Learning from nature: bottlenose dolphin care and husbandry

Abstract

The world's longest-running study of a wild dolphin population, operated by the Chicago Zoological Society since 1989, has focused on the multi-generational resident community of about 160 bottlenose dolphins in Sarasota Bay, Florida, since 1970. Observational and capture-release research on the biology, behavior, life history, ecology, and health of individually identifiable bay residents of up to 59 years of age and spanning five generations has helped to inform collection managers at the Brookfield Zoo and partner institutions. Age, sex, and genetic compositions of colonies at cooperating institutions have been based on observations of social structure and genetic paternity testing in Sarasota Bay to optimize breeding success. Breeding success, including calf survivorship, is evaluated relative to individual wild dolphin reproductive histories, spanning as many as nine calves and four decades. Individual rearing patterns for wild dolphins provide guidance for determining how long to keep mothers and calves together, and help to define the next steps in the calves' social development. Health assessments provide data on expected ranges of blood, milk and urine values, morphometrics, and body condition relative to age, sex, and reproductive condition. Calf growth can be compared with wild values. Target weights and blubber thicknesses for specific age and sex classes in specified water temperatures are available for wild dolphins, and caloric intakes can be adjusted accordingly to meet the targets. A strength of the program is the ability to monitor individuals throughout their lives, and to be able to define individual ranges of variability through ontogenetic stages.

Lacaziosis and lacaziosis-like prevalence among wild, common bottlenose dolphins Tursiops truncatus from the west coast of Florida, USA

“…1). The Sarasota Bay dolphin community, which has been monitored and studied since 1970, is a demographically closed population comprised of approximately 160 individuals, the majority of which have known ages, sex, and familial lineages (Wells 2009). Routine photo-ID surveys began in Sarasota in 1980 (Wells 1991(Wells , 2003, and capture-release projects have been conducted since 1970 therefore providing a long-term record of life history parameters, body condition, and health indicators for dolphins in this population (Wells et al 2004).…”

“…1). Anthropogenic contaminants have been suspected to be associated with lacaziosis occurrence (Van Bressem et al 2007, 2009, 2009; however, chemical contamination may not be explaining the observed differences in LD/LLD bottlenose dolphins on the east and west coasts of Florida as contaminant studies found no significant differences in polychlorinated biphenyls (PCBs), polyfluoralkyls (PFAs) (Houde et al 2005(Houde et al , 2006 or mercury (Bryan et al 2007, Stavros et al 2007) between the 2 populations.…”

“…Some authors have suggested that environmental parameters such as salinity and water temperature could affect the prevalence of LD/LLD in dolphin populations (Van Bressem et al 2007, 2009 Sherblom et al 1995), respectively. In contrast to the IRL, 3 major rivers supply freshwater input to Charlotte Harbor, resulting in a density-dependent, vertically stratified harbor with extreme hypoxic episodes at times (Pierce et al 2004).…”

“…Some authors have suggested that environmental parameters such as salinity and water temperature could affect the prevalence of LD/LLD in dolphin populations (Van Bressem et al 2007, 2009). The IRL, Sarasota Bay, and Charlotte Harbor are close in proximity; however, environmental factors such as salinity and freshwater influx are varied.…”

“…1). Anthropogenic contaminants have been suspected to be associated with lacaziosis occurrence (Van Bressem et al 2007, 2009, 2009; however, chemical contamination may not be explaining the observed differences in LD/LLD bottlenose dolphins on the east and west coasts of Florida as contaminant studies found no significant differences in polychlorinated biphenyls (PCBs), polyfluoralkyls (PFAs) (Houde et al 2005(Houde et al , 2006 or mercury (Bryan et al 2007, Stavros et al 2007) between the 2 populations.Some authors have suggested that environmental parameters such as salinity and water temperature could affect the prevalence of LD/LLD in dolphin populations (Van Bressem et al 2007, 2009 Sherblom et al 1995), respectively. In contrast to the IRL, 3 major rivers supply freshwater input to Charlotte Harbor, resulting in a density-dependent, vertically stratified harbor with extreme hypoxic episodes at times (Pierce et al 2004).…”