Observations of Atypical Habitat Use by Foothill Yellow-Legged Frogs (Rana boylii) in the Coast Range of California

Syntopy in California red-legged and foothill yellow-legged frogs in their aquatic habitat

“…Although detected in stock ponds (Wilcox and Alvarez 2019;Alvarez and Wilcox 2021a), we recognize that these species did not naturally occur in ponds to the extent that we see them today because natural ponds were uncommon prior to European settlement (Schoenherr 1976). Thus, California red-legged frogs certainly evolved in lotic systems, and these were likely ephemeral systems that had intermittent pools that were suitable for oviposition and larval development.…”

“…Our own field research produced six locations where we directly identified both species co-occurring at a site between 2 and 12 years (Table 1). Foothill yellow-legged frogs were detected in one stock pond (i.e., Turtle Pond, Mitsui Ranch, Sonoma County) and were syntopic with a large population of California redlegged frogs using the pond (Alvarez and Wilcox 2021a). Foothill yellow-legged frogs were also observed in several creeks that are typically intermittent or ephemeral.…”

“…Zwiefel (1955) noted that he rarely found foothill yellow-legged frogs more than a single hop from a creek or stream. More recently Wilcox and Alvarez (2019) and Alvarez and Wilcox (2021a) reported the foothill yellow-legged frogs occasionally use lentic systems for breeding, refuge, and presumably foraging.…”

Isthmian Central American Frogs With Different Biofluorescence Patterns

“…According to our experience finding the species Engystomops pustulosus, we suggest the use of blue light (440-460 nm) could be a good detection method in a short range (2-3 m) for this species. Although in some cases the short range is not optimal (Alvarez et al, 2022), normal visual detection is difficult due to the camouflage color pattern and the tiny size of some amphibians. Instead, blue light and the use of filter glasses enhance the detection of fluorescent individuals in the field.…”

Fluorescence in amphibians and reptiles: new cases and insights

“…In reptiles, bone fluorescence stands out (Prötzel et al, 2018;Sloggett, 2018;Jeng, 2019;Top et al, 2020;Pinto et al, 2021;Maria et al, 2022), along with dermal fluorescence (Paul and Mendyk, 2021;Prötzel et al, 2021). In amphibians, in addition to dermal (Taboada et al, 2017a, b;Deschepper et al, 2018;Chaves-Acuña et al, 2020;Whitcher, 2020) and bone fluorescence (Goutte et al, 2019;Rebouças et al, 2019;Nunes et al, 2021), ocular fluorescence was reported recently (Deschepper et al, 2018;Alvarez et al, 2022).…”