, as illustrated in ''Brehm's Life of Animals'' The beech marten is mainly a
crepuscular and
nocturnal animal, though to a much lesser extent than the
European polecat. It is especially active during moonlit nights. Being a more terrestrial animal than the pine marten, the beech marten is less
arboreal in its habits, though it can be a skilled climber in heavily forested areas. It is a skilled swimmer, and may occasionally be active during daytime hours, particularly in the summer, when nights are short. It typically hunts on the ground. During heavy snowfalls, the beech marten moves through paths made by
hares or
skis.
Social and territorial behaviours In an area of northeastern Spain, where the beech marten still lives in relatively unmodified habitats, one specimen was recorded to have had a home range of with two centres of activity. Its period of maximum activity occurred between 6 PM and midnight. Between 9 AM and 6 PM, the animal was found to be largely inactive. In urban areas, beech marten's dens are almost entirely in buildings, particularly during winter. The beech marten does not dig burrows, nor does it occupy those of other animals. Instead, it nests in naturally occurring fissures and clefts in rocks, spaces between stones in
rock slides and inhabited or uninhabited stone structures. It may live in tree holes at a height of up to 9 metres.
Reproduction and development Estrus and
copulation occur at the same time as in the pine marten. Mating occurs in the June–July period, and takes place in the morning or in moonlit nights on the ground or on the roofs of houses. The
gestation period lasts as long as the pine marten's, lasting 236–237 days in the wild, and 254–275 days in fur farms.
Parturition takes place in late March-early April, with the average litter consisting of 3–7 kits. The kits are born blind, and begin to see at the age of 30–36 days. The
lactation period lasts 40–45 days. In early July, the young are indistinguishable from the adults.
Diet The beech marten's diet includes a much higher quantity of plant food than that of the pine marten and sable. Plant foods eaten by the beech marten include
cherries,
apples,
pears,
plums,
black nightshade,
tomatoes,
grapes,
raspberries and
mountain ash. Plant food typically predominates during the winter months.
Rats,
mice and
chickens are also eaten. Among bird species preyed upon by the beech marten,
sparrow-like birds predominate, though
snowcocks and
partridges may also be taken. The marten likes to plunder nests of birds including
passerines,
galliformes and small
owls, preferring to kill the parents in addition to the fledglings. Although it rarely attacks poultry, some specimens may become specialized poultry raiders, even when wild prey is abundant. Males tend to target large, live prey more than females, who feed on small prey and carrion with greater frequency. However, in one known case, a subadult beech marten was killed by a pine marten. The beech marten has been known to kill
European polecats on rare occasions.
Red foxes,
lynxes,
mountain lions,
golden eagles, and
Eurasian eagle-owls may prey on adults, and juveniles are vulnerable to attack by
birds of prey and
wildcats. There is, however, one case, from Germany, of a beech marten killing a domestic cat, although there is also a report of a domestic cat killing a beech marten after a struggle lasting more than half an hour. ==Range==