Abstract:
Steroid hormones play an important role in
female reproductive physiology and behaviour and are
often used to monitor important female reproductive events.
However, such studies are often attempted on captive populations
alone, delivering limited data. One such example
is the African lesser bushbaby, Galago moholi, for which
contradicting observational data exist between captive and
free-ranging populations, while hormonal analyses have
only been obtained from a single captive population. To
extend and rectify the limited information, we monitored
faecal progestagen and oestrogen metabolite levels across
various important life history stages of both captive and
free-ranging G. moholi. We additionally recorded changes
in vaginal state as well as the occurrence of reproductive
and aggressive behaviour throughout the study. Data from
our captive population revealed an ovarian cycle length of
33.44 ± 0.59 days (mean ± SD), with follicular and luteal
phases of 14.2 ± 1.0 and 19.1 ± 1.5 days, respectively,
and an average pregnancy length of 128 ± 3.3 days. The initiation of female reproductive activity was closely linked
to an oestrus-related increase in faecal oestrogen metabolite
levels. Four of the seven captive females monitored in
our study conceived during the May mating period, with
one additional female fertilised in September, supporting
the idea that the September mating period functions as a
back-up for female G. moholi. Identified benchmark faecal
progestagen metabolite levels (non-pregnant: >1 μg/g dry
weight (DW), pregnant: >9 μg/g DW) should help researchers
to determine pregnancy status of randomly wild-caught
females in even a cross-sectional study setup.
