Evolution of Anoline Lizard Display Behavior

Based on my conceptual framework of anoline display behavior,I am suggesting the following evolutionary trends. Lateral presentationduring display was probably promoted by monocular vision. Alongwith lateral presentation, postures evolved to increase lateraloutline. These postures which magnified body size were probablyof selective advantage within aggressive social contexts sincelarger animals tend to dominate smaller ones through bluff.Body movement evolved along with lateral orientation and size-enhancingpostures. These movements would be most effective if they complementedlateral orientation. Effectors available for such movementswere primarily pre-adapted for vertical motion. The patternsof movement generated were probably simple oscillatory bobbingmovements by the head which were weakly stereotyped, interspecificallysimilar, appearing in many contexts, and having a weakly definedinformation content. Events having selective advantage for speciesrecognition promoted stereotypy of bobbing behavior into species-uniquedisplays; each species had its unique signature display whichserved in a manifold communicatory capacity. The signature displayappeared in assertion, courtship, and challenge contexts. Itsinformation content varied depending upon context and recipientof the display (e.g., male or female). Besides the stereotypedaspects of the display, certain features remained variable withpotential information significance. Core variability (see text)promotes individual recognition and may be the origin of newunique display patterns as sibling species emerge. Display modifiers(see text) are variable display features shared by members ofa population (many being shared interspecifically) that providea graded appearance to display performance; modifiers can indicatelevel of arousal and facilitate interspecific communication.For some species display repertoire size seems to have evolvedfrom a single display (signature display) to repertoires ofmultiple displays; these subsequent displays are generally restrictedto aggressive interactions.     

Habitat Use by Sonoran Desert Tortoises

ABSTRACT The distribution of desert tortoises (Gopherus agassizii) spans a wide range of biotic and abiotic conditions in the southwestern United States and northwestern Mexico, with physical and behavioral differences distinguishing tortoises inhabiting the Mojave Desert from those inhabiting the Sonoran Desert. Relative to tortoise populations in the Mojave Desert, populations in the Sonoran Desert have not been well-studied. To assess how habitat use of desert tortoises in the Sonoran Desert was influenced by topography, vegetation, geomorphology, and soil, we surveyed 40 randomly located 3-ha sites for presence of adult tortoises within a site-occupancy framework. We modeled both occupancy and detection probability as a function of environmental features, and compared those results with a logistic regression model that assumed detection probability was equal to 1. Results from both approaches agreed, suggesting that habitat selection of tortoises in the Sonoran Desert was influenced primarily by topographic and geomorphologic features rather than by vegetation. Specifically, tortoises were more likely to occupy sites that were steep (we detected tortoises on 29% of sites with mean slope <5° and 92% of sites with mean slope >15°) and predominantly east-facing (53% of sites with <5% of site facing E and 92% of sites with >20% facing E), and less likely to occupy north-facing slopes (100% of sites with <10% of site facing N and 14% of sites with >60% facing N). Our results contrast with patterns of habitat use in the Mojave Desert where tortoises primarily occupy valley bottoms. Habitat use of tortoises in Sonoran and Mojave Desert populations differ considerably, contributing to the mounting body of evidence suggesting that these geographically distinct populations may represent separate species.     

Enriching Tortoises: Assessing Color Preference

Environmental enrichment is a principle that is used to enhance the quality of care for nonhuman animals in captivity. To achieve this, it is necessary to understand the animal's needs. This study focused on color preference to provide food stimuli as a source of environmental enrichment for the tortoise, Chelonoidis denticulata. During this study, the stimuli green-, blue-, yellow-, and red-colored bananas and plaster blocks were randomly offered to the tortoises. Analysis of the data showed that the tortoises had a preference for the stimuli dyed with colors red and yellow over the other presented colors. It was possible to conclude that presenting food in different colors stimulated the animals to evaluate their environment and make choices in relation to their color preference. Thus, this experiment introduced an element of choice into their lives, beyond identifying color food preferences for the tortoises. The element of choice is known to be important to animal welfare.     

