Artificially incubate eggs or warm nests
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Overall effectiveness category Unknown effectiveness (limited evidence)
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Number of studies: 2
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Effectiveness
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Supporting evidence from individual studies
A replicated, controlled trial in 1991 in woodland in Oxfordshire, England (Yom-Tov & Wright 1993), found that blue tits Parus caeruleus nesting in heated nest boxes did not have significantly heavier eggs or larger clutches than those in unheated boxes. However, birds were less likely to interrupt their laying sequence in heated boxes (33% of 16 heated nests had interruptions vs. 67% of 14 unheated nests). Heat was provided by a small ‘night light’ candle, 8 cm below the bottom of the box, which raised the temperature in the box by an average of 6oc, saving roosting blue tits approximately 0.77 kcal/night, comparable to 35% of the energetic cost of producing an egg.
Study and other actions testedA small study on Codfish Island, South Island, New Zealand (Jansen 2005) found that no kakapo Strigopus habroptilus eggs or chicks died from chilling between 1997 and 2005, following the use of specially designed nest heat pads to keep eggs and chicks warm while the female is off the nest. Before pads were used, a nest containing three eggs lost failed, apparently due to chilling of the eggs and chicks as the female spent large periods of time away from the nest.
Study and other actions tested
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This Action forms part of the Action Synopsis:
Bird Conservation
Bird Conservation - Published 2013
Bird Synopsis