Gestation is about 14 to 15 months (Nowak, 1991; Leatherwood and Reeves, 1983).
B. Birth seasons.
Calves are born March through September, depending on the region. Most are born May through July (Haley, 1978).
C. Frequency of birth.
A female may give birth to a single calf every two to three years (Katona, Rough, and Richardson, 1983). Twins are rare (Haley, 1978).
1. Calves are born in bays and estuaries, where the water is relatively warm: about 10-to 15-C (50-60-F) (Katona, Rough, and Richardson, 1983).
2. Deliveries can either be tail-first or head-first. The umbilical cord snaps during or soon after delivery.
E. Calf at birth.
1. Observers of wild beluga populations have estimated that beluga calves average 1.6 m (5.2 ft.) and weigh about 80 kg (176.4 lb.) (Nowak, 1991). As of February 1995 three beluga whale calves have been born and successfully raised at Sea World parks. The average size of Sea World-born beluga calves is 1.5 m (5 ft.) and 54 to 64 kg (119-140 lb.).
2. At birth beluga calves are generally dark gray to bluish or brownish gray, becoming darker at about one month (Nowak, 1991).
3. Like other whales, beluga calves swim at birth.
F. Care of the young.
a. Like other mammals, a mother beluga whale nurses her calf. A calf suckles below the water from nipples concealed in abdominal mammary slits.
b. The calf may begin nursing several hours after birth and then nurses at hourly intervals thereafter (MacDonald, 1993).
c. According to research in zoological parks, the composition of beluga milk varies widely among individuals and fluctuates throughout the nursing period. Beluga milk may average 28% milkfat, 11% protein, 60.25% water, and less than 1% ash (SWT). The milk contains approximately 92 calories per ounce.
d. Beluga calves are dependent upon nursing for the first year, until their teeth emerge (Katona, Rough, and Richardson, 1983). They then supplement their diets with shrimps and small fishes (Haley, 1978). Most calves may nurse for 20 to 24 months (Nowak, 1991). Some have been documented to nurse as long as two years (Katona, Rough, and Richardson, 1983).
2. Mothers with calves often form pods separate from males (Haley, 1978).
3. While most maternal behavior is probably instinctive, first-time mothers are inexperienced at nursing their calves. At Sea World, the experience level of some first-time pregnant females is increased through training procedures that teach them to respond to nursing behavior.
G. Calf development.
Young belugas learn survival behaviors by observing and mimicking adults in their pod (Ridgway and Harrison, 1981).
Communication and Echolocation
SeaWorld/Busch Gardens Animal Information Database
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