From 1964 to 2016, populations of forest elephants dropped by an average of 90%, while savanna elephants saw a 70% decrease. Together, this equates to an average population decline of 77%. Data was gathered from 475 sites across 37 African countries, marking this as the most extensive survey of its kind.
The declines varied by region, with some populations disappearing entirely and others experiencing growth. George Wittemyer, a Colorado State University professor and scientific board chair of Save the Elephants, emphasized that recognizing areas where elephant populations are stable or increasing is vital for shaping conservation strategies.
"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," Wittemyer stated. "It helps to have a contextually relevant model for elephant conservation, and we've got that in a lot of different places."
Published in the *Proceedings of the National Academy of Sciences*, the study assessed elephant density at specific sites due to variations in survey area size over time. The findings underscored a trend of decreasing population sizes.
"This paper shows the scale of the declines and how widespread they are across the continent," said Wittemyer. "It shines a light on how quickly even something as big and noticeable as elephants can just disappear."
Counting Challenges
Although elephants are large and visible, counting them accurately is complex and resource-heavy. Savanna elephant counts often involve aerial surveys, while forest elephants are counted on foot. Drones have not yet proven practical for the long-distance flights required over remote regions, and analyzing drone images remains labor-intensive.
Given Africa's size - more than three times that of the United States - and varying wildlife management practices across nations, survey regularity differs significantly. The compilation of existing data relied on strategic logistical planning and resources.
"We were really happy to bring all of that data together and leverage it, given the effort and care taken to collect it," Wittemyer said.
The study accounted for reduced survey coverage and data gaps by using well-documented locations to estimate population trends in areas with sparse data. This approach allowed for a comprehensive analysis of distribution trends.
"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," noted co-author Charles Edwards from CEscape consultancy services. "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."
Wittemyer concluded, "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."
Regional Shifts
The analysis also looked at regional differences. In northern Africa's conflict-impacted Sahel, elephant numbers have plummeted. In eastern and central Africa, ivory poaching, human expansion, and land conversion have led to declines.
In contrast, southern Africa has seen more positive results, with countries like Botswana showing stable and growing elephant populations due to protective and sustainable management practices.
This comprehensive assessment is critical for directing limited conservation funding and efforts to the most effective areas.
"The overall story is one of decline, but we're focusing on long-term stability of the species," said Wittemyer. "I think we can do that in a bunch of places, but not all places."
Research Report:Survey-based inference of continental African elephant decline
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