A Review of the Releasability
of Long-Term Captive Orcas Survival rates in captivity
The limits of Lolita's world
The scientific literature is unambiguous on the subject of longevity and survival rates of killer whales both in the wild and in captivity. Based on 14 years of field work by American and Canadian researchers, Olesiuk, et al. (1990) conclude:
Females have a mean life expectancy of 50.2 years, typically give birth to their first viable calf at 14.9 years of age, produce an average of 5.35 viable calves over a 25.2 year reproductive lifespan and have a maximum longevity of about 80-90 years.
Males have a mean life expectancy of 29.2 years, typically attain sexual maturity at 15.0 years and physical maturity at 21.0 years of age, and have a maximum longevity of about 50-60 years.
This study is the only one of its kind, in which demographic data were collected from the field over a period of years and used to determine longevity estimates. There is no scientific dispute over the findings, and no alternative field studies present different estimates. The authors are Canadian Dept. of Fisheries officials, one of whom told me in November, 1995 that in the years since the publication of that study the subsequent statistics bear out the stated estimates almost exactly (G. Ellis, pers. comm.).
Based on a comparison of the estimates arrived at by Olesiuk, et al., with data derived from National Marine Fisheries Service records for captive orcas, Small and DeMaster (1995a) found that calf mortality of captive bottlenose dolphins and orcas was significantly higher than those in the wild, and that:
Survival of the wild population Olesiuk et al. studied, based on approximately 250 non-calves, was significantly higher than our estimates for non-calf captive killer whales.
In other words, mortality is significantly higher in captivity for all ages. Small and Demaster (1995b) also note that survival of killer whales in captivity has not improved recently:
...over the 5-year period between 1988 and 1992 compared with estimates based on data through 1987 [i.e., since 1965]...survival in captivity for killer whales...remained the same.
Further verification of these statistics can be found by comparison with the data from 22 years of continuous field studies of Lolita's extended family. In the Southern Resident community of currently 92 orcas in Washington waters, twelve of the more than forty adult females are estimated to be in their fifties, and five are in their sixties or older. There are 15 adult males, five of which are at least in their forties. Mortality is just over 2% per year.
At the four Sea World parks, however, just since 1987 thirteen young whales in the Sea World inventory of currently 20 orcas have died (ten since 1990). Not counting the newborn that died in 1994, the average age at death of the thirteen that died at Sea World since 1987 was under 17 years of age. The oldest was 25 at time of death. Three were males, ten were females. It is noteworthy that among the 300 individuals in the wild populations that have been studied only one female orca between the ages of 12 and 25 has died in 22 years of studies. The Sea World whales that died all died long before they would have reached their average life expectancy in the wild. Only one Sea World orca (Corky, age 32) has yet lived beyond its mid-twenties. Among the 50 orcas in captivity worldwide at the present time, only two are beyond their mid-twenties, Corky, at Sea World in San Diego and Lolita.
The captures began in earnest 36 years ago, so if survival had not been seriously reduced by captivity there would be many captive orcas over 30 years old. Sixteen orcas had been captured before 1969—none are alive. By 25 years ago 50 had been captured—only two of those survive, Corky and Lolita. By 20 years ago 65 orcas had been caught—only three of those are still alive, Corky, Lolita and Winnie, a female at Sea World in Ohio. Bacterial pneumonia is the most common cause of death for captive dolphins (Sweeney and Ridgway, 1975) and orcas (Greenwood & Taylor, 1985).
Thus, the claim that Lolita is just fine where she is, that she is healthy and happy, is not supported by the evidence. That is similar to saying that Nelson Mandela survived 27 years in prison and became the leader of his country, so we may assume that his South African jail must have been a healthy environment.
The only reasonable conclusion is that the conditions of captivity, even in the best of circumstances, leads to early death for orcas. From this insight one can further conclude that for Lolita, neither a move to another park nor to a new tank built on the Seaquarium site would appreciably lengthen her life.
Increasing public awareness that the killer whales who are confined to tanks tend to die in their youth is contributing to the public's perception that captives are neither healthy nor happy. As accurate information about survival rates in captivity becomes widely known, the experience of attending marine parks is increasingly seen as condoning the mistreatment of whales and dolphins. This evolution of public opinion has begun to redefine killer whale shows as an unpleasant experience, which has in turn reduced attendance at marine parks and thus revenues at the gate. The morale of many of the thousands of marine park employees could also be affected if they were to discover the factual longevity statistics. Many marine park employees have themselves been led to believe that the whales that have died under their care were approaching their maximum life span, and that they would have had a much more difficult life, and probably would have died even sooner, in their natural habitats (Busch Entertainment Corporation 1993).
There is no significant risk involved in Lolita's transport and phased reintroduction to her native waters, whereas her early demise is statistically inevitable if she remains in the Seaquarium facility or in any captive setting. Returning her to the waters in which she was born is the only course of action that allows her a chance of enjoying normal longevity. Home Contents Summary