Research topics

Evolution of parental care

Sexual selection

Reproductive ecology

Kin recognition and inclusive fitness

Mate choice

Aposematism and mimicry



Chytridiomycosis in Peru






The evolution of parental care

Parental care is a central feature in the life histories of many animals.  How and why one type of parental care evolves from another is a controversial issue of central importance in evolutionary ecology (Clutton-Brock, 1991).  Research on a variety of taxa suggests that several factors may affect the trajectories and equilibria of parental care evolution, including the cost of parental care to male mating success (Maynard Smith, 1977), the effect of parental care on female fecundity (Gross and Sargeant, 1985), the relationship between parental care and confidence of paternity (Wesneat and Sherman, 1993), and costs of male polygyny to female reproductive success (Weygoldt, 1987).

This last possibility has received relatively little theoretical attention, but the poison frogs may provide an ideal system in which to investigate the influence of a cost of polygyny on the evolution of female care from male care.  In collaboration with Dr. David Earn of Cambridge University (now an assistant professor at McMaster University), I have used a combination of ecological and behavioral data and game theoretic analysis to investigate the dynamics of parental care evolution in response to variations in the cost of polygyny (Summers and Earn, 1999).

In combination with this theoretical approach, I have been using molecular systematic analysis and phylogenetic reconstruction of character evolution to investigate the pattern of parental care evolution in the genus Dendrobates (Summers et al. 1999a).  This research has revealed that parental care evolution has been generally conservative over the course of time in the poison frogs, and that biparental care (as found in some Amazonian species of Dendrobates) and female care (as found in some Central American species of Dendrobates) each evolved independently from male care.


Recent publications:

Summers, K., McKeon, C.S., Heying, H., Hall, J., & Patrick, W. 2007. Social and environmental influences on egg size evolution in frogs.  Journal of Zoology 271:225-232. | PDF

Summers, K., McKeon, C.S. & Heying, H. 2006. The evolution of parental care and egg size: a comparative analysis in frogs.  Proceedings of the Royal Society of London, Series B 273:687-692. | PDF