BREVIORA Museum of Comparative Zioology a tt, DH. grea he 6 EREESS a SS: SSS, US ISSN 0006-9698 CAMBRIDGE, MASss. 10 Jury 2013 NuMBER 535 BEHAVIORAL PARTITIONING BY THE NATIVE LIZARD ANOLIS CAROLINENSITS IN THE PRESENCE AND ABSENCE OF THE INVASIVE ANOLIS SAGREI IN FLORIDA AMBIKA KAMATH,! YOEL E. STUART,! AND Topp S. CAMPBELL2 ApstractT. Animals are known to engage in different behaviors in different parts of their home range, and the overall habitat occupied by an individual influences where it engages in particular behaviors. However, few studies have investigated how changes in habitat use alter the partitioning of an animal’s behaviors into different microhabitats. In eastern Florida, the native lizard Anolis carolinensis is known to change its habitat use in the presence of invasive Anolis sagrei by perching higher in the canopy. We assessed behavioral partitioning in island populations of A. carolinensis that are sympatric with A. sagrei compared with islands where A. carolinensis is allopatric. We found that individuals of A. carolinensis exhibited behavioral partitioning, feeding relatively lower and displaying relatively higher than their initial perch height in both the presence and absence of A. sagrei. However, the relative locations chosen for feeding and displaying were not affected by the presence of A. sagrei, suggesting that habitat changes need not affect behavioral partitioning. INTRODUCTION and Shine, 2006), and nesting (Kats and Sih, ~ 1992; Angiletta’ et al., 2009). Such partitioning of an individual’s behavioral repertoire into different microhabitats is thought to be adaptive. For instance, choos- ing sleeping sites with relatively low preda- tion rates (e.g., Anderson, 1998; Clark and Gillingham, 2006) or foraging sites where the energetic returns of feeding are relatively Many animals engage in different behav- iors in different parts of their habitat, with particular microhabitats utilized for foraging (Albers and Gehlbach, 1990; Thornton and Hodge, 2009), sleeping (Anderson, 1998; Singhal et al, 2007), breeding (Hagman ‘Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard Univer- sity, 26 Oxford Street, Cambridge, Massachusetts 02138, U.S.A.; e-mail: akamath@fas.harvard.edu * Department of Biology, University of Tampa, 401 W. Kennedy Boulevard, Tampa, Florida 33606, U.S.A. high (e.g., Wanless et a/., 1998) are behaviors likely favored by selection. The optimal locations for engaging in particular behaviors likely depend on the type of habitat occupied by a species. Within © The President and Fellows of Harvard College 2013. Nw a species, habitat use often differs among populations depending on whether or not they are sympatric with closely related, ecologically similar species (e.g., Schoener, 1975: Medel et al., 1988; Schluter and McPhail, 1992; Dietrich and Werner, 2003). Interspecific interactions such as resource competition, agonistic interactions, intraguild predation, and reproductive interference of- ten have negative fitness consequences for one or both species (Polis et a/., 1989; Gronig and Hochkirch, 2008; Grether et al., 2009; Hendry et al., 2009), and changes in habitat use by species in sympatry may be favored to reduce the frequency of such interactions. Despite the prevalence of documented habitat shifts between populations of a species that differ in whether or not they are sympatric with another species, little attention has been paid to the behavioral consequences of such shifts. Anolis lizards are an excellent group in which to study the effects of among-population variation in habitat use on behavioral partitioning. At least two Anolis species are known to engage in different behaviors at different perch heights: social interactions between male Anolis polylepis occur at high perch heights, and both male and female A. polylepis and female Anolis distichus scan for and capture prey at low perch heights, relative to the average perch height of the population (Andrews, 1971; Paterson, 1999). Moreover, many Anolis species exhibit intraspecific variation in habitat use between populations that differ in whether or not they