Energy costs during incubation in Svalbard and Willow Ptarmigan hens

Studies of wild and captive Willow and Svalbard Ptarmigan hens have allowed us to estimate the daily energy cost during incubation. It was similar for the two species, varying between 70-85 kcal per day depending on number of eggs, nest insulation, ambient temperature, number of foraging periods and...

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Bibliographic Details
Published in:Polar Research
Main Authors: Gabrielsen, Geir Wing, Unander, Sigmund
Format: Article in Journal/Newspaper
Language:English
Published: Norwegian Polar Institute 1987
Subjects:
Online Access:https://polarresearch.net/index.php/polar/article/view/2441
https://doi.org/10.3402/polar.v5i1.6869
Description
Summary:Studies of wild and captive Willow and Svalbard Ptarmigan hens have allowed us to estimate the daily energy cost during incubation. It was similar for the two species, varying between 70-85 kcal per day depending on number of eggs, nest insulation, ambient temperature, number of foraging periods and total time spent away from the nest. Daily energy cost during incubation was IS-20% above resting metabolic rate in non-incubating hens but only 45?55% of that in free-living nonincubating hens. Incubating hens reduced their energy expenditure through high nest attentiveness. A reduction in food intake during incubation led to loss in body weight.