On the ground they travel at fair speed with a waddling gait. P. peregrinus is the only species whose population structure has been studied in detail. In areas where density is high, individuals are very aggressive toward one another. The species P. dahli generally associates in pairs of a male and a female, sometimes accompanied by offspring. P. peregrinus is polyestrous, with an estrous cycle of about 28 days.
Females sometimes rear two litters in a year.
Litter size is 1-3, with a mode of 2. The species P. dahli reportedly breeds all year. The Johns Hopkins University Press. All rights reserved. This document may be used, with this notice included, for noncommercial purposes within a purchasing institution .