Global mammal count rises: The World gains 1,300 new species

A new review in the Journal of Mammalogy reports nearly 6,800 species now recognised globally. The total shows a 25% rise since 2005. The update reflects knowledge improving rather than rapid evolution. Researchers say many species were simply overlooked before now. Dr Nathan Upham of Arizona State University explains species names guide biodiversity studies. He tells A-Z Animals this language shows how diversity connects globally. The findings highlight how modern tools reveal long-hidden mammal variation.

What drives the surge in newly recognised species?
The Mammal Diversity Database lists 1,579 additions since 2005. These include 805 new descriptions and 774 species splits. Another 226 species were merged or removed recently. The result gives a net increase of 1,353 species. Rapid advances in technology support this sharp increase strongly. Many mammals also live in remote and understudied regions. Tropical forests hold especially high levels of mammal diversity. Upham says improved understanding shows distinct species adapt uniquely. Each species uses different food, space, or behaviour. DNA studies now reveal these long-separate lineages clearly.

How are so many hidden mammals identified today?
Modern genomics now plays a central role here. Next-generation sequencing greatly reduces DNA analysis costs today. Upham says genome sampling now costs about $100 per sample. Low-coverage sequencing allows testing of many populations quickly. Scientists compare genomes to detect unique evolutionary histories. Imaging tools and global fieldwork add even deeper insight. Regions like Indonesia keep producing many newly recognised species. Its isolated geography creates strong evolutionary separation over time. Rodents, bats, shrews and many small mammals show repeated splits. Mouse lemurs in Madagascar rose dramatically in recognised species. They once numbered two but now hold 19 species overall. These changes reflect better understanding rather than new evolution.

Why does this expansion raise conservation concerns globally?
More recognised species means more conservation gaps appearing quickly. Around 25% of mammals lack proper threat assessments today. Upham warns this shortfall creates serious global risks. Unassessed species receive little formal protection anywhere. Another 25% are already listed as threatened or endangered. Worst-case scenarios place half of mammals at risk. Many new species also remain absent from major databases. Without updates, national systems cannot plan protection properly. Habitat pressures continue rising through land change and climate shifts. Many species face threats before scientists even find them.