Elephant populations plummet by up to 90% in 50 years: study

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By Stephen Beech via SWNS

African elephant numbers have declined by up to 90% over the last 50 years, reveals new research.

Poaching and habitat loss have driven widespread dramatic declines in the iconic species – but some areas have seen “rapid” growth, say scientists.

It is difficult to measure exact numbers and monitor changes across the entire continent.

For the new study, published in the journal Proceedings of the National Academy of Sciences (PNAS), researchers analyzed 53 years of elephant population surveys.

The team compiled data from 475 sites in 37 countries, making it the most comprehensive assessment of African elephants to date.

They found “large-scale declines” in most populations of both species of African elephants.

From 1964 to 2016, forest elephant populations decreased on average by 90%, while savanna elephant populations fell by 70% on average. Combined, populations declined by 77% on average.

Declines were not uniform across the continent, with some populations disappearing completely while others showed rapid growth.

Colorado State University Professor George Wittemyer, one of the architects of the study and chair of the scientific board of Save the Elephants, says that identifying “success stories” where elephant populations are stable or increasing could help with their conservation.

Wittemyer said: “The context and the solutions at different sites can be quite different, but there are examples where people are effectively managing and protecting these populations.

“It helps to have a contextually relevant model for elephant conservation, and we’ve got that in a lot of different places.”

The study modeled site-level elephant density rather than numbers because the survey area was not constant over time for most survey sites.

A clear trend toward smaller populations emerged.

Wittemyer said: “This paper shows the scale of the declines and how widespread they are across the continent.

“It shines a light on how quickly even something as big and noticeable as elephants can just disappear.”

Savanna elephant surveys are done by spotters in planes, while forest elephants must be counted on foot.

Drones aren’t yet capable of the long flights over remote areas necessary for elephant surveys.

Wittemyer said: “We were really happy to bring all of that data together and leverage it, given the effort and care taken to collect it.”

He explained that as elephant populations declined, some protected spaces were condensed and survey borders changed.

To compensate for shrinking survey areas and gaps in data, the research team had to use places with good information to estimate population change for nearby places with less information.

They looked at site-based trends to get a picture of the overall distribution of trends.

Study co-author Charles Edwards, a research scientist with CEscape consultancy services, said: “The strength of our approach is that we were able to infer these trends, even in places where the data were extremely poor, in a way that allowed the results from each survey site to be compared.

“Understanding how and where trends are different across the range of a species is arguably more important for their conservation than an overall change in abundance, which may only reflect change in the largest populations.”

Dr. Wittemyer said: “It’s not a metric of the number of elephants left on the continent, it’s an assessment of how each population is doing, and they’re generally not doing great.”

The study examined how African elephants fared by species and region.

In the war-ravaged Sahel region of northern Africa, elephant populations have been decimated.

Eastern and central Africa generally saw declines due to ivory poaching as well as from human population growth and wilderness conversion crowding out elephants.

However, elephants are thriving in parts of southern Africa – particularly in Botswana- where populations have been protected and sustainably managed.

The research team said that the study’s comprehensive assessment of the status of African elephants is “fundamental” to management decisions such as knowing where to invest limited funding to best protect elephants.

Wittemyer added: “The overall story is one of decline, but we’re focusing on long-term stability of the species.

“I think we can do that in a bunch of places, but not all places.”

 

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