Henk Visser is an Honorary Research Associate of the Avian Demography Unit. Henk's official association with the ADU began in 2001 with the start of a cosupervised PhD, between himself and Les Underhill. The PhD researcher is Kathy Calf and she is looking at wader chick energetics. This PhD fits in nicely with his main research interests enabling a comparison of species within the Southern Hemisphere and between hemispheres.

Henk's main research interests are:

• Energetics of (avian) reproduction in relation to latitude (growth of chicks in relation to developmental mode; parental level of energy expenditure in relation to developmental mode of the offspring and brood size).
• Effects of feeding conditions during early growth on subsequent adult performance.
• Performance, fatigue and recovery.
• Development and refinement of stable isotope methods to accurately measure energy expenditure and protein synthesis in free-living animals.

Qualifications and experience

Henk completed his "Kanditaats examen" in 1979 and his "Doktoraal examen" in 1983 both at the University of Groningen. He was awarded a PhD from the University of Utrecht, Veterinary Faculty, The Netherlands in 1991. The title of his thesis was: "Development of metabolism and temperature regulation in precocial birds: Patterns in shorebirds (Charadriiformes) and the Domestic Fowl (Gallus domesticus). From 1983 to 1985 Henk worked at the Research Institute for Nature Management, Leersum. Until 1991 he was a scientific assistant at the University of Utrecht, Veterinary Basic Sciences, Department of Physiology. In 1991 he was employed as a scientist at the University of Groningen, splitting his time between the Centre for Isotope Research (CIO) and the Zoological Laboratory. Since then his post has changed from scientist to project research manager, still dividing his time between departments (Head Biomedical Division CIO 50%, and Animal Behavior 50%).

Publications

Longer list of publications

• Visser, G.H., P.E. Boon, and H.A.J. Meijer 2000. Validation of the Doubly Labeled Water method in Japanese Quail Coturnix c. japonica chicks: Is there an effect of growth rate? Comp. Physiol. B. 170:365-372.
• Visser, G.H., A. Dekinga, B. Achterkamp, and T. Piersma 2000. Ingested water equilibrates isotopically with the body water pool of a shorebird with unrivaled water fluxes. J.Physiol. 209:R1795-R1804.
• Boon, P., P.W. Watt, K. Smith, and G.H. Visser 2001. Day length has a major effect on the response of protein synthesis rates to feeding in growing Japanese Quail. J. Nutrition 131: 268-275.
• Harun, M.A.S., R.J. Veeneklaas, G.H. Visser, and M. Van Kampen 2001. Artificial incubation of Moscovy Duck eggs: Why some eggs hatch and some others do not? Poultry Science 80: 219-224.
• Kvist, A., Å. Lindström, M. Green, T. Piersma, and G.H. Visser 2001. Carrying large fuel loads during sustained bird flight is cheaper than expected. Nature 413: 730-732.
• Schekkerman, H., and G.H. Visser 2001. Prefledging energy requirements in shorebirds: Energetic implications of self-feeding precocial development. Auk 118: 944-957.
• Trigt, R. van, E.R.Th. Kerstel, G.H. Visser, and H.A.J. Meijer 2001. Accurate stable isotope ratio measuremnts on highly enriched water samples by means of laser spectrometry. Analytical Chemistry 73: 2445-2452.
• Ziel, C.E. van der, and G.H. Visser 2001. The effect of food restriction on morphological and metabolic development in two lines of growing Japanese Quail chicks. Physiological and Biochemical Zoology 74: 52-65.
• Schekkerman, H., and G.H. Visser 2001. Prefledging energy requirements in shorebirds: Energetic implications of self-feeding precocial development. Auk 118: 944-957.
• Jodice, P.G.R., D.D. Roby, S.A. Hatch, V.A. Gill, R.B. Lanctot, and G.H. Visser 2002. Does food availability affect energy expenditure rates of nesting seabirds? A supplemental feeding experiment with Black-legged Kittiwakes (Rissa tridactyla). Can.J.Zool. 80: 214-222.