are sympatric with another anole: the average perch height of individuals in populations sympatric with other anoles often differs from the average perch height of individuals in allopatric populations (Schoener, 1975; Jenssen, 1973; Jenssen et al., 1984; Losos et al., 1993; Losos and Spiller, 1999; Campbell, 2000; Kolbe et al., 2008; Edwards and Lailvaux, 2012). BREVIORA No. 535 In this study, we first examined whether individuals of the green anole, Anolis car- olinensis, partition their behavioral repertoire such that they engage in different behaviors at different perch heights. Based on previous examples of behavioral partitioning in anoles (Andrews, 1971; Paterson, 1999), we predict- ed that, relative to their initial perch heights, A. carolinensis would feed at low perches and display at high perches. Second, we assessed whether behavioral partitioning in A. carolinensis is modified due to its perch height shift in the presence of a congeneric competitor (Collette, 1961; Camp- bell, 2000; Edwards and Lailvaux, 2012). Anolis carolinensis is the only anole native to the U.S.A. Its closest relatives are arboreal, Cuban, trunk-crown ecomorph anoles (Wil- liams, 1969; Glor et al., 2005) that partition the vertical habitat with the low-dwelling, trunk-ground anole Anolis sagrei, as well as with up to 10 other Anolis species. The absence of other anoles from the continental U.S.A. has enabled the expansion of A. carolinensis’ habitat to include a wider range of perch heights—an example of ecological release (Collette, 1961; Losos, 2009). Howev- er, the invasion of A. sagrei into the U.S.A., where it is now broadly sympatric with A. carolinensis in Florida, has led A. carolinensis to shift back to higher perches (Collette, 1961; Campbell, 2000; Edwards and Lailvaux, 2012). We assessed the effect of this perch- height shift on behavioral partitioning by comparing allopatric island populations of A. carolinensis with island populations of A. carolinensis sympatric with A. sagrei. MATERIALS AND METHODS Study system In the 1950s, the U.S. Army Corps of Engineers established 53 dredge-spoil islands in the Intracoastal Waterway along the western edge of Mosquito Lagoon in Volusia 2013 BEHAVIORAL PARTITIONING IN THE LIZARD ANOLIS CAROLINENSIS 3 TABLE 1. DISTANCE TO MAINLAND, PERIMETER LENGTH, AND AREA OF THE ISLANDS WITH AND WITHOUT ANOLIS SAGREI SAMPLED IN THIS STUDY. Island A. sagrei Presence Distance to Mainland (m) Perimeter Length (m) Area (m7?) Hornet absent 365 349 5,601 South Twin absent p99) S57 12,956 Lizard present 201 478 9,272 Line of Cedars present 335 487 12,281 and Brevard Counties, Florida (Campbell and Echternacht, 2003). These islands were colo- nized by mainland flora and fauna, including A. carolinensis. Anolis sagrei reached Mosqui- to Lagoon in the late 1980s and subsequently invaded many but not all of the Lagoon’s spoil islands (Campbell and Echternacht, 2003). For this study, data were collected from two islands where only A. carolinensis is present (hereafter one-species islands: Hornet and South Twin) and two islands with both A. carolinensis and A. sagrei (hereafter two- species islands: Lizard and Line of Cedars). Colonization by A. sagrei appears to be random with respect to island characteris- tics—islands with and without A. sagrei sampled in this study do not appear to differ in their distance to the mainland, area, and perimeter length (Table 1). Further, neither total tree height nor plant species composition differs between the islands with and without A. sagrei across Mosquito Lagoon (Y. E. Stuart, unpublished data), making it unlikely that perch availability differs between the one- and two-species islands that we sampled. Thus, any differences in A. carolinensis behav- ior between one- and two-species islands are likely due to the presence of A. sagrei rather than environmental differences between is- lands with and without A. sagrei. Data collection We conducted focal observations lasting 2-20 minutes (mean = standard error: 15.1] + 0.7 minutes) on undisturbed male and female lizards between 0700 and 1830 hours from 12 July to 6 August 