Study

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

Actions

This study is summarised as evidence for the following.

Action Category

Provide supplementary food for raptors to increase reproductive success

Action Link
Bird Conservation
  1. 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.

     

Output references

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