| duration of attachment by mites and ticks on the iguanid lizards sceloporus graciosus and uta stansburiana. | duration of attachment was determined for the mites neotrombicula californica and geckobiella texana and the tick ixodes pacificus on the iguanid lizards sceloporus graciosus and uta stansburiana from southern california. neotrombicula californica infestations lasted approximately 1 wk. attachment of ixodes pacificus larvae and nymphs lasted approximately 8 days on s. graciosus and 16 days on u. stansburiana. geckobiella texana remained attached to s. graciosus for 5 days and to u. stansburiana ... | 1991 | 1758043 |
| integumental lesions caused by ectoparasites in a wild population of the side-blotched lizard (uta stansburiana). | histopathological effects of ectoparasites on integument were examined for a wild population of the side-blotched lizard uta stansburiana. these included the trombiculid neotrombicula californica, the pterygosomatid mite geckobiella texana; the macronyssid mite ophionyssus natricis (macronyssidae) and the ixodid tick ixodes pacificus. a diffuse inflammatory response occurred at the site of chigger and tick attachment which consisted of histiocyte, heterophil, fibroblast and lymphocyte infiltrati ... | 1991 | 2023329 |
| substance p-like immunoreactivity in the parietal eye visual system of the lizard uta stansburiana. | we examined the parietal eye visual system of the iguanid lizard uta stansburiana for the presence of substance p-like immunoreactivity by use of both immunofluorescence and peroxidase-antiperoxidase techniques. in the parietal eye no substance p-containing somata were found; however, its plexiform layer contained small (ca. 1 micron diam) immunoreactive fibers. these fibers apparently originate outside the parietal eye. immunoreactive fibers also were found in the parietal nerve, the dorsal sac ... | 1982 | 6185229 |
| a genetic approach to the rock-paper-scissors game. | polymorphisms are usually associated with defenses and mating strategies, affecting the individual's fitness. coexistence of different morphs is, therefore, not expected, since the fittest morph should outcompete the others. nevertheless, coexistence is observed in many natural systems. for instance, males of the side-blotched lizards (uta stansburiana) present three morphs with throat colors orange, yellow and blue, which are associated with mating strategies and territorial behavior. the three ... | 2017 | 28385667 |
| a new species of oochoristica (cyclophyllidea: linstowiidae) from non-native mediterranean geckos, hemidactylus turcicus (sauria: gekkonidae), from texas, usa. | a new species of cyclophyllidean tapeworm, oochoristica harschi sp. nov. is described from 2 of 18 (11%) non-native mediterranean geckos (hemidactylus turcicus) collected in june 2016 from tom green county, texas, usa the new species has few characteristics in common with 17 species of oochoristica previously described from nearctic reptiles. of this group, o. harschi is most similar to o. macallisteri bursey and goldberg, 1996 from the side-blotched lizard, uta stansburiana from arizona and cal ... | 2017 | 28426409 |
| scanning electron microscope studies of the auditory papillae of some iguanid lizards. | the papillae basilares of 16 species (10 general) of iguanid lizards were studied by scanning electron microscopy. variations in the surface structures of the auditory papillae showed the following major differences: 1)papillae with localization of the unidirectional hair cells at the apical end of the papilla (anolis carolinensis); 2)papillae with absence or loss of a portion of the apical bidirectional hair-cell segment (basiliscus basiliscus); 3)papillae with a central, short ciliated, unidir ... | 1981 | 7304475 |
| postnatal skeletal ontogeny in callisaurus draconoides and uta stansburiana (iguania: phrynosomatidae). | the mineralization of the skeleton from hatching to near maximum size in two phrynosomatid lizards, callisaurus draconoides and uta stansburiana, is described in detail. observed patterns in the appearance of epiphyseal secondary centers, ossification centers, apophyseal ossifications, and calcifications, the distribution of sesamoids, and the timing of fusions, are compared and contrasted with observations of other squamates available in the literature. overall, callisaurus and uta exhibit an a ... | 2002 | 11748698 |
| chemosensory recognition of the marbled whiptail lizard, aspidoscelis marmorata (squamata: teiidae) to odors of sympatric lizards (crotophytus collaris, coleonyx brevis, eumeces obsoletus and uta stansburiana) that represent different predation risks. | the ability of the whiptail lizard aspidoscelis marmorata (teiidae) to detect and discriminate chemical stimuli associated with the integument of a sympatric saurophagous lizard (crotaphytus collaris) was tested. females of a. marmorata were presented with cotton swabs containing chemical cues from c. collaris and three species of nonsaurophagous lizards, as well as water and cologne (pungency control), and total number of tongue-flick (tf) recorded. other responses were assessed including direc ... | 2008 | 18831332 |
| phylogenetic analyses reveal that schellackia parasites (apicomplexa) detected in american lizards are closely related to the genus lankesterella: is the range of schellackia restricted to the old world? | species of schellackia reichenow, 1919 have been described from the blood of reptiles distributed worldwide. recently, schellackia spp. detected in european and asian lizards have been molecularly characterised. however, parasites detected in american lizard hosts remain uncharacterised. thus, phylogenetic affinities between the old and new world parasite species are unknown. | 2017 | 29017602 |
