Effects of episodic bamboo mast seeding on top predators in the southern Andes

• DOI: 10.1111/aec.12618
• Publication Date: 2018-05-15T04:16:29Z
• Authors: Valeria Ojeda; Laura Chazarreta
• Keywords: Tyto; Barn-owl

Abstract Woody bamboos that undergo masting on a cyclic basis constitute large‐scale endogenous disturbances in forests of America, Africa and Asia, driving long‐ short‐term effects community structure dynamics. Among the transient these nonequilibrial phenomena are rodent outbreaks whose potential bottom‐up consequences top predators have never been explored. We investigated unpredictable assemblage nocturnal raptors southern Andes after (>140 000 ha), spatially heterogeneous, Chusquea culeou event north Argentine Patagonia. compared owl numbers behaviours between pre‐masting (2009) post‐masting (2011) at subsidized (outbreaking rodents) unsubsidized (normal contiguous sites. Both generalist (opportunistic forest resident) rodent‐specialist (forest‐facultative) owls were monitored, with emphasis resident territorial rufous‐legged ( Strix rufipes ). The behaved as predicted, perceiving increases soon gathering sites, while apparently relaxing territoriality. Contrary to our predictions, later outbreak phase, turned inconspicuous, coinciding – causally or not an irruption forest‐facultative barn Tyto alba tuidara ), influx some open country short‐eared Asio flammeus suinda , which took chance breed woods). Considering whole period, besides significant changes owls’ numbers, we recorded notable adjustment foraging modes response food surplus (consuming prey heads only), null interference among all observed species. This study provides first quantitative assessment bamboo episodic carnivores globally, contributes novel data indirect events South America.