Ecology of three species of myotine bats in the Ozark Plateau

64—13,299 M YERS, Richard F re y , 1931ECOLO GY O F TH R EE SPECIES O F M Y O TIN E BATS IN TH E O ZARK P LA T E A U . U n ive rsity of M isso u ri, P h .D ., 1964 Zoology University Microfilms, Inc., Ann Arbor, Michigan Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW ECOLOGY OF THREE SPECIES OF MYOTINE BATS IN THE OZARK PLATEAU A Thesis Presented to The Faculty of the Graduate Sohool University of Missouri In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy by Richard Frey Myers June l$6k LIBRARY JUL17'64 william H. Elder Dissertation supervisor Reproduced with permission of the copyright owner. Further reproduction prohibited without permission PREVIEW The undersigned, appointed by the Dean of the Graduate Faculty, have examined a thesis entitled Ecology of Three Species of Myotine Bats In the Osark Plateau presented by Richard Frey Myers a candidate for the degree of Doctor of Philosophy and hereby certify that in their opinion it is worthy of acceptance. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW PLEASE NOTE: Figures and Plates are not original copy. These pagestend to "curl”. Filaed in the best possible way. UNIVERSITY MICROFILMS, INC. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW Dr. Richard Frey Myers University of Missouri Doctor of Philosophy June 9, 1964 ECOLOGY OF THREE SPECIES OF MYOTINE BATS IN THE OZARK PLATEAU Richard F. Myers William H. Elder Dissertation Supervisor ABSTRACT The purpose of this study was to learn of the size of Ozark bat populations, define habitats, ascertain sex ratios and describe seasonal patterns of movement of Myotis lucifugus. Myotis sodalis. and Myotis grisescens. Over a nine year period, 50,118 bats were wing-banded. Bats were taken from caves located in the southern half of Missouri, northwestern Arkansas, northeastern Oklahoma and west-central Illinois. Large cave entrances or double entrances were selected by maternity colonies of M. grisescens and hibernating lucifugus and IL_ sodalis. Caves with vertical entrances were preferred sites of wintering M. grisescens. There was little difference in temperature and relative humidity between caves with and without bats, but caves chosen by the majority of bats showed a greater range of temperature and relative humidity at all seasons. M. lucifugus hibernated at a mean temperature of 46.5°F. and at a mean relative humidity of 89.7 %\ M^ sodalis at 46.0°F. and 82.3 %\ and lit grisescens at 47.7°F. and 83.9 %. Maternity colonies of M^ grisescens lived a means of 63.2°F. and 94.5 %• Groups of sodalis and Mj_ lucifugus as well as ones of Mj. sodalis and grisescens were often found near one another in the same hibernaculum, but grisescens and lucifugus were never taken from the same cave during the winter. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW Sex ratios of all species of adults and juveniles were nearly equal over the nine year period. Some variation was noted in sex ratios from season to season because of differences in behavior of the sexes, but no segregation by sex was found during the winter. Of the 50,118 banded bats, 12.5$ were retaken; 9.9$ at the site ■where banded and 2.6$ elsewhere. Among M^ lucifugus there was a general migration north in summer and south in winter. Average distance traveled was 93*6 miles for males and 122.8 for females. All M;. lucifugus recovered north of the hibemacula and all maternity colonies were discovered close to rivers. Five per cent of the banded lucifugus returned to areas where banded; 0.5$ were found in other locations. M. sodalis showed moderate activity; 0.7$ were recovered outside the area banded while 16.1$ returned to the original site. There was a definite trend for this species to leave hibernacula in central Missouri for secluded hibernacula in eastern Missouri where the bulk of Mj_ sodalis were found wintering. In spring most flights away from the hibernacula were less than 20 miles, but some bats flew up to 300 miles north. Of the banded grisescens. 