2010. Over 98% of the observations were made between 0700 and 1400 hours. Lizards were found using the Rand census method (Rand, 1964: Losos, 2009), whereby we walked slowly through the environment until we spotted an undis- turbed individual. All observations were made by a single observer (AK) and were restricted to relatively open habitats, so that a distance of at least 2 m could be maintained between the lizard and the observer. Observations lasted until the lizard disappeared from view or up to a maximum of 20 minutes. If possible, lizards were caught and marked with a nontoxic Sharpie® marker after the observation period to ensure that lizards were not resampled during subsequent island visits. Captured lizards were also permanently tagged with nontoxic VI Alpha Tags (Northwest Marine Technology, Inc.) to further reduce the possibility of resampling. Finally, lizards were also caught on these islands for a different study (Y. E. Stuart, unpublished data), enabling us to set a lower bound on the number of lizards present on _ these islands; our mean sample size per island (9.6 + 1.2) was substantially lower than the mean minimum number of lizards present per island (93.5 + 7.0), making it unlikely that we resampled individuals during our study. After each observation period, we mea- sured initial lizard perch height (1.e., the height above the ground in centimeters where the lizard was first observed) as well a BREVIORA as lizard perch height at all observed feeding locations. We also noted perch heights for displaying lizards (including both head bob- bing and dewlap extensions; Jenssen, 1977, 1978) if they displayed at their initial perch, and measured perch heights for any displays following upward or downward vertical movements of 10 cm or more. This method is equally likely to detect displays that occur above, below, or at the same height as the initial perch, and given our directional prediction that displays will occur at rela- tively high perches, data collected by this method are not biased toward confirming our expectations. Display heights were ana- lyzed only for males because displaying is a significant component of the behavioral repertoire of male but not female A. caroli- nensis in the breeding season (Jenssen et al., 1995; Nunez et al., 1997), and, indeed, only three females were observed displaying across the four islands. These perch-height measure- ments enabled the comparison of initial perch height, perch height at feeding events, and, for males, perch height at displaying events across islands. Our comparison of feeding or displaying perch heights with initial perch height is based on the widely held but rarely mentioned assumption that the average initial perch height approximates the average perch height of individuals in a population (Rand, 1964). Statistical analyses To test whether feeding height was consis- tently lower than initial perch height across all islands, we combined independent one- tailed P-values from four within-island paired ¢ tests of initial perch height against feeding height, using the weighted Z method for combining probabilities (Whitlock, 2005) to generate a single one-tailed P-value for the comparison. One-tailed tests were justified by our directional predictions that, relative No. 535 to their initial perch heights, A. carolinensis would feed at low perches. If an individual lizard fed multiple times within an observa- tion, the mean feeding height for that individual was calculated and used in all analyses. Mean differences between initial perch height and feeding height were similar for males and females (mean difference + standard error for males [n = 13]: 15.7 + 11.6 cm; females [n = 22]: 16.9 + 4.9 cm); hence we pooled both sexes for analyses of differences between feeding height and initial height. We similarly tested whether, for males, display height was consistently higher than initial perch height across all islands. We confirmed that lizards perched higher on two-species islands than on one-species islands using a nested analysis of variance (ANOVA), with island nested within A. sagrei presence, to compare