Acoustic and Visual Display Behavior of Gekkonid Lizards

Visual and acoustic mechanisms of communication are compared.Their properties are found to be similar except that acousticsystems function more efficiently when light levels are low.The ability of geckos to receive and produce visual and acousticmessages is discussed. Geckos are found to have excellent visionand good hearing. They also possess the visual attributes andsound producing mechanisms necessary for complex displays. Thedisplay behavior of geckos is reviewed. Display types are categorizedaccording to the display mechanism used. Visual displays arefound to utilize color, pattern, posture, and movement. Thesedisplays are used in predator threat as well as in intraspecificsocial contexts such as aggression and courtship. Combined visual-acousticdisplays involve color, pattern, postures, movement, and sound.Combined displays are used in predator threat and in intraspecificaggressive encounters. Acoustic displays have little or no visualcomponent and involve sounds that may be single chirps or temporallypatterned multiple chirps. The single chirps are associatedwith distress while the multiple chirp calls are heard in intraspecificsocial contexts. The displays of diurnal and nocturnal geckosare compared and it is found that differences are correlatedwith differences in their diel activity cycles. In conclusion,it is pointed out that many areas remain to be studied beforegecko display behavior is well understood.     

Population Genetic Assignment of Confiscated Gopher Tortoises

Abstract As gopher tortoises (Gopherus polyphemus) increasingly become threatened throughout their range in Florida, USA, the need for management and conservation will intensify. Here we evaluate the forensic applicability of genetic assignment tests based on microsatellite genotypic data to 1) accurately assign individuals in our genetic database to the sample location or population of origin and 2) determine the origin of 6 confiscated tortoises. Overall, we could correctly assign 90% of the individuals in the database to their population of origin, but we were unable to determine the source of the confiscated tortoises. However, these individuals are unlikely to have come from any of our sampled sites and all 6 may have come from the same population. This approach can be used by law enforcement personnel to identify the origin of confiscated tortoises as well as by developers and wildlife managers to determine the genetic appropriateness of potential recipient populations when it is necessary to relocate individuals.     

Tracing Genetic Lineages of Captive Desert Tortoises in Arizona

Abstract: We genotyped 180 captive desert tortoises (Gopherus agassizii) from Kingman (n = 45), Phoenix (n = 113), and Tucson (n = 22), Arizona, USA, to determine if the genetic lineage of captives is associated with that of wild tortoises in the local area (Sonoran Desert). We tested all samples for 16 short tandem repeats and sequenced 1,109 base pairs of mitochondrial DNA (mtDNA). To determine genetic origin, we performed assignment tests against a reference database of 997 desert tortoise samples collected throughout the Mojave and Sonoran Deserts. We found that >40% of our Arizona captive samples were genetically of Mojave Desert or hybrid origin, with the percentage of individuals exhibiting the Mojave genotype increasing as the sample locations approached the California, USA, border. In Phoenix, 11.5% were Sonoran–Mojave crosses, and 8.8% were hybrids between desert tortoise and Texas tortoise (G. berlandieri). Our findings present many potential implications for wild tortoises in the Sonoran Desert of Arizona. Escaped or released captive tortoises with Mojave or hybrid genotypes have the potential to affect the genetic composition of Sonoran wild populations. Genotyping captive desert tortoises could be used to inform the adoption process, and thereby provide additional protection to native desert-tortoise populations in Arizona.     

Long-Term Retention of a Relocated Population of Gopher Tortoises

Abstract: Relocations of gopher tortoises (Gopherus polyphemus) in Florida, USA, are frequently employed as mitigation tools when tortoises occupy land desired for development. Here we present information about retention and health of a relocated population of gopher tortoises 17 years after relocation. We combine our 17-year postrelocation data with earlier surveys 1 year and 2 years postrelocation to examine whether retention rates change over time. We also evaluate whether retention rates vary by age and gender. Of 74 gopher tortoises relocated in 1985, 31 were present in 2002. We found a 1-year retention rate of 42%, with retention rates of 100% each year thereafter, when we used the percentage of relocated individuals captured at each survey. We found a 1-year retention rate of 73%, a retention rate of 92% from year 1 to year 2, and an overall retention rate of 98.5% from year 2 through year 17, based on the assumption that all individuals present in later surveys were present in earlier surveys. We found no significant difference in retention rate over the 17-year period for adults and juveniles and for adult males and females. Relocated gopher tortoises showed natural growth patterns, indicating good health, but 35% of these gopher tortoises had ≥1 symptom of upper respiratory tract disease, a disease associated elsewhere with population declines of tortoises. Thus, retention rates of relocated gopher tortoises change over time, with relatively low retention during the first year postrelocation but nearly 100% retention in subsequent years. In general, our study shows that relocations can successfully lead to long-term retention of gopher tortoises, but we predict that without management (e.g., fire management and predator control) this relocated population is not viable.     