9.1$ were retaken; 5*5$ at the site of banding and 3*6$ elsewhere. The major portion of M. grisescens in the Ozarks wintered in two caves; most bats from northeast Missouri, western Illinois and central Missouri went to a cave in west-central Missouri, while most bats in southwestern and south-central Missouri, northwest Arkansas and northeast Oklahoma wintered in a cave in southwest Missouri. Smaller hibernating groups were found in five other Ozark caves. Because Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW - 3 - this species was dependent on caves for shelter at all seasons, patterns of movement of grisescens were determined by location of caves. Both sexes frequently made flights of 169 miles. Censuses of bats in the Ozarks since 1954 indicate that the population of Mj_ grisescens has remained stable, but numbers of hibernating sodalis and Mj_ lucifugus have been greatly reduced in most caves in central Missouri. These losses are attributed to the increase in human disturbance. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW TABLE OP CONTENTS CHAPTER PAGE I INTRODUCTION AND ACKNOWLEDGMENTS .............. 1 Introduction .......... 1 Acknowledgments ........... ^ II GENERAL LITERATURE REVIEW ........... ..... 9 Care Biota ........................... Bats of the Ozark Region .................... 11 The Banding Process .............. ...... 16 III THE STUDY A R E A ............................... 19 Geology and Physiography .................... 19 The Ozark C a r e s ........................... 22 Group I Cares ......... 23 Group II Cares .......... 23 Miscellaneous Areas of Study .............. 2k Care Location, Visitation and Familiarization . 2k IV METHODS AND TE C H N I Q U ES ...................... 37 The Banding Process ....................... 37 Banding Techniques . ....................... 39 Effects of Disturbance Due to Banding ....... 1*0 Sample for Sex Ratios ............. Cages and T r a p s ........................... Wt Recording Temperature and Relatire Humidity in Ozark C a r e s ......... **7 Banding Records and Keysort Cards ........... k8 B4693S Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW ill CHAPTER PAGE Definition of Seasons ............... . **9 V HABITAT SELECTION ........................... 51 The Entrance ................ 51 Extent of Cave Sy s t e m ............ 53 Ceiling Structure .......................... 56 Roosting Height During Hibernation ......... 56 Predation as a Factor in Habitat Selection . . 58 Roosting Height in Nursery Colonies .......... 59 Flooding . ................. 59 Number of Entrances .................. 60 Ambient Temperature and Relative Humidity . . . 63 Ambient Temperature and Relative Humidity in Ozark C a v e s ............ 63 Temperature and Relative Humidity at Vinter Myotine Roosts ......................... 70 Myotis lucifugus . . . 71 Myotis scdalis ......................... 7^ Myotis grisescens ....... ........... 77 Associations ....... ........... ... 77 VI SEX RATIOS . . ............................... 83 Review of the Literature ......... 83 Adult Sex Ratios in Ozark Bat Populations .... 92 lucifugus ........... ......... ...92 sodalis ........................ ..... 92 grisescens .................... 9** Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW LIST OF PLATES PLATE I Intranoe to Inoa Cave, Pulaski, Co., Missouri II Entrance to Sullivan Cave, Stone Co., Missouri III Instrument used to open #0 bands. IF A bat bander with cages of bats. V A banding crew working in Rydeh Cave, Pulaski Co., Missouri. VI Collecting cages filled with N. sodalis. VII Collecting pole, closed. VIII Collecting pole, partially extended. IX M* sodalis hibernating in Pilot Knob Mine, Iron Co., Missouri X Roost of maternity colony of M. grisescens on a ceiling in Inoa Cave, Pulaski Co., Missouri. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW CHAPTER I INTRODUCTION AND ACKNOWLEDGMENTS This thesis is one of the preliminary steps in an exhaustive study of the bats of the Osark Plateau, The purpose of this investigation of Myotis lucifugus. Myotis sodalis and Myotis grisesoens of the Osark Plateau is to document the sise of the present wintering populations, to define the environmental characteristics of the natural habitats of these species, to asoertain sex ratios and present seasonal patterns of movement. This information may then be oombined with data from later studies of reproductive rates and survival rates to determine other population character istics such as age structure, mean longevity, life span and juvenile mortality. The results of suoh a study will lead to an under standing and a better appreciation of one