SURVIVAL OF 5 SPECIES OF CAPTIVE MARINE MAMMALS

Survival in captivity was calculated for 1,707 bottlenose dolphins (ED ), 72 killer whales (KW), 73 white whales (WW), 3,090 California sea l ions (CSL), and 47 Steller sea lions (SSL) based on data in the Marine Mammal Inventory Report (MMIR) of the NMFS. Mean annual survival rate s (ASRs) between 1988 and 1992 were 0.951, 0.937, and 0.954 for ED, KW , and WW, respectively, and 0.952 and 0.969 for CSL and SSL, respectiv ely. These estimates represent significant increases in survival for b oth ED and CSL over the last 5 yr. Using all of the MMIR data (1940-19 92), the ASR of ED calves (< 1 yr of age) was significantly less than the ASR of non-calves (0.666 vs, 0.948, P < 0.001). Similarly, the ASR of CSL pups (< 1 yr of age) was significantly less than survival of n on-pups (0.858 vs. 0.962, P < 0.001). Survival of captive-born CSL was significantly higher than, those born in the wild (0.962 vs. 0.945, P = 0.003), but the difference was not significantly different for ED ( 0.948 vs. 0.944, P = 0.60). For non-calf ED and KW, captive animals su rvived at a slightly lower rate (ED 0.944 vs. 0.961, P = 0.07; KW 0.93 8 vs. 0.976, P < 0.001) than animals in the wild (ED: Wells and Scott 1990, KW: Olesiuk et al. 1990). Survival of captive non-pup SSL was sl ightly higher (0.968 vs. 0.930) than animals in the wild (York 1994, l ife-table analyses). Survival rates were significantly different among institutions for ED calves and non-calves, CSL pups and non-pups, and SSL non-pups.