Implications from Monitoring Gopher Tortoises at Two Spatial Scales

Conservation biologists need to effectively monitor species given resource limitations and the inherent challenges of assessing long-term demographic processes. We assessed gopher tortoise (Gopherus polyphemus) abundance at a landscape scale and at the scale of 3 local populations within the Conecuh National Forest (CNF), Alabama, USA, between 1991 and 2017. We collected landscape-level data from line transect distance sampling arranged uniformly across the CNF during a single season (2011); we obtained data for local populations from long-term mark-recapture of individuals at 3 sites selected based on prior knowledge of high density at each. At a landscape scale, we estimated 5,242 (95% CI = 3,538–7,768) tortoises occurred across the approximately 34,000-ha forest, yielding a density of 0.14–0.32 tortoises/ha. These low densities across the landscape suggest that, on average, management activities across the property have not allowed tortoise populations to retain the social structure needed for long-term persistence. The 3 local populations, however, contained 25–60 individuals and densities of 1.9–6.9 tortoises/ha. Over the study period, populations at 2 sites were stable and the third experienced significant population growth. Mean annual survival of individuals was 0.89 and invariant across size classes. Overall, line transect distance sampling is important for assessing landscape-scale abundance of tortoises but may fail to detect local clusters of high-density sites important for population persistence. Our mark-recapture efforts at the local scale revealed that small populations on these high-density sites can exhibit long-term stability or growth even though they do not meet current established criteria for viability. Improved models that incorporate immigration and emigration and better reflect the dynamics of peripheral populations would assist in determining how such populations best contribute to species recovery and regional conservation targets. © 2020 The Wildlife Society.     

Negative Association Between Conspicuous Visual Display and Chemosensory Behavior in Two Phrynosomatid Lizards

Communication in one sensory modality can influence communication in others. Lizards in many phrynosomatid species use primarily visual but also chemical signals. The striped plateau lizard, Sceloporus virgatus , exhibits evolutionary loss of a male color signal that in many species is used during aggressive postural displays towards conspecific males. These patches are used similarly in Urosaurus , the sister genus to Sceloporus . We compared a species in which a color signal has been lost, S. virgatus , to a species retaining the ancestral character state of blue abdominal display patches, Urosaurus ornatus , the common tree lizard, to test two hypotheses: (i) conspicuous postural displays that reveal the abdominal patch location are used less in the species that has lost the color patches; and (ii) potential chemical signals are used more in the species with the color loss. We analyzed both visual display behavior (push-up, full-show) and chemosensory behavior (tongue flick and nose tap) of male lizards following their introduction to a resident conspecific male in his home terrarium. Resident males performed very low rates of all behaviors, but intruders exhibited sufficient behavior for analysis.
Supporting the first hypothesis, S. virgatus were less likely than U. ornatus to perform full-show, a display that reveals abdominal skin. Male S. virgatus were more likely to perform push-up than U. ornatus , although S. virgatus performed push-up infrequently. Push-up is a postural display that does not specifically reveal the abdominal patch location. Supporting the second hypothesis, S . virgatus were more likely to perform chemosensory behaviors and performed them at a greater rate than did U. ornatus . Work comparing more closely related species is warranted to determine whether a negative association between conspicuous visual displays and chemosensory behavior is a general pattern.     

