Supplementary feeding of Eurasian sparrowhawks Accipiter nisus before hatching increases clutch size but not hatching or fledging rate
Published source details
Newton I. & Marquiss M. (1981) Effect of Additional Food on Laying Dates and Clutch Sizes of Sparrowhawks. Ornis Scandinavica, 12, 224-229
Published source details Newton I. & Marquiss M. (1981) Effect of Additional Food on Laying Dates and Clutch Sizes of Sparrowhawks. Ornis Scandinavica, 12, 224-229
This study is summarised as evidence for the following.
Provide supplementary food for raptors to increase reproductive successAction Link
Provide supplementary food for raptors to increase reproductive success
A replicated and controlled study in mixed conifer forests in southern Scotland between 1971 and 1979 (Newton & Marquiss 1981), found that 13 pairs of Eurasian sparrowhawks Accipiter nisus provided with supplementary food in the pre-laying and laying period had larger clutch sizes, were less likely not to lay and laid earlier than 22 control (unfed) pairs (5.1 eggs/clutch for fed birds, 0% of pairs building nests but not laying, average laying date of 12th May vs. 4.0 eggs/clutch, 27% and an average laying date of 17th May for controls). Food was not provided after clutch completion and fed pairs did not have higher hatching or fledging success (69% hatching success and 62% fledging success for fed birds vs. 54% and 48% for 100 controls). Food provided consisted of either half a pigeon carcass (species not given) or two quail Coturnix coturnix carcasses every 1-4 days, was started on the 23rd-30th April and continued until late May at the latest.