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Summer Movements of Boreal Toads (Bufo Boreas Boreas) in Two Western Montana Basins
- Schmetterling, David A., Young, Michael K.
- Journal of Herpetology 2008 v.42 no.1 pp. 111-123pp. 13
- Bufo, toads, dispersal behavior, spatial distribution, wildlife habitats, summer, climatic factors, age structure, mark-recapture studies, animal identification, radio frequency identification, telemetry, monitoring, Montana
- The Boreal Toad (Bufo boreas boreas) is widely distributed in the western United States but has declined in portions of its range. Research directed at conserving Boreal Toads has indicated that their movements are largely terrestrial and often limited after the breeding season. We used a combination of stream-based netting, PIT tagging, and radio telemetry to examine patterns in captures, movements, and habitat use of Boreal Toads associated with two stream valleys in western Montana. Netting produced 514 captures of 118 adult and 203 juvenile toads from 8 July to 19 August 2003. Juveniles dominated catches initially but declined throughout the summer, whereas adult catches showed less consistent temporal trends. Of the 122 PIT-tagged toads, nearly two-thirds were recaptured 1––7 times in hoop nets, and the median total distance moved was over 1 km downstream. The median distance moved by radio-tagged toads was 2.1 km (maximum, 12.0 km) or 2.9 km (maximum, 13.0 km) if movements before and after radios were affixed are included. Over 17%% of relocations of radio-tagged toads were at upland sites, 56%% were in riparian zones, and 26%% were in or adjacent to water. We believe that Boreal Toads in this area are engaging in long-distance movements between overwintering, breeding, and summer growth sites. Downward redistribution via streams may be common in montane habitats and warrants examination in other regions.