越南黑叉尾斗鱼展示行为的偏侧化及其对镜面影像的响应

动物行为的偏侧化现象广泛存在于各个类群,特别是具有仪式化展示和打斗行为的鱼类。越南黑叉尾斗鱼(Macropodus spechti)是一种雄性个体间具有模式化展尾行为小型淡水鱼类。本文主要研究越南黑叉尾斗鱼展尾行为或眼睛使用的偏侧化现象,以及镜面影像对其行为的影响。研究发现,越南黑叉尾斗鱼中在个体(94.6%,n=35)和群体(左侧化指数:LⅠ=0.25±0.19)水平均具有明显的左侧化倾向;镜面影像会降低斗鱼的展示强度和左侧化倾向(LⅠ=0.10±0.23),但是,对水面呼吸的频次没有显著影响。这表明,越南黑叉尾斗鱼的左侧化倾向是对"头-尾"相对展示的一种适应,而镜面影像中"头-尾"展示姿势的变化对越南黑叉尾斗鱼的展示行为具有明显影响,但这种影响在反应强度(换气次数)上并没有差异,由此认为越南黑叉尾斗鱼对镜面影像缺乏自我识别能力。同时,由于偏侧化现象的存在,使得使用镜面影像无法获得和真实个体一致的行为响应结果。本研究对未来行为学研究中如何使用镜面影像研究动物行为具有重要的指导意义。     

The Catastrophic Decline of Tortoises at a Fenced Natural Area

Agassiz’s desert tortoise (Gopherus agassizii), a threatened species of the southwestern United States, has severely declined to the point where 76% of populations in critical habitat (Tortoise Conservation Areas) are below viability. The potential for rapid recovery of wild populations is low because females require 12–20 years to reach reproductive maturity and produce few eggs annually. We report on a 34-year mark-recapture study of tortoises initiated in 1979 at the Desert Tortoise Research Natural Area in the western Mojave Desert, California, USA, and provide substantive data on challenges faced by the species. In 1980, the United States Congress designated the Research Natural Area and protected the land from recreational vehicles, livestock grazing, and mining with a wildlife-permeable fence. The 7.77-km² study area, centered on interpretive facilities, included land both within the Natural Area and outside the fence. We expected greater benefits to accrue to the tortoises and habitat inside compared to outside. Our objectives were to conduct a demographic study, analyze and model changes in the tortoise population and habitat, and compare the effectiveness of fencing to protect populations and habitat inside the fence versus outside, where populations and habitat were unprotected. We conducted surveys in spring in each of 7 survey years from 1979, when the fence was under construction, through 2012. We compared populations inside to those outside the fence by survey year for changes in distribution, structure by size and relative age, sex ratios, death rates of adults, and causes of death for all sizes of tortoises. We used a Bayesian implementation of a Jolly Seber model for mark-recapture data. We modeled detection, density, growth and transition of tortoises to larger size-age classes, movements from inside the protective fence to outside and vice versa, and survival. After the second and subsequent survey years, we added surveys to monitor vegetation and habitat changes, conduct health assessments, and collect data on counts of predators and predator sign. At the beginning of the study, counts and densities for all sizes of tortoises were high, but densities were approximately 24% higher inside the fence than outside. By 2002, the low point in densities, densities had declined 90% inside the fence and 95% outside. Between 2002 and 2012, the population inside the fence showed signs of improving with a 54% increase in density. Outside the fence, densities remained low. At the end of the study, when we considered the initial differences in location, densities inside the fence were roughly 2.5 times higher than outside. The pattern of densities was similar for male and female adults. When evaluating survival by blocks of years, survivorship was higher in 1979–1989 than in 1989–2002 (the low point) and highest from 2002 to 2012. Recruitment and survival of adult females into the population was important for growing the population, but survival of all sizes, including juveniles, was also critical. Major events and activities driving the decline in populations both inside and outside the fence included illegal collecting, upper respiratory tract disease, and hyperpredation by the common raven (Corvus corax) on juvenile tortoises. Other sources of death were gunshots, vehicles, and predation by mammals. Outside the fence, fragmentation and deterioration of habitat was a critical driver. Between the first and last surveys, 2 different ecosystem processes were underway: recovery of vegetation and soils from grazing and vehicles inside the fence and continued deterioration outside the fence. Habitat outside the fence became increasingly denuded of shrubs and fragmented by roads and trails, and habitat fragments increased 50-fold. Outside the fence, biomass of non-native annual plants was higher and the cover of shrubs was lower, a reflection of ongoing deterioration. These changes and losses of habitat resulted in loss of shrub cover and sites for burrows, reduction in preferred food plants, and greater exposure to predators and extremes in temperature. Overall, the tortoise population and habitat inside the fence appeared to benefit from protection and showed signs of recovery at the end of the study. Fencing, control of vehicular access, and removal of livestock grazing were among several recommended management actions for critical habitat in the first recovery plan in 1994. At the end of the study, the Natural Area remained as 1 of 2 fenced, official protected areas for the species in the geographic range. We attribute fencing to continuing higher densities of adults inside the fence compared with outside the fence and promising signs of recovery. Densities of adults at the Natural Area also were 2.3 to 5.5 times higher than in 16 of the 17 Tortoise Conservation Areas (critical habitat units) within the geographic range. © 2020 The Authors. Wildlife Monographs published by Wiley Periodicals, LLC on behalf of The Wildlife Society.     

