AbstractsBiology & Animal Science

Longitudinal distribution and summer diurnal microhabitat use of California Red-Legged Frogs (Rana draytonii) in coastal Waddell Creek

by Neil C Keung

Institution: San Jose State University
Year: 2015
Keywords: Biology; Conservation biology; Zoology
Posted: 02/05/2017
Record ID: 2133011
Full text PDF: http://pqdtopen.proquest.com/#viewpdf?dispub=1593144


Habitat use by federally threatened California Red-Legged Frogs (CRLF; Rana draytonii) is incompletely understood. I captured, PIT-tagged, and radio-tracked CRLFs (n = 20) at Waddell Creek, Santa Cruz County, from July–December 2012. Limited tracking for movements was also conducted in 2013. Frogs were clumped in deep, complex habitats along the stream within 2 km of breeding ponds near the stream mouth, but most adults were concentrated in the lagoon. Marked and tracked frogs had very small summer home ranges, and most returned to the same home range after breeding. Frogs tended to use good aquatic (e.g., wood, undercut banks, dense willows) and bank cover (e.g., ground vegetation, wood) at all times but used open habitats more at night than during the day. Visual night surveys were biased against cryptic frogs compared to radio-tracking results. Early fall rains increased upland habitat use, but later heavy winter rains were needed to trigger migration to breeding sites and subsequent breeding. Site-specific studies using radio-tracking are needed to design protections for breeding, migration, and nonbreeding habitats.