DIFFERENTIAL INVESTMENT IN MATING BY RED FOXES

I measured physical condition, body mass, age, and mass of gut content s for 330 red foxes, Vulpes vulpes, in an area of central Italy. Femal es were fatter than males (P < 0.001), and they were fatter in the sou thern part of the study area than in the northern part (P < 0.001). Ma les had the same fat level across the study area (P > 0.887). Large ma les ate less (P = 0.069) during mating season, and their condition det eriorated immediately afterwards (P < 0.001). Small males maintained t heir body fat during the breeding season (P = 0.467), even though supe rficial fat decreased slightly (P = 0.069). Adult males maintained bod y condition for longer periods and recovered more rapidly than yearlin gs. Neither mass of gut contents nor body-fat indices varied in the sa me periods for females (P > 0.125). This pattern of differential inter -and intrasexual investment in mating suggested alternative mating str ategies in males. Large males may have spent less time hunting and mor e time searching for multiple mates and fighting with other males; sma ll males may have saved energy guarding their mates and may not have a ttempted to mate with additional females. These findings suggest that not all red foxes are monogamous.