Priorities for Future Research

The basic breeding biology of the Greater Ani is fairly well known at the northern limit of its range, but few data exist on population estimates, habitat use, diet, or reproductive parameters in South America. Nothing is known about the effect on breeding populations of habitat destruction in Amazonia (the center of its range). Other forms of habitat alteration, such as water pollution and pesticide use, also may affect ani lifespan and reproductive success. Future conservation-related research on Greater Anis must identify the factors that influence territory size, territory quality, and food abundance, on and the relationships between these variables and group size and reproductive success. In addition, very little is known about the natural history of this species during the non-breeding season.

The intriguing communal breeding systems of the crotophagine cuckoos are the subjects of ongoing research, greatly aided by the recent development of microsatellite markers for the Greater and Smooth-billed anis and the Guira Cuckoo. Current research on breeding groups of Greater Anis focuses on genetic mating patterns, the extent of reproductive skew, divisions of labor, and patterns of intraspecific brood parasitism. Many fascinating questions still remain regarding group formation and group decision-making. How do pairs of individuals form breeding groups, and what factors determine group membership? What is the relationship between individual quality and group size? Finally, how do groups of up to 10 individuals mutually decide on a single nesting location? More data on the function of group choruses may be crucial to answering these questions.

Though reasonably long-term field studies have now been performed on all four of the crotophagine cuckoos, relatively little attention has been paid to the ultimate evolutionary pressures that gave rise to their communal breeding system. The reproductive behavior of the crotophagines is remarkably well-conserved, particularly considering that the four lineages diverged several million years ago. How much does the crotophagine mating system owe to phylogenetic constraints, and how much to immediate adaptive benefits that can be measured in the field? More detailed information on the relationships between group size, reproductive success, and geographic range is needed to understand these complex questions.