
Big Bend National Park Project Goals

- Evaluate precision, bias (e.g., observer bias) and efficiency of various sampling
methods for amphibians.
- Conduct validation studies to determine the relationship between capture indices and
adjusted population estimates using capture-recapture (e.g., tadpole dying, elastomer
marking of adults).
- Assess spatial and temporal variation in amphibian populations at springs (spring
surveys), along the Rio Grande (night canoe surveys), and along roads (night driving) and
analyze distribution and abundance of amphibians from these surveys in relation to
environmental variables.
- Document contaminant levels in bullfrogs (Rana catesbeiana) collected from sites
along the Rio Grande.
- Document chorusing phenology at springs, tinajas, tanks, and flats after rains using
frogloggers (automated tape recording devices) and chorus surveys.
- Assist in metapopulation genetic studies of amphibians.
- Experimentally test the effects of ultraviolet radiation on amphibian development in the
field.
PRIMENet Amphibian Monitoring Program
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