University of Nevada, Reno Homing and Navigation in Chuckwallas

Home , Desert iguana, Sauromalus ater

University of Nevada, Reno

Homing and Navigation in Chuckwallas (Sauromalus ater)

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Biology

Stephanie Wakeling

Dr. C.R. Tracy/Thesis Advisor

May 2012

THE GRADUATE SCHOOL

We recommend that the thesis prepared under our supervision by

STEPHANIE WAKELING

entitled

Homing And Navigation In Chuckwallas

be accepted in partial fulfillment of the requirements for the degree of

MASTER OF SCIENCE

C. Richard Tracy Ph.D., Advisor

Lynn Zimmerman Ph.D, Committee Member

Michael Webster, Ph.D., Graduate School Representative

Marsha H. Read, Ph. D., Dean, Graduate School

May, 2012

ABSTRACT

In this study of chuckwalla homing and movement, we displaced 30 chuckwallas, and a total of 11 chuckwallas were able to return to home successfully. Larger animals were the most successful returners, and they only returned well from the shorter displacement distance of 200 m. Our data provides evidence that smaller lizards may have differential navigation ability, higher resistance to movements caused by conspecifics, or lower motivation to return home. Our study also illustrates displaced lizards have greater daily movements than lizards on their home ranges, and the study increases our knowledge of the size and nature of home ranges of chuckwallas during an activity season. We discuss necessary future research to help us understand movements and propensities of chuckwallas and the factors that may be important in determining movements.

ACKNOWLEDGEMENTS

This thesis would not have come together without the help and support of many people, as well as funding from the Biology Department at the University of Nevada,

Reno. Thank you to my Advisor, Dr. Richard Tracy for having confidence in my abilities, and for always caring about my progress and wellbeing, and for all of the time you’ve spent helping me develop my science. To my other close mentors, Dr.

Bridgette Hagerty, Dr. Franziska Sandmeier, and Dr. Christopher Tracy, thank you for always being supportive, your willingness to teach me new things, and your incredible talents. Also, to my family and friends, thank you for keeping me sane, and indulging my obsession with lizards.

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TABLE OF CONTENTS

Abstract i

Acknowledgements ii

Table of Contents iii

Introduction 1

Methods: Experimental Design 5

Methods: Analysis 7

Results 7 Size 9 Differences in movement patterns 10 Home Range 11 Circular Statistics 12

Figures and Table in Results Figure 1. Paths of Animals that Returned Home 8 Figure 2. Male and Female Snout vent lengths 9 Figure 3. Comparisons of paths 11 Table 1. Circular Statistics by Groups 13

Discussion 14 Homing and Movements 14 Home Range and Social Considerations 17 Social Interactions 18 Management Implications 19

Conclusion 20

Literature Cited 22

Appendix I: Animal Movement Paths 24

A. Home Range Paths 24

B. Home Range and Displacement Paths 25

C. 200 meter: Male Non-returners 26

D. 200 meter: Female Non-returners 27

E. 200 meter: Male Returners 28

F. 200 meter: Female Returners 29

G. 400 meter: Male Non-returners 30

H. 400 meter: Female Non-returners 31

I. 400 meter: Male Returner 32

Appendix II: Animal Movement Over Time 33

A. 200 meter: Male Non-returners 33

B. 200 meter: Female Non-returners 34

C. 200 meter: Male Returners 35

D. 200 meter: Female Returners 36

E. 400 meter: Male Non-returners 37

F. 400 meter: Female Non-returners 38

G. 400 meter: Male Returner 39

Appendix III: Chuckwallas Included in the Study 40

INTRODUCTION

Homing experiments are used to assess the existence, or strength, of philopatry among individuals, and to assess mechanisms by which animals can accurately find their “home.” Typically in homing experiments, individuals are displaced from their sites of capture (defined as “home”), to see if those individuals will return home.

Often different circumstances for release are experimentally manipulated to assess the importance of those experimental manipulations in improving or reducing the homing performance of individuals. This experimental approach assumes that displaced animals use the same navigational cues to return home as do dispersing and moving animals when they move in areas outside of their home ranges. Also, the approach assumes that animals have benefits associated with their territories to compel those individuals to return home.

