Martes melampus
Japanese marten

Martes melampus melampus is found on the islands of Honshu, Shikoku, and Kyushu in Japan. M. melampus melampus was introduced from Honshu to Sado and Hokkaido Islands in Japan by 1949 to increase fur products (Hosoda et al. 1999). Its distribution is southwestern Hokkaido, specifically the low altitude areas of the Oshima Peninsula and Ishikari, but research is needed to confirm its distribution (Murakami and Ohtaishi 2000). Martes melampus tsuensis is sparsely distributed on the Tsushima Islands of Japan (Buskirk 1994). Martes melampus coreensis is found on the mainland of South Korea into North Korea. (Anderson, 1970; Buskirk, et al., 1994; Hosoda, et al., 1999; Murakami and Ohtaishi, 2000)

Japanese martens are found along valleys, primarily in broad-leaved forests (dominated by Quercus serrata and Castanopsis cuspidata). This species will use conifer plantations and open fields (Tatara and Doi 1994). It will use dens in trees and ground burrows (Nowak 1999). Characteristics of the Tsushima Islands include: 88% forested, mean low January temperature of 4°C, mean high August temperature of 26°C, uncommon and light snowfall, and a low human population (Buskirk 1994). The habitat of this species is similar to that of Martes zibellina (Otsu 1972). (Buskirk, et al., 1994; Nowak, 1999; Otsu, 1972; Tatara and Doi, 1994)

The head and body length is 470 to 545 mm (Anderson 1970). The tail length is 170 to 223 mm. Age of martens is determined by tooth eruption and wear. Sexes are significantly different in size, with males being larger (Tatara and Doi 1994). Mass varies from 500 to 1,700 g for adults. Nine live-captured males averaged 1,563 g and 4 females averaged 1,011 g (Tatara and Doi 1994). Pelage coloration varies from yellowish brown to dark brown throughout with a white to cream-colored neck patch. (Anderson, 1970; Tatara and Doi, 1994)

See reproduction.

Information on mating behaviors of Japanese martens is unavailable.

Martes melampus reach sexual maturity between one and two years of age. They are seasonal breeders, mating from late March through Mid-May, and giving birth between mid-July and early August. Embryonic diapause probably occurs in M. melampus (Buskirk 1994). Japanese martens produce 1 to 5 offspring per litter, with a mean of 1.5. They are iteroparous. (Buskirk, et al., 1994; Imaizumi, 1949; Kuroda, 1940; Macdonald, 1999)

Young are altricial, and are cared for by the mother. As in all mammals, the mother produces milk with which to feed her young. Japanese Marten kits are born deaf, blind, and furred (Macdonald 1999). Young martens can kill prey by 3 to 4 months and leave their mother shortly thereafter. (Imaizumi, 1949; Kuroda, 1940; Macdonald, 1999)

Information on lifespan in Japanese martens is unavailable.

Juveniles try to establish territories shortly after becoming sexually mature. Home range of male Japanese martens averaged 0.70 square km and females averaged 0.63 square km with less than 10% overlap between any 2 home ranges (Buskirk 1994). Relatively small home range sizes may depend on abundance and distribution of food within preferred habitat. Scats were found primarily in home range peripheries in a doughnut-shaped distribution. Scat placement confirms active maintenance of boundaries by scent marking, a common social behavior in mustelids (Tatara and Doi 1994). Martes melampus has been observed jumping up to 2 m from the ground into a tree (Yoshiyuki and Mikuriya 1974). (Buskirk, et al., 1994; Tatara and Doi, 1994; Yoshiyuki and Mikuriya, 1974)

Scat analyses indicate that M. melampus is omnivorous. However, it may be characterized as an opportunistic generalist. It eats a highly diverse array of food through the year. Important foods are fruits and berries from spring to autumn, insects in summer and autumn, and small mammals and birds all year round. It likely competes with other carnivores for small mammals (Tatara and Doi 1994).

