THESIS

CARNIVORE ATTRITION OF THE KAPLAN-HOOVER BISON BONEBED: LATE

HOLOCENE PREDATORY ECOLOGY OF THE CACHE LA POUDRE BASIN,

COLORADO PIEDMONT

Submitted by

Chrissina C. Burke

Department of Anthropology

In partial fulfillment of the requirements

For the degree of Master of Arts

Colorado State University

Fort Collins, Colorado

Summer 2008

ii

COLORADO STATE UNIVERSITY

May 9th, 2008

WE HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER

OUR SUPERVISON BY CHRISSINA COLEEN BURKE ENTITLED CARNIVORE

ATTRITION OF THE KAPLAN–HOOVER BISON BONEBED: LATE

HOLOCENE PREDATORY ECOLOGY OF THE CACHE LA POUDRE BASIN,

COLORADO PIEDMONT BE ACCEPTED AS FULFILLING IN PART

REQUIREMENTS FOR THE DEGREE OF MASTER OF ARTS.

Committee on Graduate Work

__________________________________________________

Kenneth J. Berry

__________________________________________________

Jason M. LaBelle

__________________________________________________

Advisor: Lawrence C. Todd

__________________________________________________

Anthropology Department Chair: Kathleen A. Galvin

iii

ABSTRACT OF THESIS

CARNIVORE ATTRITION OF THE KAPLAN–HOOVER BISON BONEBED:

LATE HOLOCENE PREDATORY ECOLOGY OF THE CACHE LA POUDRE

BASIN, COLORADO PIEDMONT

This thesis presents the results of zooarchaeological, taphonomic, and

ethological investigations of carnivore modification at the Kaplan–Hoover bison

bonebed (5LR3953) in Windsor, Colorado. Kaplan–Hoover is a Late Archaic

Yonkee bison bonebed dated to approximately 2724+/-35 RCYBP. Prehistoric

hunters used an arroyo to trap approximately 200+ bison. After the kill, limited

use of the carcasses by hunters left a surplus of bison meat available for non-

human scavengers and predators. Carnivore attrition is present on over 40% of

the limb bones included in this study. Taphonomic analysis indicates that the

Kaplan–Hoover collection was modified and used by a range of non-human

scavengers. Using an interdisciplinary approach to methodology as well as

identifying key patterns relevant to a variety of fields of research, including

conservation biology is done. This thesis demonstrates how biogenic factors

influence the taphonomy of a faunal assemblage. In addition, this project is a

iv

part of the push to integrate zooarchaeological research and conservation

management decisions currently occurring in the field of archaeology. This

assessment suggests that in order to understand human interactions with present

and future environments, a researcher must first understand the prior behaviors

that assisted in the development of those events.

Chrissina Coleen Burke

Anthropology Department

Colorado State University

Fort Collins, CO 80523

Summer 2008

v

ACKNOWLEDGEMENTS

This thesis is the culmination of a lot of lab time, tears, and excitement. I would have

never completed it, let alone even began it without the encouragement and help from a good

many people. First of all I could not have done this thesis without my advisor Dr. Larry Todd.

Not only has he been instrumental in my success here at CSU, but he is a major reason I was able

to preserver in all of the difficult situations I have encountered during my stay. I cannot say

enough wonderful things about Dr. Todd. He is an amazing mentor, teacher, friend, and

supporter. I have never felt respect from another faculty member as I have from Dr. Todd. His

ability to discuss every interest a student has in archaeology and help push them along to greater

and greater heights is one of amazement. I appreciate his willingness to take me on as a student

and I will always strive to be a mentor to my future students as he was with me.

Dr. Jason LaBelle also deserves a great deal of credit for helping me discover my path in

archaeology. His encouragement has always been of the utmost importance and his willingness

to sit and talk every research topic, obstacle, and success out thoroughly with me has been

extremely helpful. When I was frustrated and worried I couldn’t finish, Dr. LaBelle managed to

keep me going and help me realize that the whole process of graduate school is difficult for

everyone and that the ability to keep going was a trait that was developed and learned from

understanding set backs and problems. Dr. LaBelle is a great professor and mentor and has been

an important influence for the type of mentor I would like to be in the future.

Dr. Kenneth Berry was an important addition to my committee and helped ensure that my

statistics were correct and spent a number of hours discussing graduate school and life with me.

His encouragement and willingness to join my committee has been greatly appreciated and his

vi

advice for future research and instruction on proper formatting was very helpful for the

completion of this thesis.

I could not have finished writing this thesis without the support of my friends. Bethany

Mizushima and Benjamin Jewell (nerd corp!) have been incredibly supportive in every facet of

the writing process. Without them I would not have completed let alone stayed sane the entire

time. When I thought I couldn’t keep writing, I knew I could always talk to either one of them

and they would help me get back on track, even if they were “culturals” and didn’t know what I

was talking about. Erik Otárola-Castillo has also been an important friend for and mentor in my

pursuits with archaeological research. His willingness to include me in research projects has not

only been very helpful for my future, but has also increased my understanding of working with

colleagues on presentations and papers. Lastly, Robin Roberts has been an important part of this

support network. Her ability to encourage and support my every decision and ability to always

push me to have fun has increased my sanity as well.

Finally, Abe Thompson deserves an award for living with me while I was writing my

thesis and not killing me during the many times I unloaded my stress and frustration on him. I

can not imagine living with me while I was panicking and he magically did so without moving

out or running away! My sister Michelle was and always has been my biggest supporter. No

matter how much doubt I have had about myself she has always told me that she knew I could do

it. She also saved my thesis by editing the 100 or so pages, while taking care of her own family.

To everyone above, you are greatly appreciated and without you this thesis would have

never been done. I appreciate your influence in my life every single day and hope that in the

future, I will be able to repay your thoughtfulness and I promise to always support your dreams

and goals.

vii

TABLE OF CONTENTS

ABSTRACT OF THESIS ................................................................................................. iii ACKNOWLEDGEMENTS.............................................................................................. v TABLE OF CONTENTS ................................................................................................ vii LIST OF FIGURES........................................................................................................... ix LIST OF TABLES............................................................................................................. xi CHAPTER 1: INTRODUCTION .................................................................................... 1

Questions for Research................................................................................................ 1 Site Description and Information .............................................................................. 4 Kaplan–Hoover and Other Yonkee Bison Kill Sites................................................ 8 Summary of Chapters................................................................................................ 13

CHAPTER 2: FOUNDATIONS FOR RESEARCH .................................................... 15 Methodological Changes to Understanding Biogenic Factors ............................ 16 FAUNMAP: Choosing Non-Human Scavengers to Explore............................... 20 Ethological Research: Understanding Scavenging Behaviors ............................. 27 Conservation Research.............................................................................................. 41 Summary of Chapter ................................................................................................. 50

CHAPTER 3: AN INTERDISCIPLINARY APPROACH TO METHODS .............. 53 Data Collection Procedures ...................................................................................... 54 Extant Non-human Scavengers: Ethological Methods ......................................... 75 Summary of Chapter ................................................................................................. 76

CHAPTER 4: RESULTS OF DATA ANALYSIS......................................................... 78 Herd Characteristics Analysis.................................................................................. 79 Differential Destruction Analysis ............................................................................ 90 Carnivore Modification Analysis .......................................................................... 104

CHAPTER 5: CONCLUSIONS AND FUTURE DIRECTIONS ............................. 124 Implications for Conservation Research............................................................... 133 Future Directions ..................................................................................................... 136

