Elephants may be huge in size, but that’s not the only reason they are also a big priority at the Smithsonian’s National Zoo, which is a leader in elephant conservation and science. These majestic animals are an important part of the ecosystems in the wild and African elephants are a threatened species, while Asian elephants are endangered.
That’s why the National Zoo has a dedicated team of scientists working to understand the biology, reproductive physiology and genetics of these majestic animals, using the three elephants at the National Zoo—Ambika, Shanthi and Kandula—but also animals at other zoos and elephants in the field in their native homes.
What the Zoo’s researchers learn is applied to conservation efforts in elephant-range countries and to the captive management of elephants in zoos, which inspire the public to care about the future of these giants.
Through its Elephant Reproduction Project, the National Zoo’s endocrine lab was the first to determine how to accurately predict ovulation in female elephants by monitoring their hormones. This development was significant—successful insemination must take place during a two- or three-day window around the time of ovulation, when fertilization is most likely. Endocrine lab scientists measure steroid hormone metabolites excreted in urine and feces in order to document reproductive cycles and the timing of ovulation.
The Zoo has assisted in more than a dozen artificial inseminations at other zoos, several of which resulted in pregnancy. In 2000, scientists and veterinarians at the National Zoo performed an artificial insemination that resulted in the 2001 birth of the Zoo’s male elephant, Kandula. Analyzing hormone patterns also enables Zoo researchers to monitor pregnancies, predict births, and assess thyroid and adrenal gland function.
The endocrine lab at the National Zoo aims to use its research to enhance elephant conservation and captive management.
While taking blood from an elephant is relatively simple, the National Zoo also uses non-invasive techniques to answer questions about elephant disease, evolution and genealogy. This means collecting DNA from items that the animals leave behind—including feces (scat, dung), hair, saliva or shed skin—and makes it easier to collect samples in the field. The Zoo’s genetics lab has conducted systematic and phylogeographic analyses on Asian elephants to answer questions related to the genetic diversity of Asian elephants and the need to preserve them.
Geneticists at the Zoo recently successfully analyzed part of the complex gene family that helps determine how resistant elephants are to the type of infectious diseases that have been devastating to their species, including tuberculosis and the herpes virus. Researchers at the Smithsonian’s National Zoo, with collaborators, were the first in the world to “characterize,” or interpret and describe, these genes in elephants.
During this work, Zoo researchers also found that Asian and African elephants may have evolved genetically in response to a past disease epidemic.
Asian elephant habitat has declined by 70 percent during the past 30 years, and presently fewer than 40,000 Asian elephants remain in the wild. Habitat loss is the single most important factor in this species’ plight.
Scientists at the National Zoo’s Geographic Information Systems (GIS) lab are using satellite imagery and ground studies to quantify habitat loss in various locations in Asia. The lab is mapping extant habitats and tracking the movements of individual elephants to develop conservation and management strategies that are essential for the survival of wild populations.
By collaborating with NASA, the U.S. Fish and Wildlife Service, and the U.S. Geological Survey, Zoo scientists use vast amounts of remotely-collected satellite images that show the condition of large and inaccessible areas for Asian elephants, in addition to other species.
Posted April 2011