The Hair Scale Identification Guide to Terrestrial Carnivores of Canada

Mammalian predators are keystone species in any ecosystem. But many are elusive by nature and have territories that cover large areas of land, which makes them challenging to monitor. When tracks and signs prove difficult to interpret or are non-existent, hair samples recovered from the field offer a fantastic resource – one that is often overlooked. The Hair Scale Identification Guide to Terrestrial Mammalian Carnivores of Canada provides a fully illustrated, up-to-date hair scale reference for all 25 of the terrestrial carnivorous mammals of Canada. From the tiny least weasel (Mustela nivalis) to the giant polar bear (Ursus maritimus), unique traits – as well as tricky similarities – can clearly be observed through hair scale patterns magnified at the medial portion of the hair impression. These scale patterns aid in species identification when hair is the only possible evidence available. This guide also outlines hair impression techniques for samples found in the field, assisting ecologists and technicians with wildlife monitoring studies on predatory mammals where additional identification is required. Including range maps and key identification characteristics for all species represented, as well as superb images of hair scale impressions at two magnification levels, this book is a comprehensive tool for animal hair ID.

A beacon of dung: using lemming (Lemmus lemmus) winter nests and DNA analysis of faeces to further understand predator–prey dynamics in Northern Sweden

The hypothesis that predation is the cause of the regular small rodent population oscillations observed in boreal and Arctic regions has long been debated. Within this hypothesis, it is proposed that the most likely predators to cause these destabilizing effects are sedentary specialists, with small mustelids being possible candidates. One such case would be the highly specialized least weasel (Mustela nivalis) driving the Norwegian lemming (Lemmus lemmus) cycle in Fennoscandia. These predators are often elusive and therefore distribution data can only be based on field signs, which is problematic when various mustelid species are sympatric, such as weasels and stoats (Mustela erminea). Here we present the results of using mustelid faeces in predated winter lemming nests to correctly identify the predator and thus discern which species exerts the strongest predation pressure on lemming winter populations. Samples were obtained during different phases in the lemming cycle, spanning 6 years, to account for different prey densities. Faecal mitochondrial DNA extraction and amplification of a 400-bp fragment was successful in 92/114 samples (81%); the sequencing of these samples proved that most predation occurrences (83%) could be attributed to the least weasel. These findings support the hypothesis that weasels in particular show high specificity in predation and could therefore be candidates to driving the lemming cycle in this area. We conclude that DNA analysis of faecal remains around predated nests can be a useful tool for further investigations concerning predator–prey interactions in the tundra.