The vocal behaviour of long-tailed manakins (Chiroxiphia linearis): The role of vocalizations in mate attraction and male-male interactions

Tropical birds are little studied relative to temperate birds, despite the fact that tropical species often exhibit unique behaviours, not seen in the temperate-zone. I explore the link between male vocal behaviour and female movement in neotropical lekking Long-tailed Manakins (Chiroxiphia linearis) using acoustic recordings to monitor male vocalizations and a novel telemetry system to monitor female visitation behaviour. I report surprisingly few relationships between male vocalizations and female visitation behaviour, in contrast to results from another long-term study population in a different habitat. I examine the timing of male calling behaviour, showing that males avoid overlapping known neighbours, but actively overlap unknown intruders simulated through playback. Overall, my thesis provides insight into acoustic communication in manakins, revealing that male vocalizations play less of a role than expected in female mate choice, and that males modify the timing of their calls in response to the vocalizations of other nearby individuals

The socioecology of Monk Parakeets: Insights into parrot social complexity

In many species, individuals benefit from social associations, but they must balance these benefits with the costs of competition for resources. Understanding how these competing factors generate diversity in social systems is a major goal of behavioral ecology, but one that has been hampered by a lack of basic data quantifying many aspects of social structure and associations. Although parrots are generally assumed to have complex social groups, few studies have quantitatively examined these assumptions about parrot social structure. We critically assessed 4 assumptions about parrot socioecology using data from captive and wild groups of Monk Parakeets (Myiopsitta monachus). We evaluated (1) whether pairs are the fundamental unit of parrot social structure, (2) the patterns and extent of fission–fusion dynamics, (3) patterns of aggression and dominance hierarchy structure, and (4) whether individuals share foraging information. We found evidence that supported pairs as the fundamental unit of social structure, although these close associates were not always heterosexual breeding pairs and were sometimes trios. Fission and fusion of subgroups were common, and the amount of fission–fusion dynamics varied across flock types and by fission–fusion dimension, but the amount of variation among dimensions was consistent across replicate captive social groups. Despite these levels of fission–fusion dynamics, study of aggressive interactions in our 2 captive groups indicated that dominance hierarchies existed. Hierarchies were moderately linear (0.7) but not steep