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Providing evidence to improve practice

Individual study: Parental provisioning and nestling departure decisions: a supplementary feeding experiment in tufted puffins (Fratercula cirrhata) on Triangle Island, British Columbia

Published source details

Gjerdrum C. (2004) Parental provisioning and nestling departure decisions: a supplementary feeding experiment in tufted puffins (Fratercula cirrhata) on Triangle Island, British Columbia. The Auk, 121, 463-472


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Provide supplementary food for auks to increase reproductive success Bird Conservation

A randomised, replicated and controlled experiment on Triangle Island, British Columbia, Canada, in 1999 and 2000 (Gjerdrum 2004) found that growth rates of tufted puffin Fratercula cirrhata chicks’ culmen (upper beak) and tarsi (lower leg) were significantly higher when chicks were fed daily with either 58 g of herring Clupea sp. (in 1999) or 50 g of sand lance Ammodytes sp. (in 2000), compared to control (un-fed) chicks, although analysis revealed the effect on culmen growth was only apparent late in chick development. There was no effect of feeding on the rates of either wing growth or weight gain, and, in both years, fed chicks fledged later than unfed chicks (47-48 days at fledging for 32 fed chicks vs. 43-46 days for 32 controls). Parents of fed chicks made fewer provisioning trips but did not change the number, or species, of prey delivered each time.