Joe Sapp's Homepage

Ph.D. student in behavioral ecology at UC Santa Cruz

About Me:

I am a graduate student in Bruce Lyon's lab. We study behavioral ecology in birds and a growing list of other taxa (ants, damselflies).

I am interested in social parasitisms. Just as a "traditional" parasite exploits some physiological aspect of its host organism, social parasites exploit the altruistic behaviors that occur in animal groups from families to societies.

There are myriad examples in the animal world. Cuckoos, perhaps the best known social parasites, exploit parental care by laying mimetic eggs in the nests of host species. Similarly, some catfishes sneak parasitic eggs into the mouths of mouth-brooding African cichlids. Others in my lab study conspecific brood parasitism in the American Coot.

My graduate research is on the socially parasitic "slave-making" or "amazon" ant Polyergus breviceps and its host Formica spp. It is a fascinating and bizarre system that is expertly summarized in this article by Howard Topoff in Scientific American. Briefly, P. breviceps workers conduct raids on nearby Formica nests in which they remove brood (larvae and pupae) and carry them to their home nest. The social parasitism relies on the mechanism by which Formica workers learn to recognize their home nest: when pupae eclose, they chemically imprint on their environment. Because of this, stolen brood work in the parasitic slave-maker nest as if it was their own.

I work at the Sagehen Creek Field Station in the Sierra Nevadas. I began studying slave-makers in earnest in 2008 and every day in the field generates more questions than answers. I was initially struck by the high densities of both host Formica nests and parasitic P. breviceps nests and by the large raiding ranges exhibited by the parasites. These two observations were especially striking to me given that P. breviceps are aggressively territorial. Accordingly, my current focus is on the effects of host preference and relatedness among P. breviceps nests on intraspecific territorial interactions.