Pancreatic Cancer Stem-like Cells Display Aggressive Behavior Mediated via Activation of FoxQ1

Subpopulations of cancer stem cells (CSCs) or cancer stem-like cells (CSLCs) have been identified from most tumors, including pancreatic cancer (PC), and the existence of these cells is clinically relevant. Emerging evidence suggests that CSLCs participate in cell growth/proliferation, migration/invasion, metastasis, and chemo-radiotherapy resistance, ultimately contributing to poor clinical outcome. However, the pathogenesis and biological significance of CSLCs in PC has not been well characterized. In the present study, we found that isolated triple-marker-positive (CD44⁺/CD133⁺/EpCAM⁺) cells of human PC MiaPaCa-2 and L3.6pl cells behave as CSLCs. These CSLCs exhibit aggressive behavior, such as increased cell growth, migration, clonogenicity, and self-renewal capacity. The mRNA expression profiling analysis showed that CSLCs (CD44⁺/CD133⁺/EpCAM⁺) exhibit differential expression of more than 1,600 mRNAs, including FoxQ1, compared with the triple-marker-negative (CD44⁻/CD133⁻/EpCAM⁻) cells. The knockdown of FoxQ1 by its siRNA in CSLCs resulted in the inhibition of aggressive behavior, consistent with the inhibition of EpCAM and Snail expression. Mouse xenograft tumor studies showed that CSLCs have a 100-fold higher potential for tumor formation and rapid tumor growth, consistent with overexpression of CSC-associated markers/mediators, including FoxQ1, compared with its parental MiaPaCa-2 cells. The inhibition of FoxQ1 attenuated tumor formation and growth, and expression of CSC markers in the xenograft tumor derived from CSLCs of MiaPaCa-2 cells. These data clearly suggest the role of differentially expressed genes in the regulation of CSLC characteristics, further suggesting that targeting some of these genes could be important for the development of novel therapies for achieving better treatment outcome of PC.     

Female and Male Moths Display Different Reproductive Behavior when Facing New versus Previous Mates

Multiple mating allows females to obtain material (more sperm and nutrient) and/or genetic benefits. The genetic benefit models require sperm from different males to fertilize eggs competitively or the offspring be fathered by multiple males. To maximize genetic benefits from multiple mating, females have evolved strategies to prefer novel versus previous mates in their subsequent matings. However, the reproductive behavior during mate encounter, mate choice and egg laying in relation to discrimination and preference between sexes has been largely neglected. In the present study, we used novel and previous mate treatments and studied male and female behavior and reproductive output in Spodoptera litura. The results of this study do not support the sperm and nutrient replenishment hypotheses because neither the number of mates nor the number of copulations achieved by females significantly increased female fecundity, fertility and longevity. However, females showed different oviposition patterns when facing new versus previous mates by slowing down oviposition, which allows the last male has opportunities to fertilize her eggs and the female to promote offspring diversity. Moreover, females that have novel males present called earlier and more than females that have their previous mates present, whereas no significant differences were found on male courtship between treatments. These results suggest that S. litura females can distinguish novel from previous mates and prefer the former, whereas males generally remate regardless of whether the female is a previous mate or not. In S. litura, eggs are laid in large clusters and offspring competition, inbreeding and disease transfer risks are thus increased. Therefore, offspring diversity should be valuable for S. litura, and genetic benefits should be the main force behind the evolution of female behavioral strategies found in the present study.     