Literature Cited ............................................................................................................ 142 APPENDIX A: FAUNMAP DATA............................................................................ 155 APPENDIX B: CODING SYSTEM ............................................................................. 157

viii

APPENDIX C: LANDMARK AND MEASUREMENT DESCRIPTIONS AND

CODES ........................................................................................................................... 159 APPENDIX D: KAPLAN-HOOVER DATA............................................................. 165 APPENDIX E: ANALYSIS OF SEX FOR SPECIFIC SKELETAL ELEMENTS .... 188

ix

LIST OF FIGURES

Figure 1.1: Late Archaic projectile ................................................................................. 6 Figure 1.2: Plan map of the Kaplan–Hoover bison bonebed ..................................... 8 Figure 1.3: Map of Late Archaic Yonkee bison kill sites........................................... 10 Figure 2.1: Number of sites with specific non-human scavengers ......................... 24 Figure 2.2: Percentage of non-human scavengers present in sites.......................... 26 Figure 2.3: Canis lupus maxilla ..................................................................................... 29 Figure 2.4: Carnassial pair of Canis lupus ................................................................... 30 Figure 2.5: Canis latrans maxilla ................................................................................... 32 Figure 2.6: Ursus arctos maxilla .................................................................................... 35 Figure 2.7: Ursus americanus maxilla ........................................................................... 40 Figure 3.1: Chipping back ............................................................................................. 67 Figure 3.2: Crenellations ............................................................................................... 67 Figure 3.3: Furrowing .................................................................................................... 68 Figure 3.4: Pitting ........................................................................................................... 68 Figure 3.5: Punctures ..................................................................................................... 69 Figure 3.6: Scooping out................................................................................................ 69 Figure 3.7: Tooth scoring............................................................................................... 70 Figure 3.8: Light utilization .......................................................................................... 71 Figure 3.9: Light/moderate utilization ........................................................................ 71 Figure 3.10: Light/moderate utilization ...................................................................... 72 Figure 3.11: Moderate utilization................................................................................. 72 Figure 3.12: Moderate/heavy utilization..................................................................... 73 Figure 3.13: Moderate/heavy utilization..................................................................... 73 Figure 3.14: Heavy utilization ...................................................................................... 74 Figure 3.15: Extreme heavy utilization ....................................................................... 74 Figure 4.1: Scatter plot of %MAU and bone mineral densities ............................ 103 Figure 4.2: Presence or absence of modification...................................................... 105 Figure 4.3: Percentage of carnivore utilization for the humerus........................... 106 Figure 4.4: Carnivore utilization for the radius-ulna.............................................. 110 Figure 4.5: Carnivore utilization for the femur........................................................ 113 Figure 4.6: Carnivore utilization for the tibia .......................................................... 117 Figure 5.1: Bear modification Bos taurus tibia from Dr. Haynes collection ......... 132

x

Figure 5.2: Probable bear modification on Bison bison ............................................ 132 Figure E.1: Sex analysis scatter plot for the humerus ............................................. 188 Figure E.2: Sex analysis scatter plot for the radius-ulna ........................................ 189 Figure E.4: Sex analysis scatter plot for the metacarpal ......................................... 190 Figure E.5: Sex analysis scatter plot for the metacarpal ......................................... 190 Figure E.6: Sex analysis scatter plot for the metacarpal ......................................... 191 Figure E.7: Sex analysis scatter plot for the metacarpal ......................................... 191 Figure E.8: Sex analysis scatter plot for the femur .................................................. 192 Figure E.9: Sex analysis scatter plot for the femur .................................................. 192 Figure E.10: Sex analysis scatter plot for the femur ................................................ 193 Figure E.11: Sex analysis scatter plot for the tibia ...................................................193 Figure E.12: Sex analysis scatter plot for the tibia ...................................................194 Figure E.13: Sex analysis scatter plot for the tibia ...................................................194 Figure E.14: Sex analysis scatter plot for tibia.......................................................... 195 Figure E.15: Sex analysis scatter plot for the tibia ...................................................195 Figure E.16: Sex analysis scatter plot for the metatarsal ........................................ 196 Figure E.17: Sex analysis scatter plot for the metatarsal ........................................ 196 Figure E.18: Sex analysis scatter plot for the metatarsal ........................................ 197 Figure E.19: Sex analysis scatter plot for the metatarsal ........................................ 197 Figure E.20: Sex analysis scatter plot for the astragalus......................................... 198 Figure E.21: Sex analysis scatter plot for the calcaneus .......................................... 198 Figure E.22: Sex analysis scatter plot for the calcaneus .......................................... 199

xi

LIST OF TABLES

Table 2.1: FAUNMAP age categories.......................................................................... 22 Table 2.2: FAUNMAP species codes ........................................................................... 22 Table 4.1: Cross tabulation of side and sex for MNI analysis of the humerus...... 86 Table 4.2: Cross tabulation of side and sex for MNI analysis of the radius-ulna . 86 Table 4.3: Cross tabulation of side and sex for MNI analysis of the metacarpal .. 87 Table 4.4: Cross tabulation of side and sex for MNI analysis of the femur ........... 87 Table 4.5: Cross tabulation of side and sex for MNI analysis of the tibia.............. 88 Table 4.6: Cross tabulation of side and sex for MNI analysis of the metatarsal ... 88 Table 4.7: Cross tabulation of side and sex for MNI analysis of the astragalus.... 89 Table 4.8: Cross tabulation of side and sex for MNI analysis of the calcaneus..... 89 Table 4.9: Bone mineral densities for Bison bison ..................................................... 92 Table 4.10: MNE portions for the humerus ................................................................ 93 Table 4.11: MNE portions for the radius-ulna ........................................................... 94 Table 4.12: MNE portions of the femur....................................................................... 95 Table 4.13: MNE portions of the tibia ......................................................................... 96 Table 4.14: Frequency table of landmarks on the humerus ..................................... 98 Table 4.15: Frequency table of landmarks on the radius-ulna ................................ 98 Table 4.16: Frequency table of landmarks on the femur .......................................... 99 Table 4.17: Frequency table of landmarks on the tibia ........................................... 100 Table 4.18: Minimum animal units and % MAU values for Kaplan–Hoover..... 101 Table 4.19: %MAU based on MNE portion codes for Kaplan–Hoover................ 102 Table 4.20: Spearman correlation of %MAU and bone mineral density crosses 104 Table 4.21: Chi-square analysis of sex and carnivore utilization .......................... 107 Table 4.22: Chi-square analysis of sex and modification ....................................... 107 Table 4.23: Chi-square analysis of carnivore utilization and side......................... 108 Table 4.24: Carnivore utilization and side cross-tabulation .................................. 108 Table 4.25: Chi-square analysis of carnivore utilization and portion................... 109 Table 4.26: Carnivore utilization and portion cross-tabulation ............................ 109 Table 4.27: Chi-square analysis of carnivore utilization and portion................... 111 Table 4.28: Cross-tabulation of carnivore utilization and portion ........................ 112 Table 4.29: Chi-square analysis of sex and carnivore utilization .......................... 114 Table 4.30: Chi-square analysis of sex and modification ....................................... 114

xii

Table 4.31: Chi-square analysis of carnivore utilization and side......................... 115 Table 4.32: Carnivore utilization and side cross-tabulation .................................. 115 Table 4.33: Chi-square analysis of carnivore utilization and portion................... 116 Table 4.34: Carnivore utilization and portion cross-tabulation ............................ 116 Table 4.35: Chi-square analysis of sex and carnivore utilization .......................... 118 Table 4.36: Chi-square analysis of sex and modification ....................................... 118 Table 4.37: Chi-square analysis of carnivore utilization and side......................... 119 Table 4.38: Chi-square analysis of carnivore utilization and portion................... 119 Table 4.39: Bone mineral densities from bison ........................................................ 120 Table 4.40: Bone mineral densities for bison ............................................................ 121

1

CHAPTER 1: INTRODUCTION

Questions for Research

In any archaeological site there are specific factors that illustrate formation

processes essential to understanding the spatial and temporal aspects of

paleoecology. If the site is composed of a dense bonebed of skeletal material, it is

necessary to assess the taphonomic factors that are associated. Of particular

interest to this thesis is carnivore modification, a biogenic factor that influences

the overall destruction and formation of the bonebed as well as illuminates the

predatory and scavenging behaviors of both human and non-human scavengers.

The goals of this thesis are wide-ranging, with basal questions and

integrated questions. The basal questions are useful for setting the framework

from which the integrated questions can be asked. The integrated questions

incorporate an understanding of the basal questions so that the information

presented by this thesis is useful for other researchers at a variety of different

faunal assemblages. Finally, these questions are meant to establish a framework

for analyzing carnivore modification in faunal assemblages and how that

2

information is useful for understanding human and non-human scavenger

interactions.

Basal Questions:

1. What are the herd characteristics at Kaplan–Hoover?

2. What types of carnivore modification and intensity of carnivore

utilization is present on the Kaplan–Hoover collection?

3. Where is the modification located on the appendicular skeleton and

which specific elements exhibited more destruction than others?

4. What non-human scavenger behaviors are important to understand

when discussing the taphonomy of a faunal assemblage?

Integrated Questions:

1. What relationships between prehistoric human hunters and non-

human scavengers can be observed from the faunal remains at

Kaplan–Hoover?

2. How can these same methods be used for other sites?

3. Why is the interdisciplinary approach used in this thesis beneficial for

answering all of the preceding questions?

The first question, that will build the basis for the remaining questions

asks, what are the herd characteristics? It is essential to know the demographics

of the herd to understand if carnivores were selectively scavenging the remains,

therefore analysis on size and sex of the skeletal material must be accomplished.

