Effects of food addition to willow tit Parus montanus and crested tit P. cristatus at the time of breeding
-
Published source details
von Brömssen A. & Jansson C. (1980) Effects of food addition to willow tit Parus montanus and crested tit P. cristatus at the time of breeding. Ornis Scandinavica, 11, 173-178.
Published source details von Brömssen A. & Jansson C. (1980) Effects of food addition to willow tit Parus montanus and crested tit P. cristatus at the time of breeding. Ornis Scandinavica, 11, 173-178.
Actions
This study is summarised as evidence for the following.
| Action | Category | |
|---|---|---|
|
Provide supplementary food for songbirds to increase reproductive success Action Link |
 |
-
Provide supplementary food for songbirds to increase reproductive success
A controlled trial in coniferous forest in southwest Sweden in 1976-7 (von Brömssen & Jansson 1980), found that willow tits Parus montanus and crested tits P. cristatus in a 1.8 km2 area provided with supplementary food started laying eggs significantly earlier than individuals in a 5.5 km2 control (non-supplemented) area (willow tits: average of 2-5 days earlier, 44 pairs tested; crested tits: average 5-8 days earlier, 38 tested). There was no corresponding difference in 1978, when no food was provided. Twelve-day old crested tit nestlings were significantly heavier in the fed area (average of 12.2 g for fed area vs. 11.5 g for control, number of chicks not provided) but there was no difference in willow tit nestlings (average of 10.6 g for fed area vs. 10.7 for control, number of chicks not provided). Clutch sizes did not differ between areas for either species (willow tits: average of 8.1-8.2 eggs/clutch for fed area vs. 7.7-8.2 for controls; crested tits: average of 5.3-5.4 eggs/clutch for fed area vs. 5.0-5.2 for controls). Food was provided at feeding stations located in the approximate centre of each fed territory and contained one feeder of sunflower seeds and three coconut shells containing a mixture of tallow, soy protein, wheat germ, sun-flower seeds, vitamins and minerals. In 1976 feeding started on 20th February and in 1977 on the 20-24th March, in both years it continued until all females had started laying and resumed for the first half of June (when second clutches could be expected to be laid).
