Foraging time and the northern range limits of Indian crested porcupines (Hystrix indica Kerr) Academic Article uri icon

abstract

  • From nocturnal activity durations of free-ranging animals and food intake rates of captive subjects, we predict that Indian crested porcupines (Hystrix indica Kerr) will not occur at latitudes where minimal night duration is less than 7 h. Available range records support that hypothesis. They indicate that the most northern populations of the species occur in the Aralo-Caspian region of the U.S.S.R. at about 44⚬ N, where night duration during the summer solstice is 7.3 h. To exist north of this postulated 'fitness boundary', crested porcupines would be forced to forage during daylight hours or reduce food intake. Presumably the costs associated with either of these alternatives would not promote fitness. The northern species range limits do not coincide with broad bioclimatic or vegetation boundaries.

publication date

  • January 1, 1988