Individual study: Effects of winter food supplementation on survival rates, territory acquisition and breeding densities of black-capped chickadees Parus atricapillus at Meanook Biological Station, near Athabasca, Alberta, Canada
Desrochers A., Hannon S.J. & Nordin K.E. (1988) Winter survival and territory acquisition in a northern population of black-capped chickadees. The Auk, 105, 727-736
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
A controlled study in the winters of 1985-6 and 1986-7 in two small deciduous forest sites in Alberta, Canada (Desrochers et al. 1988), found that winter survival of black-capped chickadees Parus atricapillus was higher in the 2.6 km2 area provided with supplementary food, compared to the 1.9 km2control (unfed) area (1985-6: 88% of 163 birds in the fed area vs. 80% of 143 controls; 1986-7: 65% of 192 vs. 53% of 137). However, there were no significant differences in the proportion of chickadees acquiring local breeding territories, or in local breeding densities (1986: 54% of fed birds acquiring local breeding territories and 15.3 pairs/km2 vs. 66% and 17.2 pairs/km2 for controls; 1987: 66% and 16.1 pairs/km2 vs. 71% and 14.0 pairs/km2). Supplementary food consisted of multiple feeding stations, each with between two and four feeders, filled weekly with sunflower seeds.