Together, rodents and cats wiped out 92 species of birds, says study

These cats are invasive predators introduced as pets or to check the rodents, a study on the state of avian species on earth indicates

GUWAHATI Disruptive humans have played a major role in wiping out at least 187 species of birds since 1500. Two natural enemies – rodents and cats – have almost been as lethal.

According to the State of the World’s Birds, a global study on the status of avian species, introduced mammals or invasive predators are the primary driver of extinctions of localised bird species. While rodents have been linked to the extinction of 52 bird species, cats have accounted for 40.

“At least 187 avian extinctions have been confirmed or suspected since 1500 [baseline year for the Red List of the International Union for Conservation of Nature], 90% of which pertain to endemic insular species concentrated on the Hawaiian Islands, mainland Australia and islands, the Mascarene Islands, New Zealand, and French Polynesia,” the study says in the section on patterns and trends of extinctions.

The birds that vanished from these islands belonged to 109 taxa or taxonomical groups, most of them (33) in the Hawaiian Islands.

“Cats were introduced for controlling the rodents and also reached these islands with humans as pets, companions or stowaways,” Ashwin Vishwanathan of India-based Nature Conservation Foundation told The Hindu.

He is one of the nine authors of the study led by the Manchester Metropolitan University and published on May 5.

“Over the past 600 years, the rate of extinctions increased to a peak in the late nineteenth century, falling slightly through the early and mid-twentieth century, before increasing again in the late twentieth century,” the study says.