Parasites: The Key to Dominating Your Wolf Pack.

A new study of wolves in Yellowstone National Park shows that some are infected with toxoplasma gondii, a parasite that alters the behavior of rodents to make them less risk-averse and less afraid of cats, increasing the chance that a cat will catch and eat the rodent. Infected wolves were 11 times as likely as noninfected wolves to disperse from their pack and about 46 times as likely to eventually become leaders. The findings fit in with T. gondii's apparent ability to boost boldness across a wide range of warm-blooded life.