initial perch height between one- and two-species islands. To examine whether microhabitat use during feeding differed between one- and two- species islands, we used a nested ANOVA, with island nested within A. sagrei presence, to compare the distance by which individuals descended to feed (1.e., the difference be- tween initial perch height and feeding height) between one- and two-species islands. Simi- lar analyses were performed to compare the distance by which males ascended to display (i.e., the difference between display height and initial perch height) between one- and two-species islands. All statistical analyses were carried out in JMP v. 5.0.1 (SAS Institute Inc., Cary, North Carolina 1989-2007), except the weighted Z-method for combining probabili- ties, which was implemented using the surv- comp package v 1.2.1 (Schroder et al, 2011) installed in R v 2.13.1 (R Development Core Team, 2011). Nested ANOVAs were per- formed by hand. All perch-height measure- ments were square-root transformed to 1m- prove normality. 2013 RESULTS We measured perch height at feeding for an average of 8.8 + 1.4 individuals per island, and perch height at displaying for an average of 9.5 + 1.9 males per island. On combining P-values from independent f tests from the four islands using the weighted Z method, we found that feeding height was significantly lower than initial perch height (Z = 2.65, P = 0.004; Fig. la). Display height was significantly higher than initial perch height (Z = 2.24, P = 0.012; Fig. 1b). The initial perch height of A. carolinensis was higher in the presence of A. sagrei (F > = 92.3, P = 0.01). However, the distance by which individuals descended to feed did not differ between one- and two-species islands (F, > = 0.09, P = 0.79), nor did the distance by which males ascended to display differ between one- and two-species islands (F; > = 1.55, P = 0.34). DISCUSSION Feeding heights Combining ¢ tests across all islands, we found that, relative to their initial perch height, individuals of A. carolinensis fed at lower perches. Similar partitioning by be- havior of the vertical extent of the habitat is seen in A. polylepis (Andrews, 1971) and female A. distichus (Paterson, 1999), but neither the prevalence of this phenomenon across anoles nor its causes has been established. One explanation for individuals shifting lower to feed is that prey are more abundant close to the ground. Data from islands in the Intracoastal Waterway similar to those sampled in this study show that arthropod densities are highest close to ground (Campbell, 2000), and the vertical stratification of arthropod density has been documented in other systems (Lawton, 1983; Brown et al., 1997). Moreover, a study on BEHAVIORAL PARTITIONING IN THE LIZARD ANOLIS CAROLINENSIS 5 Anolis nebulosus has shown that individuals shift the microhabitat in which they feed based on seasonal variation in prey abun- dance (Lister and Aguayo, 1992). It is hence likely that anoles choose their foraging locations based on spatial variation in prey density. Consistent with previous studies (Camp- bell, 2000; Edwards and Lailvaux, 2012), A. carolinensis perched higher on two-species islands than on one-species islands. Howev- er, the average distance that individuals of A. carolinensis descended to feed did not differ between one- and two-species islands. Our result would suggest that A. carolinensis feeds at higher perches in the presence of A. sagrei, which is confirmed by a direct comparison of feeding heights between treat- ments (nested ANOVA on feeding height, with the island effect nested within the treatment effect; treatment effect: Fj. = 10.4, pete faled = 0.042). This shift is potentially a consequence of the depletion of prey at lower perches by A. sagrei. Microhabitat shifts in sympatry are often accompanied by reduced overlap in diet (e.g., Huey et al, 1974; Schluter and McPhail, 1992). Gut content analysis from nearby islands in the Intracoastal Waterway showed that, on two-species islands where 4. car- olinensis perches higher than A. sagrei, A. carolinensis was more likely to eat flying prey, whereas