High impact information on Territoriality

• In many species, territoriality is expressed only during the breeding season, when plasma testosterone (T) is elevated [1].
• However, non-gonadal sex steroids may regulate winter territoriality (e.g. oestrogen synthesis by brain aromatase) [2].
• AVT increased courtship independent of status, while its effects on territoriality and aggression were dependent upon male status [3].
• Thus the pattern of androgen levels exhibited by reproductively active parental male midshipman may reflect a compromise between investment in paternal care versus courtship and/or territoriality [4].
• Here, we show that acute (1 day) fadrozole treatment decreases nonbreeding territoriality, suggesting relatively rapid estrogen effects [5].

Chemical compound and disease context of Territoriality

• Relative changes in testosterone between unpaired and paired females indicates that this hormone may play a role in mate acquisition and territoriality of these sex role-reversed females [6].
• Dominance indexes and androgen concentrations measured after all-male group formation were positively correlated with territoriality, courtship rate, and nest size [7].
• To our knowledge, these are the first data to suggest that nonbreeding territoriality is regulated by endogenous steroid hormones [8].
• For birds breeding in temperate areas, territoriality and courtship co-occur during spring and are mirrored by elevated plasma levels of luteinizing hormone (LH) and testosterone [9].
• Measurements of seasonal changes in circulating levels of the sex steroid hormones testosterone, progesterone, and estradiol indicated that testosterone levels in both sexes are elevated when territorial behavior is expressed, even during the period of nonbreeding-season territoriality during the summer [10].

Biological context of Territoriality

• Without controlling for phylogeny, breeding season length, type of territoriality, and altitude explained a significant proportion of the variance in testosterone levels [11].

References