|
 |
Elephant Science |
5 |
 |
Elephant Program |
Elephant Herd |
Elephant Exhibit |
Elephant Care
Elephant Science |
Elephant Experts |
Rose-Tu
Elephant Babies |
Asian Elephants |
National Elephant Center
Gestation Period for Female Asian Elephants
The Oregon Zoo’s most famous elephant, Packy, was born in 1962 –– the first successful elephant birth in the Western Hemisphere in nearly 44 years. His birth provided the zoo with a unique opportunity to gain important knowledge about elephant pregnancy and birth.
At the time, the pregnancy of Packy’s mother Belle was a huge milestone for zoos. By observing Belle, Oregon Zoo staff was able to calculate the length of her gestation. For three months, the zoo’s veterinarian, Dr. Matthew Maberry, literally lived in the elephant house, keeping a close watch on Belle. After Packy’s birth, 14 more elephants were born in zoos over the next dozen years — all of them at the Oregon Zoo. The zoo learned a lot about new calf development and maternal care, as well as determining the actual length of gestation (22 months). This important information was shared with other zoos, which began producing elephant calves from 1975 onward.
Zoo staff now had a better idea of what to expect and could better monitor their pregnant elephants, giving zoos the confidence and ability to improve their breeding programs.
CURRENT STUDIES
Characterization of Female Asian Elephant Estrous Cycles
Oregon Zoo research associates and veterinarians are collaborating with researchers at the Smithsonian National Zoological Park on a study that will characterize female Asian elephant estrous cycles over long periods of time. Long-term studies allow researchers to evaluate questions about estrous-cycle characteristics that cannot be answered with short-term research. Prior to this study, no long-term analyses (i.e., more than five years) of estrous profiles had been conducted. This dataset represents the most comprehensive analysis of within- and between-animal variability in estrous profiles to date. Over the past 18 years, the Oregon Zoo has measured hormone (progestagen) activity in nine elephants. This number of animals provides a very rich longitudinal dataset that comprises more than 120 estrous cycles encompassing birth, puberty, senescence and death. Currently, researchers are investigating the impact of significant events, such as births and deaths in the elephant herd, on estrous-cycle variation. In zoos, characterizing estrous cycles allows managers to predict ovulation in order to facilitate male-female socialization of zoo elephants while avoiding unwanted pregnancies and to schedule natural breeding. It is commonly known that some social mammals show synchronization of estrous cycles in large groups, and there is preliminary evidence of this phenomenon in the Oregon Zoo herd.
|
