Individual study: Advancement of laying of great tits by the provision of food
Källander H. (1974) Advancement of laying of great tits by the provision of food. Ibis, 116, 365-367
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 reproductive success
A controlled cross-over study in southern Sweden in 1972-3 (Källander 1974) found that great tits Parus major nesting in an 8 ha (1972) or 6 ha (1973) area of oak-hazel woodland supplied with supplementary food began laying eggs significantly earlier than great tits in an adjacent 16 ha or 18 ha control (unfed) area. The difference was significant irrespective of whether all females, one year-old females or older females were examined (average laying date of 1st-5th May for 44 nests in fed areas vs. 6th-11th May for 75 control pairs). Supplementary food consisted of 32 or 33 trays positioned throughout the wood and provided daily with 20-35 g of mealworms from 11th-27th April 1972 and between 10th April and 14th May 1973. On average there were 2 trays/territory in 1972 and 1.5 trays/territory in 1973. The authors note that other species including wood nuthatches Sitta europea and chaffinches Fringilla coelebs also took food from the trays.