Mortality of Deer Mice, Peromyscus maniculatus, in Wire Mesh Live-Traps: A Cautionary Note

Live-capture of animals occasionally results in the death of some individuals. Here, we report upon an unusual occurrence of trap-related mortality observed in Deer Mice (Peromyscus maniculatus) captured in wire mesh live-traps during field sampling in southeastern Yukon. Eight of 85 marked individuals (9.4%) were found with their snouts caught in the wire mesh of our live-traps; four of these individuals were found dead. We suggest a modification to Ugglan live-traps that would likely decrease such incidents

Unusual Beaver, Castor canadensis, Dams in Central Yukon

North American Beavers (Castor canadensis) are remarkable for their ability to build dams and modify their habitat. Dams are typically made of the boles and branches of trees and large shrubs, and reinforced with mud and rocks. Here, we report two unusual Beaver dams in central Yukon, Canada, that are made primarily of medium-sized rocks. This observation points to the adaptability of Beavers in using available materials to build their dams

Diversity and Distribution of the Terrestrial Mammals of the Yukon Territory: A Review

The diversity and distribution of the terrestrial mammals of the Yukon has not been systematically reviewed since 1975, a time when the occurrences of many species were not well known. Since then, single species and community studies, biological collections and expert observations have increased our knowledge of the land mammals of the Yukon. Taxonomic studies have resulted in some additional species. We provide an update on the diversity and distribution of recent land mammals of the Yukon, including previously unreported range extensions, and include a revised checklist. Research in adjoining jurisdictions has contributed more hypothetical species for the Yukon. The mammalian fauna of the Yukon is in a relatively dynamic state, and human-induced changes, particularly climate warming, will undoubtedly influence mammalian diversity and distributions in the coming decades

Mortality of Little Brown Bats, Myotis lucifugus, in a Rodent Trap in the Boreal Forest

Accidental mortality of bats is not often observed or reported in the literature. It may, however, have an impact on population size and structure. We report an observation of 53 Little Brown Bats (Myotis lucifugus) being trapped and drowned in a homemade rodent trap at an abandoned cabin in southern Yukon. Traps of this design may be commonly used in the boreal forest. We recommend not using such traps in cabins that are used by colonies of bats

First Confirmation of Cougar, Puma concolor, in the Yukon

Cougar (Puma concolor) have been reported from the Yukon as early as 1944. Despite many sightings, no indisputable, physical evidence of Cougar being present in the Yukon had been obtained. Here, we report on the first. In November 2000, a specimen was secured from near Watson Lake, in southeastern Yukon. Whether this specimen, and the numerous sighting records, are indicative of a low-density breeding population in the Yukon, or represent transients, is unknown

Sequential Flavour Symmetry Breaking

The gauge sector of the Standard Model (SM) exhibits a flavour symmetry which allows for independent unitary transformations of the fermion multiplets. In the SM the flavour symmetry is broken by the Yukawa couplings to the Higgs boson, and the resulting fermion masses and mixing angles show a pronounced hierarchy. In this work we connect the observed hierarchy to a sequence of intermediate effective theories, where the flavour symmetries are broken in a step-wise fashion by vacuum expectation values of suitably constructed spurion fields. We identify the possible scenarios in the quark sector and discuss some implications of this approach.Comment: 22 pages latex, no figure

Long-distance Movement of a Dispersing Deer Mouse, Peromyscus maniculatus, in the Boreal Forest

We report an apparent long-distance, non-homing movement of 3044 ± 60 m made by a dispersing subadult male Deer Mouse, Peromyscus maniculatus, in southeastern Yukon. Our observation is nearly twice the maximum distance previously recorded for non-homing Deer Mice, and apparently the longest dispersal movement recorded for this species

Using temporary dye marks to estimate ungulate population abundance in southwest Yukon, Canada

We describe the protocols of two mark-resight abundance surveys, using temporary dye-marks, for the Aishihik woodland caribou (Rangifer tarandus caribou) and wood bison (Bison bison athabascae) populations (herds) in the southwest Yukon Territory, Canada. We also provide recommendations based on experiences from these surveys for biologists and managers considering this approach. The Aishihik woodland caribou herd was the focus of intensive management in the 1990s aimed at recovering the herd. Following recovery activities, a target size of 2000 animals was determined and the Champagne-Aishihik Traditional Territory Community-Based Wildlife Management Plan recommended an estimate of the herd’s size be completed before the year 2013. We used an aerial mark-resight approach to estimate the herd’s size in March 2009. Caribou (n = 59) were marked from a helicopter with temporary dye, delivered via a CO2-powered rifle. Two independent resighting sessions were subsequently carried out via helicopter. The herd was estimated at 2044 animals (90% CI: 1768 – 2420) with an overall resighting rate of 0.47. The mean annual growth rate (λ) of the herd from 1997 – 2009 was 1.05 (SE = 0.01). The Aishihik wood bison herd was estimated at 1151 (90% CI: 998 – 1355). Our study suggests that ungulates temporarily marked with dye can be successfully used to obtain statistically sound population estimates

Apparent Predation of an American Water Shrew, Sorex palustris, by an American Marten, Martes americana

Little is known of the natural history of American Water Shrews, Sorex palustris, including their predators. We document an apparent case of predation of an American Water Shrew by an American Marten, Martes americana, in the boreal forest of southeastern Yukon

Melanistic Tundra Voles, Microtus oeconomus, from Central Yukon

Colour aberrations are not commonly observed in voles (e.g., Microtus and Myodes); thus, individual observations are of interest. We report two observations of melanism in Tundra Voles, Microtus oeconomus, collected from central Yukon. These are the second and third records of melanistic Tundra Voles, and the first reports from non-insular populations