Table 2.

Interviewee responses to inquiry of potential causes of R. boylii extirpation from southern California

Cause	Yearsa	Interview #	Explanation
Amphibian pet trade and exotic amphibians	175 [58]	10, 12, 20	Amphibians wild‐caught; availability in local department stores; pet releases into the wild
Bd	195 [49]	3, 10, 12, 20	Chytridiomycosis
Bd + climate change	54	10	Climate change exacerbates conditions when Bd is already present, making amphibians more susceptible to disease
Bd + fish stocking	56	12	Releases Bd zoospores into new waterways
Bd + flooding	56	12	Unusual frequency of rain events & overcast days reduces opportunities for frog basking (higher temperatures can mitigate chytridiomycosis)
Climate change	54	10	Declines trend from south to north; declines occurred earlier in drier climates
Drought	60	4	1955–1960 and 1971–1978 were very dry years
Non‐native fish	63	17	Non‐native fish introduced, resulting in predation
Flooding (1968–1969)	210 [53]	9, 11, 12, 19, 20	Extreme flood events scoured frogs to lower elevations/less suitable habitat; permanent change in habitat quality and suitability
Recreation	234 [59]	12, 17, 19, 20	Increased and intensified recreational uses of streams

^aCumulative years of herpetological experience represented by respondents; number in brackets shows average number of years.