Project description

Small wintering birds should at the same time be as fat as possible to avoid starvation and as lean as possible to escape predators. These counteracting selective forces produce a trade-off that may not be evident in non-flying organisms: a fat bird may not be able to escape from attacking airborne predator while a lean bird may starve to death during the long and cold night. In winter, a small passerine needs to gain around 10% of its lean body mass each day to survive the ensuing night. This has made the "little bird in winter" a model system that has attracted a lot of interest from both theoreticians and empiricists. Some species of wintering passerines can store energy also externally in the form of hoarded food. These extra reserves make it possible to spend the winter in environments that are extreme for small animals, such as the northern part of the taiga zone. In winter, days up here are short, periods with temperatures between -20 and -30 may be long. These adverse conditions combine with low availability of the food that these birds normally eat, such as seeds and invertebrates. We study energy regulation in such wintering passerines both a theoretically and empirically.

Members

Anders Brodin, Ken Lundborg

Related publications

1. Brodin A. 2007. Theoretical models of adaptive energy management in small wintering birds. Philosophical transactions of the Royal Society B 362: 1857-1871

2. Brodin A. and Clark, C. 2007. Resource storage and expenditure. Chapter 7, pp 221-269. In: Foraging, eds. Stephens D S, Brown J S, Ydenberg, R C. University of Chicago Press.

3. Brodin A, Lundborg K. Rank-dependent hoarding effort in willow tits Parus montanus - a test of theoretical predictions. Behavioral Ecology and Sociobiology 2003; 54:587-592

4. Lundborg K, Brodin A. The effect of dominance rank on fat deposition and food hoarding in the Willow Tit Parus montanus - an experimental test. Ibis 2003; 145:78-82

5. Brodin A. Mass-dependent predation and metabolic expenditure in wintering birds: is there a trade-off between different forms of predation? Animal Behaviour 2001; 62:993-999

6. Brodin A, Lundborg K, Clark CW. The effect of dominance on food hoarding: A game theoretical model. American Naturalist 2001; 157:66-75

7. Brodin A. Why do hoarding birds gain fat in winter in the wrong way? Suggestions from a dynamic model. Behavioral Ecology 2000; 11:27-39

8. Brodin A. Övervintrarens 10000 matminnen. Forskning och Framsteg 2000; 35:28-32

9. Brodin A, Clark CW. Long-term hoarding in the Paridae - A dynamic model. Behavioral Ecology 1997; 8:178-185

10. Brodin A, Kunz C. An experimental study of cache recovery by hoarding willow tits after different rentention intervals. Behaviour 1997; 134:881-890

11. Brodin A, Lahti K, Lens L, Suhonen J. A northern population of willow tits Parus montanus did not store more food than southern ones. Ornis Fennica 1996; 73:114-118

12. Ekman J, Brodin A, Bylin A, Sklepkovych B. Selfish long-term benefits of hoarding in the Siberian jay. Behavioral Ecology 1996; 7:140-144

13. Brodin A. The disappearance of caches that have been stored by naturally foraging willow tits. Animal Behaviour 1994; 47:730-732

14. Brodin A. Separation of caches between individual willow tits hoarding under natural conditions. Animal Behaviour 1994; 47:1031-1035

15. Brodin A. The role of naturally stored food supplies in the winter diet of the boreal Willow Tit Parus montanus. Ornis Svecica 1994; 4:31-40

16. Brodin A, Ekman J. Benefits of food hoarding. Nature 1994; 372:510.

17. Brodin A, Ekman J. Adaptive long-term hoarding in the boreal willow tit, Chapter 5. In: Brodin A, ed. Time aspects on food hoarding in the willow tit, an evolutionary perspective, PhD thesis,. Stockholm: Stockholm University. 1994: 1-7

18. Brodin A, Lens L, Suhonen J. Do crested tits, Parus cristatus, store more food at northern latitudes? Animal Behaviour 1994; 48:990-993

19. Brodin A. Low rate of loss of willow tit caches may increase the adaptiveness of long-term hoarding. The Auk 1993; 110:642-646

20. Brodin A. Radio-ptilochronology - tracing radioactively labelled food in feathers. Ornis Scandinavica 1993; 24:167-173

21. Brodin A. Cache dispersion affects retrieval time in hoarding Willow Tits. Ornis Scandinavica 1992; 23:7-12

22. Brodin A. Food storing in birds with special reference to the paridae. Introductory paper, Department of Zoology. Stockholm: Stockholm University. 19902, pp 1-22