Jaçanas inhabit mats of floating aquatic vegetation, in slow-moving rivers and lakes throughout the Neotropics. Steve Emlen and I studied the behavior and reproduction of Jacana jacana in the Republic of Panamá from 1989 to 1997.

Conflict Between the Sexes:
One of the most conspicuous behaviors of jaçanas in this very open, high visibility habitat, is copulation - and once the birds are banded for individual identification, it is clear that females commonly copulate with more than one male during the egg-laying cycle. In all cases these are males within the female's 'harem'.

Clearly this is of consequence to the male getting the eggs, as it is he that will spend nearly 90 days incubating and tending the chicks until their independence! Multiple mating by female jaçanas produces an obvious conflict between the sexes in this species, and understanding the ramifications of this conflict was one of the focal points of our research.

• Why do females multiply mate?
• Are such matings effective?
• Does the care-taking male have counter strategies?
  

We also explored questions stemming from theories of sexual selection; especially in how the magnitude of sexual selection affects, and is affected by, various aspects of life history.

Jaçana females are about 20% larger than males, and, because a female can monopolize more than one male, there should be more competition among females than among males to gain breeding sites. Males are expected to be 'choosy' in picking mates, not only because they are in 'demand' by females, but because they make a large contribution to parental care. But, in our study system, breeding habitat is limited, there are floaters of both sexes and it might be that neither sex can afford to be 'choosy'.

So, other questions that we are evaluating include:

• What is the relative magnitude of intrasexual competition for mates in females Vs. males?
• What morphological characters might be used in mate choice, and in what way do they reflect quality?
• Are there trade-offs,for females, between breeding intensity (a large group size) and survival?
• What are the consequences, to males, of being in a polyandrous group?