Behavioral and physiological traits of migrant and resident White-crowned Sparrows: a common garden approach

• DOI: 10.1242/jeb.148171
• Publication Date: 2017-02-10T01:50:18Z
• Authors: Marilyn Ramenofsky; Andrew W. Campion; Jonathan H. Pérez; Jesse S. Krause; Zoltán Németh
• Keywords: Subspecies; Corticosterone

To accommodate a migratory life history, migrants express greater number of physiological and behavioral stages per annum than residents are thus considered to have higher finite state diversity (FSD). investigate the mechanisms constraints associated with migration, direct comparison two subspecies white-crowned sparrow - migrant, Zonotrichia leucophrys gambelii, resident, Z. l. nuttalli were made under common garden conditions photoperiod housing, as birds progressed from winter through vernal history stages. We tested hypothesis that (higher FSD) respond differently (lower initial predictive cue, photoperiod, initiate integrate progression prenuptial molt, migration development breeding. If differences in phenology noted, then basis for distinctions was genetic. Results indicate (1) had lower threshold elevations plasma androgen, growth reproductive structures preceding those migrants; (2) only displayed preparations restlessness; (3) neither baseline nor stress-induced corticosterone differed across subspecies, suggesting energetic demands insufficient induce differential adrenocortical response either highlighting impact environmental on secretion. Thus, experiment, gambelii responds execute breeding shared stage nuttalli, confirming genetic differences.