The second question: where is the carnivore modification located on the skeletal

elements, is important to understanding how the collection was damaged. A

3

record of the types of carnivore modification present as well as where it is

located anatomically and in what abundances is relevant for comprehending

overall destruction of the material, utilization of the material, and site formation

processes. In conjunction with the remaining basal questions, ethological

literature is useful for understanding non-human scavenger behaviors,

specifically species that could be associated with the region the site is located

within.

The integrated questions for contemplation and analysis seek to

understand the interactions between human hunters and non-human scavengers

that can be observed by comparing and contrasting the answers from the basal

questions. How do the herd demographics and carnivore modification data

support inferences that specific carnivores were present at the site? Included will

be a discussion on how these data sets can be used to understand the overall

paleoecology of a region, further discussing present and future conservation

issues that may have resulted from the interactions created in the past by

humans between themselves and their environments

These questions are important for a number of reasons. First of all,

archaeologists are in a prime position to influence decision making in the natural

resources (Lyman and Cannon 2004:xv). Research done by archaeologists is

useful for understanding interactions between species through time, therefore,

4

having the ability to assist in management decisions for eradication or

reintroduction of species into habitats and regions. Currently, the natural

resources and social sciences are working in parallel directions with a distinct

lack of integration and collaboration. Instead of a parallel line of thinking by

both fields, an integrated line would benefit both in their pursuits.

In general, the questions presented by this research are important to

zooarchaeology and a number of archaeological, paleontological, and ecological

sites. When answered, these questions will provide a basic description of the

Kaplan–Hoover bison bonebed as well as an understanding of four non-human

scavenger species: Canis lupus, Canis latrans, Ursus arctos, and Ursus americanus.

Finally, this research describes an interdisciplinary methodological framework to

zooarchaeological research and carnivore modification.

Site Description and Information

The Kaplan–Hoover bison bonebed located in Windsor, Colorado is a

highly non-human scavenger modified Bison bison bonebed. Therefore, it is an

important example of why it is imperative to research the behaviors of carnivore

and rodent species to assess the specific mammals that altered the skeletal

elements after prehistoric peoples had left. To test the usefulness of the

methodological questions presented in the preceding paragraphs, the Kaplan–

Hoover site was used. Excavations were undertaken by Colorado State

5

University (CSU) from 1997-2001 and overseen by Dr. Lawrence C. Todd from

the CSU Anthropology Department.

Kaplan–Hoover is a late archaic (middle Holocene) bison arroyo trap and

single catastrophic event kill (Todd, et al. 2001:137). Located in Larimer County

Colorado, the site sits at an elevation of 1475 m and is located approximately 800

m north of the Cache la Poudre River (Todd, et al. 2001:126). Radiocarbon dating

was accomplished using several charcoal samples that were collected and

mapped in the bonebed (Todd, et al. 2001:132-133). Using AMS dating, two

larger chunks of charcoal were dated to 2740+/-40 and 860+/-40 radiocarbon years

before present (RCYBP) (Todd, et al. 2001:132-133). In addition, an intact

metatarsal was dated to 2690+/-60 RCYBP and when averaged with the date of

one of the charcoal chunks of 2740+/-40 RCYBP, Kaplan–Hoover is given a date

of 2724+/-35 RCYBP (Todd, et al. 2001:132-133).

The seasonality of the site has been determined as being a September-

October kill based on the eruption and wear of the bison mandibular molars

(Todd, et al. 2001:137). The site is composed of a dense accumulation (Figure 1.2)

of Bison bison skeletal material with the excavated portion measuring 4-5 m wide

and at least 1 m thick (Todd, et al. 2001:127-128). The minimum number of

individual animals (MNI) at the time of the first report was 44 based on the

crania recovered (Todd, et al. 2001:135). Additionally, 4000+ identifiable skeletal

6

elements have been removed from the site and are currently housed in the

Anthropology Department at Colorado State University, with exception of a

number of elements that were left in situ and thus not available for analysis

(Todd, et al. 2001). Estimations from minimum number of skeletal elements

(MNE) and number of identified specimens (NISP) suggest that the deposit could

hold roughly 200+ bison, therefore, 150 have yet to be exhumed (Todd, et al.

2001:135). From these data, the herd composition is approximately 33-39% bulls

and 61-67% females and sub-adults (Todd, et al. 2001:137). Research presented in

this thesis, which includes analysis of materials recovered subsequent to the 2001

publication, will change these numbers slightly.

Figure 1.1: Late Archaic projectile points from the Kaplan–Hoover site (Todd et al. 2001).

The majority of the skeletal elements missing from the bonebed are ribs,

thoracic vertebrae (hump meat), and femora all of which have high food utility

7

values (Todd, et al. 2001:136-137). In general the preservation of the elements is

excellent, with very little weathering cracks, which according to Todd, et al.

(2001:134) indicate burial of the remains soon after the animal’s death. However,

the site preservation is compromised due to heavy modification of the

abandoned skeletal elements by carnivores and rodents and post-depositional

deterioration.

Heavy modification due to carnivores is what separates the Kaplan–

Hoover bonebed from other sites in the prehistory of North America. During

initial examination of the skeletal elements 45 humeri were studied for degree of

carnivore damage, of those 80% had carnivore damage consuming the entire

proximal end and Todd et al. (2001:140) remark that “overall, 98% of the humeri

from the site have some carnivore damage.” These estimates surpass the Casper

site which has 37%, the Jones–Miller site with 28%, and the Bugas–Holding site

with 17% carnivore damage to the humeri (Todd, et al. 1987; Todd, 1997; Todd, et

al. 2001:140). In Chapters 4 and 5 discussions on the types of carnivore

modification and intensity of modification will clarify these numbers and give

more details pertaining to the remaining skeletal elements used for analysis in

this thesis.

8

Figure 1.2: Plan map of the Kaplan–Hoover bison bonebed (Todd, et al. 2001:134, Figure 7).

Kaplan–Hoover and Other Yonkee Bison Kill Sites

The projectile points recovered from Kaplan–Hoover include Yonkee

points, described from the Powers–Yonkee site (24PR5) in southeastern Montana

(Bentzen 1961; Bentzen 1962b; Bump 1987; Frison 1978; Roll, et al. 1992). Yonkee

points (Figure 1.1) are typically side and or corner notched with a basal notch or

indention (Frison 1978:50). The type site of this technology is the Powers–

Yonkee (24PR5) site, located in southern Montana (Bentzen 1961, 1962b; Bump

1987; Frison 1978). Other sites that contain Late Archaic Yonkee points include

Kobold (24BH406) in southern Montana, Powder River (48SH312), and

Mavrakis–Bentzen–Roberts (48SH311) both of which are in northern Wyoming

(Bentzen 1962a; Bump 1987; Frison 1968; Frison 1970; Frison 1978). The last site

9

to be discussed is Ayers–Frazier (24PE30), another bison trap in Montana (Clark

1981) (Figure 1.3).

Powers–Yonkee (24PR5) was initially dated to 4450+/-125 years before

present (Bentzen 1961). Several years later Bump (1987) dated bison skeletal

material to 2290+/-50 years before present. The site was excavated by the

Sheridan Chapter of the Wyoming Archaeological Society in August of 1961

(Bentzen 1961). The Powers–Yonkee bison kill is an arroyo trap that sits upon a

high terrace at about 1097 meters above sea level; the site is located on the north

bank of a small arroyo upon this terrace (Bentzen 1961). Bentzen (1961) states

that the bison were driven into the north-south branch of the arroyo and then

were shunted or trapped into the east-west branch of the arroyo. A bison kill is

represented at Powers–Yonkee, however, there are other faunal remains,

including one canid (Bump 1987:31). The remains are very well preserved and

major concentrations lie at approximately 89–104 cm below the surface sediments

(Bump 1987:33). As will be seen in most of the sites designated as Yonkee,

projectile points are usually recovered from rib skeletal elements (Bentzen 1961:7;

Frison 1968:32-33, 1978:203). Muscle stripping is evident from butchery cut

marks on specific elements as well at Yonkee sites (Frison 1968:33-34, 1978:203).

10

Figure 1.3: Map of Late Archaic Yonkee bison kill sites

on the Great Plains in Montana, Wyoming, and Colorado.

