Migrant and resident female songbirds differ in gonadal response to upstream stimulation during seasonal sympatry

Kimmitt, Abigail A.; Webb, Ashlee L.; Greives, Timothy J.; Ketterson, Ellen D.

doi:10.1016/j.ygcen.2020.113469

Cited by 5 publications

(1 citation statement)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Differences in secretion of androgens in response to GnRH challenge have been shown to correlate with integrated morphological and behavioral phenotypes in some male birds, suggesting that varying capacity to circulate androgens underlies phenotype expression (Cain and Pryke, 2017; McGlothlin et al, 2008b; Mills et al, 2008; Spinney et al, 2006). GnRH challenge studies in females that vary phenotypically are limited, with female White-throated Sparrow ( Zonotrichia albicolis ) morphs showing no difference in GnRH-induced testosterone levels, despite morph-specific variation in male GnRH response in the same species (Spinney et al, 2006), and a study of Dark-eyed Junco ( Junco hyemalis ) finding that response to GnRH might underlie differences in reproductive timing across populations (Kimmitt et al, 2020). Despite the commonality of female ornamentation in nature, there has been relatively little research on its mechanistic basis, leaving a gap in our understanding of the processes of signal evolution.…”

Section: Introductionmentioning

confidence: 99%

Does capacity to elevate androgens underlie variation in female ornamentation and territoriality in White-shouldered Fairywren (Malurus alboscapulatus)?

Boersma¹,

Enbody

Ketaloya

et al. 2023

Preprint

View full text Add to dashboard Cite

Historic bias toward study of male sex hormones and sexual signals currently constrains our perspective of hormone-behavior-phenotype relationships. Resolving how ornamented female phenotypes evolve is particularly important for understanding the diversity of social signals across taxa. Studies of both males and females in taxa with variable female phenotypes are needed to establish whether sexes share mechanisms underlying expression of signaling phenotypes and behavior. White-shouldered Fairywren (Malurus alboscapulatus) subspecies vary in female ornamentation, baseline circulating androgens, and response to territorial intrusion. The moretoni ornamented female subspecies show higher female, but lower male androgens, and a stronger pair territorial response relative to pairs from the lorentzi unornamented female subspecies. Here we address whether subspecific differences in female ornamentation, baseline androgens, and pair territoriality are associated with ability to elevate androgens following gonadotropin releasing hormone (GnRH) challenge and in response to simulated territorial intrusion. We find that subspecies do not differ in their capacity to circulate androgens in either sex following GnRH or territorial intrusion challenges. Whereas pre-GnRH androgens were somewhat predictive of degree of response to territorial intrusions, higher androgens were associated with lower territorial aggression. Post-GnRH androgens were not predictive of response to simulated intruders, nor did females sampled during intrusion elevate androgens relative to flushed controls, suggesting that increased androgens are not necessary for the expression of territorial defense behaviors. Collectively, our results suggest that capacity to produce and circulate androgens does not underlie subspecific patterns of female ornamentation, territoriality, and baseline androgens.

show abstract

Section: Introductionmentioning

confidence: 99%

Does capacity to elevate androgens underlie variation in female ornamentation and territoriality in White-shouldered Fairywren (Malurus alboscapulatus)?

Boersma¹,

Enbody

Ketaloya

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

Oxytocin influences parental care in male threespine stickleback across multiple time scales

Dan,

Maciejewski,

Schwaiger

et al. 2024

Hormones and Behavior

View full text Add to dashboard Cite

Females as the Gatekeepers to Seasonal Breeding: What We Can Learn by Studying Reproductive Mechanisms in Both Sexes

Kimmitt

2020

Integrative and Comparative Biology

View full text Add to dashboard Cite

Abstract Seasonal reproduction is a widespread adaptation in vertebrates, such that individuals time their reproductive efforts to match peak resource abundance. Individuals rely on environmental cues to regulate hormonal mechanisms governing timing of breeding. Historically, studies on physiological mechanisms of seasonal reproduction, specifically in birds, have disproportionately focused on males compared to females. For this review, I conducted a literature search of the last decade of avian research and found a persistent sex bias in the field of physiological mechanisms of seasonal reproduction. Using work conducted with the dark-eyed junco (Junco hyemalis) as a case study, I present a possible solution to combat the sex bias: natural comparisons of populations that differ in reproductive timing to investigate mechanisms of reproduction in both sexes. Populations of dark-eyed juncos that differ in migratory behavior (i.e., migrant and resident) exhibit overlapping ranges during winter and early spring; residents begin breeding in early spring prior to the departure of migrants. This system, and others like it, provides an opportunity to compare mechanisms of reproduction in populations that differ in reproductive timing despite experiencing the same environmental conditions in early spring. In juncos, migrant and resident females and males exhibit similar patterns of hypothalamic regulation of reproduction in early spring, but sex differences in gonadal sensitivity between the populations could be an important distinction that partially explains sex differences in reproductive development. Comparing mechanisms of reproduction in free-living populations and in captivity can reveal important mechanisms that determine the onset of reproductive development, as well as potential sex differences in these mechanisms. Understanding the mechanisms of reproductive phenology has important implications for understanding how species will survive and reproduce in a changing climate.

show abstract

Migrant and resident female songbirds differ in gonadal response to upstream stimulation during seasonal sympatry

Cited by 5 publications

References 52 publications

Does capacity to elevate androgens underlie variation in female ornamentation and territoriality in White-shouldered Fairywren (Malurus alboscapulatus)?

Does capacity to elevate androgens underlie variation in female ornamentation and territoriality in White-shouldered Fairywren (Malurus alboscapulatus)?

Oxytocin influences parental care in male threespine stickleback across multiple time scales

Females as the Gatekeepers to Seasonal Breeding: What We Can Learn by Studying Reproductive Mechanisms in Both Sexes

Contact Info

Product

Resources

About