Otter (Lutrinae) Care Manual - Association of Zoos and Aquariums

Association of Zoos and Aquariums 53
Otter (Lutrinae) Care Manual
Chapter 7. Reproduction
7.1 Reproductive Physiology and Behavior
It is important to have a comprehensive understanding of the reproductive physiology and behaviors
of the otters in our care. This knowledge facilitates all aspects of reproduction, artificial insemination,
birthing, rearing, and even contraception efforts that AZA-accredited zoos and aquariums strive to
achieve.
A. cinereus: These otters are non-seasonal and thought possibly to be spontaneous ovulators (Bateman
et al. 2009). The estrous cycle lasts 30-37 days, with breeding occurring year round. Some facilities
report this cycle extending to every few months with older animals. Estrus lasts from 1-13 days.
Behavioral signs of the onset of estrus may include increased rubbing and marking. Sexual behavior has
been observed in pups as young as 6 months, with breeding behavior having been noted in animals
(males and females) as young as 1½ years. Successful breeding has been reported for 2.1-year-old
females and 2.8-year-old males. There do not appear to be any significant environmental cues that are
involved with the onset of estrus. Breeding pairs have been introduced at various ages and have been
together for varying lengths of time before successful breeding occurs. It has been reported that pups
from previous litters have interfered with copulation, but their presence had no bearing in any other way
(Lombardi et al. 1998).
Recent work has shed light on litter intervals; Bateman et al. (2009) report: “In one female having
three consecutive pregnancies during [their] study, the interval between the first parturition and
subsequent progesterone increases owing to the next pregnancy was 169.25±11.15 days. This female
was observed nursing her pups from the first pregnancy for the first 122 days of this intergestational time
period.”
Breeding pairs need to establish a bond for successful reproduction. The male pursues the female in
courtship and most breeding occurs in shallow water. A single copulation can last from 5-25 minutes.
Courtship behavior has been recorded from 1-3 days, at one-month intervals. Gestation is roughly 60-74
days (67-77 range, average 71.17±1.49 days reported by Bateman et al. 2009).
Pseudopregnancies do occur in this species, including in females housed in single sex groups (5 of 6
females housed together exhibited pseudopregnancy) (Bateman et al. 2009). Bateman et al. (2009)
report: “…a mean duration of pseudopregnancy of 72.45±1.37 days (range: 62–84 days). The average
interval length between sequential pseudopregnancies and/or pregnancies was 39.86±3.86 days (range:
17–92 days) in paired females and 134.50±48.94 days (range: 62–279 days) in the single gender group.”
The sire plays a very active role in rearing the pups and should not be removed prior to their birth.
Male behaviors include nest building, carrying pups, and bringing food to the pups during weaning.