The Powder River site (48SH312) located in the Powder River Basin has

not been dated. The site was excavated in 1966 and is an arroyo trap single kill

event of Bison bison, with an MNI of approximately 12 (Frison 1968:32). Of the 25

projectile points found at the site, 16 are located inside rib or vertebral column

skeletal elements (Frison 1968:32-33). Butchering marks indicate that the hunters

removed meat that was easiest to obtain (Frison 1968:33-34). The majority of the

meat removed at Powers-Yonkee was hind limbs, thus leaving most of the

forelimbs present at the site (Frison 1968:33). In addition, hunters did not

remove the brains, hides, or tongues, further reinforcing the idea that the meat

11

was chosen based on easiest to access in the arroyo (Frison 1968:33). Finally, the

author makes mention that other damage to the skeletal elements is most likely

indicators of non-human scavenging behaviors, although he does not go into

detail on this topic (Frison 1968:33).

The Mavrakis–Bentzen–Roberts bison trap (48SH311) is a single kill event

located in the Powder River Basin just as the Powder River site (Bentzen 1962a;

Frison 1968, 1978). Mavrakis–Bentzen–Roberts site was excavated in 1962 and is

an arroyo trap kill with an MNI of approximately 17-26 bison (Bentzen 1962a:32).

Dated to 2600+/-200, site 48SH311 shows little evidence of marrow removal

because of few stone tools imbedded directly into shaft of the elements (Bentzen

1962a:32). Finally, 48SH311 shows butchering cut mark evidence of muscle

stripping similar to the other Yonkee sites (Frison 1978:206).

The Kobold site (24BH406) has not been dated, however, the projectile

points at the site are Yonkee points (Frison 1970b). Kobold is a multiple

component bison jump from a 7.62 meter cliff in southern Montana (Frison

1970b:7). Two of the levels at the site contain faunal remains, level two contains

badly decomposed material with some long bones broken for marrow with an

MNE of approximately 65 (Frison 1970b:15). The second level to contain faunal

materials is level four, which is mostly scapulae, humeri, radii, and metacarpals

with possible removal of marrow (Frison 1970b:22-23).

12

The final site is the Ayers–Frazier site (24PE30) dated to 2180+/-150 years

before present (Clark and Wilson 1981:23). The site was excavated in 1978 and is

interpreted as being a single kill event in an arroyo trap with 700 elements

recovered from excavations and approximately 300 more from a looter’s back

dirt pile (Clark and Wilson 1981:37). There is evidence of butchering in terms of

cut marks, chop marks, and skinning marks on the skeletal remains from Ayers–

Frazier (Clark and Wilson 1981:38). Of the 700 skeletal elements analyzed from

the test excavation area, approximately 15% have carnivore modification and the

authors go into great deal discussing the bone tools of the site, which appears to

be a description of the carnivore modification types of chipping back and

salivary polishing that will be defined later in this thesis (Clark and Wilson

1981:50–51).

Yonkee complex sites are similar in more ways than just the type of

projectile points. The bison kills from the Yonkee Late Plains Archaic are

typically arroyo traps with exception of the Kobold site, which is a jump

(Bentzen 1961, 1962; Bump 1987; Clark and Wilson 1981; Frison 1968, 1970b,

1978). Faunal material at Yonkee sites typically have points lodged in the ribs

and vertebral columns and butchering evidence suggests stripping of muscle

meat as well as some removal of marrow and long bones (Bentzen 1961, 1962b;

Bump 1987; Clark and Wilson 1981; Frison 1968, 1970b, 1978). With limited

13

carcass utilization, expecting non-human scavenger modification is reasonable.

The only authors discussing carnivore modification are Clark and Wilson with

the Ayers–Frazier site, which was published in 1981.

Focus on the Yonkee sites indicates that most of the sites with Yonkee

projectile points were arroyo traps and butchering patterns suggest that

prehistoric hunters did not use all of the bison meat available. At the Ayers–

Frazier site, there is a record of carnivore modification being present, suggesting

that a new analysis of the other sites may yield similar results considering that

the other publications were prior to intense taphonomic scrutiny at

archaeological sites.

Summary of Chapters

The remaining chapters will discuss a wide range of topics and end with a

synthesis of ideas. Chapter 2 discusses a number of background research

projects and methods. Chapter 2 begins by identifying the methodological

framework on carnivore attrition, then presents exploratory research using the

FAUNMAP database, and concludes with a discussion of non-human scavenger

behaviors and predator conservation issues in North America. Chapter 3

describes and explains the methods used to collect and analyze data from the

Kaplan–Hoover collection. Chapter 4 discusses the final results of analysis,

14

specifically discussing sex analysis, herd characteristics, carnivore modification,

and overall description of carnivore destruction on the collection. Finally

Chapter 5 allows discussion of the most important results and patterns as well as

correlations between the skeletal analysis and ethological literature review.

Chapter 5 concludes with future directions for research in biogenic factors in

taphonomy, carnivore management, and future interdisciplinary approaches to

current environmental problems.

15

CHAPTER 2: FOUNDATIONS FOR RESEARCH

This chapter presents information collected on carnivore modification in

zooarchaeology, presence of non-human scavengers in Great Plains

archaeological sites, and non-human scavenger ethological literature. First, it is

essential to discuss where and how the understanding of carnivore modification

on faunal remains emerged in the long history of archaeology and

zooarchaeology. Next a discussion on the use of the FAUNMAP database assists

in identifying non-human scavenger remains in Holocene archaeological and

paleontological sites. Finally, a review of the ethological literature on the species

of interest Canis lupus, Canis latrans, Ursus arctos, and Ursus americanus is

accomplished. This section serves as both part of the literature review and part of

the results section, as a means to illustrate animal behaviors that may have

contributed to the taphonomy of faunal assemblages. This chapter ends with a

discussion on conservation issues in regards to wolves, coyotes, and bears. In

view of the long relationship humans and these scavengers have had, it is

important to discuss how zooarchaeological research can contribute to long term

management decisions. Discussion of conservation can open interdisciplinary

16

communications that can influence an understanding of how humans have an

impact on their environment.

Methodological Changes to Understanding Biogenic Factors

In the earliest archaeological research, faunal remains were typically

thrown to the side and in some early cases recorded in lists (Reitz and Wing

1999:16-17). The reaction to exclude faunal remains from archaeological

interpretation is in part due to the lack of understanding that humans and their

environments are related and interacting (Reitz and Wing 1999:15-16). Initially,

archaeologists did not believe any data or significant information could be

gathered from faunal remains, and then gradually, archaeologists began

recording what species the faunal materials exhibited and counting how many

individuals were present (Reitz and Wing 1999:15-16). Over time, archaeologists

began interpreting damage to faunal remains as bone tools, and in several cases

the modification was interpreted as indicating tool construction (Binford 1981;

Brain 1981; Dart 1953; Dart 1956; Dart 1971). An example of the most famous

misinformed assumption that bones were altered to be tools or weapons was

established by Dart and his Osteodontokeratic Culture (Binford 1981; Brain 1981;

Dart 1953, 1956; Dart and Wolberg 1971). Dart believed that in the South African

caves, the bone accumulations were indications of a violent past in human

culture and he suggested that the breaks and crenellations exhibited in the

17

skeletal elements were created by early man (Binford 1981; Brain 1981; Dart 1953;

Dart 1956; Dart 1958; Dart 1971).

Brain (1981) took a different approach to the evidence proposed by Dart;

he studied the behaviors of African carnivores and the geology of caves and

discovered a drastically different scenario. After observing wild dogs, he found

that the types of modification Dart had been recording on bones was very similar

to the types of gnawing and crushing marks created by various carnivores

devouring a carcass (Brain 1981:22-24).

In the Great Plains, a similar situation occurred. Bison kill sites in various

settings were being excavated and skeletal elements were being analyzed. At the

Glenrock Buffalo Jump site, Frison (1970a:26-33) suggested that bone tools were

constructed as “expediency tools” and used to skin and remove meat from the

bison. At the Casper site, Frison (1974:28-31) again suggested the use of skeletal

elements as choppers and hide scrapers. Similar to Brain, Binford (1981) was

working on understanding the different processes possible to change the

dynamics of an archaeological site. In the seminal publication, “Bones: Ancient

Men and Modern Myths”, Binford illustrates the differences between bone tools

and carnivore modification of elements (Binford 1981). Moreover, he

demonstrates, with extensive actualistic research the differences between animal

and human modification to skeletal elements (Binford 1981). Finally, Binford

18

(1981:81) states that while humans may be the sole agent for change in stone by

making tools; a similar correlation does not exist for human impact to skeletal

material, especially considering that numerous mammals rely completely on

other animal resources for survival.

