Biology subjects

Moore, I. T.

Publications and source records attributed to Moore, I. T..

3 recordsLinked to original sources

bioRxiv2018

Testosterone drives status-specific patterns of cooperation and transmission of behavior in a social network

Stable cooperation requires plasticity whereby individuals are able to express competitive or cooperative behaviors depending on social context. To date, however, the physiological mechanisms that underlie behavioral variation in cooperative systems are poorly understood. We studied hormone-mediated behavior in the wire-tailed manakin (Pipra filicauda), a gregarious songbird whose cooperative partnerships are crucial for fitness. We used automated telemetry to monitor > 36,000 cooperative interactions among male manakins over three field seasons, and we examined how circulating testosterone affects cooperation using > 500 hormone samples. Observational data show that in non-territorial floater males, high testosterone is associated with increased cooperative behaviors and subsequent ascension to territorial status. In territory-holding males, however, both observational and experimental evidence demonstrate that high testosterone antagonizes cooperation. Moreover, circulating testosterone explains significant variation (2-8%) in social behavior within each status class. Collectively, our findings show that the hormonal control of cooperation depends on a males social status. We propose that the status-dependent reorganization of hormone-regulatory pathways can facilitate stable cooperative partnerships, and thus provide direct fitness benefits for males.

animal behavior and cognition↗

bioRxiv2018

Co-regulation of hormone receptors, neuropeptides, and steroidogenic enzymes across the vertebrate social behavior network

The vertebrate basal forebrain and midbrain contain a set of interconnected nuclei that control social behavior. Conserved anatomical structures and functions of these nuclei have now been documented among fish, amphibians, reptiles, birds and mammals, and these brain regions have come to be known as the vertebrate social behavior network (SBN). While it is known that nuclei (nodes) of the SBN are rich in steroid and neuropeptide activity linked to behavior, simultaneous variation in the expression of neuroendocrine genes among several SBN nuclei has not yet been described in detail. In this study, we use RNA-seq to profile gene expression across seven brain regions representing five nodes of the vertebrate SBN in a passerine bird, the wire-tailed manakin Pipra filicauda. Using weighted gene co-expression network analysis (WGCNA), we reconstructed sets of coregulated genes, revealing striking patterns of variation in neuroendocrine gene expression across the SBN. We describe regional expression variation networks comprising a broad set of hormone receptors, neuropeptides, steroidogenic enzymes, catecholamines, and other neuroendocrine signaling molecules. Our findings highlight how heterogeneity of brain gene expression across the SBN can provide functional insights into the neuroendocrine and genetic mechanisms that underlie vertebrate social behavior.

neuroscience↗

bioRxiv2017

Male parental investment reflects the level of partner contributions and brood value in tree swallows

Biparental care presents an interesting case of cooperation and conflict between unrelated individuals. Several models have been proposed to explain how parents should respond to changes in each others parental care to maximize their own fitness, predicting no change, partial compensation, or matching effort as a response. Here, we present an experiment in tree swallows (Tachycineta bicolor) in which we increased the parental care of females by presenting them, but not their mates, with additional nestling begging calls using automated playbacks. We performed this experiment in two populations differing in future breeding opportunities and thus the intensity of conflict over current parental care. We found that in response to a temporary increase in female parental effort, males in the northern population with lower sexual conflict matched the increased effort, whereas males in the southern population did not. We also found that increases in parental care during playbacks were driven by the females (i.e., females initiated the increased effort and their mates followed them) in the northern population but not the southern population. These results support the idea that with incomplete information about the brood value and need, cues or signals from the partner might become important in coordinating parental care.

animal behavior and cognition↗