Analysis of largest elephant surveys ever shows stable population, but disturbing trends
Analysis of largest elephant surveys ever shows stable population, but
disturbing trends
Jim Tan, Mongabay
April 9, 2024
See link
https://news.mongabay.com/2024/04/analysis-of-largest-elephant-surveys-ever-shows-stable-population-but-disturbing-trends/
for photos.
Ten years ago, says Mike Chase, the Kavango Zambezi Transfrontier
Conservation Area was one fluid contiguous elephant habitat. “An elephant
could be in Botswana in the morning, midday in Zimbabwe and in the evening
cross over into Zambia or Namibia,” Chase, founder of the conservation NGO
Elephants Without Borders, tells Mongabay. “It appears that that vision of
an interconnected landscape is now being compromised.”
The 520,000-square-kilometer (201,000-square-mile) area known as the KAZA
stretches across Angola, Botswana, Namibia, Zambia and Zimbabwe. It was
established in 2006 with a vision of the region’s megafauna roaming free,
unencumbered by the constraints of political borders.
More than half the world’s savanna elephants (Loxodonta africana) live in
this transfrontier area. Chase’s EWB, based in Botswana, has just published
an analysis comparing the two largest-ever aerial elephant surveys ever
completed: the Great Elephant Census, a pan-African survey led by Chase
spanning 18 countries and conducted in 2014 and 2015; and the 2022 KAZA
Elephant Survey commissioned by the KAZA Secretariat, covering the five
countries of the transfrontier conservation area with additional data from
a 2018 EWB survey in Botswana.
“It is critical to have up-to-date information on the size and status of
elephant populations to understand the status of the species,” says George
Wittemyer, a professor at Colorado State University who studies how human
and other factors influence the demographics and distribution of threatened
wildlife like elephants.
The surveys used stratified aerial counts over a portion of the elephants’
range with numbers found extrapolated to give an estimate of the total
elephant population. As well as counting live elephants, the surveys also
counted elephant carcasses; the ratio of live elephants to dead, known as
the carcass ratio, serves as an indicator of the overall population health.
The EWB analysis found that KAZA’s population of approximately 228,000
elephants has remained largely stable at the regional level since 2015. But
at a local level, the data reveal a less stable story.
The 2022 KAZA Elephant Survey confirmed that Botswana is still home to more
elephants than any other country, with an estimated 132,000 elephants. This
would represent a growth rate of 1.3% since 2015, closely matching the
average across KAZA. But the survey also found significant changes at the
local level.
Comparing numbers from its own 2018 survey of Botswana against the 2022
KAZA Elephant Survey, EWB found that elephant numbers had decreased by 25%
in areas open to hunting — and increased by 28% in areas where hunting
isn’t allowed.
Chase and EWB colleague Scott Schlossberg note that the size of the change
is not just elephants being killed but indicates elephants are moving out
of areas, potentially because they feel threatened. They also say there are
certainly more factors at play than just trophy hunting, potentially
including increased human wildlife conflict and retaliatory killings, and
that more research is needed to explain this shift.
No matter the causes, it raises questions over the sustainability of the
trophy-hunting industry.
“It’s a bit of a troubling pattern in that if you want to produce
trophy-quality animals, that’s really big older bulls, then you need to
have a sufficient population to do that,” Schlossberg says. “If the biggest
bulls in the area get killed, then new bulls need to come in to replace
them — you see the opposite happening.”
Elephants and hunting are politically hot topics in Botswana, especially in
an election year. Mokgweetsi Masisi, Botswana’s president, recently
threatened to send 20,000 elephants to Germany in response to a proposed
ban on importing hunting trophies, so that the German people could
experience what it was like to live alongside elephants.
“It’s very easy to sit in Berlin and have an opinion about our affairs in
Botswana,” Masisi told the German daily Bild. “We are paying the price for
preserving these animals for the world.”
A 2021 report by the Botswanan Department of Wildlife and National Parks
(DWNP) assessing the potential impact of trophy hunting on Botswana’s
elephants questioned survey figures produced by Chase in 2015 and 2018
(despite the 2018 survey being a collaborative effort with the DWNP). The
report instead focused on an estimate of 155,000 elephants from a 2006
survey and extrapolating a 6% annual growth rate figure for the country’s
elephant population.