Many lizard species have been shown to navigate and return home from varying distances, and under different displacement conditions. Sceloporus orcutti can home from 215 m away; older individuals and males were found to be the best at homing

(Weintraub 1970). Sleepy lizards, Tiliqua rugosa, have been found to home from up to 500 m from home, and these lizards can orient in the direction of home from 800 m (Freake 2001). Desert iguanas, Dipsosaurus dorsalis, have been shown to home from distances up to 274 m from their capture sites despite these lizards residing in discontinuous habitat types (Krekorian 1977). In the only previous homing experiment with chuckwallas (Sauromalus ater), male and female chuckwallas were

2 displaced 50 m, 100 m, and 500 m from their home ranges, and they returned home within a day or two. They appeared to return home more effectively on sunny days

(Prieto and Ryan 1978). That chuckwalla experiment was conducted on a small number of lizards (n=12, males and females total), and their animals were displaced to unsuitable patches without rock piles (Prieto and Ryan 1978). That experiment provides a framework for determining minimum displacement distances leading to reasonable expectations that chuckwallas will return home. However, it leaves open questions about potential differences in homing ability between the sexes, and about the ways in which the animals move outside of their home ranges.

Additionally, the sizes and potential differences of home ranges remain to be studied.

Here, we report the results of a homing experiment designed to help our understanding of the movements in chuckwallas. Understanding homing and navigational propensity should help us understand the ability of chuckwallas to move effectively outside the boundaries of their home ranges, and it should help us understand the processes allowing chuckwallas to recolonize new home ranges or territories. While homing, individuals often must move through defended areas occupied by other chuckwallas, and displaced lizards often have to travel through patches of unsuitable habitat. These challenges to movements can be taken to simulate similar challenges chuckwallas face outside of their home range for dispersal, courting, or foraging.

Chuckwallas, Sauromalus ater [obesus (Hollingsworth 1998)] are large iguanid lizards with a large, patchy range spanning from the Mojave Desert of southern

Nevada as far south as Baja California Sur, east into parts of Arizona, and west into parts of the Mojave Desert in southern California (Ustach and Brodie 2003). These herbivorous lizards are often sexually dimorphic and highly territorial. They exist in habitat that is comprised of rock piles or old lava flows, because they are saxicolous they depend on hiding in cracks among rocks for protection from predators (Berry

1974, Abst 1988, Hollingsworth 1998, Kwiatkowski and Sullivan 2002, Abts 1988).

Males are believed to defend large territories that include several females, but those territories generally do not overlap with those of other males (Kwiatkowski and

Sullivan 2002). Females reportedly have established territories, but their territories are not necessarily exclusive as they often overlap with both males and females

(Berry 1974). Chuckwallas are long-lived (Abst 1988) and little is known about their movements and their propensities to move, including how they navigate among sites, or disperse from natal sites or over-taken territories, from which more dominant animals displace them.

Movement behavior of chuckwallas is likely influenced by the nature of the rock piles they inhabit. In areas with more continuous rock formations, individuals may move greater distances more easily, but it may also be less important if there is more suitable habitat available for them to establish territories. In areas with less

4 continuous and smaller rock piles, chuckwallas might be forced to disperse to find suitable habitat where they can establish a territory.

Chuckwalla habitat is spatially discontinuous as chuckwallas are only found on rock piles that are often uneven in extent and spacing across the landscape (pers. obs.

2010). Chuckwallas are also very territorial animals, which can affect the ability of a wandering chuckwalla to use rock outcrops during its journey. Chuckwallas have a polygynous mating system (Berry 1974, Kwiatkowski and Sullivan 2002), so according to Greenwood’s prediction of males being the dispersing sex in dimorphic species (1980), male chuckwallas may be more likely to disperse further to find suitable territory space and mates. Females can set up non-exclusive territories within other animals’ territories, but adult males are likely to be “runoff” and pushed out of another male’s exclusive territory. In more homogeneous landscapes, it may be easier for chuckwallas to find refuge from predators and to accomplish behavioral thermoregulation, but there might also be more resistance against movement from other male chuckwallas defending and maintaining territories.

