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Providing evidence to improve practice

Individual study: Effects of supplementary food provision on local abundance of black-capped chickadees Poecile atricapillus wintering near Flagstaff Lake, Maine, USA

Published source details

Wilson W.H. Jr. (2001) The effects of supplemental feeding on wintering black-capped chickadees (Poecile atricapilla) in central Maine: population and individual responses. Wilson Bulletin, 113, 65-72


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Provide supplementary food for songbirds to increase adult survival Bird Conservation

A randomised, replicated and controlled study in coniferous woods along a road in Maine, USA (Wilson 2001) found that significantly more black-capped chickadees Parus  carolinensis (also known as Poecile carolinensis) were recorded during censuses at four sites fed continuously from late October 1995 to mid-March 1996, compared to at four unfed control sites (average of 5.5 birds/census for fed sites vs. 0.1 birds/census for controls, 18 censuses at each). Sites provided with food from October until January (early-fed sites) had significantly higher chickadee numbers than those fed from January until March (late-fed sites), with both being lower than continuously-fed sites and higher than controls (average of 1.8 birds/census and a maximum of approximately 5 birds/census for early fed vs. average of 0.1 birds/census and maximum of 3.0 birds/census for late-fed, 18 censuses at each). Chickadee numbers declined at early-fed sites when feeders were removed and increased at late-fed when feeders were established. No such patterns were seen at control or continuously-fed sites. Birds took longer to discover feeders at late-fed sites, compared to those supplied from October (all feeders at both continuously- and early-fed sites discovered within 15 days, a maximum of 33 days before the last feeder was discovered in late-fed sites). Feeding consisted of two feeders at each site refilled every week with black oil sunflower seeds.