INIBIOMA   20415
INSTITUTO DE INVESTIGACIONES EN BIODIVERSIDAD Y MEDIOAMBIENTE
Unidad Ejecutora - UE
artículos
Título:
Effects of episodic bamboo mast seeding on top predators in the southern Andes
Autor/es:
CHAZARRETA, L.; OJEDA, V
Revista:
AUSTRAL ECOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2018
ISSN:
1442-9985
Resumen:
Woody bamboos that undergomasting on a cyclic basis constitute large-scale endogenous disturbances in forestsof America, Africa, and Asia, driving long and short-term effects on communitystructure and dynamics. Among the transient effects of these nonequilibrialphenomena are rodent outbreaks whose potential bottom-up consequences on top predatorshave never been explored. We investigated the effects of unpredictable rodentoutbreaks on the assemblage of nocturnal raptors of the southern Andes after alarge-scale (>140.000 ha), spatially heterogeneous, Chusquea culeou masting event in north Argentine Patagonia. We comparedowl numbers and behaviours between pre-masting (2009) and post-masting(2011) at subsidised (outbreaking rodents) and unsubsidised (normal rodents) contiguoussites. Both generalist (opportunistic forest resident) and rodent-specialist (forest-facultative)owls were monitored, with emphasis on the resident territorial Rufous-leggedowl (Strix rufipes). The resident owls behavedas predicted, perceiving the rodent increases soon andgathering at subsidised sites, while apparently relaxing territoriality.Contrary to our predictions, later at the rodent outbreak phase, residentterritorial owls turned inconspicuous, coinciding -causally or not- with an irruptionof forest-facultative Barn owls (Tytoalba tuidara), and influx of some open country Short-eared owls (Asio flammeus suinda, some of which took a chance to breed in the woods). Considering thewhole rodent outbreak period, besides significant changes in owls? numbers, werecorded a notable adjustment in owls? foraging modes in response to food surplus (consuming prey heads only), and null interferencebehaviours among all observed species. This study provides a first quantitativeassessment of the effects of bamboo episodic masting on top carnivoresglobally, and contributes novel data on the indirect effects of these events inforests of South America.