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

Association of Zoos and Aquariums 59
Otter (Lutrinae) Care Manual
vocalizations associated with copulation in this species in zoos (R.Willison, personal communication) or in
the wild (Reed-Smith in prep.). The rate of conception is increased if the male breeds the female for the
entire 5-7 day cycle of a typical female; the conception rate is poor if the male only breeds the female for
2-3 days (Schollhamer 1987).
Gestation is roughly 60-63 days (R.Willison, personal communication). Ex-situ population births in
North America have occurred in January/February and April (R.Willison, personal communication). Births
in the wild were recorded during September, based on one year of observation in Tanzania (Proctor
1963); ongoing research in Tanzania substantiates this observation with breeding observed twice in June
(2006 and 2007), which would result in late August to mid-September births. However, work by Bateman
et al. (2009) and observations of half-grown animals throughout the year in Tanzania indicate that births
may occur anytime with a peak during August/September. Further research is required.
P. brasiliensis: Estrus generally occurs every three months, typically lasting 5-7 days with a range of 1-
11 days (Autuori & Deutsch 1977; Trebbau 1978; Hagenbeck & Wünnemann 1992; Wünnemann 1995b;
Marcato de Oliveira 1995; Corredor & Muñoz 2004; Sykes-Gatz 2005, 1999-2006). The pair will begin
exhibiting an increase in rough play and chasing behaviors a few days prior to breeding. These behaviors
continue throughout the estrus period (S.Sykes-Gatz, personal observation). Copulation generally takes
place in the water, but also may occur on land. The copulatory act is typically repeated several times a
day over the course of 5-7 days and may last from 30 seconds to 30 minutes or more (Hagenbeck &
Wünnemann 1992; V.Gatz, personal observation; S.Sykes-Gatz, personal observation).
There can be an estrus 5-7 days postpartum/post-loss of a litter that lasts for 3-5 days (Hagenbeck &
Wünnemann 1992; Wünnemann 1995b). Delayed implantation occurs in zoos (Flügger 1997; Corredor &
Muñoz 2004; Sykes-Gatz 2005, 1999-2006; V.Gatz, personal observation). Generally, this species
produces one litter annually in the wild. In zoos, false or pseudo pregnancies are not uncommon in this
species (Sykes-Gatz 2005). Gestation ranges from 64-71 days, and in one case a gestation of 77 days
occurred in a 9-year-old, although this was unusually long for this female (Autuori & Deutsch 1977;
Trebbau 1978; Hagenbeck & Wünnemann 1992; Wünnemann 1995a,b; Corredor & Muñoz 2004; Sykes-
Gatz 2005; V.Gatz, personal communication). Often the female’s mammary glands become enlarged 30
days prior to parturition and the vulva may become swollen about 14 days prior. In zoos and aquariums,
inter-birth intervals of 63 days, 74 days, and 94-103 days have been recorded in cases of pairs that lost
litters at birth (Hagenbeck & Wünnemann 1992; Wünnemann 1995b).
Sexual maturity is reached at roughly 2 years of age. Ex-situ population records show that at 2 years
and 5 months, females can come into their first estrus, mate, and bear a litter at the age of 2 years 7
months. Males can mate at 2.5 years of age, with their first litter born when they are 2 years and 8
months. Due to limited records, it is not known if this is the earliest age at which giant otters can become
sexually mature and bear litters. There is some indication that at least some giant otter females, from the
age of 10-11 years, may experience a slowing or end to their reproductive capabilities. Females of this
age may alternatively experience health problems or other difficulties during gestation and parturition.
Whether this is due to their advancing age or a high number of previous litters is unknown. An 18 years
and 9 month old male is the oldest successful sire on record (Sykes-Gatz 2005 & 1999-2006, V.Gatz,
personal communication).
The International Giant Otter Studbook Husbandry and Management Information and Guidelines
(Sykes-Gatz 2005) should be consulted for greater detail on management of this species, particularly
their requirement for isolation and pupping den specifications.
Separation of Sexes/Conspecifics: If it is necessary to separate animals for reasons associated with
reproduction (e.g., to promote or prevent it), a holding area connected to the exhibit is recommended;
ideally this should include a pool with clean water available at all times, proper lighting, a sleeping or den
box, enough floor space for grooming and drying areas, and at least one nest box that is heavily bedded
to allow excess moisture to be removed from the animals’ coats (Lombardi et al. 1998; Reed-Smith 2001).
Holding pens should have non-climbable sides. If chain-link barriers are present, the sides should be
covered with lexan or similar material to prevent animals from climbing too high and falling. See speciesspecific
recommendations below.
A. cinereus: Females become very aggressive prior to parturition and remain so post-parturition. It is not
necessary to separate them from the male or older siblings. It is necessary to provide multiple nest boxes.
The sire plays a very active role in rearing the pups and should not be removed prior to their birth. Male