Study

The effect of food supplementation on the reproductive success of black-billed magpies Pica pica

  • Published source details Dhind M.S. & Boag D.A. (1990) The effect of food supplementation on the reproductive success of black-billed magpies Pica pica. Ibis, 132, 595-602.

Actions

This study is summarised as evidence for the following.

Action Category

Provide supplementary food for songbirds to increase reproductive success

Action Link
Bird Conservation
  1. Provide supplementary food for songbirds to increase reproductive success

    A study in Alberta, Canada, between 1986 and 1988 (Dhind & Boag 1990) found that black-billed magpies Pica pica that used supplementary food provided in a single feeder in an urban area laid eggs 6-7 days earlier than magpies that did not use the feeder (seven pairs used the feeder in 1987, six in 1988; 22 pairs did not use the feeder in 1987, 11 in 1988). Nestlings from parents that used feeders were heavier and had higher survival and fledging rates than those from parents that didn’t use the feeder, (fed nests: average weight of 184 g, ten nests, 71% survival of seven through a snow storm in 1987, 4.1-4.5 nestlings fledged/nest for 13 nests; unfed nests: 163-168 g for 13, 15% survival of 20, 1.1-1.8 nestlings fledged/nest for 31) although there were no differences in clutch size or breeding density (fed nests: 7.4-7.8 eggs/clutch for ten clutches, 126-134 m between 13 nests; unfed nests: 6.8-6.9 eggs/clutch of 23, 134-153 m between 57 nests). Supplementary food consisted of approximately 1 kg of dog food pellets provided each week from August 1986 until June 1988.

     

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