A. sagrei was more likely to feed on terrestrial prey (Campbell, 2000). Similarly, the higher-perching Anolis angu- sticeps and Anolis smaragdinus were more likely to eat flying prey than the lower- perching A. distichus or A. sagrei when these species were in sympatry (Schoener 1968), and male A. polylepis both perched higher and ate more arboreal prey than females (Perry, 1996). The shift in the feeding height of A. caroli- nensis between one- and two-species islands might therefore lead to intraspecific varia- tion in diet and diet-related morphological 6 BREVIORA No. 535 a. 250 One-Species Islands Two-Species Islands 200 --{=}-- Hornet --4--- Lizard --~©--- South Twin ---@-- Line of Cedars E 150 — IS > - 100 00° fee : Initial Feeding Initial Feeding b. 290 200 = 150 = = > = "100 50 0 Initial Display Initial Display Figure 1. Comparisons of island means of (a) initial perch height and feeding height, and (b) initial perch height and display height for one-species islands (left) and two-species islands (right). Error bars indicate +1 standard error. Note that mean initial perch heights differ between (a) and (b) because different individuals were included in each data set; only individuals observed feeding were included in the computation of mean initial perch height for the former comparison, and only males observed displaying were included in the latter. 2013 characters of A. carolinensis between sympat- ric and allopatric populations. Although this shift to feeding at higher perches in sympatry is potentially explained by the consequences of resource competition for food, it might also result from direct agonistic interactions between the two spe- cies if A. carolinensis shifts to feed at higher perches to avoid potentially costly interac- tions with A. sagrei. These selective pressures are difficult to distinguish from each other and often act simultaneously (reviewed in Grether et al, 2009). Though interspecific resource competition is widely thought to drive character displacement and diversifica- tion in Anolis (reviewed in Losos, 2009), sympatric anoles sometimes interact aggres- sively (Jenssen et al., 1984; Hess and Losos, 1991), and the role of agonistic interactions in driving behavioral shifts in sympatry (e.g., Ord and Martins, 2006) cannot be ruled out. Display heights Combining f¢ tests across all islands, we found that display heights were significantly higher than initial perch heights. Andrews (1971) observed similar behavioral partition- ing in A. polylepis and proposed that displaying from higher perches increases the conspicuousness of the displaying male to conspecific males and females. Factors such as the light environment and movement of background vegetation are known to influ- ence where a lizard chooses to display (Leal and Fleishmann, 2002, 2004; Ord et al., 2007), and might play a role in determining the visibility of an individual displaying from relatively high perches to conspecifics, con- geners, or predators. Studies of territorial behavior in Anolis do not typically measure the vertical extent of territories (e.g., Fleming and Hooker, 1975; Stamps and Crews, 1976; Johnson et al., 2009; but see Reagan, 1992; Jenssen et al., 1995; Jenssen and Nunez, BEHAVIORAL PARTITIONING IN THE LIZARD ANOLIS CAROLINENSIS 7 1998). If relatively high perches within a territory are required by anoles for effective displaying to conspecifics, then the vertical extent of a territory might be a crucial indicator of male fitness. The difference between initial perch height and display height is similar on both one- and two-species islands. One explanation is that display perches are chosen relative to conspecifics, irrespective of the presence of A. sagrei. Given the overall shift to higher perches in the presence of A. sagrei, this explanation implies that A. carolinensis males on two-species islands will be limited by their display behavior to taller trees. Indeed, A. carolinensis males on two-species islands are found on taller trees than individuals on omne-species islands, even though the distribution of tree heights does not differ across island