Cuckoos, cowbirds and hosts: adaptations, trade-offs and constraints.
The interactions between brood parasitic birds and their host species provide one of the best model systems for coevolution. Despite being intensively studied, the parasite-host system provides ample opportunities to test new predictions from both coevolutionary theory as well as life-history theory in general. I identify four main areas that might be especially fruitful: cuckoo female gentes as alternative reproductive strategies, non-random and nonlinear risks of brood parasitism for host individuals, host parental quality and targeted brood parasitism, and differences and similarities between predation risk and parasitism risk. Rather than being a rare and intriguing system to study coevolutionary processes, I believe that avian brood parasites and their hosts are much more important as extreme cases in the evolution of life-history strategies. They provide unique examples of trade-offs and situations where constraints are either completely removed or particularly severe.
Krüger
Oliver
O
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. ok212@cam.ac.uk
D000222:Adaptation, Physiological; D000818:Animals; D005075:Biological Evolution; D009425:Nesting Behavior / Q000502:physiology*; D046109:Passeriformes / Q000235:genetics / Q000502:physiology*