Western Toad – State Wildlife Action Plan

Western Toad

Photo Credit: ODFW

Western toads are relatively large, stout-bodied amphibians that are well camouflaged. The color of adult western toads is highly variable: individuals can be anywhere from olive green to reddish brown or even black in color overall. On their underside, their skin is a mottled cream to tan with dark blotches. Regardless of body color, western toads have a distinct white stripe that runs down the middle of their back. This stripe is more prominent on females than on males. They have roundish bumps covering their dorsal surface, which are often reddish brown in juveniles, though this color is often lacking in adult toads. They have prominent parotid glands behind their eyes and horizontal pupils. Adult female western toads are larger than males, and can grow up to 5 inches snout to vent, though 4.3 inches is more typical. Adult males typically only grow up to 3.7 inches in length snout to vent.

Overview

  • Species Common Name Western Toad
  • Species Scientific Name Anaxyrus boreas
  • State Listing Status Sensitive

Ecoregions

    Special needs

    Western toads use wetlands, ponds, lakes, and streams and side channels with slow moving water for breeding. They prefer extensive, sunny shallows with short, sparse, or no vegetation for egg-laying and for tadpole schools to move widely as they forage on organic mud and surface diatoms. Western toads also require habitat that includes open forest canopies or landscapes with few to no trees, south-facing slopes, close proximity to water, and a high density of burrows (often rodent burrows), rocks, or logs for cover.

    Limiting factors

    Loss of breeding habitat, largely due to changes in water level management and drought, has been linked to declines of western toads. Western toads are sensitive to habitat fragmentation which affects connectivity of breeding and non-breeding areas. Diseases such as chytridiomycosis (chytrid) have been linked with population declines, and warming trends may exacerbate risks of mortality from infectious diseases or increasing densities of competitors like American bullfrogs which serve as reservoirs for disease. Pollutants, siltation, road mortality, ultraviolet radiation, invasive species (bullfrogs), acidification, and recreational impacts are also considered as threats to toads in some areas.

    Conservation actions

    • Identify and implement best management practices to minimize impacts of land management actions on toad populations (e.g. protect riparian habitats, maintain water levels and vegetation buffers at major breeding sites).
    • Manage habitat to improve site conditions for toad populations, including periodic control of vegetation height and density at occupied sites where these factors could interfere with breeding.
    • Install culverts or drift fences at problem road crossings near major breeding sites. Inform recreationists about the importance of minimizing shoreline impacts.
    • Perform periodic control of vegetation height and density at occupied sites where these factors could interfere with breeding.
    • Use distribution information when considering new developments, especially at mid- or low-elevation locations.
    • Monitor populations where toads are known to occur, and identify important habitats characteristics needed to sustain these populations.
    • Identify and prioritize protection of habitats with higher climate-resiliency.
    • Establish priorities for disease monitoring and invasive species removal to protect or restore populations in key areas.

    Key reference or plan

    Technical Conservation Assessment Read here

    Assessment and Status Report on the Western Toad, Anaxyrus boreas Read here

    Life History Traits