part of the fauna of the Osark Plateau, There is great need to develop a sense of the un iqueness of the natural environment, and this need will not diminish in coming years. More people are turning to cave exploration for reoreation eaoh year. The disdain and callousness with which many of these "spelunkers” regard caves and cave life is increasingly apparent in disfigured oaverns and disappearing oave faunas. But this is not the. with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW only typo of disturbance; scientific investigations are another threat. Cave organisms, especially bats, are sought for personal and institutional collections. Bats are sub ject to intense research because some aspects of their behavior and physiology are poorly understood. The way in which they avoid obstacles and catch food with eoholocation poses a challenging question, and, apparently with echolocation, they are able to migrate long distances. Some bats show amasing ability to home when carried far afield. Because of the ability to hibernate, bats are frequent subjects of experiments in hypothermia. Recently, it was discovered that bats could carry diseases, particularly rabies. Now an animal historically connected with witchcraft and superstition is regarded with new suspicion, and a hue and cry has been raised in some quarters for complete extermination of bats. Wanton collecting and experimentation may eom< to be condoned under these conditions. We realise that our study has had an effect upon Osark bat populations, but we have ^attempted to avoid un necessary disturbance of bats in hibernation and of bats in nursery colonies. Our equipment has been designed to lessen Injury and mortality due to banding and to reduce the amount of time required in handling bats. Still we have inadvertently killed bats and oaused bats to leave cave sites for more remote areas. It is hoped that this study will enable the general Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW publie to batter appreciate bats and help to dispel the prejudice and mystery which surround bats. When enough is learned of population dynamios and life cycles of bats, a program of conservation may be initiated so that bats may be used as experimental animals and not be threatened by extinction. But the foremost purpose of this thesis is to cast light upon natural phenomena which up to now have been in the shadow. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW 1* Acknowledgments A study of this magnitude would hare been impossible if it were not for the interest, assistance, and enthusiasm of mcny people. The banding and handling of bats has been one of the major tasks, and grateful acknowledgment for generous and willing assistance is extended to: Jere Sherrard, Robert Lewis, Stanley Dupre, Jaok Reppert, Edward and Joyce Cannard, Rodney Longsinger, Wayne Davis, William Lidioker, William Dumale, Robert Diokman, Kenneth Kamps, Gerald Larson, and Riohard Rosenberg, who assisted during my Fort Leonard Wood residence; Milton Weller, Kadabah Prahlad, Thomas Bets, Robert and Helen Myers, Leslie Knapp, Otto Fajen, James Henley, Joseph Linton, Earl Heller, Willis Gordon, David Lyons, Roy Tomlinson, Mike Carson, Riohard Fulkerson, F. Eugene Wood, James and Lois Joyner, David Snyder, Miohael Hull, Robert Wilkinson,Jr., Joseph Karbanks, Donald Lindsey, L. B. Matthews, Stephen Bamholts, James Cope, Hixon Wilson, Jay Sohnell, Richard Matter, Glenn Chambers, Nioholas Holler, Kent Higgins, David Basterla, John and Sarch Rogers, Jack Sites, Jim Salyer, Clarence Sims, John Hall, Charles Vaughn, Kohler Martinson, Herman Mols, and Paul Ferguson, associates and friends in Columbia, Missouri; Ronald Freese, Thomas' and.Barbara Taylor, Harry Gregory, Ronald Oeseh, Jack Reynolds, Riohard Innes, Laura Nahm, Neta Pope, Robert Clark, Karen Dyer Gary Dyer, Stephen and Jennie Chrisman, Richard Miller, Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW Jerry MoGovan, James Kunx, Donna Dale, Donald Dobson, Larry Gadt, Charles Harper, James Haves, David Hensley, Calvin Ovens, Millard Seoora, Joseph Vhite and Robert Viley at Central Missouri State College. I am particularly grateful to Robert Wilkinson,Jr., and Miohael Hull for discovery of the hibernaeulum in Pilot Knob Mine; to Otto Tajen for leading me to Carroll Cave; and to Osoar Havksley and Jaok Reynolds for