The 2021 DWNP report expected the then-soon-to-be-completed 2022 KAZA
Elephant Survey would settle the debate. Instead, the 2022 survey’s figure
of 131,909 elephants is consistent with the 2015 Great Elephant Census
estimate of 130,451 and the 2018 survey figures, suggesting a stable rather
than growing population.
“The population growth rate is not as high as certain people made it out to
be. Instead of a 6% growth rate, it’s barely growing,” Chase says. “At the
local level we have huge influxes and massive exoduses — what are the
underlying causes of that?”
Botswana’s carcass ratio further highlights the inconsistencies. A carcass
ratio of more than 8% indicates that death rates may be exceeding birth
rates: within Chobe National Park and Moremi Game Reserve, both in
Botswana, and other areas used for non-hunting tourism in 2022, the carcass
ratio had remained at approximately 8%, while in other areas it had
increased to an average of 12%.
The DWNP investigated several of the carcasses and found no evidence of
poaching. However, between October 2023 and February 2024, EWB found 56
carcasses with the tusks removed — evidence of poaching — in one of the
areas surveyed.
“We can only surmise based on the carcass ratios which are very concerning
and above the 8% threshold, that elephants are being persecuted, but in the
absence of any research on the ground we don’t know,” Chase says. “So
that’s the call in this report — let’s make research more transparent, open
it up to better understand these landscape dynamics.”
Not Quite What It Seems
The EWB report also highlights a concerning change in the Angolan elephant
population. During Angola’s brutal civil war from 1975-2002, elephants were
among the casualties, with meat and ivory becoming valuable resources for
all sides. According to some reports, as many as a 100,000 elephants may
have been killed in the conflict.
After the war ended, there was good evidence of elephants repopulating
their former range, with elephant numbers observed in Angola’s Luiana
Partial Reserve increasing from 366 in January 2004 to 1,827 in November
2005, and satellite-collared elephants tracked moving from northern
Botswana into Angola.
At first glance, the Angolan elephant population appears to have increased
by 80% between the 2015 and 2022, but closer analysis suggests that all
isn’t quite as it seems, Chase says. The average herd size in Angola was
double that found in the rest of the KAZA area, resulting in large numbers
counted in a small area; when this figure is extrapolated across the range,
this leads to a larger estimate. Chase says the large herd sizes have
distorted survey numbers and may also be evidence of a persecuted
population, as elephants group together when threatened.
The EWB report also points out that elephant numbers have fallen by an
alarming 98% in the western part of the study area, with no clear
indication of how or why.
“The Angola story is really interesting — on the one hand we have had clear
evidence of elephants moving into Angola over the last decade of survey
efforts, on the other hand you have concerning high carcass ratios in that
country, though they have declined in the most recent survey,” Wittemyer
says. “Angola offers important elephant habitat that needs better
protection.”
“There’s a disturbance so severe that it’s killing elephants and driving
them out of Angola, especially along the Kavango and Cuito rivers,” Chase
says. “But in the absence of any research being done on the ground, the
reasons remain speculative.”
Accurate data to inform decisions is one of the core challenges for
conservationists looking to manage a landscape on the scale of the KAZA
area, which is larger than Spain.
“In KAZA, because the elephants are moving so much, if you just focus on
certain places, you could get a very misleading picture,” Schlossberg says.
“To make sure you understand what’s happening overall, you have to survey
the whole area at one time.”
The KAZA Transfrontier Conservation Area is the most significant elephant
population in the world by some way. The headline finding of a stable
population is certainly good news, but the finer details hint at the myriad
challenges the region’s elephants face, including poaching, human-wildlife
conflict, habitat loss, and, increasingly, drought and the impacts of
climate change.
More research will be needed to understand the how best to manage the many
different issues that the KAZA’s elephants face across the range — research
that Chase says is sorely lacking and in part for political reasons.
“This is still the best place in the world to come and see elephants moving
as they were 100 years ago across the Kalahari into the oasis of the
Okavango,” he says. “It is so rare, so fragile and so important that we
must do everything we can to ensure that future generations get to see
these wonderful animals in a habitat that is still open for them to move,
because nowhere else, I suspect, in Africa will you have this grand scale
of elephant conservation.”