Effect of the interintromission interval on lordotic response and attack latency in golden hamsters (Mesocricetus auratus).

Abstract

After 12-15 ejaculatory series, each consisting of several short intromissions (2- to 3-s vaginal penetration) and an ejaculation, male golden hamsters adopt an altered copulatory pattern consisting of long intromissions (5- to 25-s penetration with intravaginal thrusting). Receptivity declines and the tendency for the female to attack the male increases at about the time of this shift in copulatory pattern. Because the mean interintromission interval (III) between short intromissions is about 8 s compared to 100 s between long intromissions, it is possible that females detect this difference and adjust their mating accordingly. When the III between short intromissions from a rested male was experimentally increased to 100 s by use of a halter and lead device, the duration of lordosis was significantly less than that displayed by females paired with control males (8-s III) and virtually the same as that displayed by females paired with males that produced only long intromissions. This suggests that the female uses the temporal patterning of intravaginal stimulation as one criterion for terminating mating with a particular male.

Sperm competition and diversity in rodent copulatory behaviour

“…Such opposing selection pressures could explain why males of many rodents such as Mesocricetus and Peromyscus species switch from a copulatory pattern involving rapid multiple ejaculations to one of slower multiple intromissions with prolonged inter‐intromission intervals once the ejaculatory series are complete (e.g. Dewsbury, 1974; Huck et al. , 1988).…”

Effects of paced mating and intromissive stimulation on feminine sexual behavior and estrus termination in the cycling rat.

“…Sensitivity to the timing of sexual stimulation during mating has been reported in golden hamsters, a species in which intromissions separated by long intervals signal the end of mating. In that species, artificial prolongation of the inter–intromission interval early in a mating session by separating the male and female for controlled periods decreases the likelihood of lordosis and increases the likelihood of aggressive behavior by females (Huck, Lisk, & Parente, 1988). Preliminary work by Erskine (1989, Figure 2) suggests that copulatory stimulation accumulated within a mating session by the female rat may exert similar effects on female behavior insofar as the intervals between consecutive intromissions increase when females are mated under paced conditions.…”