Because chuckwallas have a polygynous mating system and males court females for long periods of time (Berry 1974, Doughty et al 1994, Kwiatkowski et al 2002), males may tightly maintain their home as a way to prevent other males from courting and copulating with their females. Thus, we hypothesize that navigation is more important to male chuckwallas, and males displaced from home will return at a greater rate than will females.

Other reptiles are known to use a variety of cues in navigating; chemical, visual, and magnetic, so a variety of cues may be important to chuckwallas (Southwood and

Avens 2010). If there are gender differences in navigation and movement ability, then those differences are likely to be represented in homing ability.

METHODS

Experimental Design

Chuckwallas were captured in the Newberry Mountains ten miles southwest of the town of Laughlin, Nevada between March and June 2010 before and during the breeding season. Animals were captured by noosing from rock surfaces, and by manual extraction from rock crevices. Lizards were outfitted with a transmitter, which required fabrication of an individually-fitted vest (described by Wakeling et al, unpublished manuscript 2012). Special attention was given for the well being of the animals as well as maintaining the working condition of the transmitters.

Animals were displaced 0 m, 200 m, or 400 m away from their sites of capture.

These displacement distances were devised from our own pilot data (from 2009), and from a prior study of homing in chuckwallas (Prieto and Ryan 1978). Each lizard was placed in a cloth bag, and this bag was placed into a box, and then the box was taken to the displacement site using a circuitous route to avoid giving orientation or navigation cues to contained lizard. The capture location was

6 recorded using a handheld GPS device. Displacement direction and distance were predetermined by a random schedule of displacement quadrants and distances. The lizard was then released onto a rock pile, and a separate investigator, from a vantage point out of view of the experimental lizard, observed the animal for thirty minutes following release as a means to ensure that the lizard behaved normally.

A total of 35 animals were caught and tracked during the 2010 season. 30 of these animals were displaced; eight males and eight females were displaced 200 m from their capture points, and seven males and seven females were displaced 400 m from their capture points. Five males and five females were released at their capture point to provide data on movements of lizards on their home ranges. Five “home range animals” were displaced (one female 400 m, one male 400 m, one male 200 m, and two females 400 m).

Experimental animals were tracked daily, and their physical locations (GPS coordinates) and movements were recorded. Animals that returned home were tracked several days after arrival to, or near, the capture site to ensure the animal really had resumed occupation of its original home range. Successful returnees were then released from the study. All non-returning animals were tracked through to the end of the field season, and then were recaptured and returned to their original capture sites.

METHODS

Data Analysis

Determining returnees - Animals were considered to have returned home, if they came within 60 meters or less of his or her capture point and ceased moving except to move about with their home range area. Most return animals were re-sighted at the precise point of the original capture.

Differences among experimental groups were analyzed by chi-square, Fisher’s Exact,

Rayleigh’s test for circular uniformity, and paired and unpaired t-tests. Movement parameters were analyzed through use of the software ArcGIS and Geospatial

Modeling Environment.

RESULTS

Of the 30 animals that were displaced during the 2010 season, 10 returned to within

60 meters of his or her capture point. There were no significant sex differences in returns among the 200 m or 400 m displacement groups (Fisher’s exact, two-tailed:

P = 0.99, and P = 0.99 respectively). However, lizards were statistically more likely to return from closer displacement distances (Fisher’s exact, two-tailed: P = 0.0067).

Example paths of returners are shown below in Figure (1).

To determine if there was an effect of the direction of displacement a Rayleigh’s test for circular uniformity was conducted on the displacement angles for the returning animals. Both the 200 m and 400 m returners satisfied Rayleigh’s test for circular uniformity indicating no directionality of displacement for the group of returns. The frequency of returns from each quadrant of displacement was not significantly different from random (χ2 = 4.64, P = 0.20). However, no animals returned from the southwest quadrant of displacement, so a Rayleigh’s test for circular uniformity was conducted on the displacement angles of non-returning animals. The alpha obtained indicated directionality of those displacement values (0.2 < α < 0.5). However, we later found significant differences in returns based on size, and found more small animals to have been displaced to one quadrant by accident alone. Those results are presented under Size.

