J. Pete Schroeder1, DVM; Debbie A. Duffield2, PhD
The Wildlife and Conservation Management Committee (WCMC) of the American
Zoo and Aquarium Association (AZA) called for the formation of a Marine Mammal Taxon Advisory
Group (TAG) which would act in accordance with the missions of the World Conservation Union
(IUCN). The first TAG meeting was in September, 1991, with participation by representatives from
virtually every institution managing marine mammals in North America. It was immediately decided
to petition the WCMC for permission to create a bottlenose dolphin studbook. June, 1992, the WCMC
completed review and approved the petition for the formation of a North American regional studbook
for the Bottlenose Dolphin, Tursiops truncatus.
Demographic data, including; date of birth or acquisition, date of death or
removal, cause of death, place of birth, place of transfer, sex, and parent identification has
been obtained for all captive bottlenose dolphins in the region providing the basis for the
studbook. We have taken the conservative approach and consider all bottlenose dolphins as
Tursiops truncatus with no designation of subspecies. Seventeen collection areas are
designated to track individuals from specific stocks, ecotypes or variations. The primary goal of
the studbook is to maintain and distribute an accurate data base on Tursiops allowing the
captive population to be managed demographically and genetically. Additionally, other conservation
projects involving the species may benefit from the baseline biological data.
We have collected the data presented in the Tursiops Studbook from the
current and historical records of 33 individual institutions providing a species pedigree which
links animals through past generations to wild born ancestors (founders). All wild caught
bottlenose dolphins that have reproduced in captivity, captive births and still births are
included in the data base. Sequential numbers are issued to each dolphin based on its acquisition
or birth date.
The studbook's first edition includes data on 492 dolphins, including 113
first generation, 17 second generation and one third generation. The oldest dolphin is 44 years of
age; at 39 years she calved successfully.
Data is stored in a computer program (SPARKS) enabling genetic analysis of the
population. To eliminate inbreeding depression it is necessary to equalize founder representation,
maximize individual ancestry mixture, maximize hybridity, minimize rate of increase of inbreeding
and to select for genetically appropriate parents. Using the GENES program within the SPARKS
program, suggested mating pairs can be determined based on mean kinship values and inbreeding
Demographic parameters include age class in years, age-specific survival,
survivorship and fertility probabilities. Only when individuals survive and reproduce
sufficiently, can one consider genetic management of the population. The AZA and the IUCN
Resources' Captive Breeding Specialist Group (IUCN/CBSG) have a formal working relationship and
have as goals the use of captive propagation to assist in prevention of species extinctions and
promotion of species conservation in natural habitats.