Effects of supplementary feeding on breeding success of black-legged kittiwakes Rissa tridactyla nesting on Middleton Island, Alaska, USA

  • Published source details Gill V.A. & Hatch S.A. (2002) Components of productivity in black-legged kittiwakes Rissa tridactyla: response to supplemental feeding. Journal of Avian Biology, 33, 113-126


This study is summarised as evidence for the following.

Action Category

Provide supplementary food for gulls, terns and skuas to increase reproductive success

Action Link
Bird Conservation
  1. Provide supplementary food for gulls, terns and skuas to increase reproductive success

    A replicated, controlled study during the breeding seasons of 1996-7 in the northern Gulf of Alaska, USA (Gill & Hatch 2002) using the same data as (4), found that black-legged kittiwake Rissa tridactyla pairs that were provided with supplementary food had significantly higher fledging success in both years than pairs fed until laying or hatching, or than control (unfed) pairs (81-85% fledging success and 1.0-1.3 chicks/pair for 43 fed pairs vs. 51-53% and 0.3-0.6 chicks/pair  for 128 controls). Fed pairs also had larger clutch sizes and higher hatching success in 1997 but not 1996 (1996: 1.9 eggs/clutch and 76% hatching success for 73 and 49 clutches from fed pairs vs. 1.9 eggs/clutch and 65% for 59 and 83 clutches for controls; 1997: 1.8 eggs/clutch and 74% hatching success, 76 and 50 clutches from fed pairs vs. 1.6 eggs/clutch and 50%, for 59 and 85 control clutches). There was no effect of feeding on laying success (92-97% success for 157 fed pairs vs. 91-94% for 128 controls). Supplementary food consisted of 163 g/day of small pieces of herring, provided two or three times daily beginning in May, three weeks before first laying and ending in mid-August.


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