BRANTA — Lewis G. Halsey
The behavioural physiology of diving animals, in particular Tufted Ducks (Aythya fuligula), and the implications for models of optimal diving
Institution: University of Birmingham, UK
Supervisors: T Woakes & P Butler
Details: PhD 2003 (Completed)
Current Address: School of Biosciences, University of Birmingham, Edgbaston, B15 2TT UK (Oct 2005) Email
Subject Keywords: diving behaviour, optimal foraging
Species Keywords: Tufted Duck Aythya fuligula
Abstract
Tufted ducks were trained to dive to and from a respirometer box on a 1.7 m dive tank, so that measurements of respiratory gas exchange could be measured, along with time budget data. These data were combined with power cost estimates of diving to show that the optimal breathing model quantitatively predicted surface duration and the oxygen metabolised during foraging for the mean of all subject ducks but not for individual birds. Respirometry data also showed that both the oxygen and carbon dioxide stores were close to full adjustment after mean surface duration suggesting they have a similar influence on surface duration in tufted ducks, while pre-dive hyperventilation caused hypocapnia suggesting carbon dioxide is more often a limiting factor on dive duration. Oxygen uptake was not affected by hypercapnic exposure between dives and minimally affected by hypoxia, however dive time budgeting changed in both cases. This confirmed an influence of carbon dioxide on diving behaviour while estimates of respiratory exchange ratios above one during dives from hypoxia suggested the employment of anaerobic metabolic pathways in hypoxic conditions. Allometric studies investigating relationships between body mass and diving parameters across and within taxonomic groups of divers highlighted a number of limitations in our current knowledge of diving animals and also questioned some of the mass associated correlations that have been widely considered to exist across diving species.
Published Papers
Halsey, L.G., Blackburn, T.M. & Butler, P.J. In Press. Physiology, ecology and diving behaviour in birds and mammals. Journal of Animal Ecology
Halsey, L.G., Butler, P.J. & Blackburn, T.M. In Press. A phylogenetic analysis of the allometry of diving.American Naturalist
Halsey, L.G., Brand, O.J., Woakes, A.J. & Butler, P.J. In Press. Experiments on single diving animals in the laboratory often measure dives of decreased effort. Ibis
Green, J.A., Halsey, L.G. & Butler, P.J. 2005. To what extent is the foraging behaviour of aquatic birds constrained by their physiology? Physiological and Biochemical Zoology 78:766-781.
Halsey, L.G., Wallace, S.E., Woakes, A.J., Winkler, H. & Butler, P.J. 2005. Tufted ducks Aythya fuligula do not control buoyancy during diving. Journal of Avian Biology 36: 261-267.
Halsey, L.G., Butler, P.J. & Woakes, A.J. 2005. Breathing hypoxic gas affects the physiology as well as the diving behaviour in tufted ducks. Physiological and Biochemical Zoology 78: 273-284.
Halsey, L.G., Reed, J.Z., Woakes, A.J. & Butler, P.J. 2003. The influence of oxygen and carbon dioxide on diving behaviour of tufted ducks, (Aythya fuligula). Physiological and Biochemical Zoology 76: 436-446.
Halsey, L.G., Woakes, A.J. & Butler, P.J. 2003. Testing optimal foraging models for air-breathing divers. Animal Behaviour 65:641-653.
Parkes, R., Halsey, L.G., Woakes, A.J., Holder, R.L. & Butler, P.J. 2002. Oxygen uptake during post dive recovery in a diving bird (Aythya fuligula): implications for optimal foraging models Journal of Experimental Biology205:3945-3954.
Halsey, L. 2002. Ultimate divers. Biologist 49: 161-164.