types (mean + standard error of total height of trees utilized by lizards on one-species islands: 305.3 + 7.4 cm; two-species islands: 386.2 + 6.1cm: Y. E. Stuart, unpublished data). Shifts in the horizontal spatial distribution of A. caroli- nensis to taller trees in the presence of A. sagrei might therefore be mediated by a constraint on male display height relative to the perch height of conspecifics. It is possible that, by observing lizards from eye level, we failed to observe displays that occurred at higher perches. In particu- lar, such a detection method might prevent us from uncovering a larger difference between initial and display heights on two- species islands than on one-species islands. However, our conclusions about the shift of A. carolinensis males on two-species islands to taller trees due to higher display perches would remain unchanged. Given that initial perch heights and feeding heights are lower than display heights (Fig. 1), this detection bias is unlikely to alter our other conclu- sions, unless initial perch heights or feeding heights are bimodally distributed. 8 BREVIORA Conclusion The partitioning of an individual’s behav- ioral repertoire into different parts of its habitat is common in animals (e.g., Albers and Gehlbach, 1990; Kats and Sih, 1992; Hagman and Shine, 2006; Angiletta er al., 2009; Thornton and Hodge, 2009) and has previously been documented in two species of Anolis lizards (A. polylepis, Andrews, 1971; A. distichus, Paterson, 1999). In this study, we show that individuals of 4. carolinensis also partitioned behaviors by feeding and display- ing at different heights relative to their initial perch position. Moreover, though the pres- ence of the congeneric competitor, A. sagrei, has caused an overall shift to higher perches in A. carolinensis (Campbell, 2000; Edwards and Lailvaux, 2012; this study), the relative positions of feeding and displaying locations were not affected by the presence of A. sagrei. The functional reasons for behavioral parti- tioning as well as the mechanisms leading to overall habitat shifts in sympatry will need to be established before we can understand whether and how behavioral partitioning can vary as habitat use changes. CONFLICT OF INTEREST The authors declare that they have no conflict of interest. ACKNOWLEDGMENTS We thank M. Legare and J. Lyon at Merritt Island National Wildlife Refuge (U.S. Fish and Wildlife Service permit: 2009-SUP-027) and J. Stiner and C. Carter at Canaveral National Seashore (National Park Service permit: CANA-2009-SCI-0006) for their gra- cious help with permits and logistics. The experiments were in accordance with Harvard University Institutional Animal Care and Use Committee Protocol 26-11. J. McCrae gener- ously lent us his boat to access the islands. We No. 535 thank J. Losos, G. Gartner, M. Munoz, and the Losos Lab, as well as several anonymous reviewers for comments that improved the manuscript. AK was supported by the Am- herst College Schupf Scholars Program and YES by a Museum of Comparative Zoology Miyata Award. LITERATURE CITED ALBERS, R. P., AND F. R. GEHLBACH. 1990. Choices of feeding habitat by relict Montezuma quail in central Texas. Wilson Bulletin 102: 300-308. ANDERSON, J. R. 1998. Sleep, sleeping sites, and sleep- related activities: awakening to their significance. American Journal of Primatology 46: 63-75. ANpREws, R. M. 1971. Structural habitat and time budget of a tropical Anolis lizard. Ecology 52: 262-270. ANGILETTA, M. J.. M. W. SEARS, AND R. M. PRINGLE. 2009. Spatial dynamics of nesting behavior: lizards shift microhabitats to construct nests with beneficial thermal properties. Ecology 90: 2933-2939. Brown, J. L., S. Varco, E. F. Connor, AND M. S. Nucko Ls. 1997. Causes of vertical stratification in the density of Cameraria hamadryadella. Ecological Entomology 22: 16-25. CampPBELL, T.S. 2000. Analyses of the effects of an exotic lizard (Anolis sagrei) on a native lizard (Anolis carolinensis) in Florida, using islands as experimental units. Unpublished Ph.D. Dissertation. Knoxville, Tennessee, University of Tennessee. CAMPBELL, T. S., AND A. C. ECHTERNACHT. 