Conservation of two native Gartersnakes

From CTLpedia

Andy Holycross

3:00 p.m. Wednesday, March 7, 2007

LB 145 in the Elsner Library at MCC

Introduced species, siltation (from fires or agriculture), de-watering, impoundments, dams, and pollutants are all threats to native biological communities in southwestern streams. Our team (including William Burger, Thomas Brennan, and Ernest Nigro) spent two summers assessing the conservation status of Mexican and Narrow-headed gartersnakes, two species dependent on aquatic ecosystems for survival. We assessed the historical distribution of both species by querying 94 institutional collections and by examining reports and literature. Then, during 2004–2005, we surveyed for gartersnakes at 57 sites (many historically occupied sites). We spent 1,968 person-hours searching for snakes and had gartersnake traps deployed for ca. 161,725 hours. Our observations indicate that both of these gartersnakes are experiencing population declines and local extirpations throughout their U.S. distributions. For example, Mexican Gartersnakes appear to be extirpated from the Agua Fria River system and Narrow-headed Gartersnakes are probably extirpated from at least 5 sites at which they were recently common. In addition to reviewing the survey team’s findings, Dr. Holycross will review the natural history of these two snakes, discuss the panoply of threats that these (and other aquatic )species are facing, and introduce the role of Mesa Community College and its students in efforts to reverse these trends.

As an “Air Force brat” Andrew Holycross grew up in places as diverse as the plains of Wyoming and Nebraska, Washington State, Alabama, and the Philippine Islands. By the age of about 8, his bedroom was filled with jars of dissected specimens, field guides to plants and animals, and was co-occupied by Tiger Salamanders and a gartersnake named Sir Hiss. These early, and possibly innate passions later blossomed into a career. After earning a Bachelors degree in Biology from the University of Nebraska, Andrew earned a Masters degree in Biology studying the natural history of Prairie Rattlesnakes denning in a Prairie Dog “town” in the Sand Hills of Nebraska. At Arizona State University he earned a Ph.D. studying various aspects of the conservation biology and conservation genetics of two endangered rattlesnakes. Since then, Andrew has co-authored the first field guide to Arizona’s amphibians and reptiles, and is working on a scholarly treatise on the Snakes of Arizona. Dr. Holycross is a faculty member in the Life Sciences Department at Mesa Community College and an Assistant Research Professor in the School of Life Sciences at Arizona State University. He has authored over 20 peer-reviewed scientific papers as well as numerous notes, popular articles, and government reports.