Complementary research by Haynes (1980a, 1980b, 1981, 1982, and 1983)

also emerged in the early 1980s. Instead of Binford’s system to understand the

types of specific marks produced by scavenging predators, Haynes (1981 and

1982) sought out to understand how entire carcasses were utilized. Instead of

coding the types of modification present on the skeletal elements, Haynes

(1982:275) recorded the amount of destruction to the elements and compared this

to actualistic research of scavenging behaviors. Combining the methods

presented by Binford and Haynes, such as: ethological literature, actualistic

research, and skeletal material properties, changes have been made to how

archaeologists understand the influence of biogenic factors in site formation

processes.

Researchers in current carnivore modification studies have begun to ask

how one could identify the specific predator that left the marks on the remains

found at hominid sites in Africa (Coard 2007; Dominguez-Rodrigo and Piqueras

2003; Pickering, et al. 2004; Selvaggio and Wilder 2001). Arguments could be

made that these researchers cannot discover the specific species consuming

19

carcass materials from faunal remains. It is difficult to assess specific carnivore

modifying assemblage by tooth marks because of the nature of carnivore

scavenging, which has been shown to be multiple marks overlapping one

another. Further it can be argued that they are not discussing the ethological

literature or doing ethological research as Binford (1981), Haynes (1980a, 1980b,

1982, and 1983), and Burgett (1990) had done. Trying to determine species from

tooth marks invariably led to the assessment (thus far) that the size class of

predators responsible could be discovered, however because of the processes of

gnawing and the plasticity and density of the skeletal material, accurate

measurements are not attained and comparison with the various African

carnivores can not be determined to any defining degree (Selvaggio and Wilder

2001). Selvaggio and Wilder (2001) specifically found that it is very difficult to

assess species of scavenger on skeletal elements based on size and shape of tooth

marks, specifically because skeletal element densities affect the resistance to force

of the skeletal material.

Appreciating how the methodological framework for studying faunal

remains developed over the course of archaeological history assists a researcher

in developing their own methods. Thus, illustrating what methods have worked

in the past and what needs to be changed to improve the field as a whole. Faunal

remains have not always been considered an important part of archaeological

20

assemblages, however, an increasing awareness of the dynamic nature of

archaeological sites has improved the questions asked and thus the methods

needed to resolve them. One possible method used in this research to help

decide which non-human scavenger species to focus on is the use of the

FAUNMAP database of faunal remains at archaeological and paleontological

sites across North America.

FAUNMAP: Choosing Non-Human Scavengers to Explore

This part of the project was used to achieve an understanding of the

specific species of predators represented in Bison bison archaeological

assemblages and to evaluate the overall changes, through time, space, and in

terms of population numbers between various species and bison. Collection of

data from FAUNMAP assists in the increase of information on how the Kaplan–

Hoover bonebed was used and why it is used at such a high intensity by non-

human scavengers when compared to other Holocene Great Plains bison kills.

The FAUNMAP database was created in an effort to document the

mammalian species in paleontological and archaeological deposits in North

America during the Quaternary period (Graham, 1995). This database is not

exhaustive, but is fairly extensive on species within paleontological and

archaeological deposits. Initially the database was created to facilitate the

21

information on the evolution and movement of mammalian communities, but

can be used as an important resource for archaeologists attempting to

understand the biogenic ecology of a region, such as the locality of their specific

site (Graham and Lundelius 1995).

The FAUNMAP database was used as a method for understanding what

species could have been present during the late Holocene on the Great Plains.

From FAUNMAP information has been collected on the states of Montana,

Wyoming, and Colorado (coded as MT, WY, and CO respectively). The

information collected for each site includes: site name, number, state, county,

latitude and longitude, FAUNMAP age group (Table 2.1), species and family

(Table 2.2), minimum number of individuals (MNI), number of individual

specimens per taxon (NISP), and literature citation (to seek out any information

not provided by the FAUNMAP database). The species of interest for this

research study were Canis familiaris, Canis latrans, Canis lupus, Ursus arctos, Ursus

americanus, and Bison bison. To begin, all sites containing Bison bison in Montana,

Wyoming, and Colorado were documented, followed by information on above

species, and finally collection of the rest of the information listed above.

22

FAUNMAP Age Categories

HOLO

EHOL

EMHO

MHOL

LMHO

LHOL

HIHO

HIST

Age CategoriesHolocene 0-10,000 B.P.

Early Holocene 7,500-10,500 B.P.

Early/Middle Holocene 3,500-10,500 B.P.

Middle Holocene 3,500-8,500 B.P.

Middle/Late Holocene 0-8,500 B.P.

Late Holocene 450-4,500 B.P.

Late Holocene/Post-Columbian 0-4,500 B.P.

Post-Columbian 0-550 B.P.

FMAGE

Table 2.1: FAUNMAP age categories used for background research.

FAUNMAP Species Codes

CAN

CA

CA fa

CA lu

CA la

UR ar

UR am

BI bi

SpeciesCanidae

Canis sp.

Canis familiaris

Canis lupus

Canis latrans

Ursus arctos

Ursus americanus

Bison bison

FMSP

Table 2.2: FAUNMAP species codes used for background research.

Analysis began by assessing the overall numbers of sites in each state and

within specific latitudes and longitudes. There are 30 sites located in Montana,

46 in Wyoming, and 13 in Colorado. This disparity could be accounted for by

bison populations during the middle Holocene. An increase in numbers in the

northern plains occurred because bison thrive on the abundance of C4 grasses

which are tolerant of drought and thus typical of the warm and dry

23

Hypsithermal period (8,000 – 4,000 B.P.), which began in the northern plains and

moved south through time (Kay 1998:25-27). This was then overlapped and

followed by the Neoglacial which began around 4,500 B.P. and lasted into

present times in the northern plains. The Neoglacial period contrastingly was

associated with higher precipitation and thus expansion of boreal forests, this

could have also increased bison population numbers and bison kills by

providing more precipitation to grasses, further this could have also expanded

Ursidae habitats (Kay 1998:27-28). Interestingly, Montana and Wyoming (Figure

2.1) have both grizzly bears and black bears present in faunal assemblages,

whereas Colorado (Figure 2.1) does not, and may have been too warm and dry to

accommodate the bears. Finally, these relationships correspond with the number

of sites containing non-human scavengers in the late Holocene.

The numbers of predators in archaeological assemblages increased in the

late Holocene (Figure 2.2), from 7% to 45%! From the time when the Neoglacial

began about 4,500 B.P. at the beginning of the FAUNMAP age group for the late

Holocene, it would be assumed that this drastic increase in predator

representation was related to moisture in the northern plains. Increasing

precipitation increases boreal forests, grasses, and other botanical species, thus

increasing amount of resources for a multitude of mammalian and ornithologic

species as well. It should be assumed that Canis familiaris, Canis latrans, Canis

24

lupus, Ursus arctos, and Ursus americanus were not solely sustaining themselves

on Bison bison. Therefore, the increase in numbers could have come in part on

the increase in the family Lagomorpha or the variety of berries whose population

numbers could have increased as well.

0

1

2

3

4

5

6

7

8

Montana Wyoming Colorado

State

Nu

mb

er o

f S

ites Canis familiaris

Canis latrans

Canis lupus

Ursus arctos

Ursus americanus

Figure 2.1: Number of sites with specific non-human scavengers in Montana, Wyoming, and

Colorado from the FAUNMAP database.

Transitioning from the late Holocene to the Post-Columbian is an

interesting shift as well. Again, 45% of late Holocene sites contain predator

remains, whereas the late Holocene/Post-Columbian switch has 23% and then

decreases again in the Post-Columbian period to 12% (Figure 2.2). Euro-

American settlement of the Great Plains, decimation of bison populations, and

human death caused by disease, all of which limited bison kills, may have

impacted the number of bison kill sites on the Great Plains. Therefore, the

numbers of predators represented in bison faunal assemblages would have been

25

impacted. Furthermore, as bison began to disappear, so too would have the

predators that likely used them. This could have occurred by population

movements to the east, west, or south and by reduction in number of offspring

produced.

In relation to the paleoclimatic fluctuations, there are distinct differences

in which species live in which regions. Ursidae and Canidae can live in a wide

range of environments (Fitzgerald, et al. 1994). Ursidae, are typically scavengers,

and scavenge in the spring months after their winter lethargy period has ended

(Green, et al. 1997:1040; Mattson 1997:165). If these bears were scavenging

human produced carrion, then it could be assumed that human-predator

interactions would have occurred and possibly led to domestication.

Canids account for 97% of predator remains in the sites in Montana,

Wyoming, and Colorado. To what extent did wolves and coyotes follow humans

for sustenance? Later in this chapter a discussion on coyote behaviors indicates

that coyotes follow wolves to kills and wait to scavenge the remains. It has been

suggested that dog domestication and or hybrid dog remains are present as early

as 6,500 B.P. at the Hawken Site in Wyoming and 4,300 B.P. at the Dead Indian

Creek site in Wyoming (Walker and Frison 1982:127-128). Given that dog

domestication occurred at this time it is plausible that the increase in canid

remains in the late Holocene could be related to their domestication by humans.

