Social influences on oestrous cycle length and plasma progesterone concentrations in the female lesser mouse lemur (Microcebus murinus)

Abstract

Plasma progesterone concentrations were recorded during one breeding season in 19 lesser mouse lemur females living in different social conditions. The oestrous cycle length and the progesterone profile mainly depended on the social environment of the female. For totally isolated females, the oestrous cycle lasted 38 +/- 5.7 days and included a 25-30-days spontaneous luteal phase with a progesterone peak about 100 ng/ml between the 20th and 25th days after oestrus, and a prolonged preovulatory period of 10-15 days which could be considered equivalent to the follicular phase of a menstrual cycle. When females were able to communicate through olfactory, visual and auditory signals, the oestrous cycle was significantly lengthened (53.7 +/- 5.9 days). When females had tactile contacts, the oestrous cycle was further lengthened (62.7 +/- 0.8 days). This lengthening of the oestrous cycle was related to an extension of the luteal phase associated with a decrease in progesterone concentrations during this period. In females maintained with one male (paired) or with males and females (heterosexually grouped), large individual variations were shown in cycle lengths or in progesterone concentrations. In these females, cycle lengths and progesterone concentrations were inversely correlated to plasma cortisol concentrations.

Multimodal Oestrus Advertisement in a Small Nocturnal Prosimian, Microcebus murinus

“…The cycle length of the study females was slightly longer than that reported by Perret [14], but was well within the range reported by Adriantsiferana [15]. In primates, vaginal morphology usually changes due to endocrinological processes during the ovarian cycle [8,9].…”

“…As in most lemurs, vaginal morphology shows distinct changes according to the reproductive state of the female, with the vagina being open for only the short period when mating occurs, the periovulatory period. The length of the ovarian cycle of females housed in captivity varies between 38 and 58 days, depending on the conditions in which they are kept [14], but may last up to 100 days [15]. The fertile phase lasts only 2-4 h [16] and occurs normally on the second day of vaginal opening [17].…”

Female reproductive activity and its endocrine correlates in the African lesser bushbaby, Galago moholi

“…Environmental cues, such as food availability, temperature and constant social stimuli have all been attributed to the initiation of oestrus (Perret 1986;Savini et al 2008) and might play a role for initiating oestrus in G. moholi as well. In our study, the fEM increase seen in conjunction with female reproductive activity seems to play an important role in initiating not only physical changes (vaginal opening), but also respective behavioural alterations (mating acceptance) and presumably female receptivity, as seen in various primate species such as common marmosets (Callithrix jacchus, Barnett et al 2006 moholi reproductive activity (Lipschitz 1997).…”

“…However, even for hormone analyses via faecal samples, continuous access to the study individuals is required to determine longitudinal hormone metabolite patterns. This challenge in acquisition has resulted in the majority of studies monitoring endocrine activity on captive or semi-captive populations, rarely comparing their findings to free-ranging populations (Buesching et al 1998;Perret 1986;Williams et al 1991).…”

Social and reproductive conditions modulate urinary cortisol excretion in black tufted-ear marmosets (Callithrix kuhli)

“…Under conditions of group stability, subordinate individuals tend to have increased activity in the HPA axis relative to dominant individuals [see review in Sapolsky, 1993]. Indeed, many accounts of reduced fertility in subordinates primates (particularly old world and hominoid primates) attribute the low reproductive output in subordinate individuals to stress associated with their low social rank [Wasser and Barash, 1983;Adams et al, 1985;Kaplan et al, 1986;Perret, 1986;Harcourt, 1987;Dunbar, 1989;Rivier & Rivest, 1991]. In contrast to the demonstrated link between HPA activity and social status in old world primates, however, recent studies have found no link between social status and levels of activity in the HPA axis in a variety of species [e.g., Schoech et al, 1991;Saltzman et al, 1994;Ziegler et al, 1995;Faulkes & Abbott, 1996].…”