Conparison of Temporal and Geographical Skutt VarÍat,íon amongi Nearctic Modern, Holocene and Late Pleistocene Gray Wolves (Canis Tupusl (and select,ed Canis) by Gloria D. Goulet A thesis presented to the University of Manitoba in ful-fil-ment of the thesis requj-rement for the degree of Master of Science 1n Department of Zoology I^Iinnipeg, Manitoba (c) Gl-oria Goul-et, 7-993 ffiWW NationalLibrary Bibliothèque nationale w 'r W of Canada du Canada Acquisitions and Direction des acquisitions et Bibliographic Services Branch des services bibliographiques 395 Wellington Street 395, rue Wellington Ottawa, Ontario Ottawa (Ontario) K1A ON4 K1A ON4 Your lile Votre élércnce Ou l¡le Notre élérence T'he author has granted am B-'auteun a accordé ¡,ine lice¡'lce irrevocable non-exclusive licence irrévocable et norÌ exc¡L¡s¡ve allowinE the håational Libnary of pern'¡ettarnt à !a Bibllothèque Ganada to rep¡'oduce, loan, nationale du Canada de distribute o¡' sell cop¡es of reprodu¡re, prêter, distribuer ou his/her thesis hy any rîeans and vendre des copies de sa thèse in any forrn or forrmat, making de quelque rnanière et sous this thesis available to interested quelque fo¡'me que ce soit pour persons. mettre des exemplaires de cette thèse à la disposition des personnes intéressées. The author retains ownership of l-'auteur conserve la propriété du the copyright in his/her thesis. droit d'auteur qu¡ protège sa ñtüeither the thesis nor substantial thèse. fVi la thèse ni des extraits extracts from it may be printed or substantiels de celle-ci ne otherwise reproduced without doivent être imprimés ou his/her permíssion. autrement ¡'ep¡'odu¡ts sans son autorisatio¡'¡" ISBN 0-315-86052-9 C,aNeaCääi COMPARISON OF TEMPORAL AND GEOGRAPHICAL SKULL VARIATION A-},ÍONG NEARCTIC MODERN, HOLOCENE AND LATE PLEISTOCENE GRAY I^/OLVES (Canis lupus ) (and selected Canis ) BY GLORIA D. GOULET A Thesis submitted to the Faculty of Graduate Studies of the University of Manitoba in partial fulfillment of the requirements of the degree of MASTER OF SCIENCE o 1993 Permission has been granted to the LIBRARY OF TlfE TINWERSITY OF MÄNTIOBA to lend or sell copies of this thesis, to the NATIONAL LIBRARY OF CANADA to mic¡ofilm this thesis and to lend or sell copies of the film, and LIBRARY MICROFILMS to publish an abstract of this thesis. The author reserves other publication rights, and neither the thesis nor extensive extracts from it may be printed or other-wise reproduced without the authols written perurission f hereby declare that f am the sole author of this thesis. I authorize the University of Manitoba to lend this thesis to other institutions or individuals for the purpose of schol-arl-y research. Gloria Goulet f further authorize the University of Manitoba to reproduce this thesis by photocopying or by other means, in total or in part, ât the request of other institutions or individual-s for the purpose of scholarly research. Gloria Goulet 1I For my children Sara Danielle and L. Christian Goul-et, in recognition of their unwavering encouragement and support. av ItThe worl-d needs an embodiment of the frontier mythology, the sense of horízons unexpl_ored, the mystery of uninhabited rniles. rt needs a prace where worves stark the strand lines in the dark, because a tand that can produce a wolf is a healthy, robust and perfect land.rl -Robert B. hieeden Ã.BSTR.ACT The hypothesis that current gray wolf geographic popuJ-ations differ as a resul-t of adaptation to varying ecologicai- requirements in different habitats was tested. The relationship between variation in skull characteristics among temporal (l-ate Pleistocene and Holocene) and rnodern geographical populations and prevailing environmental conditions \,vas investigated in an atternpt to determine the cause of variation (genetic divergence or physiological response) . Resufts indicated that size variation among modern gray wolf geographical- populations $/as due to physiological adaptation to environmental conditions, while skull shape variation among temporally separated North American canj-d populations may be due to genetic divergence. Based on the resul-ts I suggest that wol-f-like canids evolved allopatrically in both the Nearctic and Patearctic. Further, the modern Nearctic gray wolves included here \,vere descendants of Eurasian wol-ves that spread to North America across the Beringian land bridge during intermittent Pl-eistocene glaciation events. Evidence suggests that the great ptains subspecies (C. l-. nubiLus) evolved with the prairie habitat that developed in mid-l-atitude North Arnerica at the end of the l-atest glaciation. Despite the lack of evidence for herj-tability of distinctive traits, subspecies designation should be vl_ retained because of evidence indicating that the plains gray wol-f was ecologically distinct from gray wol-ves inhabiting adjacent regions. I suggest that ecologj-cal- preferences communicated from parent to