University of Missouri - Saint Louis

The Graduate School

Announcement

An oral examination in defense of the dissertation for the degree

Doctor of Philosophy

Renata Durães
M.S. Ecology, Conservation and Wildlife Management, Universidade Federal de Minas Gerais, Brazil, 2001
B.S. Ecology, Universidade Federal de Minas Gerais, Brazil, 1998

Spatial and Temporal Dynamics of Lekking Behavior and Female Mate Choice in the Blue-crowned Manakin
(Lepidothrix coronata, AVES: Pipridae)

Abstract

Lekking is an unusual mating system in which males aggregate at display grounds called ‘leks’ that females visit to copulate. Lekking systems are non-resource-based and males often vary widely in their reproductive output. This dissertation investigates in various aspects how spatial and temporal factors influence the lekking dynamics and female mate choice of a Neotropical frugivorous bird, the blue-crowned manakin Lepidothrix coronata, in eastern Ecuador. The first chapter is related to the spatial dynamics of lekking behavior, and specifically investigates whether leks are formed by the establishment of territorial males on sites where they maximize their contact with females (the ‘hotspot hypothesis’). Predictive maps of the spatial distribution of females were built based on field data and contrasted to the distribution of existing leks. Surprisingly, leks were found to be located in sites where males would encounter less females than expected by chance, and this seems to result in part from differences in sex-specific habitat preferences. The second chapter is related to the temporal aspects of lekking behavior, and specifically investigates how leks are formed and change over time, and how leks, which are very traditional in location, can persist in face of relatively high rates of male turnover. The fate of individual territorial males was followed during 4 years at up to 15 leks to estimate rates of male persistence at territories, recruitment, and expected tenure times. These estimates were then used to simulate changes in lek size and composition over time. The results suggest that rates of male recruitment and disappearance compensate each other such that leks have the potential to persist for several decades after the original males have disappeared from them. In the third chapter, molecular analyses of paternity and behavioral observations were used to investigate the process of female mate choice at two spatial scales, within- and among-leks. Females moved beyond their regular home ranges to mate, suggesting that they increase travel costs to assess a larger number of potential mates. Although there was not a general preference for larger leks, females nesting close to small leks tended to travel further and mate at larger leks. Siring males were not less related to females or more heterozygous than expected by chance. Within leks, siring male were those with higher vocalization rates. Because vocalization rates change according to lek sizes, however, they should not be a reliable indicator of male quality in most leks.

Defense of Dissertation Committee