| size distributions and sex ratios of colonizing lizards. | this paper reports the body size distributions and sex ratios of four species of phyrnosomatid lizard that colonized experimentally created density sinks. the experiments were conducted in western colorado in 1992, and lizards colonizing the habitats in 1993 were compared to those removed in 1992 and those present in 1991. lizards colonizing the density sinks were able to disperse from adjacent habitat. for two of the species (urosaurus ornatus and sceloporus undulatus), colonizing lizards were ... | 1998 | 28307519 |
| morphology of the spermatozoa of the iguanian lizards uta stansburiana and urosaurus ornatus (squamata, phrynosomatidae). | the spermatozoa of uta stansburiana and urosaurus ornatus show the following squamate autapomorphies: a single perforatorium extending anteriorly from the apical tip of the paracrystalline subacrosomal cone; the presence of an epinuclear electron lucent region; intermitochondrial dense bodies; and the fibrous sheath extending into the midpiece. the acrosome vesicle is flattened and concentrically zoned apically; basally it overlies a subacrosomal cone which invests the nuclear rostrum. a stopper ... | 2000 | 11085215 |
| reproductive cycles of the iguanid lizards urosaurus ornatus and uta stansburiana in southeastern arizona. | | 1964 | 14191392 |
| metabolic responses to different immune challenges and varying resource availability in the side-blotched lizard (uta stansburiana). | the energetic cost of immunity depends on many factors, including the type of challenge, the timing of the response, and the state of the animal. we measured changes in the standard metabolic rates of side-blotched lizards (uta stansburiana baird and girard, 1852) in response to different immune challenges and nutritional states. in the first experiment, lizards were randomly assigned to one of four treatments: lipopolysaccharide (lps) injection (to stimulate the response to a pathogen), cutaneo ... | 2017 | 28405747 |
| physiological correlates of multiple parasitic infections in side-blotched lizards. | we investigated the presence of ectoparasites and hemoparasites in side-blotched lizards (uta stansburiana) across a large part of their range and measured how parasitic infection related to several key physiological indicators of health. blood samples were collected from 132 lizards from central arizona, southern utah, and eastern oregon. hemoparasites were found in 22 individuals (3.2% prevalence in arizona, 19.1% in utah, and 6.3% in oregon), and ectoparasites were found on 51 individuals (56 ... | 2017 | 28384422 |
| increased testosterone decreases medial cortical volume and neurogenesis in territorial side-blotched lizards (uta stansburiana). | variation in an animal's spatial environment can induce variation in the hippocampus, an area of the brain involved in spatial cognitive processing. specifically, increased spatial area use is correlated with increased hippocampal attributes, such as volume and neurogenesis. in the side-blotched lizard (uta stansburiana), males demonstrate alternative reproductive tactics and are either territorial-defending large, clearly defined spatial boundaries-or non-territorial-traversing home ranges that ... | 2017 | 28298883 |
| assessing spatial learning and memory in small squamate reptiles. | clinical research has leveraged a variety of paradigms to assess cognitive decline, commonly targeting spatial learning and memory abilities. however, interest in the cognitive processes of nonmodel species, typically within an ecological context, has also become an emerging field of study. in particular, interest in the cognitive processes in reptiles is growing although experimental studies on reptilian cognition are sparse. the few reptilian studies that have experimentally tested for spatial ... | 2017 | 28117775 |
| effects of diet restriction and diet complexity on life history strategies in side-blotched lizards (uta stansburiana). | organisms must balance energy invested into self-maintenance, reproduction, and somatic growth over their lifetime. in this study, the effects of diet restriction and diet complexity on side-blotched lizards (uta stansburiana) were analyzed. thirty male lizards, housed in the laboratory, were fed either an ad libitum or a restricted diet for 18 days (phase 1). individuals from both treatments were then assigned to a diet of the same quantity of food that was either simple (only crickets) or comp ... | 2016 | 28102007 |
| the role of the kisspeptin system in regulation of the reproductive endocrine axis and territorial behavior in male side-blotched lizards (uta stansburiana). | the neuropeptide kisspeptin and its receptor are essential for activation of the hypothalamic-pituitary-gonadal (hpg) axis and regulating reproduction. while the role of kisspeptin in regulating the hpg axis in mammals has been well established, little is known about the functional ability of kisspeptins to activate the hpg axis and associated behavior in non-mammalian species. here we experimentally examined the effects of kisspeptin on downstream release of testosterone and associated aggressi ... | 2017 | 28017596 |
