Northern Jaçana

Almost every day during our Costa Rican trip, we saw at least a few new dragonflies (as to be expected on a dragonfly tour). Several days, however, were outstanding. The afternoon of 3 July was one of those mega-days. We explored two freshwater ponds in the Tárcoles District near the Pacific Ocean. The ponds were quite different, one surrounded by forest and the other beside a motel in the outskirts of the village of Tárcoles. I have combined these locations in my posts.

But first a bird—Northern Jaçanas greeted us at the motel pond. Everything about jaçanas is interesting. The cedilla hanging below the c in jaçana is often found in French and is pronounced like an “s” rather than a “k,” as in façade or garçon.

Northern Jaçanas range from coastal Mexico south to Panama. Occasionally they stray into eastern Texas. Note the yellow spurs, outgrowths of their wrist (carpometacarpus) bones. These are displayed during courtship. These structures are not unique to jaçanas, some plovers also have them.

Female jaçanas are larger than their males and their sex roles are reversed. Males build the nest, incubate, and bood their young. Females rarely brood the chicks. The females mate simultaneously with up to four males. The females defend their mates' nests against other females and other male jaçanas. This polyandry occurs in rich habitat. In poorer habitat, male territories tend to be larger, the result being their females may mate with fewer or just one male (Birds of North America).