Breeding biology of Purple Sandpipers Calidris maritima on the Hardangervidda, southern Norway

Rab Rae,Keith Brockie,Mike Nicoll,Stuart Rae,Ron Summers

doi:10.34080/os.v21.22606

Abstract

Breeding Purple Sandpipers Calidris maritima were studied within an area of approximately 32 km2 on the Hardangervidda, southern Norway during 1978 to 1986. The minimum average density was 1.0 pairs per km2 in 1984. Clutch sizes were 3–4 (mean = 3.74), and egg sizes were small, reflecting the small size of the females compared to other populations. Hatching was in late June and clutch survival was 75%. The eggs in one nest were believed to have been trampled by a Reindeer. Chick growth was described for two broods. Broods were mostly attended by males. Only 8% (2 of 24 broods) were attended by females. Adult masses declined during the breeding season, supporting the theory that brood desertion by Arctic-breeding sandpipers could be related to loss of condition in the breeding adults. However, females, who usually desert the brood, did not decline in mass any faster than males. Birds from one pair were faithful to mate and site; the birds wintered apart (the female was seen in winter) and the pair re-united on the breeding territory.

Highlights

The Purple Sandpiper Calidris maritima is an Arctic-breeding sandpiper that nests in Canada, Greenland, Iceland, Fennoscandia, Svalbard and Russia (Cramp & Simmons 1983)
One of our group (KB), took part in this trip and we continued to visit the same area and extended the observations during 1980 to 1986. Results from these studies have described adult biometrics (Nicoll et al 1991), incubation scheduling (Cresswell & Summers 1988) and their migration using ringing recoveries (Rae et al 1986). This paper complements these by describing the breeding biology of Purple Sandpipers on the Hardangervidda; in particular the nesting density, time of breeding, clutch and egg size, hatching success, chick growth, and fidelity to mate and site
Observations from a hide found that incubating birds walked off the nest once or twice during an incubation shift to feed in the immediate area of the nest for several minutes at a time. The masses of both sexes dropped during the breeding season and there was no evidence that females declined more than males (Figure 5)

Summary

Introduction

The Purple Sandpiper Calidris maritima is an Arctic-breeding sandpiper that nests in Canada, Greenland, Iceland, Fennoscandia, Svalbard and Russia (Cramp & Simmons 1983). This paper complements these by describing the breeding biology of Purple Sandpipers on the Hardangervidda; in particular the nesting density, time of breeding, clutch and egg size, hatching success, chick growth, and fidelity to mate and site. Breeding density was calculated from the mean nearest-neighbour distance between nests and/or broods.

Results

Conclusion