.05) heavier than those of Lacombe. Animals from both fields were, on average, heavier than those previously studied in natural-vegetation communities. Differences in the food nutritional quality may explain the observed variation in body weights among populations

Long-tailed Weasel, Mustela frenata, Movements and Diggings in Alfalfa Fields Inhabited by Northern Pocket Gophers, Thomomys talpoides

Little is known about the movements of Long-tailed Weasels (Mustela frenata) in alfalfa (Medicago spp.) fields inhabited by Northern Pocket Gophers (Thomomys talpoides). In central Alberta, I intermittently followed the movements of Long-tailed Weasels during two consecutive winters. Three types of movements were observed: straight-line movements across the fields; sinuous movements along the edges of the field; and arc movements within the field, over concentrations of Northern Pocket Gopher burrow systems. Arc movements were 0.6-28-m-wide at their base, and extended from 6 to 45 m into the field. Movements of Long-tailed Weasels into the fields were accompanied by fresh diggings in Northern Pocket Gopher burrow systems, which became inactive thereafter. This study suggests that Long-tailed Weasels may have a cognitive map of the distribution of Northern Pocket Gophers in their home range

Winter Habitat Use by American Marten, Martes americana, in Western Alberta Boreal Forests

Although the American Marten (Martes americana) is found in most forest regions of Alberta, little is known about its choice of winter habitats. This study investigated winter habitat use by American Marten in Weyerhaeuser’s Grande Prairie Forest Management Area (FMA) using snowtracking along 128.2 km of seismic lines inventoried in winters 1999, 2002, and 2005 with snowmobiles. American Marten tracks (n = 44) occurred significantly less frequently than expected (P < 0.001) in immature/young pole stands, but more frequently than expected (P < 0.02) in mature/old growth mixedwood stands. American Martens apparently used young forests, and mature/old coniferous and deciduous stands, according to their availability. Forest development plans should be developed locally to retain late successional forests that meet the winter habitat requirements of American Marten

Verification of a Forest Rating System to Predict Fisher, Martes pennanti, Winter Distribution in Sub-boreal Forests of British Columbia, Canada

This study verified the ability of a forest rating system to predict the winter distribution of Fisher (Martes pennanti) in the Sub-boreal Spruce Biogeoclimatic Zone of central interior British Columbia. Forest polygons (i.e., homogenous areas with similar forest stand characteristics) were classified according to their age and structural development, canopy closure, basal area in mature trees, average tree diameter at breast height, and percentage of shrub cover. Approximately 170 km of transects randomly distributed across polygons were inventoried (snowshoed) from December to February 2005-2008. A total of 278 Fisher tracks were recorded. The observed frequency of Fisher tracks per polygon type was significantly (P < 0.05) different from expected. The majority (245 or 88.1%) of tracks were recorded in excellent- and high-quality polygons corresponding mostly to mixed coniferous stands. On average, these stands were 138.2 years old, and had 54.4% canopy closure, 38.1 m2/ha basal area, 27.8 cm dbh, and 11.4% shrub cover. This study showed that the forest rating system was adequate to predict Fisher winter distribution, and could be used to develop forest management plans that are compatible with the species habitat requirements

Persistence of a Reintroduced Fisher, Martes pennanti, Population in Cooking Lake-Blackfoot Provincial Recreation Area, Central Alberta

In order to confirm the persistence of a Fisher (Martes pennanti) population reintroduced in 1990 in Cooking Lake-Blackfoot Provincial Recreation Area, central Alberta, we inventoried trails in the winters of 2006 and 2007. We recorded the presence of Fishers in 16 locations, and we confirmed the presence of at least two animals. We believe that the presence of Fishers 17 years after their release in the recreation area indicates that there is a self-sustaining population

Uterine Prolapse in an Adult Richardson's Ground Squirrel, Spermophilus richardsonii

During a study of Richardson's Ground Squirrel (Spermophilus richardsonii) populations in southern Saskatchewan, we captured one adult female with a partially prolapsed uterus. This is the first known case of uterine prolapse in a Richardson's Ground Squirrel

Rodent outbreaks in North America

Fluctuations in rodent population densities in North America are a reality. Our understanding of the factors causing such fluctuations is incomplete; therefore, it is important to monitor populations to increase our understanding of natural wildlife communities so as to avoid substantial damage to agriculture, forestry, and urban infrastructures, and to prevent rodent-borne disease transmission to humans. There is a need to establish integrated pest management programs in which monitoring, preventive cultural practices, and various control methods (mechanical, physical, biological, and chemical) are strategically coordinated to maintain rodent population densities at acceptable pest levels

Rodent outbreaks in North America

Fluctuations in rodent population densities in North America are a reality. Our understanding of the factors causing such fluctuations is incomplete; therefore, it is important to monitor populations to increase our understanding of natural wildlife communities so as to avoid substantial damage to agriculture, forestry, and urban infrastructures, and to prevent rodent-borne disease transmission to humans. There is a need to establish integrated pest management programs in which monitoring, preventive cultural practices, and various control methods (mechanical, physical, biological, and chemical) are strategically coordinated to maintain rodent population densities at acceptable pest levels

Winter Habitat Use by Moose, Alces alces, in Central Interior British Columbia

In central British Columbia, recent epidemics of Mountain Pine Beetle (Dendroctonus ponderosae) have resulted in the use of expansive clearcut areas to remove infested mature and old Lodgepole Pine (Pinus contorta) stands. This study aimed to determine if Moose (Alces alces) use late-successional Lodgepole Pine stands in mid- to late-winter. Moose activity and habitat use was determined during February-March track surveys in 2000 (60 km) and 2001 (55.7 km). In 2000 (69 tracks) and 2001 (313 tracks), Moose track distribution differed significantly (P < 0.05) from random. They were significantly more abundant than predicted in young stands (dominated by Picea spp.), or early seral stages; they were less abundant than predicted in mature and old Lodgepole Pine stands. It is unlikely that harvesting late-successional Lodgepole Pine stands would affect Moose winter habitat supply