Role of small rodent in the seed dispersal process: Microcavia australis consuming Prosopis flexuosa fruits

CLAUDIA M. CAMPOS; CAMPOS VALERIA; GIANNONI S.; RODRIGUEZ D.; ALBANESE S.; CONA, M.I.

AUSTRAL ECOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2017 vol. 42 p. 113 - 119

1442-9985

Understanding the functional role of animal species in seed dispersal is central to determining howbiotic interactions could be affected by anthropogenic drivers. In the Monte Desert, mammals play differentfunctional roles in Prosopis flexuosa seed dispersal, acting as opportunistic frugivores (endozoochorous medium-sized and large mammals) or seed hoarders (some small sigmodontine rodents). Our objective was assessing thefunctional role of Microcavia australis, a small hystricognathi rodent, in the fruit removal and seed depositionstages of P. flexuosa seed dispersal, compared to sympatric sigmodontine rodents. In situ, we quantified fruitremoval by small rodents during non-fruiting and fruiting periods, and determined the distance seeds were trans-ported, particularly by M. australis. In laboratory experiments, we analysed how M. australis stores seeds(through scatter- or larder-hoarding) and how many seeds are left in caches as living seeds, relative to previousdata on sigmodontine rodents. To conduct field studies, we established sampling stations under randomly cho-~sen P. flexuosa trees at the Nacu~n an Man and Biosphere Reserve. We analysed fruit removal by small rodentsand seed dispersal distance by M. australis using camera traps focused on P. flexuosa fruits covered with wirescreen, which only allowed entry of small animals. In laboratory trials, we provided animals with a known num-ber of fruits and assessed seed conditions after removal. Small rodents removed 75.7% of fruit supplied duringthe non-fruiting period and 53.2% during the fruiting period. Microcavia australis and Graomys griseoflavus werethe main fruit removers. Microcavia australis transported seeds to a mean distance of 462 cm and cached seedsmainly in scatter-hoards, similarly as Eligmodontia typus. All transported seeds were left in fruit segments or cov-ered only by the endocarp, never as predated seeds. Microcavia australis disperses P. flexuosa seeds by carryingfruits away from a source to consume them and then by scatter-hoarding fruits and seeds.