Ecology, Behavior and Conservation of the Japanese Mamushi Snake, Gloydius Blomhoffii: Variation in Compromised and Uncompromised Populations
Total Page：16
File Type：pdf, Size：1020Kb
ECOLOGY, BEHAVIOR AND CONSERVATION OF THE JAPANESE MAMUSHI SNAKE, GLOYDIUS BLOMHOFFII: VARIATION IN COMPROMISED AND UNCOMPROMISED POPULATIONS By KIYOSHI SASAKI Bachelor of Arts/Science in Zoology Oklahoma State University Stillwater, OK 1999 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY December, 2006 ECOLOGY, BEHAVIOR AND CONSERVATION OF THE JAPANESE MAMUSHI SNAKE, GLOYDIUS BLOMHOFFII: VARIATION IN COMPROMISED AND UNCOMPROMISED POPULATIONS Dissertation Approved: Stanley F. Fox Dissertation Adviser Anthony A. Echelle Michael W. Palmer Ronald A. Van Den Bussche A. Gordon Emslie Dean of the Graduate College ii ACKNOWLEDGMENTS I sincerely thank the following people for their significant contribution in my pursuit of a Ph.D. degree. I could never have completed this work without their help. Dr. David Duvall, my former mentor, helped in various ways until the very end of his career at Oklahoma State University. This study was originally developed as an undergraduate research project under Dr. Duvall. Subsequently, he accepted me as his graduate student and helped me expand the project to this Ph.D. research. He gave me much key advice and conceptual ideas for this study. His encouragement helped me to get through several difficult times in my pursuit of a Ph.D. degree. He also gave me several books as a gift and as an encouragement to complete the degree. Dr. Stanley Fox kindly accepted to serve as my major adviser after Dr. Duvall’s departure from Oklahoma State University and involved himself and contributed substantially to this work, including analysis and editing. Dr. Michael Palmer was more than just a committee member, he provided me with various insights into the life sciences, as well as valuable opportunities and experiences. His family has contributed to making my stay in Stillwater memorable. Dr. Anthony Echelle, his wife, Alice, and her father, Dr. Henry Fitch, have not only given me important suggestions for this study, but also made my stay in Stillwater memorable. Dr. Ronald A. Van Den Bussche helped to improve analysis and writing. Dr. Robert Capers, though he was not on my committee, reviewed and helped to improve this dissertation. Dr. James Shaw helped to write grant proposal for this work. Dr. Aaron Place helped and iii encouraged me especially during my difficult times. Dr. Sen Takenaka from Hokkaido Tokai University helped me in various ways, including providing helpful suggestions for this study, as well as some equipment. Day Ligon, a graduate student, helped with some analysis. My parents, Yoshinori and Mitsuko Sasaki, were extremely supportive in various ways. My father’s contribution was significant. He found locales of mamushi populations by asking government officials and local people. Without such help, I could not even have begun my study. Gathering information and references for religious aspects of snakes in Japan was mostly done by my father, which was not possible for me to do while staying in the U.S. Mr. Masanori Sasaki, my father’s former student, also helped to find mamushi populations. Dr. Hifumi Tsuruga and colleagues taught me environmental characteristics of my study area, including vegetation of the area. My wife, Fumiko, helped me a great deal with many aspects during my pursuit of a Ph.D. She also assisted me in the field, especially when I was incapacitated by snakebites. Her help was essential. Local people at my study site were very supportive and helped me during my stay there, especially the Furudate family, Otani family, and Murotsuka family. Mr. and Mrs. Furudate kindly let me stay in their house and cooked and did laundry for me. Mr. Takahashi (my father’s former student) and Mr. Tahata took me to a hospital when I was bitten by a mamushi. I would be dead if they had not helped me. Many people, including my relatives and the Inoue family, took care of me when I was bitten by mamushi on three occasions. Mr. Mukai and Haru Koike kindly volunteered in some fieldwork. Songoku restaurant served a lot of good food, including sake, often free of charge. Dr. Kawamata and others in Kawamata Animal Hospital kindly took X-ray pictures of snakes iv free of charge. Mr. Shuzo Sugai, the principal, and other personnel of Chiisago elementary school were very supportive of my snake conservation education activities. Hokkaido University allowed me to use their facilities and experimental forest. Dr. Kyo Matsuda kindly taught me about the forest. v TABLE OF CONTENTS Chapter Page I. SURVEY OF LITERATURE Introduction to the Japanese Mamushi ....................................................................1 Conservation concerns.......................................................................................1 Mamushi biology and ecology...........................................................................5 Conservation through Traditional Religious/Spiritual Beliefs in Japan ..................7 Snake- and nature-beliefs...................................................................................9 Imperiled divine snakes and nature..................................................................16 Rapid Evolution .....................................................................................................19 Human predation as an evolutionary force ......................................................22 II. A NATURAL EXPERIMENT Objectives and Associated hypotheses ..................................................................25 Methods..................................................................................................................30 Study area.........................................................................................................30 General study methods.....................................................................................32 Characteristics of mamushi hunting.................................................................34 Antipredator behavior ......................................................................................35 Reproduction and offspring .............................................................................36 Analysis............................................................................................................37 Results....................................................................................................................43 Body size..........................................................................................................43 Flight threshold radius .....................................................................................45 Defensiveness ..................................................................................................47 Response to repeated exposure to an approaching human...............................49 Latency to emerge from refuge........................................................................50 Microhabitat cover...........................................................................................51 Movement and Activity ...................................................................................51 Reproduction....................................................................................................52 Thermal ecology ..............................................................................................53 Discussion..............................................................................................................53 Body size..........................................................................................................57 Flight threshold radius .....................................................................................62 Defensiveness ..................................................................................................67 vi Response to repeated exposure to an approaching human...............................69 Latency to emerge from refuge........................................................................69 Microhabitat cover...........................................................................................70 Movement and Activity ...................................................................................72 Reproduction....................................................................................................73 General Discussion and Conservation Implications ........................................74 LITERATURE CITE...................................................................................................77 vii LIST OF TABLES Table Page Chapter II. 1. Selected summary statistics (xF ± 1 SE and sample size in parentheses) for males and nonpregnant and pregnant females of adult mamushi in Hokkaido, Japan, studied between 1999 and 2002...........................................................................................96 2. Distances moved and the number of moves in males (M), pregnant (PF) and nonpregnant (NPF) females for radio-tracked mamushi in Hokkaido, Japan.........97 viii LIST OF FIGURES Fi gure Page Chapter I. 1. Photograph illustrating Japanese mamushi, Gl oydius blo mhoffii , in Hokkaido. ....99 2. Map of Japan, showing four major islands (Hokkaido, Honshu, Shikoku, and Kyushu) where Japanese mamushi ( Gl oydius blomhoffii ) inhabit. .....................................100 3. Number of males found during 1999-2002 and of shedding individuals (including those are