Lr. Meek et Tm. Lee, FEMALE MEADOW VOLES HAVE A PREFERRED MATING PATTERN PREDICTED BY PHOTOPERIOD, WHICH INFLUENCES FERTILITY, Physiology & behavior, 54(6), 1993, pp. 1201-1210
In a previous study, Meek and Lee (26) found that female meadow voles
mated within three distinct time periods after pairing with a male, an
d fertility was influenced by the time of mating and photoperiod. In t
he present studies, we tested the hypothesis that different patterns o
f mating would correlate with high and low fertility. We found two ver
y different patterns of mating were correlated with high fertility. Fe
males housed in long daylengths (long day; 14 h light/day) and mating
within 48 h of pairing with a male, received few mounts, intromissions
, and intromissions per ejaculatory series, with very short interintro
mission intervals. All long-day females utilizing this mating pattern
ovulated, and 86-100% produced litters. We suggest this pattern of mat
ing is associated with spontaneous estrus. In contrast to long-day fem
ales mating within 48 h, females housed in short daylengths (short day
; 10 h light/day) and mating between 14-48 h after pairing with a male
, received significantly more short mounts and intromissions, with lon
ger interintromission intervals. These short day females all ovulated
and 86% produced litters. We suggest that this pattern of mating is as
sociated with an induced estrus. Short-day females that did not exhibi
t this pattern of mating (66%) produced far fewer litters. We discuss
two mechanisms by which fertility may be inhibited in most short-day f
emales.