Assessing Bottlenose Dolphin Neonatal and Calf Health at the U.S. Navy Marine Mammal Program: 1978-2008
The U.S. Navy Marine Mammal Program (MMP) houses and cares for a population of bottlenose dolphins (Tursiops truncatus). In 1997, a formal breeding program was initiated to focus on the health care of pregnant and lactating dams, neonates (animals aged < 30 days), and calves (animals aged < 2 years). To assess the effectiveness of the breeding program on protecting neonatal and calf health over time, we determined neonatal mortality rates and 2-year calf survival rates for 1978-2008. During 1978-1997, 1998-2002, and 2003-2008, neonatal mortality rates were 30.1%, 25%, 12.5%, respectively; calf 2-year survival rates were 85.8%, 86.2%, and 91.5%, respectively. This study demonstrates that the MMP's breeding program has improved the health of its neonatal and calf dolphin populations, especially during the study period of 2003-2008. We believe this improvement was due to active efforts to address the following risk factors for neonatal survival: poor maternal health during the last trimester and especially at the time of parturition, failure to intervene during the first 24 hours when expected behavior and vital signs are not consistent with normals for the population, and not conducting a calf and mother "wellness exam" at 7-10 days post-parturition to identify sub-clinical health issues in the animals. Updated analyses are needed to assess similar improvements in other managed dolphin populations since 1990, and more data are needed from wild dolphin populations to enable proper comparisons with the MMP.
The authors wish to thank the management team and animal care staff at the U.S. Navy Marine Mammal Program (MMP) for their outstanding efforts in supporting and caring for animals in the MMP breeding program.