News

Welcome aboard to our new student Eran Altschuler

25 October 2018

We welcome our new M.Sc. student Eran Altschuler!

Congratulations and warm wishes to our students Inbal and Yosef

27 January 2018

To Inbal for the birth of her daughter, and to Yosef for the birth of his son. We wish them and their families joy and happiness

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New publications

Contrasting aspects of tailswinds and asymmetrical response to crosswinds in soaring migrants

21 February 2018

Becciu, P., Panuccio, M., Catoni, C., Dell'Omo, G., and Sapir, N. 2018. Behavioral Ecology and Sociobiology 72(28). https://doi.org/10.1007/s00265-018-2447-0  

Hovering hummingbird wing aerodynamics during the annual cycle. II. Implications of wing feather moult

21 February 2018

Achache Y, Sapir N, Elimelech Y. 2018. Hovering hummingbird wing aerodynamics during the annual cycle. II. Implications of wing feather moult. Royal Society Open Science 5: 171766. http://dx.doi.org/10.1098/rsos.171766  

Moving in the Anthropocene: Global reductions in terrestrial mammalian movements

24 January 2018

Science 359 (6374): 466-469 http://science.sciencemag.org/content/359/6374/466  

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Drinking water boosts food intake rate, body mass increase and fat accumulation in migratory blackcaps (Sylvia atricapilla)

Tsurim, I., Sapir, N., Belmaker, J., Shanni, I., Izhaki, I., Wojciechowski, M. S., Karasov, W. H. and Pinshow, B. 2008. Drinking water boosts food intake rate, body mass increase and fat accumulation in migratory blackcaps (Sylvia atricapilla). Oecologia 156:21-30.

 

ABSTRACT

Fat accumulation by blackcaps (Sylvia atricapilla) is a prerequisite for successful migratory flight in the autumn and has recently been determined to be constrained by availability of drinking water. Birds staging in a fruit-rich Pistacia atlantica plantation that had
access to water increased their body mass and fat reserves both faster and to a greater extent than birds deprived of water. We conducted a series of laboratory experiments on birds captured during the autumn migration period in which we tested the hypotheses that drinking water increases food use by easing limitations on the birds’ dietary choices and, consequently, feeding and food processing rates, and that the availability of drinking water leads to improved digestion and, therefore, to higher apparent metabolizable energy. Blackcaps were trapped in autumn in the Northern Negev Desert, Israel and transferred to individual cages in the laboratory. Birds were provided with P. atlantica fruit and mealworms, and had either free access to water (controls) or were waterdeprived. In experiment 1, in which mealworm availability was restricted, water-deprived birds had a fourfold lower fruit and energy intake rates and, consequently, gained less fat and total mass than control birds. Water availability did not affect food metabolizability. In experiment 2, in which mealworms were provided ad libitum, water availability influenced the birds’ diet: water-restricted birds ate more mealworms, while control birds consumed mainly P. atlantica fruit. Further, in experiment 2, fat and mass gain did not differ between the two treatment groups. We conclude that water availability may have important consequences for fat accumulation in migrating birds while they fatten at stopover sites, especially when water-rich food is scarce. Restricted water availability may also impede the blackcap’s dietary shift from insectivory to frugivory, a shift probably necessary for successful pre-migratory fattening.

About us

We are a group of scientists devoted to the study of animal flight, including animal movement ecology, behavior, physiology and biomechanics. We study wild animals in the field and in the lab using a diversity of research approaches. We welcome applications for M.Sc. and Ph.D. studies and post-doctoral work in our group at the Department of Evolutionary and Environmental Biology at the University of Haifa.