Remote monitoring of a Western Diamond-backed Rattlesnake (Crotalus atrox) Den in Northwest Arkansas: Phenology, Reproduction, and Interspecific Interactions.

Beaupre, Steven J.

sbeaupre@astate.edu

Department of Biological Sciences

University of Arkansas

Fayetteville, AR

Dean of the Graduate School

Arkansas State University

Jonesboro, AR

Isaac Lord

Department of Biological Sciences

University of Arkansas

Fayetteville, AR

Brad Birchfield

Para-Herpetologist

Mountainburg, AR

Jeremy Sloan

Para-Herpetologist

Greenwood, AR

J.D. Willson

Department of Biological Sciences

University of Arkansas

Fayetteville, AR

Max Carnes-Mason

Department of Fisheries, Wildlife, and Conservation Sciences

Oregon State University

Corvallis, OR

The natural history and status of the Western Diamond-backed Rattlesnake (Crotalus atrox, SGCN) in Arkansas is largely unknown.  We monitored a den site in the Boston Mountains during fall ingress (2023, 2024) and spring egress (2023, 2024) using Motion-activated cell cameras (Tactacam Reveal 2.0™, Decorah, IA) and Timelapse (Reconyx Hyperfire 2, Holmen, WI). Three cameras were positioned to monitor the den entrance, and the immediately adjacent ground.  When triggered, cameras recorded ten seconds of continuous video and a single still photograph, resulting in a large collection of stills and short videos. Visual records were assembled into video sequences using Davinci Resolve 19 (version 19.1.3, ©2024, Blackmagic Design PTY, LTD).  Snakes of every age class (young of the year to very large adults) were observed. Reproductive activities (male combat, courtship, mating, mate guarding and den-tending) commenced upon emergence.  Some snakes with injuries or infections emerged to bask on warm days (>14°C, sunny) throughout the winter and occasionally stayed on the surface well into the night.  Male-male agonistic combats were common (n=23) from late February through March and involved repeated pairings of the same two large males. Some combats were lengthy (minimum duration:10s to 53m, avg=12.86m, std=16m, n=17) and vigorous, but were not limited to daylight hours (3/23 starting or continuing after dark).  Emergence and reproductive activities concluded by late March when snakes dispersed into the surrounding habitat.  Dominant males returned to the den in early April for short bouts of den-tending.  Fewer visual captures and lower levels of activity at the den entrance were observed during Fall ingress.  No reproductive behaviors were observed at ingress. Snakes at the den encountered a suite of common small to medium mammals and potential predators; however, only a single defensive or predatory strike was observed.  General phenology and behavior were concordant (with caveats) with other sites in the species range.