We studied dispersal, mate retention, apparent survival, and renesting in a subarctic breeding population of the Semipalmated Plover (Charadrius semipalmatus) near the southern limits of its breeding range on Akimiski Island, Nunavut, Canada, from 2002 to 2007. The risk of predation at this site is higher than in more northern parts of this species' range. Dispersal of breeding birds was biased toward females, as found also at Churchill, Manitoba, a more northerly location. Mate retention was low both within (33.3%) and between (6.5%) seasons and much lower than previous estimates from Churchill. Return and encounter rates of adult males were higher than those of females, but apparent survival of adult males and females did not differ and was lower than that reported for Churchill. Within a season, renesting after a failed nest attempt was common (53%) with some pairs nesting three times in a season. Differences between the two study areas in rates of renesting may help to account for persistence of the southern population. Differences in weather at the two latitudes affect the duration of the breeding season and appear to have significant consequences for the strength of social monogamy but not for general patterns of dispersal.