From Continental Priorities to Local Conservation: A Multi-Level Analysis for African Tortoises

Terrestrial tortoises are the most endangered group of vertebrates but they are still largely ignored for defining global conservation priorities. In this paper, we explored within a hierarchical framework the potential contribution of prioritization studies at the continental scale to the planning of local initiatives for the conservation of African tortoises at the regional level. First, we modeled the distribution of all the African tortoise species, we calculated three indicators of conservation priority (i.e. species richness, conservation value, and complementarity), and we carried out a gap analysis at continental scale. Second, we focused on the most important region for tortoise conservation and performed the same analyses at higher resolution. Finally, we compared the results from the two scales for understanding the degree to which they are complementary. Southern Africa emerged from the continental analysis as the most important region for tortoises. Within this area, the high-resolution analysis pointed out specific core sites for conservation. The relative degree of species protection was assessed similarly at the two different resolutions. Two species appeared particularly vulnerable at both scales. Priority indices calculated at high resolution were correlated to the values calculated for the corresponding cells at low resolution but the congruence was stronger for species richness. Our results suggest to integrate the calculation of conservation value and complementarity into a hierarchical framework driven by species richness. The advantages of large scale planning include its broad perspective on complementarity and the capability to identify regions with greatest conservation potential. In this light, continental analyses allow targeting fine scale studies toward regions with maximum priority. The regional analyses at fine scale allow planning conservation measure at a resolution similar to that required for the practical implementation, reducing the uncertainty associated with low resolution studies.     

Lineage Identification and Genealogical Relationships Among Captive Galápagos Tortoises

Genetic tools have become a critical complement to traditional approaches for meeting short‐ and long‐term goals of ex situ conservation programs. The San Diego Zoo (SDZ) harbors a collection of wild‐born and captive‐born Galápagos giant tortoises (n = 22) of uncertain species designation and unknown genealogical relationships. Here, we used mitochondrial DNA haplotypic data and nuclear microsatellite genotypic data to identify the evolutionary lineage of wild‐born and captive‐born tortoises of unknown ancestry, to infer levels of relatedness among founders and captive‐born tortoises, and assess putative pedigree relationships assigned by the SDZ studbook. Assignment tests revealed that 12 wild‐born and five captive‐born tortoises represent five different species from Isabela Island and one species from Santa Cruz Island, only five of which were consistent with current studbook designations. Three wild‐born and one captive‐born tortoise were of mixed ancestry. In addition, kinship analyses revealed two significant first‐order relationship pairs between wild‐born and captive‐born tortoises, four second‐order relationships (half‐sibling) between wild‐born and captive tortoises (full‐sibs or parent‐offspring), and one second‐order relationship between two captive‐born tortoises. Of particular note, we also reconstructed a first‐order relationship between two wild‐born individuals, violating the founder assumption. Overall, our results contribute to a worldwide effort in identifying genetically important Galápagos tortoises currently in captivity while revealing closely related founders, reconstructing genealogical relationships, and providing detailed management recommendations for the SDZ tortoises. Zoo Biol 31:107;–120, 2012. © 2011 Wiley Periodicals, Inc.     

Display Behavior and Habitat Use in Single and Mixed Populations of Anolis carolinensis and Anolis sagrei Lizards

Introduced species can have a variety of effects on the behavior and ecology of native species. We compared display behavior and habitat use of introduced Anolis sagrei and native Anolis carolinensis lizards across three sites in Southern Louisiana. The chosen sites were similar in that they were all located in urban settings with clumped vegetation. The first site contained only A. sagrei, the second supported sympatric A. sagrei and A. carolinensis populations, and the third site harbored only A. carolinensis. We found that (1) A. carolinensis perched significantly higher when A. sagrei was present, consistent with previous studies, whereas perch height of A. sagrei was not altered by the presence of A. carolinensis; (2) A. carolinensis in single and mixed sites exhibited different proportions of display types, with individuals at the mixed Tulane site performing significantly more C displays than those at the single site; and (3) Anolis sagrei at the Tulane mixed site exhibited less push‐ups than those in the site with A. sagrei alone. These data suggest that the arrival of congeners can affect display behavior of anoles, although such effects are different for the natives and the invaders.