Figure 1. Paths of animals that returned home. Capture points are depicted by the red stars, and points where animals were tracked are shown by black dots. Navigational paths are included for all animals in

Appendix I.

Size

No differences in mean snout vent lengths were found between males and females, despite that the smallest animals in the study were females and the largest animals were males (paired t: t(28) = 1.09, two-tailed P = 0.286). Boxplots of snout vent lengths for males and females are presented below in Figure (2) to demonstrate the differences and similarities in size.

Figure 2. Male and female snout vent lengths. The snout vent length of every displaced animal is represented by a dot on the chart. Red dots are animals that were able to return home, and black dots are animals that did not return home from displacement.

Analysis of Covariance using sex (as a categorical variable) and size (as a covariate) indicated that snout vent length predicted returns from 200 m (F1,13 = 7.27,

P=0.018). Larger animals returned more frequently, and no small females returned

10 from displacements of any distance. The smallest males did not return either, however, two males of snout-vent length 160 mm (just above the 25th percentile for size) did return successfully.

Differences in movement patterns

To compare the movement behaviors of the different treatment groups the mean number of meters moved per day was calculated for each animal. There were no differences in the mean number of meters moved per day between the 200 m and

400 m displacement groups (F1, 26 = 0.12, p > 0.5). Additionally, there were not differences in movement per day for males and females (F1, 26 = 2.02, p = 0.167), and there was no relationship between snout vent length and movement per day (F1, 27 =

0.24, p > 0.5). To understand the effects of displacement on movement behavior we analyzed the movement of five animals for which we had paired data of their movements on home ranges and then movements for them off home ranges after displacement. The daily average movements on versus off home range were significantly higher (t4 = 5.51, P=0.005). A figure showing the paths moved during displacement and while on home range is included in Figure (3).

Figure 3. Comparisons of paths of the same individuals on home range and displaced. Home ranges are indicated by red points and displacement paths are shown in black. Home range clusters and navigational paths of all animals are included in the appendix.

Home Range

The furthest distance between any two points in each home range were calculated to characterize the greatest possible distances covered in home range. The average largest width was 93.0 m for males and 75.4 m for females. There were no significant differences between males and females furthest distance points (paired t- test: t(8) = -1.24, two-tailed P = 0.25). The average width of all home range animals was 84.2 m. Figure (2) below shows the paths of animals that returned to home.

Notably, two animals showed instances of excursions, or a departure from a typical constrained home range and made a movement that went well out of the area in which they typically were found. One female and one male each went 181 m away from their furthest home range points, and were only found in these excursion

12 places for short durations. The female, Kelsey (excursion path can be seen in

Appendix I), went to the rock pile of a nearby male and stayed there for seven days before returning to her home range, and was never found at the excursion location again during the season. The male, Rex, that made an excursion was found on a nearby small hillside residing in areas with very poor rock formations. There appeared to be poor coverage for protection on those sites. A large neighboring male (Lars, his path is included in Appendix I) was observed on Rex’s rock pile while he was away. Rex made excursions to the nearby hillside three times, and two of those times Lars was seen on Rex’s home range rock pile, and once observed with a female on the pile. These excursion distances were not considered in the comparisons for longest distance points in home range, but were rather considered movement off of home range.

Circular Statistics

Displacement orientations were non-directional by Rayleigh’s test of circular uniformity, the α and P values for groups can be seen in Table (1) below. A significant P-value indicates non-random directionality. The only directional statistic found was among non-returners from the 200 m group, indicating a similar displacement treatment for all non-returners. However, all but one animal that did not return from 200 m were also among the smallest fiftieth percentile for snout vent length, which was found to be a predictive factor for all non-returners. This indicates the directionality of non-returning animals displaced 200 m to be a by-

13 product of more small animals being unintentionally displaced in a direction and not an indicator of directionality of displacement itself.

Table 1: Circular Statistics by Groups. Male and Female groups are presented for consideration, however they have smaller n values than the test can reliably provide α values for.

