Forest Investment Account

Abstract of FIA Project 6080009

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Refining the funnel trapping protocol for monitoring amphibians and movement patterns of red-legged frogs

Author(s): Chan-McLeod, Ann
Imprint: Vancouver, B.C. : Dept. of Forest Sciences, 2003
Subject: Forest Investment Account (FIA), Frogs, British Columbia, Variable retention harvesting
Series: Forest Investment Account (FIA) - Land Base Investment Program


The major objectives for the 2002 field season were to 1) refine the funnel trapping protocol for monitoring aquatically-breeding amphibians; 2) quantify movement patterns of resident Red-Legged Frogs in the riparian habitat where they were found; and 3) asses the effects of experimental variable-retention harvesting on movement patterns of transplanted Red-Legged Frogs along riparian areas. The results indicated that the effectiveness of a funnel-trapping monitoring protocol would not be substantially increased by targeting an optimal sampling window or phenological stage, or by conducting multiple trapping sessions within a season. The effectiveness of funnel trapping would be better realized by using a habitat-based approach to trap allocation, and by checking traps multiple times (on consecutive days) within one trapping session. In agreement with last year’s data, the radio-tracking data for resident frogs in their natural habitats suggested that most frogs stayed very close to the water’s edge, and do not move excessively between the sampling period of May to October. Of 2 frogs that made rapid, unidirectional movements during the monitoring period, one followed the riparian corridor and the other headed away from the stream. The post-harvest movement patterns of Red-Legged Frogs did not differ significantly among the 5 stream treatments in the Tsitika experimental site, including those released in unbuffered riparian areas in the clearcut. These results are not consistent with movement behaviour of frogs previously transplanted into clearcuts. It is postulated that weather conditions (cool and wet) during the late experimental period, the presence of the creek, and low sample sizes contributed to these unexpected results.

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Updated August 02, 2006 

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