KILLER WHALE (ORCINUS-ORCA) REPRODUCTION AT SEA-WORLD

Sea World has maintained killer whales (Orcinus orca) since 1965. The total killer whale inventory (1965-1993) has included 39 whales (25 fe males, 14 males); 28 were wild-caught and 11 captive-born, including o ne second-generation calf. As of September, 1993, there were 19 whales in the breeding program. Ten of these whales (53%) were captive-born, either at Sea World or other facilities in North America. The live wi ld-caught whales ranged in estimated age from 12-27 years ((x) over ba r +/- sd = 17.6 +/- 4.2 years). The captive-born whales ranged in age from <1 to 8 years. In the Sea World breeding program (through Septemb er, 1993), there have been nine live births and one stillbirth, with e ight calves part of the current inventory. Births occurred from July t o February. Calving intervals ranged from 32-58 months. Female age at birth of first calves ranged from 8 years to an estimated 17 years ((x ) over bar +/- sd = 12.7 +/- 3.0 years). Gestation, based on conceptio n estimates from serum progesterone analysis, averaged 17 months ((x) over bar +/- sd = 517 +/- 20 days), but successful pregnancies with vi able calves occurred from 15-18 months (468-539 days). Females, in the presence and absence of males, were polyestrus with periods of cyclin g interspersed with individually variable noncycling (presumed anestro us) periods ranging from 3-16 months. Mean serum progesterone levels ( +/-se) were as follows: noncycling periods = 121 +/- 20 pg/ml; peak el evations during nonconceptive ovulatory (estrous) cycles = 3,962 +/- 2 ,280 pg/ml; first pregnancies = 14,592 +/- 3,854 pg/ml; second pregnan cies = 8,389 +/- 395 pg/ml; and third pregnancy = 8,180 +/- 4,556. (C) 1995 Wiley-Liss, Inc.