Group Analyzed Rayleigh’s R Rayleigh’s z n α Result

All Non-Returners 4.37R R 1.00 20 > 0.5 Non-directional Large Non-returners 1.71 0.37 8 > 0.5 Non-directional without small Small Females 2.09 0.62 7 > 0.5 Non-directional femalesReturners 4.00 1.46 10 0.2-0.5 Non-directional 200 Non-returners 4.62 3.04 7 0.02- Directional

400 Non-returners 3.93 1.19 13 0.20.05-0.5 Non-directional

Male Non-returners 0.79 0.06 10 > 0.5 Non-directional

Female Non- 3.59 1.29 10 0.2-0.5 Non-directional returnersMale Returners 2.79 1.56 5 0.2-0.5 Non-directional

Female Returners 2.79 1.56 5 0.2-0.5 Non-directional

DISCUSSION

Homing and Movements

We found no differences in homing ability for male and female chuckwallas. This pattern could result from males and females having comparable costs associated with territory acquisition and maintenance, and that females have comparable abilities to navigate the landscape.

The lack of return of small lizards returning to home suggests either that small lizards have limited navigational ability, or they may have less compelling reasons to return to home sites, or that small lizards have greater difficulty navigating in unfamiliar terrain potentially because of competition from conspecifics, threats of predation, or physical limitations.

Larger lizards may return home more reliably because they have more established territories on rock piles, or may return home for some other benefit, such as courting desirable mates within their territories. Additionally, larger lizards may simply have more experience navigating the landscape. Males and females could acquire knowledge about the landscape over time simply by moving in and around their territories as a result of defending territories, foraging for food, and courting and breeding. They also could acquire knowledge of the surrounding territories if they formerly occupied those territories. It is typical to find large tyrant males on top of large rock piles (Berry 1974), but every tyrant male likely inhabited smaller

15 less-desirable territories earlier in his life. This would mean that he experienced the lay of surrounding territories before he acquired his current territory. It would also mean the smaller, therefore younger males, have not experienced as many potential territories as have larger males.

Spatial knowledge and experience may be similarly gained for females, but there could be additional ways females acquire knowledge about the surrounding habitat.

Little is known about chuckwalla egg laying behavior in natural habitats, and there is only one reported observation of a female digging a nest (Johnson 1965). It is possible that females travel outside of their home ranges to find the best and most suitable oviposition sites. Traveling outside of the home range to deposit eggs could be a form of dispersal for the resulting offspring, which could mechanistically reduce future inbreeding depression. This off-territory oviposition could result in females gaining spatial knowledge of surrounding territories and habitat. There were not details in the literature to help us provide examples of off-territory oviposition, however it is likely these data are simply hard to collect.

Female sand lizards, Lacerta agilis, displaced near their offspring reportedly are more likely to move away from the area when released where their own offspring were present (Ryberg et al 2004). This suggests that female lizards have a way of recognizing kinship and demonstrates mechanisms to avoid competition and inbreeding with their offspring. Any study of nesting or dispersal in chuckwallas

16 should consider the relatedness of animals on a rock pile, as often several females inhabit a single rock pile with only one dominant male (Berry 1974, Kwiatkowski and Sullivan 2002). It is possible that these females could be siblings, and even members of the same clutch. Evidence of female relatedness on rock piles could provide evidence for a male-biased dispersal system without any actual observance of dispersal events.

It is likely that chuckwallas in different types of habitats may have developed different movement patterns and tendencies based upon available territory sites and other resources. The length of activity season varies across the range of chuckwallas (Tracy 1999), and studies of chuckwalla movements could be influenced by season length. Similarly, habitat heterogeneity is a factor that could influence chuckwalla movements, as areas with rock piles versus lava flows can have big differences in spacing of available territories. In a study in common lizards,

Lacerta vivipara, comparing the effects of differing habitat continuity on dispersal

(Massot and Clobert 2000), one microhabitat was highly variable in its structure and less continuous, while the other microhabitat was relatively more uniform and more continuous. These treatments seemed to cause a difference in the dispersal of males; they dispersed further in the variable environment, however females dispersed very little in both treatments (Massot and Clobert 2000). It is likely that lizards will have different movements and dispersal mechanisms in different habitat types.

