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Lots of animals were lost when the sea surrounded Zanzibar

A recent effort to chart the extinction of various animals from Zanzibar shows rising sea levels played a big role in their disappearance.

Researchers charted the history of sea level change by examining mangrove sediments and analyzing animal remains found in Kuumbi Cave—an important archaeological site.

They focused on evidence from three distinct time periods: the end of the last Ice Age, the stage when Zanzibar became an island 11,000 years ago, and the time of being an island. They say numerous large mammals had disappeared by the latter stage.

The findings are based on an analysis of more than 6,000 bone specimens, which showed that large fauna such as zebra, buffalo, waterbuck, and gazelle were present at the time the island formed. However, they disappeared after sea levels climbed and coastal cultures developed. Other small fauna, such as porcupines and hares, were also lost.

This is the first time researchers have combined with archaeological data on the history of the island’s fauna through excavation to chart Zanzibar’s history.

“An understanding of the longterm history of faunal change allows us to identify patterns in the interplay of natural and anthropogenic factors that have shaped Zanzibar’s ecosystems today,” says Robert Marchant of the University of York, who was involved in the research.

“Such longterm insights are crucial in helping with current conservation efforts, laying a foundation for future research on impacts of island formation, climate change, and human occupation on animals and their habitats.”

The team’s findings are published in PLOS ONE. The European Research Council funded the project.

Source: University of York