United States Department of Agriculture Conservation Assessment Forest Service Rocky of the Pale Milk Snake in Mountain Region Black Hills the Black Hills National National Forest Custer, Forest, South Dakota and South Dakota May 2003 Wyoming Brian E. Smith and Nathan T. Stephens Conservation Assessment of the Pale Milk Snake, in the Black Hills National Forest, South Dakota and Wyoming Brian E. Smith Nathan T. Stephens Department of Biology Black Hills State University 1200 University Street Unit 9044 Spearfish, South Dakota 57799-9044 [email protected] Correspondence to senior author Dr. Brian E. Smith is a professor at Black Hills State University, where he teaches a variety of courses in vertebrate biology and ecology. He maintains an active research program on the reptiles and amphibians of the Black Hills and surrounding plains region of South Dakota and Wyoming. He is also active in research on the conservation biology of reptiles and amphibians in the Lesser Antilles island chain in the Caribbean Ocean. He has published several papers on the reptiles and amphibians of the Black Hills and surrounding plains, the Caribbean region, and Central America. Mr. Nathan T. Stephens is a student at Black Hills State University. His research interests are conservation biology, wildlife biology, and herpetology. He has assisted in research on the Black Hills National Forest. Table of Contents INTRODUCTION.......................................................................................................................................................1 CURRENT MANAGEMENT SITUATION ..............................................................................................................1 Management Status.................................................................................................................................................1 Existing Management Plans....................................................................................................................................1 REVIEW OF TECHNICAL KNOWLEDGE .............................................................................................................1 Systematics .............................................................................................................................................................1 Distribution.............................................................................................................................................................2 Estimates Of Local Abundance..........................................................................................................................2 Movement Patterns .................................................................................................................................................3 Habitat Characteristics............................................................................................................................................3 Food Habits.............................................................................................................................................................4 Prey Items ..........................................................................................................................................................4 Breeding Biology....................................................................................................................................................5 Demography ...........................................................................................................................................................6 Community Ecology...............................................................................................................................................7 Risk Factors ............................................................................................................................................................8 RESPONSE TO HABITAT CHANGE.......................................................................................................................9 Management Activities...........................................................................................................................................9 Timber Harvest ..................................................................................................................................................9 Recreation ..........................................................................................................................................................9 Livestock Grazing............................................................................................................................................10 Mining..............................................................................................................................................................10 Prescribed Fire And Fire Suppression .............................................................................................................10 Non-Native Plant Establishment And Control.................................................................................................10 Fuelwood Harvest ............................................................................................................................................11 Natural Disturbances ............................................................................................................................................11 Insect Epidemics ..............................................................................................................................................11 Wildfire............................................................................................................................................................11 Wind Events.....................................................................................................................................................11 SUMMARY ..............................................................................................................................................................12 REVIEW OF CONSERVATION PRACTICES.......................................................................................................12 Management Practices And Management Models................................................................................................12 Survey, Inventory, And Monitoring Approaches .................................................................................................12 Additional Information Needs ..............................................................................................................................12 LITERATURE CITED..............................................................................................................................................14 DEFINITIONS ..........................................................................................................................................................16 i INTRODUCTION The milk snake, Lampropeltis triangulum, is possibly the widest-ranging species of American snake and is found in North, Central, and South America. It is divided into many subspecies that occur in different climatic regions and consequently have developed very different life history strategies. These subspecies express significant geographic variation in many physical and ecological characteristics including size, color and pattern, prey preferences, and reproduction. The pale milk snake, Lampropeltis triangulum multistriata, is a North American subspecies that occurs in the northern Great Plains of the United States. The United States Department of Agriculture (USDA) Forest Service Rocky Mountain Region, which includes the Black Hills National Forest, considers it a sensitive species. Extremely little is known about the pale milk snake in the Black Hills area. It is a harmless and secretive snake that is rarely encountered. Long-term studies of a milk snake population in Kansas have revealed much that may be relevant to pale milk snakes in the Black Hills. However, even long-term studies of milk snakes have not been successful in compiling significant data due to the rarity and elusiveness of the snake. This assessment is a review of the literature on milk snakes and also includes anecdotal information pertaining to local populations based on observations of pale milk snakes in the Black Hills. Our intent is to review the literature and make suggestions for management of pale milk snakes in the Black Hills. CURRENT MANAGEMENT SITUATION Management Status The milk snake, Lampropeltis triangulum, is not considered threatened or endangered by any federal or state agency in the United States, although there are some concerns in some areas. The milk snake is a species of special concern in Arizona, Oklahoma, and Utah. Montana and Wyoming list the pale milk snake, L. t. multistriata, as a sensitive species due to its rarity and/or limited range within these states. In South Dakota it is considered to be secure and it is not legally protected. The USDA Forest Service Rocky Mountain Region, which includes the Black Hills National Forest in South Dakota and Wyoming, considers this snake a sensitive species. Existing Management Plans We could not find any published management plans for Lampropeltis triangulum. REVIEW OF TECHNICAL KNOWLEDGE Systematics The milk snake, Lampropeltis triangulum,