The effect of the male bush dog (Speothos venaticus) on the female reproductive cycle

In a 2-year study of the bush dog (Speothos venaticus), a small canid from Central and South America, we examined the reproductive physiology of mature females and the effect of male presence on the incidence and timing of ovulation. Fecal hormones, vulvar measurements, and mating behavior were used to characterize reproductive cycle dynamics. As described for all other canids, female bush dogs have an obligate pseudo-pregnancy after an infertile mating or ovulation without mating. However, the female cycle is not fixed to a single rigid breeding season each year, as in most canids. Unlike other canids, the presence of a male was associated with shortened interestrous intervals and increased number of estrous cycles. Examination of preliminary testosterone data from males showed a nonseasonal pattern suggesting that males have year-round, not seasonal, sperm production. The results from this study, including the validation of the noninvasive fecal hormone monitoring technique used, can provide managers of captive animals with tools for optimizing breeding potential of this species.