Day-roosting habitat of female long-legged myotis in ponderosa pine forests

Michael D. Baker, Michael J. Lacki

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


We studied use of day roosts by adult, female long-legged myotis (Myotis volans) in 4 watersheds dominated by ponderosa pine (Pinus ponderosa) forest east of the Cascade Crest in Washington and Oregon, USA, 2001-2003. To investigate maternity habitat in managed, xeric forests we radiotracked 87 bats to 195 snag roosts and 34 rock crevices totaling 842 roost-days. Bats changed roosts every 2.7 ± 0.1 (SE) days and averaged 3.6 ± 0.3 roosts per bat. Roosts were 2.0 ± 0.1 km from capture sites, and bats moved 1.4 ± 0.1 km between successive roosts. Six bats (6.9%) day-roosted in rock crevices exclusively, 9 bats (10.3%) used snags and rock crevices, and the remaining bats (82.8%) day-roosted in snags exclusively. Most snag roosts were thick-bark ponderosa pine (n = 103; 52.8%) or thin-bark grand fir (Abies grandis,) and white fir (Abies concolor) (n = 74; 37.9%). Over half of all snag roosts (n = 101; 52%) were used by solitary bats; 28 snag roosts (14%) housed >50 bats (large-flyout roosts). Ninety-three percent of large-flyout roosts were in ponderosa pine snags. Large-flyout roosts were larger, taller, and retained more exfoliating bark and total bark than small-flyout roosts (P < 0.05), and small-flyout roosts were larger, taller, and retained more exfoliating bark and total bark than random snags (P < 0.05). Snag roosts were closer to other snags, located in areas of greater snag density, with greater snag basal area and greater basal area of snags > 25 cm diameter, and were lower in elevation than random snags (P < 0.05). Pregnant bats divided roost-days almost evenly between thick and thin-bark snags (52.7 vs. 47.3%), whereas lactating bats roosted in thickbark snags more often than they did in thin-bark snags (80.3 vs. 19.7%, P < 0.0001). Pregnant bats roosted in both upslope and riparian zones (57.5 vs. 42.5%), but lactating bats spent more days roosting upslope than in riparian zones (73.1 vs. 26.9%, P < 0.0001). These findings suggest that reproductive female long-legged bats choose roosts relative to their changing physiological needs. We recommend that management of forests for sustaining habitat of female long-legged myotis in the east Cascades ensure the continued availability of both thick- and thin-bark snags in early stages of decay, in both riparian and upslope positions.

Original languageEnglish
Pages (from-to)207-215
Number of pages9
JournalJournal of Wildlife Management
Issue number1
StatePublished - 2006


  • Day-roost
  • Grand fir
  • Habitat
  • Long-legged myotis
  • Pacific Northwest
  • Ponderosa pine
  • Radiotelemetry
  • Riparian zone
  • Snag
  • Upslope
  • White fir
  • Xeric forest

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Ecology
  • Nature and Landscape Conservation


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