2003. Introduced species and moving targets: changes in body sizes of introduced lizards following experi- mental introductions and historical invasions. Biological Invasions 5: 193-212. CiarK, D. L., AND J. C. GILLINGHAM. 2006. Sleep-site fidelity in two Puerto Rican Lizards. Animal Behaviour 39: 1138-1148. CoL_eTTeE, B. B. 1961. Correlations between ecology and morphology in anoline lizards from Havana, Cuba, and southern Florida. Bulletin of the Musuem of Comparative Zoology 125: 137-162. DietricH, B., AND R. WERNER. 2003. Sympatry and allopatry in two desert ant sister species: how do Cataglyphis bicolor and C. savignyi coexist? Oeco- logia 136: 63-72. Epwarps, J. R., AND S. P. LattvAux. 2012. Display behavior and habitat use in single and mixed populations of Anolis carolinensis and Anolis sagrei lizards. Ethology 118: 494-502. 2013 FLEMING, T. H., AND R. S. Hooker. 1975. Anolis cupreus: the response of a lizard to tropical seasonality. Ecology 56: 1243-1261. Guor, R. E., A. LARSON, AND J. B. Losos. 2005. Out of Cuba: overwater dispersal and speciation among lizards in the Anolis carolinensis subgroup. Molec- ular Ecology 14: 2419-2432. GRETHER, G. F., N. Losin, C. N. ANDERSON, AND K. Oxamorto. 2009. The role of interspecific interfer- ence competition in character displacement and the evolution of competitior recognition. Biological Reviews 84: 617-635. GRONIG, J., AND A. HocukircH. 2008. Reproductive interference between species. Quarterly Review of Biology 83: 257-282. HAGMAN, M., AND R. SHINE. 2006. Spawning site selection by feral cane toads (Bufo marinus) at an invasion front in tropical Australia. Austral Ecology 31: 551-558. Henpry, A. P., S. K. Huser, L. F pE LEON, A. HERREL, AND J. Popos. 2009. Disruptive selection in a bimodal population of Darwin’s finches. Proceed- ings of the Royal Society B 276: 753-759. Mess.c. Ne E.. AND. J. _B. Losos..1991: Interspecific aggression between Anolis cristatellus and _ A. gundlachi: comparisons of sympatric and allopatric populations. Journal of Herpetology 25: 256-259. Huey, R. B., E. R. Pranka, M. E. EGAN, AND L. W. Coons. 1974. Ecological shifts in sympatry: Kala- hari fossorial lizards (Typhlosaurus). Ecology 55: 304-316. JENSSEN, T. A. 1973. Shift in the structural habitat of Anolis opalinus due to congeneric competition. Ecology 54: 863-869. JENSSEN, T. A. 1977. Evolution of anoline lizard display behavior. American Zoologist 17: 203-215. JENSSEN, T. A. 1978. Display diversity in anoline lizards and problems of interpretation, pp. 269-285. In N. Greenberg, and P. D. MacLean eds. Behavior and Neurology of Lizards. Rockville, Maryland, Na- tional Institute of Mental Health. JENSSEN, T. A., N. GREENBERG, AND K. A. Hovpe. 1995. Behavioral profile of free-ranging male lizards, Anolis carolinensis, across breeding and postbreed- ing seasons. Herpetological Monographs 9: 41-62. JENSSEN, T. A., D. L. MARCELLINI, C. A. PAGUE, AND L. A. JENSSEN. 1984. Competitive interference between the Puerto Rican lizards, Anolis cooki and A. cristatellus. Copeia 1984: 853-862. JENSSEN, T. A., AND S. C. Nunez. 1998. Spatial and breeding relationships of the lizard, Anolis caroli- nensis: evidence of intrasexual selection. Behaviour 135: 981-1003. BEHAVIORAL PARTITIONING IN THE LIZARD ANOLIS CAROLINENSIS 9 JoHNSON, M. A., L. J. REVELL, AND J. B. Losos. 2009. Behavioral convergence and adaptive radiation: effects of habitat use on territorial behavior in Anolis lizards. Evolution 64: 1151-1159. Kats, L. B., AND A. StH. 1992. Oviposition site selection and avoidance of fish by streamside salamanders (Ambystoma barbouri). Copeia 1992: 468-473. Kose, J. J.. P. L. CoLBerT, AND B. E. Smitu. 2008. Niche relationships and interspecific interactions in Antiguan lizard communities. Copeia 2008: 261-272. Lawton, J. H. 1983. Plant architecture and the diversity of phytophagous insects. Annual Review of Ento- mology 28: 23-39. LEAL, M., AND L. J. FLEISHMANN. 2002. Evidence for habitat partitioning based on adaptation to envi- ronmental light in a pair of sympatric lizard species. Proceedings of the Royal Society of London B 269: 351-359. LEAL, M., AND L. J. FLEISHMANN. 