| lack of supercooling evolution related to winter severity in a lizard. | as organisms move into higher latitudes, they may evolve physiological mechanisms to survive in harsher climates. one such mechanism is supercooling, the capacity to survive at subzero temperatures without freezing. while interspecific comparisons reveal greater thermal tolerances at higher latitudes in insects and vertebrates, evidence for intraspecific evolution in supercooling related to latitude is only evident in insects. we measured the supercooling points of lizards from 12 populations re ... | 2015 | 26590458 |
| a heterogeneous thermal environment enables remarkable behavioral thermoregulation in uta stansburiana. | ectotherms can attain preferred body temperatures by selecting specific temperature microhabitats within a varied thermal environment. the side-blotched lizard, uta stansburiana may employ microhabitat selection to thermoregulate behaviorally. it is unknown to what degree habitat structural complexity provides thermal microhabitats for thermoregulation. thermal microhabitat structure, lizard temperature, and substrate preference were simultaneously evaluated using thermal imaging. a broad range ... | 2014 | 25535549 |
| frequency-dependent and correlational selection pressures have conflicting consequences for assortative mating in a color-polymorphic lizard, uta stansburiana. | genetically determined polymorphisms incorporating multiple traits can persist in nature under chronic, fluctuating, and sometimes conflicting selection pressures. balancing selection among morphs preserves equilibrium frequencies, while correlational selection maintains favorable trait combinations within each morph. under negative frequency-dependent selection, females should mate (often disassortatively) with rare male morphotypes to produce conditionally fit offspring. conversely, under corr ... | 2014 | 25058279 |
| wound healing reduces stress-induced immune changes: evidence for immune prioritization in the side-blotched lizard. | immune system function is affected by a variety of exogenous and endogenous stressors. most studies have focused on the effect of stressors on immune function, but not necessarily on trade-offs within the immune system and interactions with energy-mobilizing hormones. in this study, we examined how bactericidal ability and corticosterone interacted by applying acute restraint stress in a non-model organism, the side-blotched lizard (uta stansburiana), 10 days after receiving a cutaneous wound. w ... | 2014 | 24736888 |
| evidence of maternal effects on temperature preference in side-blotched lizards: implications for evolutionary response to climate change. | natural populations respond to selection pressures like increasing local temperatures in many ways, including plasticity and adaptation. to predict the response of ectotherms like lizards to local temperature increase, it is essential to estimate phenotypic variation in and determine the heritability of temperature-related traits like average field body temperature (t b) and preferred temperature (t p). we measured t p of uta stansburiana in a laboratory thermal gradient and assessed the contrib ... | 2013 | 23919144 |
| interaction between territoriality, spatial environment, and hippocampal neurogenesis in male side-blotched lizards. | differences in an animal's spatial environment can have dramatic effects on the hippocampus, an area of the brain involved with spatial processing. animals in spatially impoverished environments have decreased hippocampal attributes. however, we do not know if differences in the spatial environment differentially interact with territorial status, which also covaries with hippocampal attributes. here, we asked whether territoriality and differential spatial-area use interact to generate different ... | 2013 | 23731068 |
| stress-induced tradeoffs in a free-living lizard across a variable landscape: consequences for individuals and populations. | current life history theory suggests that the allocation of energetic resources between competing physiological needs should be dictated by an individual's longevity and pace of life. one key physiological pathway likely to contribute to the partitioning of resources is the vertebrate stress response. by increasing circulating glucocorticoids the stress response can exert a suite of physiological effects, such as altering immune function. we investigated the effects of stress physiology on indiv ... | 2012 | 23185478 |
| adaptive color polymorphism and unusually high local genetic diversity in the side-blotched lizard, uta stansburiana. | recently, studies of adaptive color variation have become popular as models for examining the genetics of natural selection. we examined color pattern polymorphism and genetic variation in a population of side-blotched lizards (uta stansburiana) that is found in habitats with both dark (lava) and light colored (granite) substrates. we conducted a limited experiment for adult phenotypic plasticity in laboratory conditions. we recorded both substrate and lizard color patterns in the field to deter ... | 2012 | 23133520 |
| spatial memory: are lizards really deficient? | in many animals, behaviours such as territoriality, mate guarding, navigation and food acquisition rely heavily on spatial memory abilities; this has been demonstrated in diverse taxa, from invertebrates to mammals. however, spatial memory ability in squamate reptiles has been seen as possible, at best, or non-existent, at worst. of the few previous studies testing for spatial memory in squamates, some have found no evidence of spatial memory while two studies have found evidence of spatial memo ... | 2012 | 22933038 |