Foods eaten include plants (mostly berries and seeds): Diospyros kaki, Actinidia arguta, Rubus hirsutus, Elaeagnus pungens, E. umbellata, Vitis ficifolia, Ficus electa, Morus australis, Rhus spp., Stauntonia hexaphylla, and Camellia japonica, rabbits and other small mammals: Lepus brachyurus angustidens, Petaurista leucogenys niddonis, Clethrionomys rufocanus andersoni, Apodemus speciosus, Apodemus argenteus, Mus musculus, and Rattus, birds and their eggs: Phasianus soemmeringii scintillans, Phasianus colchicus karpowi, Turdus naumanni eunomus, and Emberiza cioides ciopsis, invertebrates: Coleoptera and Mantodea centipedes and spiders, Scolopendra subspinipes, frogs and their eggs: Rana tsushimensis, earthworms, fish, gastropods, and crustaceans: Ligia exotica and Sesarma haematocheir.

Japanese martens adapt their fruit and berry foraging to local plant phenology. In the presence of interspecific competitors or human disturbance, they change to alternative food resources, making them more adaptable than Mustela sibirica and Felis bengalensis, which are more prey specific (Tatara and Doi 1994). (Obara, 1970; Otsu, 1972; Tatara and Doi, 1994)

Den selection is the most obvious adaptation to protection from predation. Martes melampus rests in tree and ground dens. Five adults were found killed by feral dogs and 38 killed by vehicle collisions between 1986 and 1989 (Tatara and Doi 1994). Humans also trap them. (Tatara and Doi, 1994)

Little is known about the ecology of the M. melampus (Buskirk 1994). It may be surmized from its predatory feeding habits, however, that populations of M. melampus affect local populations of small mammals and birds, thereby affecting seed dispersal, etc. (Buskirk, et al., 1994)

Martes melampus is trapped for fur from 1 December through 31 January (Nowak 1999) except on Hokkaido and the Tsushima Islands, where it is protected (Buskirk 1994). It is illegal to harvest females (Otsu 1972), a restriction that helps to preserve the population. Martes melampus predation of Lepus brachyurus is beneficial to the timber industry, because L. brachyurus browsing may destroy tree quality (Otsu 1972). (Buskirk, et al., 1994; Nowak, 1999; Otsu, 1972)

These martens may consume insects that are beneficial to agriculture (Otsu 1972). (Otsu, 1972)

Martes melampus is a species of concern due to pressure from human activities in recent years, which has brought drastic changes in the natural environment of Japan. It is decreasing in numbers due to excessive trapping for its fur and because of the harmful effects of agricultural insecticides. As a result, females are protected from trapping (Otsu 1972).

Martes melampus tsuensis was designated a vulnerable Natural Monument Species by the Japanese Agency of Cultural Affairs in 1971 (Buskirk 1994), which supported its classification as vulnerable by the IUCN (Hilton-Taylor 2000). This subspecies is now legally protected on the Tsushima Islands (Schreiber et al. 1989). Although the Tsushima Islands are 88% forested, 34% of the forest is conifer plantation. This poses a challenge, because important foods of M. melampus tsuensis may not be common in these plantations (Tatara and Doi 1994). Between 1986 and 1989, 38 M. melampus tsuensis were found killed by vehicles and another 5 were found killed by feral dogs. The conservation plan for this subspecies should consider further habitat degredation by forestry practices and road development, as well as a method to control feral dogs (Buskirk 1994).

If there are no mating isolation mechanisms between endemic M. zibellina and introduced M. melampus in Hokkaido, natural hybridization between them may be possible (Hosoda et al. 1999). Hosoda suggests protection of M. zibellina from gene contamination by introduced M. melampus. Fortunately, there is no documentation of hybridization yet. However, mating isolation mechanisms between them have not been studied. Further research should evaluate whether there are different pre- and post-mating isolation mechanisms, in order to maintain the endemism of M. zibellina. (Buskirk, et al., 1994; Hosoda, et al., 1999; Otsu, 1972; Schreiber, et al., 1989)

Genetic studies show that M. melampus separated from Martes zibellina about 1.8 million years ago (Hosoda et al. 1999; Kurose et al. 1999).

Hepatozoonosis is prevalent, but susceptibility to it may be low. The most commonly parasitized organ was the heart (Yanai et al. 1995). (Hosoda, et al., 1999; Kurose, et al., 1999; Yanai, et al., 1995)