Spotlight on Zoo Science
June 18, 2004
Artificial Insemination Produces Killer Whales
National Zoo scientist Steven Monfort and his colleagues have succeeded for the first time in producing live births of orcas following artificial insemination.
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Kasatka and Nakai (male, born September 1, 2001), the first marine mammal offspring ever born by artificial insemination. Photograph courtesy of Sea World Adventure Parks. |
A systematic program of research into the reproductive physiology of killer whales by a team of scientists from Sea World, the National Zoological Park, and the Zoological Society of San Diego has culminated in the first live births of cetaceans (whales and dolphins) by means of artificial insemination. Although killer whales, or orcas, are common throughout the oceans of the world, the captive population numbers only 48, mostly in small, genetically isolated groups.
The natural breeding of captive killer whales has led to 27 births since 1985, but it often requires moving these large animals between facilities. This landmark research will allow the sperm and ova of captive killer whales to be stored by a technique known as “genome resource banking,” or GRB. Used in conjunction with artificial insemination, GRB can reduce the need for moving these animals and help to maintain their genetic diversity.
The research team, which is headed by Todd Robeck of Sea World Texas, and includes Steven Monfort from the National Zoo's Conservation Research Center, studied one male and three female killer whales to evaluate their reproductive systems. The females were between 13 and 20 years old and weighed about 5,000 pounds, and the male was 20 years old and weighed more than 11,000 pounds. The researchers used noninvasive techniques to collect data on the orcas’ hormonal patterns, and ultrasound exams helped establish the time of ovulation. Semen collected from the male orca for use in the artificial insemination trials was frozen and later thawed, or was obtained as fresh samples.
Eight attempts at artificial insemination over the course of two years led to three pregnancies, one from thawed sperm and two from fresh sperm. One male calf and one female calf were born. The third pregnant female, who died of unrelated causes, was carrying a male fetus. Paternity tests confirmed that all three calves resulted from artificial insemination.
Note to Media: If you would like more information about this project, or any of the Zoo's conservation and science programs, please contact the Zoo's Office of Public Affairs.
