Simulating winning in the wild — The behavioral and hormonal response of black redstarts to single and repeated territorial challenges of high and low intensity

Phenotypic differences between the sexes in the sexually plastic mangrove rivulus fish (Kryptolebias marmoratus)

“…Androgens are an essential mediator of the development and activation of male-specific behavioral expression (Apfelbeck et al, 2011;Arnold and Breedlove, 1985;Burmeister and Wilczynski, 2000;Godwin, 2010;Wingfield, 2005). It was, however, peculiar that males had elevated levels of estradiol compared with hermaphrodites, which is inconsistent with findings in most other sex-changing teleosts (Godwin, 2010).…”

The challenge hypothesis across taxa: social modulation of hormone titres in vertebrates and insects

“…For example, males in multibrooded avian species typically show a greater androgen response to territorial challenge than males from single-brooded species . Contextual and cognitive factors are also likely to play important roles in the type and extent of androgen responsiveness (Apfelbeck, Stegherr, & Goymann, 2011;Salvador & Costa, 2009). As a result, current research is exploring whether androgen responsiveness is influenced by an individual's perception of the challenge.…”

Does a short-term increase in testosterone affect the intensity or persistence of territorial aggression? — An approach using an individual's hormonal reactive scope to study hormonal effects on behavior

“…Unlike the song sparrow and a few other species, the majority of birds tested so far do not show a testosterone surge after simulated territorial intrusions (see [14][15][16][17][18][19][20][21][22][23] for recent studies and a review [24] for studies conducted before 2007). This includes the black redstart (Phoenicurus ochruros), a socially monogamous and bi-parental songbird of the western Palaearctic, and our main study species regarding territorial aggression (e.g.…”

“…This includes the black redstart (Phoenicurus ochruros), a socially monogamous and bi-parental songbird of the western Palaearctic, and our main study species regarding territorial aggression (e.g. [15][16][17]). Although black redstarts do not increase testosterone in response to simulated territorial intrusions, they have the hormonal reactive scope to do so (and may increase testosterone following other cues, i.e.…”