Abstract

RAMOS-PALACIOS, Carlos Renato  and  BADANO, Ernesto I.. The relevance of burial to evade acorn predation in an oak forest affected by habitat loss and land use changes. Bot. sci [online]. 2014, vol.92, n.2, pp.299-308. ISSN 2007-4476.

Seed burial has been proposed as an effective mechanism to evade predation in continuous forests. However, its relevance may be compromised in fragmented forests because: (1) predators are usually concentrated within forests patches, which elevates consumer pressure on seeds; and (2) fragmentation reduces seed production in remnant trees, decreasing food availability for seed consumers. Thus, predators might be forced to consume buried seeds after seeds on the soil surface are depleted. Indeed, they may explore the surrounding matrix in search of food when seeds within patches become scarce. This study assesses these issues in a fragmented oak forest where human activities have generated four habitat types: forest patches, patch edges, matrix habitat surrounding patches, and an abandoned agricultural field in the neighborhoods of the fragmented forest. In this landscape, we assessed what animals consume acorn and compared removal rates between buried acorns and acorns exposed on the soil surface across these habitat types. Mice of the genus Peromyscus and birds of the genus Aphelocoma were the main responsible of removing acorns in all habitats types, but mice were only recorded during night and birds were only recorded during day. Buried acorns were less removed (12-35%) than exposed ones (42-68%) in the matrix habitat and the abandoned field. Nevertheless, within forest patches and their edges, buried (78-81%) and exposed acorns (91%) showed no differences in removal rates. These results suggest that burial may be an effective mechanism to evade acorn predation in habitats strongly affected by human activities, while it would have little relevance within forest patches.

Keywords : birds; fragmentation; Mexico; mice; seed predation.

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