Future studies of movements in chuckwallas should experimentally test the roles of different environmental cues for orientation and navigation for chuckwallas. For example, sleepy lizards that could see the sky, and nothing else, during displacement events were found to be better at homing than lizards without a view of the sky

(Freake 2001). Our chuckwallas were allowed no view of the sky during their displacements, and most olfactory cues during displacement were likely masked or completely covered by the barriers of the handling bag and the cardboard transport box. A study with a constant displacement distance, but only experimentally altering specific cues could provide more information on the most important cues in chuckwalla orientation and navigation.

Home Range and Social Considerations

During our field season, we witnessed many social interactions that must be understood when interpreting our observations. Animals moving among established territories of resident male chuckwallas can both influence the behavior of resident lizards, and resident lizards could have influenced movements of homing animals.

When one animal is removed from its territory, this leaves an open and undefended territory that is disruptive to the structure of multiple territories. Additionally, displaced animals can enter territories of resident lizards on its journey toward home or on its wanderings without heading home. All of our experimental treatments were conducted within a small area (the site was approximately a square that is 700 m on a side), so there had to be considerable overlap of home

18 ranges, and wandering, of lizards during the study. Indeed, it seems possible that our measurements of home range movements and area could have been influenced by the wanderings of displaced individuals within the study site.

Additionally, we observed occasional movements of some lizards that appeared to venture outside the usual range of home range movements. For example, two animals for which we monitored normal movements on their home ranges, made conspicuous excursions from their normal movements on their home range. Both of these excursions were up to 180 m from the furthest home range point of the animal.

Thus, animal movements outside of the home range are not extraordinary, but they are not typical. The complexity of normal, occasional, and extraordinary movements of lizards must be kept in mind while interpreting results of experiments in which movements (e.g., during homing) are the data to be analyzed. For example, it is possible that our movement of animals on the landscape could have altered behavior or complex webs of social interactions for the chuckwallas on the field site.

Social Interactions

The only male to have made an excursion from its home range during our monitoring of movements within its home range, was a midsize male with a relatively well-established territory. For this animal, there were no resident females observed on the rock pile comprising this male’s territory until a displaced female took up residence near the resident male. This midsized male appeared to go on an

19 excursion only when a neighboring male entered the territory of the midsized male.

It appeared that the midsized male made his excursion to avoid combat with the larger male, because he promptly returned to his rock pile after the larger male was no longer present.

On numerous occasions, displaced animals were seen interacting with resident chuckwallas. Indeed, it was not uncommon to see males engaging in combat, or females checking out new arrivals to their resident rock piles. We do not know at what frequency males encountered aggression from other males, but it was the most frequent social interaction observed. There were instances of courting and displaying behaviors, but those were less frequently observed.

Management Implications

Our finding of significantly increased movement of chuckwallas when these lizards are moved away from home ranges is concordant with results for desert tortoise.

Tortoises were translocated to new habitat to remove animals from harm’s way due to human encroachment in habitat. This increased movement has potentially important implications for management of these and other reptilian species

(Nussear et al 2012). Specifically, the different animal behaviors associated with translocations tends to increase risks of exposure to predators, and increases energetic demands resulting from increased movements. Notably, two animals translocated in our study were depredated; both lizards were displaced females.

The increased predation risks for displaced animals, as well as disruptions to social systems, and the complications of resulting social interactions that occur when new animals are introduced into existing social systems can result in increased risks to the animals. Managers should take these consequences into careful consideration.

As habitat is consumed by human projects (e.g., new solar and wind farms), managers may consider translocating chuckwallas to another site. However, it may not be advisable to translocate chuckwallas into existing territorial systems, because it is likely that any imagined benefits of saving chuckwallas from modified habitat will not outweigh the negative effects to displaced animals, as well as to resident chuckwallas at the potential translocation site.

CONCLUSION

There are likely different costs and benefits of homing for small and large lizards.

