Instream movements by boreal toads (Bufo boreas boreas)
Determining the nature and extent of bufonid movements is critical to understanding the autecology of each species, as well as to developing effective conservation strategies. Within many toad (Bufo spp.) populations, individuals must migrate considerable distances to reach habitats essential for fulfilling requirements that change seasonally and ontogenically (deMaynadier and Hunter 2000; Sinsch 1990). Summer home range movements (sensu deMaynadier and Hunter 2000) are often necessary to allow individuals to meet multiple resource needs (e.g., food and thermoregulation sites; Zug et al. 2001). Documenting movement patterns helps biologists determine the nature, timing, spatial extent, and distribution of habitat use by a species. Moreover, understanding movements can be essential to predicting the population-level effects of some ecosystem alterations (e.g., habitat alteration, creation of barriers to movements, or introduction of predators along travel corridors) and to planning habitat restoration that will conserve toad populations. Boreal Toads (Bufo boreas boreas) are declining throughout much of their range in western North America (Corn 2000); documenting their movement patterns may prove integral to understanding and arresting the declines.