Research topics

Evolution of parental care

Sexual selection

Reproductive ecology

Kin recognition and inclusive fitness

Mate choice

Aposematism and mimicry



Chytridiomycosis in Peru






Inclusive fitness and kin discrimination

Kinship is of fundamental importance in understanding the evolution of behavior (Hamilton 1964).  The study of kin recognition, or how and why animals do or do not recognize and discriminate among kin and non-kin, has received considerable attention (Sherman et al. 1997).  Kin recognition among anuran larvae comprises a large part of the literature on kin recognition (Waldman 1991).  Despite frequent demonstrations that anuran larvae can and do recognize kin, the function of such recognition has remained obscure in most cases.

Prior work (Pfennig et al. 1993) on tadpoles of the spadefoot toad has demonstrated a clear functional context for kin recognition and discrimination.  In this species, there are two morphs of tadpoles, one of which is highly cannibalistic.  Tadpoles were predicted to be more likely to cannibalize non-kin than kin because cannibalizing kin reduces one component of inclusive fitness (Pfennig  et al. 1993).  This prediction was confirmed: cannibalistic tadpoles prefer to cannibalize non-kin, although they will cannibalize kin and non-kin indiscriminately under certain circumstances.

Tadpoles of a number of species of poison frogs in the genus Dendrobates are well known for high levels of cannibalism (Weygoldt 1987).  Hence, this genus is an excellent candidate for investigations of kin recognition in a functional context. Recently, I have carried out field and laboratory experiments experiments on cannibalism and kinship in the Amazonian poison frog, Dendrobates ventrimaculatus, from Amazonian Ecuador (Summers and Symula, submitted manuscript).  We have found only a weak tendency to behave less aggressively towards kin under laboratory conditions, and no tendency for reduced mortality of kin under field conditions.  This suggests that the costs of foregoing cannibalism of kin may be higher for Amazonian Poison Frog tadpoles than for Spadefoot Toad tadpoles.

Recently my colleagues and I have been carrying out experiments on kin recognition and cannibalism in another poison frog species, the Green Poison Frog (Dendrobates auratus) from Panama, which utilizes larger pools than D. ventrimaculatus.  We are in the process of analyzing the results of these experiments.