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Insights from the eco-physiological book of records: Bewick's swans outperform the canonical intake-maximizing vertebrate

Klaassen, M.R.J. and Hangelbroek, H.H. and De Boer, T. and Nolet, B.A. (2010) Insights from the eco-physiological book of records: Bewick's swans outperform the canonical intake-maximizing vertebrate. Oikos, 119, 1156-1160. ISSN 0030-1299.

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Official URL: http://dx.doi.org/10.1111/j.1600-0706.2009.18186.x

Abstract

During periods of high energy demand an animal may be constrained by a physiological maximum to its energy intake rate. Predictions by allometric equations describing this maximum for endotherms were significantly surpassed during a few recent laboratory experiments on birds and mammals, being given access to food 24 h day−1. How relevant this is in the field remains to be assessed. We predicted that Bewick's swans Cygnus columbianus bewickii might surpass this maximum during stopover on their migration. We determined intake rate by measuring initial and final biomass density, and dividing the biomass difference by the feeding time required to reach this difference. This feeding time was given by the functional response. After conversion to daily energy intake rates, these exceeded the previously assumed maximum on two of the three stopover sites studied. The exception was a stopover site where daily foraging time was limited by the tidal cycle. Our study confirms that intake rates may exceed the formerly generally supposed maximum under natural conditions when foraging is possible day and night.

Item Type:Article
Institutes:Nederlands Instituut voor Ecologie (NIOO)
ID Code:6440
Deposited On:01 Jul 2010 02:00
Last Modified:24 Apr 2012 16:43

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