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

Association of Zoos and Aquariums 60
Otter (Lutrinae) Care Manual
behaviors include nest building, carrying pups, and bringing food to the pups during weaning. Access to
pools and water sources should be strictly monitored to prevent newborns from drowning.
A. capensis: Pregnant females should be offered nest box choices and separated from the male to give
birth (R.Meyerson, unpublished data). To date, records indicate two institutions have successfully bred
this species in North America. One facility had one male with two females; both females bred and
produced offspring. The other facility housed a pair. The animals were housed together 24 hours a day;
females were separated to give birth at both facilities (Reed-Smith & Polechla 2002; R.Meyerson,
personal communication). The male can be reintroduced to the female and pups when they are swimming
well.
L. canadensis: There seems to be a mate preference for breeding, with some females showing a definite
preference for particular male and lack of interest in others when they have a choice. Some successful
zoos separate pairs for several months prior to the breeding season, introducing them every few days
once the female’s estrus begins. Others offer multiple mate selections to the females, and others have
been successful keeping single pairs together year around. An extensive ex-situ population study
(N=13.14 animals) attempted to determine breeding associated behaviors in zoos and aquariums across
the species over two years. The study’s behavioral results show an increase in pair association, mutual
grooming, and extended copulation in those pairs that reproduced successfully (N=3), but was
inconclusive otherwise (J.Reed-Smith, data in preparation).
In the wild, males do not participate in pup rearing (Melquist & Hornocker 1983; Rock et al. 1994). In
zoos and aquariums, parturient females should be given privacy (particularly for primiparous females) and
nest box choices supplied with plenty of dry bedding (all females). Males have been successfully left in
the exhibit with parturient females in large exhibits that provide numerous visual barriers and allow the
male to stay out of the female’s sight. In all other cases, the male and female should be separated prior to
the birth to prevent injury to the male or neglect of the pups by the female. In multi-female groups, other
females may also need to be separated from the parturient female. When separated, the male or non
parturient female should not be required to pass the parturient female’s den to enter the exhibit; if this
cannot be done, the other animals should be removed entirely from the exhibit or the female sequestered
away until she deems it time for the pups to meet the male (see below). Males can be reintroduced to the
female and pups once they are swimming proficiently, as early as 60-75 days or more typically by 80 to
90 days (Reed-Smith 2001).
Actual gestation is calculated at roughly 68-73 days (Bateman et al. 2009.); pair separation should
occur either when the female becomes aggressive towards the male or roughly 10-14 days prior to
anticipated parturition date. Due to this species’ delayed implantation and total gestation time of >10
months, it is often difficult to anticipate delivery date, particularly for primiparous females. In these cases,
staff should base their management decisions on the female’s behavior. If she becomes aggressive to the
male or other exhibit mates, begins to show excessive nesting behavior, or spends increasing amounts of
time in her nest box, the pair should be separated. It is important to remember that the female should be
monitored for health issues during this time, as these behaviors also can be signs of illness.
Management change should be scheduled so that they do not interfere with the birth and rearing of
the pups. Any modifications to the exhibit should be finished several months prior to possible pupping
season. Denning/nest box choices should be introduced at least one month prior to possible pupping
season. Changes in management routines, e.g., closing the female in holding at night, closing her in
holding alone, etc. should be introduced to the female at least a month prior to the possible parturition
period to allow her time to become comfortable with the new routine. If the male will have to be removed
from the exhibit entirely, this should be done several weeks prior to possible parturition to allow the
female a period of adjustment.
Generally, the best way to handle pair separation is setting up the female in off-exhibit holding
(providing there is adequate space). Once the pups are old enough to begin swimming lessons (some
females begin this instruction as early as 30 days, more typically at 40-50 days), the family group and the
male can be alternated on exhibit. When the pups are swimming well, after about three months, the male
can be introduced to the family group. This should be handled, as with any introduction, via olfactory,
visual, and then physical introduction to the female alone first, and under controlled circumstances as far
as possible (see Introduction/Reintroduction).