IBIGEO   22622
INSTITUTO DE BIO Y GEOCIENCIAS DEL NOA
Unidad Ejecutora - UE
artículos
Título:
Natural history, distribution and conservation of two nomadic Sporophila seedeaters specializing on bamboo in the Atlantic Forest.
Autor/es:
ARETA JI; BODRATI A; THOM G; EISEN RUPP A; VELAZQUEZ M; HOLZMANN I; CARRANO C; ZIMMERMAN CE
Revista:
THE CONDOR
Editorial:
COOPER ORNITHOLOGICAL SOC
Referencias:
Año: 2013 vol. 115 p. 237 - 252
ISSN:
0010-5422
Resumen:
Semelparous woody bamboos flower fairly synchronously and in clocklike fashion after many years,providing abundant and nutritious seeds. However, this resource is ephemeral, localized, and unpredictable from theperspective of birds that feed on those seeds. Birds specializing on bamboo seeds track this food source and are nomadic.We recorded Temminck?s Seedeater (Sporophila falcirostris) at 29 localities and the Buffy-fronted Seedeater(S. frontalis) at 23 localities in Argentina, Paraguay, and southeastern Brazil. In these species, nomadism is unassociatedwith any seasonal factor: birds may persist year round over several consecutive years if the seed supply is constantenough. Most occurrences and all breeding records were related to masting of bamboo; records of isolated birdsaway from seeding bamboo must represent individuals searching for bamboo patches. We report winter breeding ofthese species for the first time and demonstrate that the supply of bamboo seeds is the main limitation to their breeding.On a broad spatiotemporal scale, large-seeded bamboos (e.g., Guadua spp.) may function as strong populationpumps, small-seeded bamboos (e.g., Chusquea spp.) as maintenance stations. Both species fed mostly on bambooseeds, occasionally on bamboo flowers, and rarely on alternative food sources. They consumed insects frequentlyand occurred in mixed-species flocks, especially during autumn and winter. Creation of a network of protected areasis essential to preserve bamboo patches that flower at different times and localities in sufficiently large quantities toguarantee the long-term survival of the peculiarly dynamic populations of bamboo seedeaters.