Individual study: Nest characteristics, fate and predation of Barrow's goldeneyes Bucephala islandica and bufflehead B. albeola nests in nest boxes and natural cavities in Cariboo Parklands, British Columbia, Canada
Evans M., Lank D., Boyd S. & Cooke F. (2002) A comparison of the characteristics and fate of Barrow's goldeneye and bufflehead nests in nest boxes and natural cavities. The Condor, 104, 610-619
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Provide artificial nesting sites for wildfowl
A replicated, controlled study in a deciduous forest in British Columbia, Canada, in 1997-9 (Evans et al. 2002), found that Barrow’s goldeneyes Bucephala islandica laid larger clutches but had lower nesting success in nest boxes, compared to natural nest cavities (10.5 eggs/clutch and 45-50% success for 174 clutches in nest boxes vs. 7.5 eggs/clutch and 54-86% for 41 clutches in natural cavities). There were no differences for buffleheads B. albeola (8.4 eggs/clutch and 75-90% success for 46 clutches in boxes vs. 8.5 eggs/clutch and 55-90% success for 100 clutches in natural cavities). Hatching dates did not differ for either species between nest types. Goldeneye nests in boxes were predated mainly by black bears Ursus americanus compared with small mammals and common starlings Sturnus vulgaris in natural nests. Predation of all bufflehead nests was low and mainly by American red squirrel Tamiasciurus hudsonicus and American pine marten Martes americana. The authors suggest that differences in goldeneye nests were due to nest boxes being concentrated in highly visible locations, whilst natural nests were widely dispersed. Natural bufflehead nests, however, were positioned similarly to nest boxes.