These differences are apparent from the different rates of successful homing of the two size classes. Future investigation of the cause of these differences could include social and experiential causes.

Our study also builds upon the study of chuckwallas in the Colorado Desert by Abts

(1987). Abts reported that very few large males made large movements during the course of his 7-year study, and that other animals were always recaptured or re- sighted within the vicinity of their previous captures over the timespan of the study.

Revisiting Abts’s data may be warranted to understand the cumulative home range shifts of individuals. His body of research may show the differences in experience for large versus small lizards that we suspect from our research.

Further, our research provides evidence to managers of the importance of home range, and the social dynamics of these lizards. There are likely many complex processes at play in the development of chuckwalla movement tendencies and propensities.

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APPENDIX I: ANIMAL MOVEMENT PATHS

A. Home Range Paths: Dots represent points where animals were animals were found during tracking. Lines indicate movement between subsequent points.

B. Home Range and Displacement Paths for animals that were tracked both on home range and were also displaced: Home range clusters are represented by red dots, and paths travelled during displacement are shown by black dots and lines. Arrows indicate the paths for same animals, one animal returned home and does not have an arrow to show home.

C. 200 meter displacement paths with capture point: Male Non-returners

Black dots and lines show the paths of displaced animals, and the red stars indicate the capture point of each animal.

D. 200 meter displacement paths with capture point: Female Non-returners

E. 200 meter displacement paths with capture point: Male returners

F. 200 meter displacement paths with capture point: Female returners

G. 400 meter displacement paths with capture point: Male Non-returners

H. 400 meter displacement paths with capture point: Female Non-returners

I. 400 meter displacement paths with capture point: Male returner

APPENDIX II: ANIMAL MOVEMENT OVER TIME

The following graphs show the amount of movement animals moved between time- points represented on the x-axis. The distance, in meters, to each point is represented on the y-axis. Lines with circles show the distance an animal is away from its capture point, and lines with triangles show the distance an animal moved between each point (representing a daily movement amount).

A. 200 meter displacement: Male Non-returners

B. 200 meter displacement: Female Non-Returners

C. 200 meter displacement: Male Returners

D. 200 meter displacement: Female Returners

E. 400 meter displacement: Male Non-Returners

F. 400 meter displacement: Female Non-Returners

G. 400 meter displacement: Male Returner

APPENDIX III: CHUCKWALLAS INCLUDED IN THE STUDY

Actual Chuck name Snout- Displacement Distance Return vent Quadrant Displaced Sex Treatments Home? length (meters) (mm) Amelia 156 2 228 female 200 No Chitty 180 1 200 female 200 Yes Georgia* 152 3 205 female 200 No Nubs 173 4 210 female 200 Yes Jiffy 175 2 203 female 200 Yes Cruella 177 1 221 female 200 Yes Buttercup 150 3 229 female 200 No Jaime 157 1 230 male 200 No Tom 160 2 224 male 200 Yes Napoleon 155 1 226 male 200 No Reptar 179 4 201 male 200 Yes Sheriff 155 3 200 male 200 No Neil 160 2 213 male 200 Yes Elvis 196 4 236 male 200 Yes Dr. Girlfriend* 169 4 400 female 400 No Daisy 166 2 400 female 400 No Bella 180 3 405 female 400 No Nancy 169 3 417 female 400 No Lucy 168 4 413 female 400 No Clark 161 2 405 male 400 No Bill 192 1 400 male 400 No Lars 182 4 430 male 400 Yes Bucky 176 1 410 male 400 Yes Mambo 170 3 400 male 400 No Wezul 168 4 432 male 400 No Big Mama 179 4 209 female 200 and HR Yes Mufasa 188 3 217 male 200 and HR No Kelsey 152 1 401 female 400 and HR No Christa 157 3 420 female 400 and HR No Rory 178 2 451 male 400 and HR No Caroline 160 Home Range 0 female HR NA Mitey 167 Home Range 0 female HR NA Charles 190 Home Range 0 male HR NA Rex 174 Home Range 0 male HR NA Bach 184 Home Range 0 male HR NA * indicates the animal was depredated during the course of the study