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Biomedical subjects

T E Rowell

Publications and source records attributed to T E Rowell.

At least 19 recordsLinked to original sources
PubMed1977

Variation in age at puberty in monkeys.

5 female and 3 male patas monkeys and 6 female and 3 male talapoin monkeys matured in a captive breeding colony. Age at puberty is given, and some variation discussed. The talapoin, a very small monkey, becomes adult at 4 1/2 years for females, 1 or 2 years later for males. The patas, a rather large monkey, becomes adult at 2 1/2 years, for females, and 1 or 2 years later for males. Both these ages for puberty differ from data for the rhesus monkey which has been accepted as generalizable to all Old World monkeys. Possible causes of differences between species in average age at puberty are discussed, including nutrition, environmental inconstancy, and relative size of infant and mother. It is suggested that age at first conception, a biologically more relevant index than menarche, should be considered as a potentially important adaptive variable when describing primate species.

Age Factors↗
PubMed1977

Reproductive cycles of the talapoin monkey (Miopithecus talapoin).

Reproductive cycles of female talapoins living in caged breeding groups were followed over 7 years, using visible changes of the perineum. Changes in the perineum during the extended adolescence of this species are described. There was a clearly defined breeding season, although its onset was not so abrupt as in the wild. During the summer months females show very small perineal swellings or none at all. Even during the breeding season all stages of the follicular phase of cycles are highly variable. Completed menstrual cycles are relatively rare since talapoins are highly fertile; they may be somewhat shorter than fertile cycles. Cyclical activity is modifiable by social stimuli, and it is suggested that differences in synchrony of breeding between wild and captive populations might be due both to indequate climate cues and to a lower level of social stimulation in captivity. The concept of the menstrual cycle had limited value in predicting reproductive activity in this highly fertile seasonal breeder.

Animals↗
PubMed1975

Changes in social organization during the breeding season of wild talapoin monkeys.

Two adjacent troops of talapoin monkeys were studied near Mbalmayo, Cameroon, during a predicted 3-month breeding season. Mating continued for just over 2 months. One troop began to mate at least 2 weeks before the other, suggesting that, though climatic changes were probably important, precise timing was mediated through some intra-troop social facilitation effect. Before the breeding season, adult males and females lived in separate sub-groups. Males began to move into female sub-groups before there was any sign of the perineal swellings characteristic of receptive talapoin females. Copulation occurred only with females with medium or large swellings, except towards the end of the season. It is probable that the majority of females were monoestrous. At the height of the mating period, females joined mainly male sub-groups, leaving their infants with the mainly female groups which also included a few males. Copulations were observed in both these types of sub-groups. Consort behaviour was not observed, males frequently returning to all-male sub-groups immediately after ejaculation. Intersexual grooming was not characteristic of sexual interactions. At the end of the season, adults were seen more frequently in groups of their own sex or with juveniles only, and there was some indication that increased aggressiveness by newly pregnant females might be partly responsible for this separation.

Age Factors↗