Corticosterone regulation in house sparrows invading Senegal
What traits help organisms expand their ranges? Several behavioral and life history traits have been identified,
but physiological and especially endocrinological factors have been minimally considered. Here,
we asked whether steroid hormonal responses to stressors might be important. Previously, we found that
corticosterone (CORT) responses to a standard restraint stressor were stronger at a range edge than at the
core of the recent house sparrow (Passer domesticus) invasion of Kenya. In related work in the same system,
we found that various behaviors (exploratory activity, responses to novelty, etc.) that are affected by
CORT in other systems varied among sparrow populations in a manner that would suggest that CORT regulation
directly influenced colonization success; birds at the range edge were less averse to novelty and
more exploratory than birds from the core. Here, we asked whether the pattern in CORT regulation we
observed in Kenya was also detectable in the more recent (1970) and independent invasion of
Senegal. We found, as in Kenya, that Senegalese range-edge birds mounted stronger CORT responses to
restraint than core birds. We also found lower baseline CORT in range–edge than core Senegalese birds,
but little evidence for effects of individual sex, body mass or body size on CORT. Follow-up work will be
necessary to resolve whether CORT regulation in Senegal (and Kenya) actively facilitated colonization
success, but our work implicates glucocorticoids as a mediator of range expansion success, making stress
responses potentially useful biomarkers of invasion risk
Auteur(s) : Lynn B. Martin a,?, Holly J. Kilvitis a, Massamba Thiam b, Daniel R. Ardia
Pages : 15-20
Année de publication : 2017
Revue : General and Comparative Endocrinology
N° de volume : 250
Type : Article
Mise en ligne par : THIAM Massamba