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Synopsis Females of some species are considered sex-role reversed, meaning that they face stronger competition for mates compared to males. While much attention has been paid to behavioral and morphological patterns associated with sex-role reversal, less is known about its physiological regulation. Here, we evaluate hypotheses relating to the neuroendocrine basis of sex-role reversal. We refute the most widely tested activational hypothesis for sex differences in androgen secretion; sex-role reversed females do not have higher levels of androgens in circulation than males. However, we find some evidence that the effects of androgens may be sex-specific; circulating androgen levels correlate with some competitive phenotypes in sex-role reversed females. We also review evidence that sex-role reversed females have higher tissue-specific sensitivity to androgens than males, at least in some species and tissues. Organizational effects may explain these relationships, considering that early exposure to sex steroids can shape later sensitivity to hormones, often in sex-specific ways. Moving forward, experimental and correlative studies on the ontogeny and expression of sex-role reversal will further clarify the mechanisms that generate sex-specific behaviors and sex roles.
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Contrasting parental roles shape sex differences in poison frog space use but not navigational performance
Sex differences in vertebrate spatial abilities are typically interpreted under the adaptive specialization hypothesis, which posits that male reproductive success is linked to larger home ranges and better navigational skills. The androgen spillover hypothesis counters that enhanced male spatial performance may be a byproduct of higher androgen levels. Animal groups that include species where females are expected to outperform males based on life-history traits are key for disentangling these hypotheses. We investigated the association between sex differences in reproductive strategies, spatial behavior, and androgen levels in three species of poison frogs. We tracked individuals in natural environments to show that contrasting parental sex roles shape sex differences in space use, where the sex performing parental duties shows wider-ranging movements. We then translocated frogs from their home areas to test their navigational performance and found that the caring sex outperformed the non-caring sex only in one out of three species. In addition, males across species displayed more explorative behavior than females and androgen levels correlated with explorative behavior and homing accuracy. Overall, we reveal that poison frog reproductive strategies shape movement patterns but not necessarily navigational performance. Together this work suggests that prevailing adaptive hypotheses provide an incomplete explanation of sex differences in spatial abilities.
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- Award ID(s):
- 1845651
- PAR ID:
- 10454980
- Date Published:
- Journal Name:
- eLife
- Volume:
- 11
- ISSN:
- 2050-084X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.7554/eLife.80483