26

Figure 2.2: Percentage of non-human scavengers present in sites within FAUNMAP age groups.

Use of the FAUNMAP database is important for recognizing patterns in

the archaeological and paleontological record of the Great Plains. It is evident

now from FAUNMAP research that canids are slightly more represented in

Holocene archaeological sites on the Great Plains. Additionally, it is evident that

more bison kill sites occur in Montana and Wyoming. Finally, there are more

non-human scavengers present in Montana and Wyoming. This information has

placed the Kaplan–Hoover bonebed in the context of other sites within the Great

Plains, within the Holocene, within bison sites, and within mammalian

population fluctuations. Besides placing Kaplan–Hoover in context, it is

important for questioning why this site is heavily modified and why other sites

may not be. Therefore, a discussion of non-human scavenger behaviors is

essential for understanding how scavengers used the bonebed.

27

Ethological Research: Understanding Scavenging Behaviors

There are thousands of books, articles, conference proceedings, and

reports published on the behaviors of carnivore and omnivore scavengers in the

Great Plains, North America, and the world. Because of this, the research

presented in this section is not conclusive or exhaustive. This research

background gives a brief description of Canis lupus, Canis latrans, Ursus arctos,

and Ursus americanus behaviors and feeding habits to inform further questions

about interactions with bison kill remains from prehistory. Research on wolves

and grizzly bears is very expansive; including numerous books and articles

whereas research on coyotes and black bears is slightly limited. For this project,

future research could include behaviors of other mammal scavengers that utilize

faunal remains.

Canis lupus: Wolves

Wolves were at one point common all over the United States, which

indicates that they could have easily been located in various places on the Great

Plains. With the introduction of domesticated cattle, however, the species has

been eradicated from most states for livestock slaughter (Fitzgerald, et al.

1994:307). Canis lupus can occupy a wide range of environments, including high

altitudes and the species typically lives in regions where there are high

populations of large bodied ungulate species (Fitzgerald, et al. 1994:306).

28

Documentation of kills demonstrates that the gray wolf mostly predates elk,

mule deer, bison, and mountain sheep and in some instances beavers (Fitzgerald,

et al. 1994:306; Mech 1970).

Anatomically, canids (Figure 2.3) are designed to make numerous shallow

bites while attacking to take down its prey, whereas a felid can take one deeper

bite and hold on to take their prey down (Peterson and Ciucci 2003:112-113).

Wolves having heterodont sharp high cusped teeth are able to break and chew

through a variety of gross materials, the molars are used to rip and shred meat,

while the canines and premolars are used to crush and crack bone material

(Peterson and Ciucci 2003). In addition to the dental specialization for meat

consumption, the mandibular structure of a wolf is robust with several massive

muscles that act in unison to close the jaw rapidly and efficiently (Peterson and

Ciucci 2003). Further adaptation for the lifestyle of a carnivore is the carnassial

pair (Figure 2.4), which are the upper fourth molar and the lower first molar that

act together as scissors for shearing and slicing through hide materials (Peterson

and Ciucci 2003).

29

Figure 2.3: Canis lupus maxilla (Myers, et al. 2008).

Wolves can swallow pieces of carcasses whole; in one study two whole

caribou tongues were found in a wolf stomach (Mech 1970:169-170). Wolf

stomach contents have been known to contain anywhere from 2.40 to 5.98

kilograms of meat, bone and hair, with the largest known amount being close to

8.62 kilograms (Mech 1970:170-171). Typically wolves begin feeding on the

internal organs after tearing open the carcass, then move to hind limbs and other

parts, while avoiding the entrails and stomach contents (Mech 1970; Peterson

and Ciucci 2003). Wolves will feed until their stomachs are full and their sides

distended and in the winter, after feeding, wolves will collapse and sleep up to 5

hours, which aids in digestion after gorging (Peterson and Ciucci 2003:124). In

addition, wolves rely heavily on skeletal materials from kills, often scavenging

on them to sustain their mineral nutrient intake (Peterson and Ciucci 2003:125).

30

Further, single wolves that have not had access to a fresh kill can sustain

themselves for long periods of time on only skeletal material and then may be

willing to eat any part of the gross tissue (Peterson and Ciucci 2003:125).

Figure 2.4: Carnassial pair of Canis lupus (Myers, et al. 2008).

Gray wolves have been recorded scavenging significantly more bison

carcasses as opposed to red deer and wild boars in Bialowieza Primeval Forest in

Poland (Selva, et al. 2005:1593). Interestingly, of all the predators monitored in

Bialowieza Primeval Forest (including: ravens, buzzards, eagles, red foxes,

raccoon dogs, pine martens, and domestic dogs), gray wolves were the only

species able to open dead bison carcasses (Selva, et al. 2005). In the winter

season, Huggard (1993) noted that wolves scavenged in shallower snow than

deep snow and would hunt more often if the snow was at great depths. Wolves

are even known to cache carcass remains for later use, specifically in the summer

to keep flies away and preserve the meat out of the summer heat (Mech 1970;

31

Peterson and Ciucci 2003). Further this caching can be done to save food for later

after the wolf is satiated, and typically wolves will take their food for caching

long distances (up to 5 km) from the kill to avoid theft by other scavengers

(Peterson and Ciucci 2003:117).

Canis latrans: Coyotes

Canis latrans (Figure 2.5) is still considered common all across Colorado

and is easily adapted to all elevations (Fitzgerald, et al. 1994:302). In addition,

the species is well adapted to living amongst human populations and may have

thrived after the eradication of the gray wolf (Fitzgerald, et al. 1994:302).

Typically, Canis latrans is an opportunistic feeder, often preferring animal meat,

but also consuming vegetation and insects in some instances (Fitzgerald, et al.

1994:303). In most situations coyotes will eat jackrabbits, cottontail rabbits, and

rodents, likewise; they are known to scavenge carrion of cattle and big game

which has been killed by other larger predators and do often themselves kill

livestock such as sheep and goats (Fitzgerald, et al. 1994; Hilton, 2001; Kleiman,

2001; Paquet, 1992). Coyotes can and will alter their natural diet to exploit foods

introduced by humans and other scavengers to lessen the amount of energy

needed to gain food (Kleiman and Brady 2001). Coyote stomachs typically

contain large quantities are scavenged foods (indicated by large quantities of

32

maggots) as well, suggesting that in the wild they are not necessary hunters, but

scavengers (Kleiman and Brady 2001:168-169).

Figure 2.5: Canis latrans maxilla (Myers, et al. 2008).

Canis latrans is known for defecating on their kills and carrion to mark

their property and deter other animals from consuming it (Acorn and Dorrance

1990; Acorn and Dorrance 1998; Wade and Bowns 1985). When hunting, coyotes

attack the neck/throat first of sheep and goats and attack the hind limbs in calves

of other ungulates (Wade and Bowns 1985). They primarily begin feeding in the

hind limbs or just below the ribs and choose viscera first when consuming

carcasses (Acorn and Dorrance 1990; Acorn and Dorrance 1998; Wade and Bowns

1985). In almost every case of carrion scavenging, however, the coyote will either

follow gray wolves or scavenge gray wolf kills (Paquet 1992). In some instances

it is difficult to assess the amount of material in a coyote stomach as carrion or

33

hunted; however, the presence of maggots and fly larvae have been used as a

means to determine if the coyote hunted its meal (Kleiman and Brady 2001:168).

Comparing Wolves and Coyotes

A research study at Riding Mountain National Park in Manitoba,

documented 194 ungulate wolf kills from July 1982 through March 1986 (Paquet

1992:338). Within this same time frame Canis latrans killed 59 ungulates and

were documented to visit every wolf kill (Paquet 1992:338). On average, large

gray wolf packs consume more of the killed carcasses than do coyotes; this is

likely due to size and energy expenditure needed by each non-human scavenger

(Hilton 2001; Paquet 1992). During this research study Paquet (1992:341) found

that all wolf-killed ungulates remains (n = 194) were scavenged by coyotes and

this was evident by coyote tracks to every wolf-kill and skeletal disarticulation

and hide removal of carcasses. Moreover, Paquet (1992:341) observed coyotes

waiting 100 m from a fresh wolf kill and noticed that the coyotes moved in

quickly to consume the remains immediately following wolf departure. This of

course led to the demise of some coyotes that were impatient; however, this

danger did not deter them (Paquet, 1992; Wilmers, 2004).