| glycogen, not dehydration or lipids, limits winter survival of side-blotched lizards (uta stansburiana). | climate change is causing winters to become milder (less cold and shorter). recent studies of overwintering ectotherms have suggested that warmer winters increase metabolism and decrease winter survival and subsequent fecundity. energetic constraints (insufficient energy stores) have been hypothesized as the cause of winter mortality but have not been tested explicitly. thus, alternative sources of mortality, such as winter dehydration, cannot be ruled out. by employing an experimental design th ... | 2012 | 22875774 |
| maternal adjustment of egg size organizes alternative escape behaviors, promoting adaptive phenotypic integration. | numerous integrated traits contribute to any aspect of organismal performance, but favorable trait combinations are difficult to maintain in the face of genetic recombination. we investigated the role of maternal effects in promoting integration of alternative reproductive strategies (throat colors) with antipredator traits (escape behaviors and dorsal patterns) in the side-blotched lizard (uta stansburiana). previously, we reported that maternally derived estradiol adaptively pairs dorsal patte ... | 2010 | 20624182 |
| dorsal cortex volume in male side-blotched lizards (uta stansburiana) is associated with different space use strategies. | spatial abilities have been associated with many ecologically-relevant behaviors such as territoriality, mate choice, navigation and acquisition of food resources. differential demands on spatial abilities in birds and mammals have been shown to affect the hippocampus, the region of the brain responsible for spatial processing. in some bird and mammal species, higher demands on spatial abilities are associated with larger hippocampal volumes. the medial and dorsal cortices are the putative repti ... | 2009 | 20161271 |
| selective loss of polymorphic mating types is associated with rapid phenotypic evolution during morphic speciation. | polymorphism may play an important role in speciation because new species could originate from the distinctive morphs observed in polymorphic populations. however, much remains to be understood about the process by which morphs found new species. to detail the steps of this mode of speciation, we studied the geographic variation and evolutionary history of a throat color polymorphism that distinguishes the "rock-paper-scissors" mating strategies of the side-blotched lizard, uta stansburiana. we ... | 2010 | 20160090 |
| alternative mating strategies and the evolution of sexual size dimorphism in the side-blotched lizard, uta stansburiana: a population-level comparative analysis. | population-level comparative analyses can link microevolutionary processes within populations to macroevolutionary patterns of diversification. we used the comparative method to study the evolution of sexual size dimorphism (ssd) among populations of side-blotched lizards (uta stansburiana). uta stansburiana is polymorphic for different male mating and female life-history strategies in some populations, but monomorphic in others. we tested whether intrasexual selection among males, fecundity sel ... | 2010 | 19659598 |
| intralocus sexual conflict over immune defense, gender load, and sex-specific signaling in a natural lizard population. | in species with separate sexes, antagonistic selection on males and females (intralocus sexual conflict) can result in a gender load that can be resolved through the evolution of sexual dimorphism. we present data on intralocus sexual conflict over immune defense in a natural population of free-ranging lizards (uta stansburiana) and discuss the resolution of this conflict. intralocus sexual conflict arises from correlational selection between immune defense and orange throat coloration in these ... | 2009 | 19624721 |
| [specific organization of ribosomal dna arrays in squamata]. | a first report on structural organization of ribosomal dna arrays in some members of the order squamata is presented. the data obtained point to unusually small (for vertebrates) size of the rdna repetitive unit (approximately, 10 to 15 kb) in the lizard species examined. analysis of bac library of uta stansburiana (iguania) showed that haploid genome of this lizard contained a single cluster, consisting of about ten rdna repeats. determination of the extent of rdna unit repetition in some other ... | 2008 | 19137739 |
| climate change trade-offs in the side-blotched lizard (uta stansburiana): effects of growing-season length and mild temperatures on winter survival. | an expanding body of literature has demonstrated that global climate change continues to adversely affect many populations, species, and ecosystems. however, life-history theory also predicts possible benefits from longer growing seasons and less severe winters, particularly for ectotherms. to test the idea that climate change will have benefits as well as costs, i studied the impacts of growing-season length on growth and overwintering conditions on survival time using side-blotched lizards (ut ... | 2008 | 18826371 |
