title: Intra- and interspecific challenges modulate cortisol but not androgen levels in a year-round territorial damselfish.
abstract: Interactions between individuals of different species are commonplace in animal communities. Some behaviors displayed during these interspecific social interactions may be very similar to those displayed during intraspecific social interactions. However, whether functional analogies between intra- and interspecific behaviors translate at the proximate level into an overlap in their underlying endocrine mechanisms remains largely unknown. Because steroids both mediate social behaviors and respond to them, we approached this question by comparing the behavioral and steroid response of free-living dusky gregories (Stegastes nigricans) to standardized territorial intrusions (sTI) of either conspecific or heterospecific food competitors. Stegastes nigricans is a year-round territorial fish that 'cultivates' the algae on which it feeds and is highly aggressive to both intra- and interspecific intruders. Behavioral differences between intra- and interspecific aggressive responses to sTI were marginal, and sTI tests caused an increase in cortisol levels that was positively related with the levels of aggression. In contrast, androgen levels did not increase in response to sTI, yet they showed a positive relationship with agonistic behavior. These results parallel a pattern that was first described for year-round territorial bird species. Furthermore, they suggest that changes in endocrine-hormone levels during territoriality might be independent of the species that induces the territorial response.
authors.affiliation: Université de Neuchâtel, CH-2000 Neuchâtel, Switzerland albert.ros@unine.ch.
authors.forename: Albert F H
authors.initials: AF
authors.lastname: Ros
authors.affiliation: Université de Neuchâtel, CH-2000 Neuchâtel, Switzerland Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
authors.forename: Philippe
authors.initials: P
authors.lastname: Vullioud
authors.affiliation: Université de Neuchâtel, CH-2000 Neuchâtel, Switzerland College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4SB, UK.
authors.forename: Rick
authors.initials: R
authors.lastname: Bruintjes
authors.affiliation: Université de Neuchâtel, CH-2000 Neuchâtel, Switzerland.
authors.forename: Armelle
authors.initials: A
authors.lastname: Vallat
authors.affiliation: Université de Neuchâtel, CH-2000 Neuchâtel, Switzerland.
authors.forename: Redouan
authors.initials: R
authors.lastname: Bshary
mesh_terms: D000374:Aggression; D000728:Androgens / Q000097:blood*; D000818:Animals; D001522:Behavior, Animal; D003163:Competitive Behavior; D006854:Hydrocortisone / Q000097:blood*; D010473:Perciformes / Q000097:blood* / Q000502:physiology; D012621:Seasons; D013731:Territoriality; D013739:Testosterone / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D000728:Androgens; D013739:Testosterone; D006854:Hydrocortisone
keywords: 11-ketotestosterone; Cortisol; Interspecific behavior; Teleost; Territorial aggression; Testosterone