2004. Differences in visual signal design and detectability between allo- patric populations of Anolis lizards. The American Naturalist 163: 26-39. LisTER, B. C., AND A. G. AGuayo. 1992. Seasonality, predation, and the behaviour of a tropical mainland anole. Journal of Animal Ecology 61: 717-733. Losos, J. B. 2009. Lizards in an Evolutionary Tree: Ecology and Adaptive Radiation of Anoles. Berkeley, University of California Press. Losos, J. B., J. C. MARKs, AND T. W. SCHOENER. 1993. Habitat use and ecological interactions of an introduced and a native species of Anolis lizard on Grand Cayman, with a review of the outcomes of anole introductions. Oecologia 95: 525-532. Losos, J. B., AND D. A. SpiLLeR. 1999. Differential colonization success and asymmetrical interactions between two lizard species. Ecology 80: 252-258. MEDEL, R. G., P. A. MARQUET, AND F. M. Jaxsic. 1988. Microhabitat shifts of lizards under different contexts of sympatry: a case study with South American Liolaemus. Oecologia 76: 567-569. Nunez, S. C., T. A. JENSSEN, AND K. ERSLAND. 1997. Female activity profile of a polygynous lizard (Anolis carolinensis): evidence of intersexual asym- metry. Behaviour 134: 205-223. Orp, T. J., AND E. P. Martins. 2006. Tracing the origins of signal diversity in anole lizards: phylogenetic approaches to inferring the evolution of complex behaviour. Animal Behaviour 71: 1411-1429. Orp, T. J.. R. A. PETERS, B. CLucas, AND J. A. STAMPs. 2007. Lizards speed up visual display in noisy motion environments. Proceedings of the Royal Society of London B 264: 1057-1062. 10 BREVIORA PaTerSON, A. V. 1999. Effects of prey availability on perch height of female bark anoles, Anolis distichus. Herpetologica 55: 242-247. Perry, G. 1996. The evolution of sexual dimorphism in the lizard Anolis polylepis (Iguania): evidence from intraspecific variation in foraging behaviour and diet. Canadian Journal of Zoology 74: 1238-1425. Potts, G. A., C. A. Myers, AND R. D. Ho_tT. 1989. The ecology and evolution of intraguild predation: potential competitors that eat each other. Annual Review of Ecology and Systematics 20: 297-330. R DEVELOPMENT Core TEAM. 2011. R: a language and environment for statistical computing. R Founda- tion for Statistical Computing, Vienna, Austria. Ranp, A. S. 1964. Ecological distribution in anoline lizards of Puerto Rico. Ecology 45: 745-752. REAGAN, D. P. 1992. Congeneric species distribution and abundance in a three-dimensional habitat: the rain- forest anoles of Puerto Rico. Copeia 1992: 392-403. SCHLUTER, D., AND J. D. McPuait. 1992. Ecological character displacement and speciation in stickle- backs. American Naturalist 140: 85—108. SCHOENER, T. W. 1968. The Anolis lizards of Bimini: resource partitioning in a complex fauna. Ecology 49: 704-726. SCHOENER, T. W. 1975. Presence and absence of habitat shift in some widespread lizard species. Ecological Monographs 45: 233-258. No. 535 SCHRODER, M. S., A. C. CULHANE, J. QUACKENBUSH, AND B. HarBe-Kains. 2011. survcomp: an R/Bioconduc- ter package for performance assessment and com- parison of survival models. Bioinformatics 27: 3206-3208. SINGHAL, S., M. A. JOHNSON, AND J. T. LADNER. 2007. The behavioral ecology of sleep: natural sleeping site choice in three Anolis lizard species. Behaviour 144: 1033-1052. Stamps, J. A., AND D. P. Crews. 1976. Seasonal changes in reproduction and social behaviour in the lizard Anolis aeneus. Copeia 1976: 467-476. THORNTON, A., AND S. J. HopGe. 2009. The development of foraging microhabitat preferences in meerkats. Behavioral Ecology 20: 103-110. WANLESS, S., D. GREMILLET, AND M. P. Harris. 1998. Foraging activity and performance of Shags Phalacrocax aristotelis in relation to environmental characteristics. Journal of Avian Ecology 29: 49-54. WuitLock, M. C. 2005. Combining probability from independent tests: the weighted Z-method is supe- rior to Fisher’s approach. Journal of Evolutionary Biology 18: 1368-1373. WiiuiaAMs, E. E. 1969. The ecology of colonization as seen in the zoogeography of anoline lizards on small islands. Quarterly Review of Biology 44: 345— 389.