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

Association of Zoos and Aquariums 63
Otter (Lutrinae) Care Manual
L. canadensis: Due to delayed implantation (also known as embryonic diapause), it is difficult to
determine when a female is near parturition; therefore, close attention should be paid to her behavior
changes, appetite, and physical appearance. These may include, but are not limited to: aggression
towards exhibit mates or keeper staff, refusal to leave holding or her den, increased or decreased
appetite, obvious teat development, slow movements, more frequent floating in the pool, and lethargy.
Parturition boxes should be at least 50.8cm long x 45.72cm wide x 38.1cm high (20" x 18" x 15"), be
large enough for an adult animal to move around in, and large enough to accommodate the pups. Slightly
smaller boxes with entrance foyers have been used successfully. This box type allows the female to be
secluded in a location near the pups but not actually with them. Females should be offered denning
choices for parturition and den choices of different sizes to allow for the growth of the pups.
Dimensions for a sample nest box are as follows: total width = 68.58cm (27in), chamber width =
48.26cm (19in), chamber depth = 45.72cm (18in), entrance foyer = 20.32cm (8in), entrance diameter =
16.5cm (6.5in), and 26.67-38cm (10.5-16in) high, with a 16.5cm (6.5in) height at the end of the ramp, and
a 36.83cm (14in) height at the entrance to the ramp. The top is hinged on one side for easy lifting and
cleaning. The ramp floor is made of wire mesh and the chamber floor should have drainage holes.
L. maculicollis: Spotted-necked females should be separated from exhibit mates prior to parturition at
roughly day 55 of a 60-63 day pregnancy (Schollhamer 1987), or when the female begins to show a
tendency to keep the male or other group members away from her denning area (R.Willison, personal
communication). Generally, females give birth to one pup, sometimes twins (Schollhamer 1987;
R.Willison, personal communication).
Secured sleeping dens (R.Willison, personal communication) or nest boxes that are 27" long x 20"
wide x 15" high (68.6cm x 51cm x 38cm) have been successful (Schollhamer 1987). Typically, females do
not use any nesting material, however, bedding should be offered to all females.
Females should be given rubber tubs in which to swim just prior to parturition (1-3 days), and for the
first two months or so of the pup’s life. The female will begin to bring the pup(s) out of the denning box
when it is roughly 3-4 weeks old; at this point, she should start teaching pups to swim by placing them in
the water tub for a few minutes at a time. It is important that the water level in tubs be kept high (which
allows pups to hang on the lip), or that tubs/pools have a slopping ingress and egress so pups can get out
of the water. While females are typically very vigilant, pups have suffered from hypothermia from being
left too long in the water (Schollhamer 1987).
P. brasiliensis: Giant otters (especially mothers) are susceptible to any human disturbance, especially
within the surroundings of the natal den, and to discomfort created by enclosure variables (see in Sykes-
Gatz 2005; 2.1 & 6.7; Sykes-Gatz & Gatz 2007). Several steps have been recommended to increase the
comfort of the reproductive pair and older siblings, and improve pup-rearing success (Sykes-Gatz 2005):
• Build a positive keeper-animal relationship and allow only familiar staff to work with the otters
after parturition
• The provision of food and clean water should be accomplished with minimal disturbance to the
otters during pup rearing.
• Cleaning should be minimal and not disruptive to the otters.
• Reduce stress as far as possible, including loud sounds, unfamiliar people, and the introduction
of anything new to the exhibit.
• Prohibit visitor and zoo staff (other than immediate caretakers) access to the enclosure area.
• Provide multiple nest box choices located in separate locations to allow parental choice according
to their comfort level.
• Provide appropriate substrate and exhibit conditions to include the recommended land/water
ratio, substrate depth, digging opportunities, and dry substrate conditions.
• Isolation of the natal den and limitation of all human activity in the vicinity at and prior to the birth
is very important.
• Monitoring of the natal den and early pup rearing should be done from a hidden location or
carried out via audio and video monitoring equipment with infrared capability.
Exhibits should be provided with multiple den sites; these can include both natural (e.g., dug by the
otters) and man-made dens. Dens are often 48-102ft 2 (4.5-9.5m 2 ) in size. Ideally, pupping boxes just
large enough to hold the adults, older siblings, and pups should be placed within the dens to allow the
parents choices and maximum privacy. Dens should be provided in locations where the animals are