Habitat selection by two species of small mammals in the Atlantic Forest, Brazil: Comparing results from live trapping and spool-and-line tracking

Abstract

Habitat selection by small mammals is usually evaluated using data from live trapping, which provides little information about the movements of individuals. Few studies used movement data or compared the results of different sampling methods to study habitat selection by these animals. We evaluated habitat selection by the rodent Nectomys squamipes and the marsupial Micoureus paraguayanus in the Atlantic Forest of Brazil using the spool-and-line technique. We also determined if percentage of captures reflected the amount of movements in each habitat. Habitat selection was determined comparing use and availability of five habitat types at two spatial scales (movement paths and movement areas) using compositional analysis, which allowed ranking of habitats according to their relative use by animals. The use of available habitat types was non-random for both species at both spatial scales. The two species had contrasting habitat affinities directly related to their particular habits, with N. squamipes using predominantly the stream habitat, and M. paraguayanus using mainly the restinga forest habitat. Patterns of habitat selection were similar at both spatial scales probably due to the small size of movement areas, which may not represent habitat use at a broader scale. For both species, live trapping and movement data provided the same ranking in habitat use, demonstrating that simple capture indices may be used to study habitat selection by these species across different habitat types.