Scientists discover why dozens of endangered elephants dropped dead In 2020, 350 elephants mysteriously died in Botswana, with a further 35 dying in similar circumstances in Zimbabwe. Now scientists think they may have found the reason why.

In May and June 2020, the death of 350 elephants in Botswana’s Okavango delta baffled conservationists and sparked global speculation about what had caused it. Elephants of all ages and both sexes were affected, with many walking in circles before dying suddenly, collapsing on their faces. Two months later, 35 more elephants died in north-western Zimbabwe.

At the time, the deaths in Botswana were attributed to an unspecified cyanobacterial toxin, government officials said, and no further details were published.

But tests on the elephants that died in Zimbabwe have finally come back and shown the cause was a little-known bacterium called Pasteurella Bisgaard taxon 45, which resulted in septicaemia, or blood poisoning.

Ecologists have long thought animals acted on instinct alone. But a growing body of evidence shows many animals, much like us, have complex brains and social lives.

In our new research published in Trends in Ecology & Evolution, we argue the science of ecology can learn a great deal from the study of animal cognition and culture. Cognition is what goes on in the mind, which determines how animals perceive and respond to the world around them. Culture is the development and spread of socially learned behaviors. These are important—but generally overlooked—mechanisms influencing ecosystems.

Dolphins are likely the most intelligent animals on our planet. They use complex sounds to communicate in ways we’re only beginning to understand. But noise pollution from tourist boats is destroying their acoustic habitat. We went to Portugal's Algarve coast to learn more about the secret language of dolphins and help protect them.

Chapters
0:00 Why we should care about dolphins
2:19 Out on the sea: Observing dolphins
3:32 Three fascinating dolphin facts
5:15 Underwater noise pollution
7:11 How we’re helping
10:05 Longterm benefits of our support

But researchers also warn that the vast majority of new plant discoveries are endangered species, which should be listed as threatened with extinction by default, warning that three-quarters of undescribed species are likely to be at risk of disappearing.