locating Coffin Cave and its group of hibernating bats. Special thanks go to Robert Wilkinson,Sr., for giving so generously of his knovledge of the Oxark area, its oaves and streams, and for his logistic support of bat banding expeditions into Pilot Knob Mine. Oscar Havksley and his students, Bari Heller, John Cantvell, and Jerry Vineyard, vere a constant source of information on banded bats vhieh either they recovered or reoeived from other cave explorers and relayed to me. Cave own0rs and managers of commeroial oaves have been sympathetic and most cooperative. Mrs. Louis Sohulx gave me free use of Piquet Cave, as did Bdv&rd Tarbell and K. B. Sveet at Inoa Cave. Jack and Peter Herschend vent to some inoonvenienoe to allov me to study the vinter colony of M. grisescens in Marvel Cave. Lyman Riley at Onondaga Cave provided me vlth facilities vhile in the field. Walker Povell helped me examine Tairy Cave and led me to others in the area. Miss Basel Povell graoiously directed me to caves on her property and Homer Harkhac. made the with permission of the copyright owner. Further reproduction prohibited without permission PREVIEW facilities of Old Spanish Care available. Special thanks go to Charles Carroll, R. E. Kelley and A. E. Robenson, owners of Carroll Cave, Ryden Cave, and Grandpa Chippley Cave respectively, who were always willing to let me study bats on their properties. Daniel McKinley pointed out obscure references to Missouri bats, aiding the literature review considerably. Vayne Davis generously gave me information on populations of M. sodalis in Tunnel and Inca caves whioh he studied in the central Osarks during the winters of 1953 and 195^. Clair Kuoera and Robert Fleming loaned meteorological instruments which greatly facilitated measurements of temperature and relative humidity in oaves. Clinton Conaway was always available for oounsel and was an excellent companion in the field. Special thanks are given Thomas Baskett who handled many of the problems of administrative detail, provided for some of the transportation so necessary in the study, and was a source of advice and encouragement. Members of the Missouri Conservation Commission have been most helpful during this study in many ways. Conserva tion Agents and their supervisors, Vernon Bennett and James Bailey, have been an excellent source of cave locations. Missouri Conservation Agents have supplied me with numerous recoveries} some of the most interesting and valuable data have come from these men. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW Paul G. Barniokol's Interest In the study has been most stimulating and I greatly appreciate the financial support he supplied in the early phases of the field work* Charles and Elisabeth Schwarts newer failed to answer questions about bats of Missouri, pro-rided me with informa tion on recoveries, and gave much encouragement during the study. I am indebted to Carl 0. Mohr and Thomas G. Scott for their assistance is tue spring, summer and fall of 1957 which made it possible for me to study bats of the Mississippi Talley of Illinois and Missouri under the auspices of the Section of Wildlife Research, Illinois Natural History Survey. The Bat-Banding Office of the United States Pish and Wildlife Service has supplied the bands used in this study, coordinated retakes of banded bats and helped in deciphering numbers on mutilated bands. All parts of the thesis have profited by the intensive reading and editorial suggestions of William H. Elder. I appreciate his presenoe in the field and the enoouragement given during the study. He made available the funds from National Science Foundation Grant No. kj86 whioh were the major support of this work. It is difficult for me to express all that I owe to my wife, Esther. In her roles as record keeper, typist, constructive critic, and bat bander, she has given me some Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW of tho most valuable assistance and encouragement of the study. This research has been supported by funds from the Missouri Cooperative Vildlife Research Units the National Science foundation, Grant No. 1*386; and the Seotion of Vildlife Researoh of the Illinois Natural History Survey, (National Institutes of Health Grant for a sylvan rabies program, project B-13l*9). Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. PREVIEW