Few impacts of introduced cutthroat trout (Oncorhynchus clarki) on aquatic stages of boreal toads (Anaxyrus boreas boreas)
Crockett J, Lanier WE, Bailey L. 2019. Few impacts of introduced cutthroat trout (Oncorhynchus clarki) on aquatic stages of boreal toads (Anaxyrus boreas boreas). Canadian Journal of Fisheries and Aquatic Sciences
ABSTRACT: Introduced salmonids have major impacts on aquatic ecosystems through both direct predation and indirect effects. We explored the effects of introduced cutthroat trout (Onchoryncus clarki) on boreal toad (Anaxyrus boreas boreas) survival and habitat use during two aquatic life stages of toads. We used robust methods to account for imperfect detection in estimating survival and habitat use during the embryo and tadpole stages at two toad breeding sites, one with trout and one without. We found no difference in embryo survival and higher tadpole survival at the site with trout. Trout are unlikely to use the shallow areas where toad eggs are deposited; however, during the tadpole stage, trout and tadpoles overlap broadly in near-shore (<15m) aquatic habitats. Frequency of tadpole habitat use is lower in trout-used areas, but we observed no obvious behavioral or temporal avoidance of trout by toads. Our results suggest that trout do not have a negative effect on boreal toad embryo or tadpole survival in wild settings and that trout presence does not preclude tadpoles from using habitats.
- Type
- Journal Article
- Authors
- Crockett, John; Lanier, Wendy; Bailey, Larissa
- Units
- ROMO
- Keywords
- AMPHIBIANS, ENDANGERED SPECIES, MARK-RECAPTURE, PREDATOR-PREY INTERACTION, TROUT