People working in the zoo
field have been very disappointed by the breeding rates
of elephants under their care. This is because captive
elephants are having babies at a rate that is only about
one fourth of that shown by their wild counterparts.
Not only is this disappointing, it is puzzling. Nearly
all other species respond to the good nutrition and lack
of predation in captivity by producing babies at a
higher rate than experienced in nature. But, so far,
this has not been true for elephants and we do not know
why.
Whatever the reason, it is now quite evident that with
this species it clearly takes more than simply bringing
a male and female together. Even when we optimize
temperature, humidity, access to water, environmental
enrichment, and the best nutrition that we know how to
provide, captive elephants do not reproduce like their
wild counterparts.
photo M. Noonan
And
this is a most urgent problem. Even in the best of
circumstances, elephants are very slow reproducers.
When they do get pregnant, they go through a gestation
period that is 22 months long, and then the baby nurses
from its mother for about two years after that. This
means that female elephants can usually have only one
baby every four years. This is probably the slowest
reproductive rate of any animal in nature.
Sadly,
the population of elephants now in captivity is
gradually getting older and older. One by one, most of
the female elephants held in zoos around the world are
passing out of their reproductive years without having
babies. And this means that the chances of preserving
the species through captive breeding programs is getting
smaller and smaller.
We
don’t know what it is about traditional zoo life that
has made simple reproduction so unsuccessful for this
species. However, it is hoped that by better simulating
natural conditions, the breeding success that these
wonderful creatures experience in the wild will finally
also be achieved in captivity. The thinking is that we
should start keeping elephants in much larger groups,
and in much larger spaces -- conditions that will allow
them to form the equivalent of large matriarchal family
groups similar to those seen in wild populations. This
is an idea that is gaining increasing support in the zoo
community.