offspring likely contributed to the temporal maintenance of size variation among post- Pleistocene gray wol-f populations. Similarities in sku1l shape characteristics between Ranchol-abrean dire wolves (C. dirus ) and gray wolves of Eurasian ancestry suggest that the two species \,üere closely related. Based on the resul-ts I suggest that the dire wolf was a "hypermorphicfr form (Geist, L987 ) of the gray wolf, that evolved in response to abundant resources, more equable climatic conditions and possible interspecific competition with contemporaneous late Pleistocene predators. vl_ l- CONTESITS ABSTRÀCT . " ".vi ACKNOWLEDGEMENTS " ". " " "aX LIST OF TABLES.... " ". "xi LIST OF FIGURES "xT1 LIST OF ABBREVIATIONS "...xiii ÏNTRODUCTION ".""""1 METHODS AND MÀTERIALS ......1]- Specimens and measurements ......1-1 Specimen categorization ....1-6 Statistical anal-ysis . .18 RESULTS .....2O Geographical Variation in Modern gray wolf skull-s (18s1-1972).. ..2O Modern gray wolf skulls (1851-1920).. .....22 Temporal- variation among gray wolf skulls... ...26 Fossil- and Modern canids ...28 North American fossil- wol-ves from the mid- Irvingtonian to Iate Pleistocene Interva1.... ..32 DISCUSSTON. 35 Modern gray wolf skulls (1851--l-972) 35 Modern gray wolf sku1Is (1851-1920) 36 Temporal variation among gray wolf skull-s 38 Fossil and Modern canids 42 North American fossil wolves from the mid- Irvingtonian to l-ate Pleistocene Interval- 44 Ecological vs. genetic adaptation.. 55 TemporaJ- maintenance of geographical populations. 65 SUMMARY AND CONCLUSIONS. 68 LÏTERÀTURE CÏTED 69 APPENDÏX ].... ...78 ÀPPENDIX II... .".84 vl- l- I ÃCK}{O3{LEDGEMENTS I am indebted t.o my advisor and friend, DL. George Lammers for giving me the opportunity to complete this project. I am thankful for his advice and encouragement and grateful for the geological knowledge that I have gained during extensive conversations and field trips over the past few years. Members of my advisory commitLee, Drs" Ken Stewart, W.O. Pruitt, Jr. and R.J. El-ias rnade several important suggestions. I am particularJ-y grateful to Dr. Stewart for his interest in this project and his excell-ent editorj-a1 advice. A number of faculty, staff and graduate students are acknowledged for their support, advice and friendship: Urmil-Ia Deonauth, Dr. BilI Diehl--Jones, Marilyn Fabris (BioJ-ogy Teaching Unit), Dorothy HiII, Dr. Jim Duncan, A1vin Dyck, Judy Johnson, Dr. Spencer Sealy and Xiuwei Yang. Rob Balshaw and Alex McIlraith provided val-uable statistical_ advi-ce. I am especially gratefuÌ for the unlimited support and encouragement (and levity) provided by my good friend Diane Neudorf. My chil-dren Sara and Christian encouraged and supported me through aII stages of ny education and I dedicate this thesis to them. My former spouse Lorne was equalJ_y supportive. lx A number of museum staff made rny visit to institutions with collections preasant as wel-r as productive. Dr. Birl Akersten (ISUH), Dr. Larry Martin and Bitt Chorn (KUVP), the mammal- col-l-ections staff at the unj-versity of Kansas Museum of Natural- History, Dr" Dick Cannings (UBC), Linda Gordon (usNM), David campberl (cMN) and Davj-d Baron (SMNH). r am indebted to chris shaw (LACM) for providing me with extensive information as well as specimen measurements and to Dr. Carron Meaney (DMNH) for personally transporting valuabl-e specimens. Ross Li11y and Dr. Jim clayton (DFo) and Jack Dubois (MMMN) provided herpful information. Lorne Gourd, Jane Rawruk and many members of the speleological society of Manitoba provided volunteer assistance and/or guidance through Manitoba's karst formations. G. Dyck very kindly translated portions of Bibikov's (t-985) text. This project was partially funded by research grants from the Manitoba Heritage Federation (through the Manitoba Museum of Man and Nature) and the Manitoba Naturalists Society. LÏST OF TÃBLES TABLE PAGE l-. Local-ities where C. dirus and C" Tupus fossils 49 hrere recovered " xl_ LTST OF FÏGURES FIGURE PAGE l-. GeologicaJ- age and range of selected Nearctic 5 and Palearctic wolf-like Canis" 2. Canis skul-l- el-ements j-ncluded in the analyses " 1-2 3 . Map of l-ocalities of C . Tupus and fossil Canis " 17 4 " Plot of first two principal components scores 2a for gray wolves (C. Iupus) collected in the western half of North America from 1,851,-1972. 5. Plot of first two principaJ- components scores 23 for MALE and FEMALE gray wol-ves (C. Tupus) coll-ected in the western hal-f of North America from l-851-1-920. 6. Pl-ot of f irst two principal components scores 24 for gray wolves (C. lupus ) collected frorn NORTH and SOUTH of 50o N. Lat. from 1851-l-920. 7. Plot of first two principal cornponents scores 25 for gray wolves (C. Tupus ) collected from TREED and OPEN habitats from 1851-1920. 8. Pl-ot of first two principal components scores 27 for Nearctic Modern (1851--1920) , Hol-ocene and l-ate Pleistocene gray wolves (C. Tupus) .