A team of researchers have found that stray and free-roaming domestic cats fed by humans are preying on rare species on Tokunoshima island in Kagoshima Prefecture.
“We hope people will know that feeding promotes the population growth of cats and affects the natural environment,” said the team, which consisted of researchers from institutes such as Kyoto University and the Forest Research and Management Organization’s Forestry and Forest Products Research Institute.
Predation by cats on endangered endemic species inhabiting the island, such as the Amami rabbit, has been a problem due to the proximity of forests and human-populated areas. The Amami rabbit, which has the scientific name Pentalagus furnessi, is a government-designated special natural treasure.
Yuya Watari, chief researcher at the Forestry and Forest Products Research Institute, and others collected the feces and fur of cats captured in the forests between December 2014 and January 2018.
Their analysis of the feces from 174 cats revealed that some 20 percent of them preyed on six kinds of rare species, including the Amami rabbit; the Ryukyu long-haired rat, or Diplothrix legata; and the spiny rat, or Tokudaia tokunoshimensis, in the few days before they were captured. The Ryukyu long-haired rat and spiny rat are also designated natural treasures.
Studying the fur showed that most cats ate cat food for several months before they were captured, suggesting that cats move between the residential areas and forests and prey on endangered species.
“The impact is tremendous as animals on the island have low levels of alertness and can be easy prey. It is desirable for cats to be kept indoors,” Watari said.
Their research paper has been published in British journal Scientific Reports.