Reference |
Matsuda, B. M. & S. J. Richardson. 2000. Clearcut timber harvest and movement patterns in tailed frogs. In L. M. Darling (ed.) Proceedings of a conference on the biology and management of species and habitats at risk. Kamloops, B.C., Vol 2. B.C. Ministry of Environment, Lands and Parks, Victoria, B.C. and University College of the Cariboo, Kamloops, B.C. pp 485-488. |
Abstract |
Despite many studies of tailed frog (Ascaphus truei) larvae, there has been little study of juvenile and adult habitat use, patterns of movement, and dispersal. Grids of pitfall traps and drift fences were established in “control” sites (mature stands >81 years, n= 3) and clearcut habitats (<5 years, n= 3) to determine whether: 1) movement became limited to upstream / downstream activity only within the immediate riparian area in clearcuts without riparian buffers; 2) tailed frog abundance was lower in clearcut stands than in mature stands; and 3) pre-reproductive juveniles were the main dispersers. In clearcut sites, the highest proportion (44%) of frogs moved downstream, and the lowest proportion (11%) moved away from the creek. There was no notable difference between movement towards the creek (20%) and upstream (24%). Within mature sites, the highest proportion of frogs (40%) moved upstream, followed by movement towards the creek (32%). The lowest proportions moved away from the creek (13%) and downstream (15%). Captures were highest within 5 m of creekside in both clearcuts (41%) and mature sites (35%), followed by captures at 45-m (26% and 31% respectively) and 25-m intervals (22% and 23%respectively), with the lowest number of frogs caught at 65 m (11% in both habitats). Abundance of frogs was lower in clearcuts (n= 63) than in mature sites (n= 88). Of the frogs caught in clearcuts, 78% were juveniles and 22%were reproductive-age adults. Within mature stands, 53% of captures were juveniles and 47% were adults. Marking techniques indicated that frogs caught within the study sites were predominantly new individuals moving through the area. These findings suggest that although movement direction differs in clearcuts, distance traveled from streamside does not significantly change, with juveniles being the main dispersers in clearcuts. |
Tag |
Visible Implant Elastomer (VIE) |
Objective |
Evaluate habitat use |
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