The pine marten is a small native predator. This mustelid lives at low density (often 0.3 to 1.5 adults per square kilometre), has low fecundity and is vulnerable to persecution, road traffic mortality and stochastic events, particularly when populations are small or fragmented.
For the reader unfamiliar with the species, there is a comprehensive range of generalist publications covering population dynamics, life history and behaviour. Although primarily a forest-dwelling species associated with mature woodland, the pine marten can persist in open landscapes containing fragmented woodland, scrub and rough grassland habitats. It can occur in suburban habitat provided there is a matrix of woodland cover.
The field vole is a major component in a diet, which includes a range of other small mammals, birds, fruit, hazel nuts, eggs and carrion. This is often an opportunistic predator and, as such, will take advantage of food scraps on bird tables, and it may on occasion predate game birds and domestic fowl. Zalewski reported that the proportion of birds in marten diet varied seasonally from a spring/summer high.
Martens are relatively long-lived, reaching sexual maturity at two years of age and have an intra-sexual social system where female territories are largely discrete and are overlapped within male territories.
The most recent historical local pine marten record from the project area was from 1994 on the island of Anglesey (DJ Jefferies).
Pine martens frequently visit red squirrel feeders in the Gwynedd forests.