International Giant Otter Studbook Husbandry and Management
International Giant Otter Studbook Husbandry and Management
International Giant Otter Studbook Husbandry and Management
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of course, because information regarding these issues is so limited, specific conclusions can not<br />
be drawn. Males have been able to breed successfully at 14 years of age. This occurred with at<br />
least two males in two institutions (Brasilia Zoo & Hagenbecks Tierpark). It is crucial that<br />
research be continued on these matters <strong>and</strong> that zoos record in detail <strong>and</strong> openly share their<br />
reproduction information. (See the earliest age of breeding <strong>and</strong> reproduction below.)<br />
At Hagenbeck “The number of cubs per litter varied from 1 to 6. Most of the litters consisted of<br />
2 - 4 cubs. There were 2 litters with 5 cubs <strong>and</strong> 1 litter with 6 cubs.” (Wünnemann 1995 b ). At<br />
Brasilia Zoo, 5 cubs in one litter all survived (i.e. to one year of age or older).<br />
A historical survey on litter births in zoos world-wide revealed that litter size (n=31-where the<br />
litter size was known) ranged from 1 to 6 cubs, with a mean of 2.9 <strong>and</strong> common litter size of 2<br />
cubs (Sykes-Gatz 2001, Sykes-Gatz 1998/2002). See cub rearing success under Chapter 1.<br />
Cub Development in Captivity<br />
Information on physical <strong>and</strong> behavioral cub development is limited because parents<br />
rearing cubs must not be disturbed by humans except for when it is necessary to ensure<br />
the survival of the otters (i.e. during emergencies, vaccinations, or necessary medical care).<br />
Information on parental care, cub development <strong>and</strong> behavior has been gathered by monitoring<br />
otters with videocameras <strong>and</strong> microphones or from hidden viewing areas. See Chapter 2<br />
Section 10B for these monitoring methods. Following are the most thoroughly documented <strong>and</strong><br />
available records of cub development at this time.<br />
Nursing in Very Young Cubs:<br />
At Dortmund Zoo very young giant otter cubs, being reared by their parents from birth to at<br />
least 7 days old when the last cub was pulled for h<strong>and</strong>rearing, nursed frequently during each<br />
hour of the day (Sykes-Gatz, pers. obs. 2002). (The last cub was h<strong>and</strong>reared from 7 days old to<br />
11 days old when it died because of a malfunctioning thyroid gl<strong>and</strong>. This cub although<br />
appeared to be at a healthy weight (but it was significantly injured) when it was pulled for<br />
h<strong>and</strong>rearing <strong>and</strong> its hunger seemed to be satisfied when it was with its parents. See Chapter 1<br />
Sections 2 & 4 for more information on malfunctioning thyroids.) It was much easier to<br />
determine when cubs were actually nursing with auditory monitoring (in connection with the<br />
video monitoring), because they made from the first day of birth, “nursing hums” when they<br />
were suckling. This hum is a somewhat higher pitched <strong>and</strong> faster vocalization than the contact<br />
hum (described in Duplaix 1980). It is also unlike the contact hum in that it has a twittering<br />
quality to it <strong>and</strong> it was only performed when the cub was actually suckling. It was performed<br />
both when the cub was nursing from the mother <strong>and</strong> the h<strong>and</strong>rearer’s bottle. (When replicated<br />
by the h<strong>and</strong>rearer, it can encourage cubs to feed.) The cubs also displayed “tail wagging” when<br />
they nursed (from the first day of birth) from the mother <strong>and</strong> nursed from the h<strong>and</strong>rearer’s<br />
bottle. The cubs wagged their tails, rather quickly <strong>and</strong> repeatedly, from side to side (i.e.<br />
horizontally, but not vertically/up <strong>and</strong> down), when they suckled. The tip of the tail can also be<br />
kept raised upwards while wagging. (Note: sometimes when the cub might be anxious to nurse<br />
or immediately preparing for nursing it might wag its tail.) This behavior is different from the<br />
“tail waving” that is described by Duplaix (1980) in that it is performed during nursing only<br />
(except during the situations mentioned above) from the first day of birth <strong>and</strong> the tail only<br />
moves horizontally in direction. The “nursing hums” <strong>and</strong> “tail wagging” behaviors are not<br />
known to have been described before in literature <strong>and</strong> the descriptions <strong>and</strong> terms in quotes are<br />
originally made by Sykes-Gatz (pers. obs., unpublished reports 1999-2002).<br />
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