Long-tailed Weasel

The long-tailed weasel, *Neogale frenata* (formerly *Mustela frenata*), is a slender mustelid measuring 28–45 cm including a black-tipped tail that accounts for roughly 40–70% of head-body length, with males (160–450 g) markedly larger than females (80–250 g). Summer pelage is cinnamon-brown dorsally with cream to buff underparts; in northern populations the coat moults to white (ermine phase) in winter while the tail tip stays black. Breeding occurs in mid-summer, but implantation is delayed roughly 8–9 months so a single litter of 4–8 kits is born the following April–May. Kits are weaned at about 5 weeks and are hunting independently by 8 weeks; lifespan is 1–3 years in the wild. Their extremely high metabolic rate requires them to eat 20–30% of body weight daily.

Long-tailed weasels are solitary, largely crepuscular but active at any hour, and hunt by scent along tunnels, stone walls, and dense cover. They are obligate carnivores specialising in voles, mice, chipmunks, rabbits, and ground-nesting birds, killing prey with a precise bite to the base of the skull. Surplus killing is well documented: when confined with concentrated prey such as poultry or caged birds they may kill far more than they can consume and cache the excess, which is the behaviour that generates most human conflict. Their narrow, flexible bodies allow entry through openings as small as 25 mm (about 1 in.), including weep holes, vent gaps, and gnawed rodent runs. They defend loose home ranges of 4–120 ha with scent marks from anal glands and are typically intolerant of conspecifics outside the breeding season.