Kerry M. Borkin

Sex-Specific Roost Selection by Bats in Clearfell Harvested Plantation Forest: Improved Knowledge Advises Management

To maximize energetic savings, female bats often roost communally whilst pregnant or with non-volant dependents, whereas male bats more often roost alone; however, differences in selection of roosts by sex have not often been investigated. Better understanding of female colony locations could focus management to protect the majority of bats. New Zealands long-tailed bat (Chalinolobus tuberculatus) roost in exotic plantation forest, where sex-specific roost selection has not been investigated, and therefore such management is not possible. We investigated sex-specific roost selection by long-tailed bats for the first time. Roosts and paired nonroosts were characterized testing predictions that males and females select roosts that differ from non-roosts, and males and females select different roosts. Females and males chose Pinus radiata roosts that differed from non-roost trees. Results suggest each sex chose roosts that maximized energetic savings. Female bats used roosts closer to water sources, that warmed earlier in the day, which allowed maintenance of high temperatures. Males appeared to choose roosts that allowed torpor use for long periods of the day. Males may be less selective with their roost locations than females, as they roosted further from water sources. This could allow persistence of male bats in marginal habitat. As all female long-tailed bats chose roosts within 150 m of waterways, management to protect bats could be focused here. To protect bats least able to escape when roosts are harvested, harvest of forest stands selected by female bats as roost sites should be planned when bats are not heavily pregnant nor have non-volant dependents.

Plantation forests are used by the lesser short-tailed bat, Mystacina tuberculata rhyacobia

Abstract Lesser short-tailed bats, Mystacina tuberculata rhyacobia, use Pinus radiata plantation forests within the central North Island of New Zealand for foraging, commuting, and roosting. These plantations are generally contiguous with a large native forested area from which this species is already known. Short-tailed bats have been detected using native remnants and reserves within plantations, and have been radio-tracked to long-dead native tree roosts within young Pinus radiata stands. We provide the first list of exotic plantations known to be used by short-tailed bats.