Habitat selection of the arboreal marsupial Dromiciops gliroides and potential effects on the seed dispersal of the mistletoe Tristerix corymbosus

Habitat selection of seed-dispersing animals influences where seeds are deposited, seedling establishment, and population dynamics. In the Patagonian temperate forests there is a key mutualistic relationship between the mistletoe Tristerix corymbosus and its seed disperser, the nocturnal arboreal marsupial Dromiciops gliroides. In this study, we analyzed the habitat selection of D. gliroides at two different habitat scales: site selection and step selection. Also, we analyzed if the selected microsites by this marsupial are suitable for the establishment of T. corymbosus. We captured 24 individuals in Parque Municipal Llao Llao (San Carlos de Bariloche, Argentina) during the austral summer of 2014 and 2015. The captured individuals were equipped with a spool and line device to register habitat use: substrate, vegetation cover, diameter and angle of branches. We used a conditional hierarchical logistic Bayesian regression at each habitat scale. We found that, at the site scale, D. gliroides selected habitats with more shrub cover and, at the step scale, D. gliroides selected more T. corymbosus host species. Besides, our results show that D. gliroides selected branches with intermediated size (4–10 cm) and also horizontal branches. The relationship between the selected sites and those where it deposits the T. corymbosus seeds suggests that the marsupial dispersing the seeds to suitable hosts and branch sizes. Therefore, the behavior of D. gliroides would be favoring the regeneration of T. corymbosus.