Habitat use and nocturnal activity of lesser short‐tailed bats(Mystacina tuberculata)in comparison with long‐tailed bats(Chalinolobus tuberculatus)in temperate rainforest

Abstract

Habitat use and nocturnal activity patterns of the threatened lesser short-tailed bat (Mystacina tuberculata) were sampled during late spring and early summer using automatic bat detector units in temperate beech (Nothofagus) rainforest in Fiordland, New Zealand. Detector units recorded the number of bats passing per hour as an index of activity. Habitat use patterns were compared with longtailed bats (Chalinolobus tuberculatus) sampled concurrently. Activity levels in lesser short-tailed bats varied significantly among five habitat types and amongst hours of the night. Of the total activity recorded, most passes (82.6% of n = 657 bat passes) were in red beech forest >200 m from the forest edge; 13.7% were in silver beech within 100 m of forest edges, 2.6% were along roads through forest, 0.9% were on the forest-grassland edge, and 0.2% were in the open grassland. Lesser short-tailed bats were active throughout the night but especially at dawn and dusk. There was no correlation between levels of activity by lesser short-tailed bats and overnight minimum or dusk temperatures. Patterns of habitat use and activity in long-tailed bats were significantly different from those of lesser short-tailed bats. Z06009; Online publication date 19 April 2006 Received 20 December 2005; accepted 3 April 2006Of the total activity recorded, most (56.0% of n = 2929 bat passes) was along forest-grassland edges; 15.7% of passes were in open grassland, 13.1% were along roads through forest, 11.0% were in silver beech forest within 100 m of forest edges, and 4.2% within red beech forest. The implications of these findings for conservation and for improving survey techniques are discussed. For example, lack of use of open and edge habitats by lesser short-tailed bats suggests they would not adapt to highly fragmented and cleared forest habitats. The two species of New Zealand bat used available habitats differently while inhabiting the same sites. Therefore, a range of habitats, including forest interior, forest edges and grasslands, are required to sustain both species within reserves and management areas. Surveys for lesser short-tailed bats should focus on mature forest stands >200 m into the forest to maximise the chance of encountering this species, whereas surveys for long-tailed bats would best focus on forest edges.

Large Home Range Size in the Ground Foraging Bat,Mystacina tuberculata, in Cold Temperate Rainforest, New Zealand

“…The low levels of overlap recorded in this study, and the similarity to previous colonial home range estimates of 130 km 2 , indicates that 150 km 2 is a good estimate of the colonial home ranges for M. tuberculata in the Eglin ton Valley. Furthermore, the long narrow shape of the home ranges is likely driven by the location of preferred habitat, red beech dominant forest interiors (O'Donnell et al, 2006), which only occurs on the valley floor and lower slopes. Although radio transmitters have been used to locate roosts in this species (e.g., Sedgeley, 2003;Lloyd, 2005) Ranges (Lloyd, 2005), could also have large colonial home ranges, in contrast to populations present on offshore islands, such as Codfish Island and Little Barrier Island (Arkins et al, 1999;Lloyd, 2005;O'Donnell et al, 2010) which should have relatively small ranges, as they are restricted by island size.…”

“…Population persistence may require the entire foraging range to be protected, as inadequate food resource availability, may threaten bat population viability (Findley, 1993;Ge rell and Lundberg, 1993). Furthermore, lack of use of open and edge habitats (O'Donnell et al, 2006), except for commuting to other forest areas , suggests M. tuberculata would not thrive in highly fragmented forest habitats. Protecting large continuous tracts of forest maximises the chances of M. tuberculata population persistence.…”

Influence of winter weather conditions on lesser short‐tailed bat(Mystacina tuberculata)activity inNothofagusforest, Fiordland

“…Lesser short-tailed bats live in old growth indigenous forest, and roost in cavities in mature trees (Daniel 1979;Daniel & Williams 1984;O'Donnell et al 1999;Sedgeley 2003;O'Donnell et al 2006). They are gleaners, catching prey on or near surfaces (Parsons 1997;O'Donnell et al 1999;Jones et al 2003), feeding mainly on arthropods, but also taking pollen and plant matter (Daniel 1976(Daniel , 1979Arkins 1996;Arkins et al 1999 Zoology, 2006, Vol.…”

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

“…In the Eglinton Valley's Nothofagus forest, shorttailed bats were more often detected in the forest interior (82.6% of all calls recorded were more than 200 m from the forest edge), than along forest edges and roads through the forest (only 3.5%) (O'Donnell et al 2006). Longtailed bats (Chalinolobus tuberculatus) within the same valley used the habitat quite differently, so surveys designed to detect the presence of long-tailed bats will not be effective at detecting short-tailed bats.…”

“…Difficulties in detecting lesser short-tailed bats Short-tailed bats are difficult to detect because they more often use forest interiors than forest edges (O'Donnell et al 2006) and because their echolocation calls are emitted at relatively low intensity (S Parsons unpublished data). In the Eglinton Valley's Nothofagus forest, shorttailed bats were more often detected in the forest interior (82.6% of all calls recorded were more than 200 m from the forest edge), than along forest edges and roads through the forest (only 3.5%) (O'Donnell et al 2006).…”