Global warming could lead to more kittens

Shelters across the country are reporting an increased intake of cats and kittens. Some experts blame climate change.

"Each year it seems to get worse and worse," said Christina Gin, an animal shelter volunteer in Hayward, Calif., to the Hayward Daily Review earlier this month.

She was talking about the shelter's surplus of kittens, a problem that animal shelters across the country face every summer. But lately, it seems that there have been more and more of the furry carnivores.

Ms. Gin blames global warming for the feline glut, and she's not alone. The Humane Society has observed that kitten season, which usually starts in March and April, has been starting earlier and lasting longer.

The Kansas City infoZine quotes Nancy Peterson, manager of the Humane Society's feral cat program, who explains how warmer weather sends female cats into heat: "The brain receives instructions to produce a hormone that basically initiates the heat cycle in a cat," said Ms Peterson, "and those instructions are affected by the length of day and usually the rising temperatures of spring."

The story quotes some dissenting voices, however, such as a veterinary professor at Iowa State University who argues that the cat's sexual cycle is based on the length of day, not the temperature.

But the warmer weather could still lead to a population increase, by increasing kitten survival rates, hastening the onset of cat puberty, or by helping more rats and mice survive, providing a more abundant food source.

Last year, Pets Across America – an umbrella organization for animal shelters – said that shelters are seeing spikes in the number of incoming cats and kittens. According to a press release from the organization, several shelters experienced an increase of more than 30 percent from 2005 to 2006.

An increase is not just perceived in the United States. The BBC recently reported a dramatic increase in kittens in a shelter in Bristol, England.

No definitive link has been established, but climate change has been shown to change the breeding patterns of at least some mammals. In 2003, for example, researchers at the University of Alberta discovered that Canadian red squirrels are giving birth an average of 18 days earlier than their great-grandparents, a shift that they attributed to rising temperatures.

[via Grist]