Eliurus myoxinus (Rodentia: Nesomyidae, Nesomyinae) is one of the four species of endemic Malagasy rodentsknown to exist in the Ankarafantsika National Park, northwestern Madagascar. In order to study growth parameter...Eliurus myoxinus (Rodentia: Nesomyidae, Nesomyinae) is one of the four species of endemic Malagasy rodentsknown to exist in the Ankarafantsika National Park, northwestern Madagascar. In order to study growth parametersand to determine at which age E. myoxinus commences breeding, we used two different techniques: captivebreeding and a capture-mark-release field program in the species’ natural habitat. The data collected on thebreeding of E. myoxinus in captivity demonstrated that females can give birth to a litter of up to four pups, with upto four litters per calendar year. Reproduction of E. myoxinus was more likely to be continuous in captivity thanunder natural habitat conditions. If parturition failed, then post-partum mating occurred. Pups had a rapid lineargrowth phase from birth until 1 month of age. Between 1.5 and 2 months of age, the growth rate continued toincrease, but then decreased at around the time of weaning, which occurred by 3.5 months of age. The successivemaximum method of age determination showed that individuals at the “young” stage had an average body length of90 mm and a weight of 30 g and were between 1.5 and 2 months old. The greatest variation in measurements ofjuveniles occurred at the age of 3.5 months. At this stage, sub-adults resembled adults but their external genitaliawere not well developed. Individuals were classified as adults if they had reached a body length of 110 mm and abody weight of 40 g. This occurred at more than 4.5 months of age when the animals were generally reproductivelyactive. The Von Bertalanffy method indicated that individuals reach the adult stage by 6 to 7 months. Males grewmore rapidly than females, reaching adulthood by 5.5 months of age, whereas females only reached adulthoodseveral weeks later. This species is polygamous. The sex ratio of pups at birth favored females by approximately3:1. The higher proportion of female pups at birth may represent a survival strategy of this species, possiblyassociated with ecological conditions.展开更多
文摘Eliurus myoxinus (Rodentia: Nesomyidae, Nesomyinae) is one of the four species of endemic Malagasy rodentsknown to exist in the Ankarafantsika National Park, northwestern Madagascar. In order to study growth parametersand to determine at which age E. myoxinus commences breeding, we used two different techniques: captivebreeding and a capture-mark-release field program in the species’ natural habitat. The data collected on thebreeding of E. myoxinus in captivity demonstrated that females can give birth to a litter of up to four pups, with upto four litters per calendar year. Reproduction of E. myoxinus was more likely to be continuous in captivity thanunder natural habitat conditions. If parturition failed, then post-partum mating occurred. Pups had a rapid lineargrowth phase from birth until 1 month of age. Between 1.5 and 2 months of age, the growth rate continued toincrease, but then decreased at around the time of weaning, which occurred by 3.5 months of age. The successivemaximum method of age determination showed that individuals at the “young” stage had an average body length of90 mm and a weight of 30 g and were between 1.5 and 2 months old. The greatest variation in measurements ofjuveniles occurred at the age of 3.5 months. At this stage, sub-adults resembled adults but their external genitaliawere not well developed. Individuals were classified as adults if they had reached a body length of 110 mm and abody weight of 40 g. This occurred at more than 4.5 months of age when the animals were generally reproductivelyactive. The Von Bertalanffy method indicated that individuals reach the adult stage by 6 to 7 months. Males grewmore rapidly than females, reaching adulthood by 5.5 months of age, whereas females only reached adulthoodseveral weeks later. This species is polygamous. The sex ratio of pups at birth favored females by approximately3:1. The higher proportion of female pups at birth may represent a survival strategy of this species, possiblyassociated with ecological conditions.
