Androgen-armoured amazons: reversed sex roles in coucals are associated with testosterone in females but not males

Proceedings of the Royal Society B Biological Sciences, Journal Year: 2023, Volume and Issue: 290(1995)

Published: March 29, 2023

In some species, sexual selection is stronger in females than males. classically polyandrous birds, for instance, compete mating opportunities and males care offspring. Sex steroids such as testosterone have been suggested to regulate the behaviours of ‘role-reversed’ males, but comparative studies did not find evidence a role relation sex roles. However, large variability hormone measurements across laboratories may prevent detecting subtle differences levels. To circumvent this caveat, I compared steroid concentrations two closely related cohabiting species with different systems: black coucal ( Centropus grillii ) monogamous white-browed C. superciliosus ). Baseline gonadotropin-releasing (GnRH)-induced were twice high female coucals coucals, low pre-breeding progesterone consistent progesterone's modulatory during agonistic interactions species. GnRH-induced differ between both This study provides first that elevated associated sex-role-reversed traits females, whereas levels be necessary facilitate sex-role reversal

Language: Английский

---

Levels of Sex Steroids in Plethodontid Salamanders: A Comparative Study Within the Genus Aneides

Ecology and Evolution, Journal Year: 2024, Volume and Issue: 14(11)

Published: Nov. 1, 2024

Derived monomorphism is a condition in which males and females are phenotypically similar, but the similarity derived. typically evolves from sexual dimorphism or different monomorphic state. We examined hormonal basis of derived salamander genus

Language: Английский

---

Adaptive Response to Gillnets Bycatch in a North Sardinia Mediterranean Shag (Gulosus aristotelis desmarestii) Population

Animals, Journal Year: 2023, Volume and Issue: 13(13), P. 2142 - 2142

Published: June 29, 2023

Mediterranean Shag (Gulosus aristotelis desmarestii) is a seabird endemic to the and Black Seas, recently included in IUCN list of threatened Species. Most reproductive colonies are hosted Sardinia surrounding islets. Bycatch fishing nets one most significant threats for this population. Our work aimed assess alterations sex ratio caused by bycatch study adaptive response population skewed adult ratio. The Shags found drowned gillnets near that nestlings Corcelli (northeast Sardinia) colony was determined using sex-linked polymorphism gene Chromobox-Helicase-DNA-binding 1. data shags evidenced high mortality rate (83.3%; p < 0.001) larger size males (35% heavier than females, 0.05) compared supporting theory individuals able forage at great depths. With 64.8% being male, statistically different from parity (p 0.05). Furthermore, it related brood size. In one- two-chick broods, 73% 70% nestlings, respectively, were males, while three-chick only 33% males. identify higher male as factor causing an alteration According Sex Allocation Theory, adjustment made females restores Mendelian

Language: Английский

---

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

Hormones and Behavior, Journal Year: 2023, Volume and Issue: 154, P. 105393 - 105393

Published: June 16, 2023

Language: Английский

---