Supplementary feeding does not increase measures of reproductive productivity in Wahlberg’s eagles Aquila wahlbergi in South Africa

  • Published source details Simmons R.E. (1993) Effects of supplementary food on density-reduced breeding in an African eagle: adaptive restraint or ecological constraint? Ibis, 135, 394-402


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 controlled trial in subtropical savanna in northeast South Africa in 1989-90 (Simmons 1993) found that Wahlberg’s eagle Aquila wahlbergi pairs that were provided with supplementary food did not breed more often, have significantly larger clutches or eggs and did not lay earlier than control (unfed) pairs (75% of eight fed pairs breeding vs. 76% of 74 control pairs; average of 1 egg/clutch for both six fed and 56 unfed pairs; average egg volume of 76.7 ml for five fed pairs vs. 76.1 ml for five controls). Feeding consisted of approximately 200 g of meat provided daily from when pairs arrived in a territory until seven days after the first egg was laid (between three and six weeks of feeding).


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