Gunfire no aphrodisiac for African elephants

From ANIMAL PEOPLE, October 2006:
Zimbabwe Conservation Task Force chair Johnny Rodrigues and
Presidential Elephant Conservation Project elephant fertility
researcher Sharon Pincott contend that the stress associated with
gunfire has actually suppressed elephant fecundity–a finding which,
if verified, would contradict other studies showing that wildlife
populations tend to increase their fecundity under hunting pressure.
Both coyotes and deer, for example, notoriously raise more
young successfully when hunting has thinned their populations,
making more food available to the survivors.
But different mechanisms are at work.
While coyotes are hunted year-round, intensive hunting
pressure on coyotes tends to be limited to the spring birthing season
for cattle and sheep, and the fall deer hunting season, when deer
hunters often shoot coyotes as well.

Deer hunting occurs almost entirely within a rifle season
typically lasting only 10 to 14 days. Far fewer hunters participate
in the bow hunting and other “special” seasons that precede and
follow the rifle season, when gunfire is most frequent.
Intensive shooting in the Zimbabwean elephant study area
continued for several years.
Pincott, an Australian, has studied the Presidential
Elephants “for more than five years,” Rodrigues e-mailed to ANIMAL
PEOPLE. The Presidential Elephants are “a clan of more than 400
free-roaming elephants, individually known in more than 20 family
groups, so named when President Robert Mugabe decreed them
‘protected’ in 1990, to be a symbol, it was then said, of
Zimbabwe’s commitment to responsible wildlife management.
“These habituated elephants can be found on the unfenced
Hwange Estate,” Rodrigues said, “bordering Hwange National Park.
“The home range of the Presidential Elephants was
underhandedly taken over by hunters, a situation now thankfully
rectified,” Pincott told Rodrigues. “The elephants did, however,
endure more than two years of unethical hunting.”
Said Rodrigues, “Elephant conception rates during this
period were negatively affected, with elephants coming into estrus up
to four times before they eventually conceived.”
Elaborated Pincott, “Female elephants only come into estrus
once every three months. Some elephants took another six and even
nine months to conceive after the first time I witnessed them in
estrus. Some elephants whom I witnessed in estrus and being mated
during late 2003 have only recently had their babies, some 31 months
later. They endured four sessions with the bulls before becoming
pregnant. This differs markedly from elephants whom I witnessed in
estrus during 2001 and 2002, before gunfire increased substantially,
who had their babies the usual 22 months later.
“Occasionally, at that time, elephants were sighted back in
estrus three months after an unsuccessful estrus, but this was not
the norm. Certainly there are no previous records of the fertile
elephants in this population taking up to nine months to conceive.”
Added Rodrigues, “Data collection continues now that the
gunfire is better under control, to confirm that conception rates
have improved.
“Elephant numbers in Zimbabwe have often been cited as having
a negative impact on the numbers of smaller species,” Rodrigues
noted, “which are said to be declining, despite scientific studies
in neighboring Botswana confirming that the numbers of smaller
species there continue to increase, despite their even larger
elephant population.
Concluded Rodrigues, “Gunfire continues, legally, inside
of Zimbabwe’s National Parks. Although supposedly limited, this
‘ration hunting’ gunfire has at times been reported to be out of
control. Some conservationists are now asking, ‘Is gunfire
negatively impacting conception of all wildlife?”
“It is difficult for me to believe that only elephants would
be negatively affected,” said Pincott.
The Pincott findings come amid continued debate in South
Africa over what to do about alleged elephant overpopulation in
Kruger National Park. Some park officials would like to cull the
elephants, as was done from 1967 to 1994, and seek Convention on
International Trade in Endangered Species permission to sell the
elephants’ tusk ivory.
Southern Africa Association for the Advancement of Science
president Ian Raper recommends dart-administered non-hormonal
contraception. “There are 5,326 female elephants in Kruger,” Raper
estimated for Agence France-Presse in 2005, “and it would cost only
1.4 million rand, $208,303 or 178,459 euros annually, to administer
the contraceptive, which would work for two years.”
“When people talk about threats to bio-diversity,” Raper
added, “it would be well to remember that old bull elephants topple
trees, not the females and calves who would be the targets of
culling.”
Relatively little has been done to research ways to control
bull elephant reproductive behavior, but Walt Disney’s Wild Animal
Kingdom and the San Diego Wild Animal Park in 2005 funded Colorado
State University veterinary surgery professor Dean Henderickson to
experimentally vasectomize several South African wild bull elephants
in mid-2005.
“Except on smaller reserves,” Henderickson told Denver Post
staff writer Katy Human, “the elephant herds are so big that going
in and vasectomizing some will not make enough of a difference fast
enough. We’re hoping that once the population has been brought down
to a reasonable number, we can help them prevent having to cull
again.”
Vasectomizing an elephant is no simple task, Henderickson
added. “The approach into the abdomen is very difficult because it’s
so hard to find landmarks. If you want to know what it’s like to
find a rib in an elephant,” he said, “walk up to a textured wall
and try to find a stud by looking.”