REPRODUCTIVE CHARACTERISTICS OF AMERICAN COOTS (FULICA AMERICANA) IN NORTHERN ARIZONA.

I studied coots nesting at semipermanent and seasonal wetlands near Flagstaff, Arizona. Coot nests in bulrush (at the semipermanent wetland) were spaced closer together than nests in spikerush (at seasonal and semipermanent wetlands). Nests were much more successful in bulrush at the semipermanent wetland than in spikerush at seasonal wetlands. Coots nesting in bulrush laid larger eggs than coots nesting in spikerush. However, coots nesting in spikerush at seasonal wetlands laid larger clutches than coots nesting in bulrush at the semipermanent wetland. Better nesting success was related to better vegetative concealment of the nest from crows and ravens. Smaller territories and larger eggs among nests in bulrush were related to better food resources in the vicinity of the nest as indicated by a greater abundance and diversity of emerging aquatic insects. Clutches with more eggs, however, did not correspond to nest sites associated with more abundant aquatic insects. I suggest that clutch size might have been influenced by some aspect of nutrients stored prior to egg-laying which were not necessarily gained from resources on the territory. In general, in areas where nests were more closely spaced (e.g., bulrush) clutches contained fewer eggs than in areas where nests were spaced further apart (e.g., spikerush at seasonal wetlands) indicating the amount of energy expended by the female on the defense of territories might also affect clutch size