Spring phenology of ecological productivity contributes to the use of looped migration strategies by birds.
Proc Biol Sci
; 281(1793)2014 Oct 22.
Article
em En
| MEDLINE
| ID: mdl-25209934
ABSTRACT
Migration is a common strategy used by birds that breed in seasonal environments. The patterns and determinants of migration routes, however, remain poorly understood. Recent empirical analyses have demonstrated that the locations of two North America migration flyways (eastern and western) shift seasonally, reflecting the influence of looped migration strategies. For the eastern but not western flyway, seasonal variation in atmospheric circulation has been identified as an explanation. Here, we test an alternative explanation based on the phenology of ecological productivity, which may be of greater relevance in western North America, where phenology is more broadly dictated by elevation. Migrants in the western flyway selected lower-elevation spring routes that were wetter, greener and more productive, and higher-elevation autumn routes that were less green and less productive, but probably more direct. Migrants in the eastern flyway showed little season variation but maintained associations with maximum regional greenness. Our findings suggest the annual phenology of ecological productivity is associated with en route timing in both flyways, and the spring phenology of ecological productivity contributes to the use of looped strategies in the western flyway. This fine-tuned spatial synchronization may be disrupted when changing climate induces a mismatch between food availability and needs.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Aves
/
Migração Animal
/
Meio Ambiente
Tipo de estudo:
Prognostic_studies
Limite:
Animals
País como assunto:
America do norte
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article