from the anogenital scent gland on small branches and other objects. Reproduction Reproduction starts in November for Coquerel's giant mouse lemur at Kirindy Forest; the estrous cycle runs approximately 22 days, while estrus lasts only a day or less. The mating season in this southern population is limited to a few weeks, whereas the northern giant mouse lemur is thought to breed throughout the year, a trend seen in only two other species of lemur: the aye-aye (Daubentonia madagascariensis) and the red-bellied lemur (Eulemur rubriventer). The northern giant mouse lemur had been observed breeding year-round in captivity if their litter did not survive or was removed, but at the time this population was thought to be Coquerel's giant mouse lemur. One to three offspring (typically two) are born after 90 days of gestation, weighing approximately . Because they are poorly developed, they initially remain in their mother's nest for up to three weeks, being transported by mouth between nests. Once they have grown sufficiently, typically after three weeks, the mother will park her offspring in vegetation while she forages nearby. After a month, the young begin to participate in social play and grooming with their mother, and between the first and second month, young males begin to exhibit early sexual behaviors (including mounting, neck biting, and pelvic thrusting). By the third month, the young forage independently, though they maintain vocal contact with their mother and use a small part of her range. Females start reproducing after ten months, while males develop functional testicles by their second mating season. Testicle size in the northern giant mouse lemur does not appear to fluctuate by season, and is so large relative to the animal's body mass that it is the highest among all primates. This emphasis on sperm production in males, as well as the use of copulatory plugs, suggests a mating system best described as polygynandrous where males use scramble competition (roaming widely to find many females). In contrast, male Coquerel's giant mouse lemurs appear to fight for access to females (contest competition) during their breeding season. Males disperse from their natal range, and the age at which they leave varies from two years to several. Females reproduce every year, although postpartum estrus has been observed in captivity. In the wild, the lifespan of giant mouse lemurs is thought to rarely exceed five or six years, though in captivity they can live