File(s) under permanent embargo

The influence of cover on nesting Red-capped Plovers: a trade-off between thermoregulation and predation risk?

journal contribution
posted on 2014-10-01, 00:00 authored by Lomas, Stephanie, Whisson, Desley, Maguire, Grainne, Tan, laura, Guay, Patrick-Jean, Mike WestonMike Weston
Some ground-nesting birds adopt a mixed strategy of nesting in the open, or under cover (e.g. vegetation). This may represent a trade-off between thermally favourable nest sites (covered) and those that enable the early detection and avoidance of predators (open). This study examined whether such a trade-off exists for Redcapped Plover Charadrius ruficapillus, whose eggs are preyed upon principally by Little Raven Corvus mellori. For real and artificial nests, nest temperatures under cover (real, 25.9 ± 0.1°C; false, 16.2 ± 0.5°C) were cooler than those in the open (real, 26.8 ± 0.1°C; false, 17.4 ± 0.9°C). Covered nests had more visual obstructions than open nests (covered, 65.5% ± 11.4%; open, 7.4% ± 2.8%) and a standardised measure of incubator escape distance, initiated by experimental human approaches, indicated incubators fled open nests at longer distances than for covered nests. Nests under cover showed a slightly (non-significant) higher probability of surviving one day (Daily Survival Rate [DSR] = 0.978) than those in the open (DSR = 0.950). For false nests containing model eggs, covered nests exhibited better survival to 10 days compared with open nests (20.4% vs. 4.7%). Thus, covered nests are associated with enhanced thermal environments and egg survival, but predators can approach the incubator more closely. Overall, the proposed trade-off between thermal and predation risks associated with nest sites appears to exist and explains the ongoing occurrence of nests in open and covered locations.

History

Journal

The Victorian naturalist

Volume

131

Issue

4

Pagination

115 - 127

Publisher

Field Naturalists Club of Victoria

Location

Blackburn, Vic

ISSN

0042-5184

Publication classification

C Journal article; C1 Refereed article in a scholarly journal

Copyright notice

2014, Field Naturalists Club of Victoria

Usage metrics

Categories

Keywords

Exports