Anatomically, wolves and coyotes are similar; however, the coyote is

constrained by being significantly less powerful than the wolf and much smaller

in size (Hilton 2001). In terms of scat, wolf and coyote scats are similar in

34

appearance, contents, and can overlap in size; however, coyote scat rarely

exceeds three centimeters in diameter, while wolf scats can exceed three

centimeters and typically go beyond or up to 4 centimeters in diameter (Mech

1970). In appearance, wolf and coyote scat is arranged with the skeletal

fragments in the center while hide and hair are wrapped around the outside,

therefore protecting the intestines (Mech 1970). Unlike wolves, coyotes scavenge

and typically hunt alone, allowing more time to be dedicated to following other

hunters (Kleiman and Brady 2001).

Ursus arctos: Grizzly Bears

Ursus arctos (Figure 2.6) is known to live in a wide variety of environments

from plains grasslands to alpine tundra and is most content in a habitat of

seasonally changing food stuffs (Fitzgerald, et al. 1994; Servheen 1999). Use of

FAUNMAP to get a rough estimate of where grizzly bears were on the Great

Plains during the Holocene indicates that they were present at various

archaeological sites during all geological time periods, including Colorado

during the early and middle Holocene. Predominately, Ursus arctos consumes

vegetation; nevertheless, the species is known for scavenging carrion (especially

in the spring), and killing small mammals such as marmots, large mammals such

as elk and other ungulates, and livestock such as cattle and sheep (Craighead, et

al. 1995; Fitzgerald, et al. 1994; Wade and Bowns 1985).

35

Figure 2.6: Ursus arctos maxilla (Myers, et al. 2008).

These mammals are incredibly efficient as omnivores, and are fairly

inefficient as carnivores, so scavenging is the main way for them to get meat

protein (Craighead and Craighead 1972:304). Winter-killed ungulate species are

of importance to grizzly bears, specifically in the spring after they have

awakened from winter lethargy; however, carrion feeding is at its peak from

March through May (Craighead, et al. 1995; Green, et al. 1997; Mattson 1997). In

Yellowstone National Park, grizzly bears consume mostly elk, bison, and moose

meat (Craighead, et al. 1995; Mattson 1997). Carrion availability can drastically

affect these behaviors by increasing the amount of time bears use carrion

(Craighead, et al. 1995:258-260). Mattson (1997:171-172), states that the frequency

in which grizzly bears used ungulate carcasses, varied during months, years, and

regions of the park. In addition, use of ungulates was related to availability of

whitebark pine seeds (Mattson 1997:169). However, if large numbers of

carcasses exist in a grizzly bear’s territory, they will forego eating other foods

36

and just sustain themselves on carrion. Bears typically do not feed in groups or

at the site of the kill and typically remove pieces of carcasses and retreat to

concealed areas for feeding purposes (Craighead, et al. 1995). Bears are also

known for caching carcasses for future use and will return to feed numerous

times if the carcass is not located by other scavengers (Craighead, et al. 1995:259).

Moreover, Green, et al. (1997) discovered that date of death was less important in

determining if a bear would scavenger a carcass if the death occurred between

February and early March and more important between middle March to late

April. This could be due to increase in temperature and rate of decomposition of

the carcasses. Green, et al. (1997:1047) further reported that Ursus arctos typically

scavenges more Bison bison than Cervus elaphus in Yellowstone National Park.

Ursus arctos exploits carrion more frequently in higher altitudes in Yellowstone

National Park than lower altitudes during the late spring (Green, et al.

1997:1048).

Ursus arctos is an animal that, as argued by Craighead, et al. (1995) and

Craighead and Craighead (1971), is conditioned by humans for food resources.

There is a large body of literature on grizzly bears feeding in garbage dumps,

campgrounds, and boneyards (cattle carcass piles) in Montana and Yellowstone

National Park (Craighead and Craighead 1971; Craighead, et al. 1995; Rogers

1987; Wilson et al. 2005). After consumption of ungulate species in the early

37

spring, snow decreases and tourist activity increases allowing grizzlies to stock

up on more calorie rich foods from garbage dumps, which are particularly

important to the feeding habits of Yellowstone National Park bears (Craighead,

et al. 1995:44-47). Garbage dump feeding does not have a specific seasonal time

period however, as bears use this resource continually throughout their non-

lethargy season as a consistent and stable food supply (Craighead, et al.

1995:270).

A significant research study from 1977 to 1987 suggested that grizzly

bears on the east front of the continental divide of Montana were frequenting

rancher boneyards as a secondary source of all protein (Craighead, et al. 1995;

Wilson, et al. 2005; Wilson et al. 2006). These sites are typically frequented

during the spring when bears need to gain calories and protein quickly after

winter lethargy (Mace et al. 1987; Wilson et al. 2006).

According to Craighead and Craighead (1972), grizzlies who feed at

garbage dumps, campgrounds, and boneyards exhibit less fear of humans and

human smells; however, in other areas of national parks and human landscapes

they are fearful and tend to avoid contact with humans. Within Yellowstone

National Parks campgrounds, grizzlies return for garbage foraging during spring

and fall migratory movements to gain access to another food source with limited

energy expenditures and the animals that frequent campgrounds on a regular

38

basis become conditioned to human presence, a difference from grizzlies that

frequent isolated garbage dumps where humans move into and out of the area

on a more predictable regular basis (Craighead and Craighead 1972:309-311).

The conditioned behaviors exhibited by grizzly bears could be attributed

interactions with humans (Craighead and Craighead 1972). Given that these

interactions are occurring more frequently, due to human encroachment on

natural habitats, grizzly bears will become acclimated to human scents and

environments (Craighead and Craighead 1972). Therefore, bears become less

fearful, further causing more conflicts in homes, cars, and camp sites (Craighead

and Craighead 1972).

Understanding feeding ecocenters as defined by Craighead, et al. (1995)

assists in the general knowledge of how bears feed and the patterns that may be

observed from their feeding behaviors. Craighead, et al. (1995:321), define bears

as an ecocentered population “that congregates at a high-quality food source in a

relatively confined, predictable portion of an entire ecosystem during an

extensive, annually predictable time period.” In view of the fact that bears have

a regimented feeding pattern based on availability of food stuffs, it would be

expected that bears could have evolved behaviors that rely heavily on this

feeding style to ensure existence.

39

Finally, boneyards as feeding ecocenters are important in terms of where

bear behaviors have been constant over time. Across the Great Plains and

Western United States, cattle ranchers have sometimes used boneyards or cattle

carcass dumps when their livestock have died (Craighead, et al. 1995; Mace et al.

1987; Wilson et al. 2005; Wilson; et al. 2006). Craighead et al. (1995:324–326)

compare boneyards to bison kill sites, suggesting that these were predictable and

stable events across the Great Plains, allowing bears to be conditioned further by

humans by expecting large quantities of carrion to be available throughout the

year. As stated previously, Craighead, et al. (1995:322-326) indicate that this

phenomenon of using feeding ecocenters is a biological phenomenon that has

existed in bears not necessary because of a reliance on humans, but possibly

because of the environment bears have been a part of since human hunters began

hunting large numbers of bison in the Great Plains. In the present time grizzly

bears have been shut out of garbage dumps thus increasing human-bear

conflicts.

Ursus americanus: Black Bears

Ursus americanus (Figure 2.7) is arboreal by nature and is therefore

commonly found in montane shrublands and forests and subalpine forests at

moderate elevations (Fitzgerald et al. 1994:318). Primarily, black bears are

vegetarians; however, they have been known to consume carrion and will kill elk

40

calves and other wild ungulate calves, sheep, goats, and pigs (Fitzgerald et al.

1994; Wade and Bowns 1985).

Ursus americanus commonly predates in the spring and summer (Wade

and Bowns 1985). Green et al. (1997), discuss Ursus americanus use of lower

altitude carrion as opposed to Ursus arctos. Additionally, the black bear is more

likely to use carcasses during the late spring than the early spring (Green, et al.

1997:1052). In the attack, black bears typically use their paws and break the back

or neck with strong blows, eventually killing the prey by biting the neck and

shoulders (Wade and Bowns 1985). Black bears are inclined to drag their food to

a secluded area for feeding; however they will defecate on the carrion as Canis

latrans to discourage other non-human scavengers from consuming it (Wade and

Bowns 1985:10). Finally, both bears do not scatter, chew, and break up carcasses,

which is typical canid behavior (Wade and Bowns 1985).

Figure 2.7: Ursus americanus maxilla (Myer et al. 2008).

