Division of parental roles in the monogamous western sandpiper, Calidris mauri

Abstract

I investigated whether male and female Western Sandpipers (Calidris mauri) contributed equal amounts of parental care during the breeding season, near Nome, AK, USA (64 ̊N) during 1998 and 1999. I repeatedly observed which parent was present at the nest during incubation and which parent tended the brood during the brood care period. Females incubated predominantly at night (18:00-06:00 hr ADT); males incubated predominantly during the day (06:00-18:00 hr ADT). Males spent more time incubating than females (57% vs. 43%, P<0.05). Females deserted their broods on average 5.6 days after hatch, while males tended broods on average 13.0 days after hatch (P<0.001). Nests that hatched earlier in the season received significantly more bi-parental care during the brood care period (P=0.01). Timing of nest initiation had the greatest effect on the division of parental care between sexes for Western Sandpipers.