The breeding biology of Hooded Plovers, Thinornis rubricollis, on Phillip Island, Victoria

Abstract

The breeding biology of Hooded Plovers, Thinornis rubricollis, was examined between 1992 and 1996 on Phillip Island, Victoria, Australia. Particular attention was paid to their breeding success in relation to local population dynamics and the activities of humans and introduced predators. Three of twelve beaches used accounted for 52% of nesting attempts but only 10% of fledged young. The most common nest site was on flat beaches (52% of clutches); followed by nests on stony terraces (25%) or on the sides of primary dunes above flat beaches (23%).

Clutches were laid from August to March with a peak of laying in January. The average clutch recorded was 2.4 ± 0.1 eggs (range 1–3, median 3, n = 60). Hatching success was 25 of 149 eggs (16.8%) and 13 of 60 clutches (22%). Of the 83% eggs (in 78% of clutches) that failed to hatch, 29% eggs (25% of clutches) were in nests that had been disturbed by dogs, foxes (9% of eggs or 10% of clutches), or had been trampled by sheep (3% of eggs and clutches).

Annual breeding success was 0.0–11.1% of chicks fledged per egg laid, and, in the four years, only 6.7% of eggs resulted in fledged young. All 15 chicks that did not fledge were lost in the first three weeks after hatching.

The number of plovers recorded in counts on Phillip Island declined significantly between 1982 and 1998 and it is proposed that breeding success was too low to sustain the local population. Anthropogenic causes of nest failure were high and some management solutions and further research are recommended.