41

Non-human scavenger behaviors vary between species. When discussing

canids and ursids it is important to note that they are very distinct in terms of

type of dentition, scavenging styles and patterns, and various other behaviors.

Differences in dentition are due in large part to the type of carnivore or omnivore

it is. Canids are generally hunters therefore sharp cusped teeth are necessary to

rip flesh and muscle, whereas ursids are typically omnivores and need rounded

low cusped teeth useful for eating a larger variety of food stuffs.

There are great differences in terms of how canids and ursids scavenge.

First of all canids typically scavenge and hunt in groups, therefore when there

are a number of individuals together at one carcass, fighting for food increases

the tearing, dragging, and movement of a carcass. Bears on the other hand are

solitary or with cubs, therefore individuals generally take a limb or piece of the

carcass and drag it away to a concealed location for feeding.

Conservation Research

Zooarchaeological research in the past and present is addressing the use

of faunal remains associated with human behaviors by non-human scavengers

(Reitz and Wing 1999:135). Given that research on carnivore modification lends

information to how a faunal assemblage was altered through time, this research

can be useful when applied to management decisions in animal conservation.

42

Managers deciding whether to reintroduce or eradicate a particular species can

benefit from understanding the expansive time period in which a species has co-

existed with others. As stated previously, archaeologists are in a prime position

to influence management decisions by sharing their data with the natural

sciences to assist in understanding the impacts of species management changes.

The following discussion highlights the history of eradication and specific

conservation issues currently for wolves, coyotes, grizzly bears, and black bears.

Canis lupus and Canis latrans: Conservation Issues

Wolves and coyotes have always been considered a nuisance by ranchers

and hunters (Clark and Rutherford 2005; Fritts et al. 2003; Smith, Brewster, and

Bangs 1999; Wilmot and Clark 2005). Public interest is varied, with some people

believing that wolves and coyotes destroy their products (livestock) and profits

while others believe that they should be left alone, to allow them to live naturally

in the wilderness (Clark and Rutherford 2005). On another side, hunters argue

that introduction or reintroduction of non-human predators significantly reduces

population numbers for wild game hunting and eliminates the traditional

heritage of American settlers (Wilmot and Clark 2005).

While settling the west, ranchers would kill wolves and coyotes since they

were seen as decimating their livestock and adding competition to hunting wild

game (Smith, et al. 1999:108-109). After prey species populations of the wolf,

43

such as bison, deer, elk, and pronghorn declined in the west, wolves began to

feed on livestock provided by the ranchers (Young 1946). The rough lifestyle of

western settlers and the depredation of their livestock caused animosity towards

the wolves, which in a short period of time led to the eradication of wolves

(Young 1946). Wolves were almost completely eradicated, with few singles and

pairs from the lower United States, except for northern parts of Minnesota by the

1930s (Smith, et al. 1999:108). In 1974, wolves were listed on the Endangered

Species Act and mandated to be reintroduced to Yellowstone National Park and

not until 1995 and 1996 were 31 individuals reintroduced (Smith, et al. 1999;

Smith, et al. 2003). After a year, 44 adult wolves and an unknown number of

litters were present in and around the park (Smith, et al. 1999). Prior to the

count, 26 had been killed from human caused deaths such as illegally or legally

being shot and hit by cars (Smith, et al. 1999). To this day, humans are the largest

cause in wolf mortality, and influence the behaviors and predatory ecology of the

species (Fritts et al. 2003). Finally, this reintroduction has changed the numbers

of coyotes drastically and changed their breeding and hunting behaviors as well

(Smith, et al. 1999).

The importance of wolves in ecosystems cannot be overstated. The

species is responsible for much of the available carcasses for scavenging species

(Mech 1970). In addition, wolves are imperative to some ungulate species

44

population control; without predator-prey relationships, some species such as

elk become overpopulated, which will lead to starving and more accidents with

cars. A research project on the influence of reintroduction of wolves to Cervus

elaphus (elk) and Bison bison suggests that the elk population suffered a shift in

diet quality to low, while bison remained stable with females and calves

increasing vigilance (Hernandez and Laundre 2005; Laundre, et al. 2001).

Coyotes have been seen in a similar light throughout western settlement

and are still seen as a problematic nuisance with ranchers today (Beckoff and

Gese 2003). Livestock predation amongst coyotes is a contentious issue, with a

disparity between human belief that coyotes kill livestock or leave livestock

alone (Beckoff and Gese 2003:475). As the wolf’s habitat has decreased and

human eradication of them has occurred, coyotes have been able expand their

habitat ranges (Nowak 2001). In addition, coyotes are very efficient at adapting

to human environments such as neighborhoods, towns, and larger cities by

exploiting garbage, livestock, and pets (Beckoff and Gese 2003; Nowak 2001).

For the sheep industry, stockmen have stated that coyote depredation is the most

problematic cause of profit loss (Beckoff and Gese 2003; Sterner and Shumake

2001). Coyote population control and determent from sheep and livestock

depredation has been done using a number of non-lethal methods, including:

exclusion fences, aversive agents, and chemosterilants (Acorn and Dorrance

45

1998; Acorn and Dorrance 1990; Beckoff and Gese 2003; Sterner and Shumake

2001). Of the methods to deter coyote depredation, aversive agents such as

olfactory and gustatory products have done little to decrease predation (Beckoff

and Gese 2003). In recent years, other methods, such as sheep collars that release

toxic chemicals and trapping have been somewhat productive (Beckoff and Gese

2003). Interestingly, with all of the control methods and killing of coyotes by

humans, population numbers of coyotes have remained stable (Beckoff and Gese

2003).

Ursus arctos and Ursus americanus: Conservation Issues

Human relationships with bears are a highly contentious issue in wildlife

conservation (Craighead, et al. 1995; Gilbert 1989). Bears are typically

omnivores, and easily adapt to change. They are able to adapt so well to human

surroundings, that people have been accidentally conditioning bears for a long

time (Gilbert 1989). From the opening of Yellowstone National Park, humans in

the west have been feeding and taking care of bears, to which bears have

responded by being less fearful of humans (Craighead, et al. 1995; Gilbert 1989).

Grizzly bear populations today in the lower 48 states are located in

Greater Yellowstone Ecosystem, with another smaller population located in the

northern Cascades, with approximately 1000 bears between the two (Schwartz, et

al. 2003:558). From the 1930s through the 1960s, visitors of the Park would feed

46

grizzlies and did not anticipate that building a reliance and acceptance of human

presence could influence future problems, such as personal injuries to humans

and property damage (Craighead, et al. 1995:24). Early attempts to educate the

public on wildlife included lecture series, where park rangers would place food

wastes in a central location and then visitors would sit on bleachers watching the

bears feed and hear about their behavior and ecology (Craighead, et al. 1995:44-

47). The last of the lecture series food waste sites were closed by the mid-1940s

in a hope to decrease human-bear interactions; however, bears did not stop

feeding in these locations or other established tourist dumps and may have

become accustomed to including garbage into their seasonal feeding habits at

this point (Craighead, et al. 1995:270). These human induced bear interactions

led researchers to believe that the major causes of bear mortality had less to do

with habitat and more to do with their relationships with humans (Gilbert 1989).

Mortality rates in grizzly bear populations are caused mostly by human impacts

to populations through hunting, poaching, and habitat loss (Servheen 1999;

Schwartz, et al. 2003). Cause for eradication of grizzly bears was due to fear of

attack from them or destruction of campsites and livestock (Craighead, et al.

1995; Primm and Murray 2005).

Human-bear interactions are among the most important to consider when

discussing conservation, specifically for the grizzly bear, which has been

47

conditioned to trust and in some instances rely on humans to provide food

(Gilbert 1989). Researchers believe that in parks, like Yellowstone National Park,

when humans began feeding bears or when lectures were centered on bear

feeding, that bears became conditioned or accepting of human smells and

therefore less fearful (Craighead, et al. 1995; Gilbert 1989). Beginning in 1968,

Yellowstone National Park personnel began reducing the amount of garbage

held in the remaining Park tourist dumps and by 1971 closed the rest of the

dumps (Primm and Murray 2005). Other researchers believed that the dumps

should not have been closed instantaneously and that the bears should have been

weaned off of human garbage as sustenance (Craighead, et al. 1995; Primm and

Murray 2005).

After the closure of the dumps, there was a dramatic decline in the

number of grizzly bears in the park. With the constant source of garbage

unavailable, the bears began going into camps, livestock areas, and surrounding

community garbage dumps outside of Yellowstone National Park, leading to

more human-bear conflicts, and more deaths caused by human shootings

(Primm and Murray 2005). After this, researchers and public relationships

declined dramatically. Finally,