| gonadotropin hormone modulation of testosterone, immune function, performance, and behavioral trade-offs among male morphs of the lizard uta stansburiana. | sexual selection predicts that trade-offs maintain trait variation in alternative reproductive strategies. experiments often focus on testosterone (t), but the gonadotropins follicle-stimulating hormone and luteinizing hormone may provide a clearer understanding of the pleiotropic relationships among traits. we assess the activational role of gonadotropins on t and corticosterone regulation in traits expressed by polymorphic male side-blotched lizards uta stansburiana. gonadotropins are found to ... | 2008 | 18201140 |
| corticosterone manipulation reveals differences in hierarchical organization of multidimensional reproductive trade-offs in r-strategist and k-strategist females. | life history trade-offs are often hierarchical with decisions at one level affecting lower level trade-offs. we investigated trade-off structure in female side-blotched lizards (uta stansburiana), which exhibit two evolved strategies: yellow-throated females are k-strategists and orange-throated are r-strategists. corticosterone treatment was predicted to differentially organize these females' reproductive decisions. corticosterone-treated yellow females suppressed reproduction but survived well ... | 2008 | 18179517 |
| simple identification of mitochondrial lineages in contact zones based on lineage-selective primers. | a variety of research projects focus on genetic variation among and within maternal lineages as encompassed by mitochondrial dna (mtdna). while mtdna often differs substantially between species, large differences may also be found within species. the evaluation of such divergent lineages, for example in intraspecific contact zones (hybrid zones), commonly involves sequencing numerous individuals. large-scale sequencing is both expensive and labour-intensive. based on sequences from 15 individual ... | 2008 | 21585720 |
| fasting increases delta15n-values in the uric acid of anolis carolinensis and uta stansburiana as measured by nondestructive sampling. | previous studies suggest that a nutritional/energetic state may be determined from the delta(15)n-values of an animal's tissues. it has been hypothesized that if an animal is in a negative nutritional/energetic balance, (15)n will be retained by the tissues preferentially and (14)n preferentially excreted. over time, this should cause enrichment of the delta(15)n-values of the tissues. tests of this hypothesis have met with mixed results. to date, these studies have focused on endotherms. few st ... | 2007 | 18023076 |
| adaptive social and maternal induction of antipredator dorsal patterns in a lizard with alternative social strategies. | maternal effects facilitate adaptation to changing environments because they alter individual offspring traits to match current conditions. we show that maternal effects can also resolve context-dependent, correlational selection on multiple offspring traits, promoting adaptation to more complex environments. in side-blotched lizards (uta stansburiana), two alternative pathways of dorsal pattern induction involve maternal oestradiol and alleles for throat colouration ( approximately social strat ... | 2007 | 17663713 |
| an experimental test of frequency-dependent selection on male mating strategy in the field. | we provide field-based experimental evidence for the frequency-dependent nature of the fitness of alternative mating strategies. we manipulated the frequency of genetically determined phenotypic strategies in six wild populations of the side-blotched lizard, uta stansburiana. the within-population pattern of mating was assessed using nine microsatellite loci to assign paternity. within populations of the side-blotched lizard exist three colour morphs (orange, blue and yellow) associated with mal ... | 2007 | 17550882 |
| corticosterone, locomotor performance, and metabolism in side-blotched lizards (uta stansburiana). | elevated levels of circulating corticosterone commonly occur in response to stressors in wild vertebrates. a rise in corticosterone, usually in animals of subordinate rank, results in a variety of effects on behavior and physiology. behavioral and physiological responses to short-term increases in corticosterone are well studied. in contrast, the effects of chronic elevated levels of corticosterone are poorly understood, particularly in lizards. here, we examined the long-term effects of exogeno ... | 2007 | 17379216 |
| spatial scale and temporal component of selection in side-blotched lizards. | spatial variation in selection has long been recognized as promoting population divergence and in maintaining genetic polymorphisms, but selection at a fine spatial scale is seldom measured directly. we analyzed spatial and temporal variation in selective regimes on egg size using long-term population data of the side-blotched lizard (uta stansburiana). juvenile survival rates varied between years at a small spatial scale that was reflected as a strong interaction between the local neighborhood ... | 2004 | 15122490 |
| within-clutch variation in offspring sex determined by differences in sire body size: cryptic mate choice in the wild. | sexual selection theory predicts that paternal quality should drive female investment in progeny. we tested whether polyandrous female side-blotched lizards, uta stansburiana, would adjust within-clutch progeny investment according to sire phenotypes. in two different years, polyandrous females selectively used sperm from larger sires to produce sons and used sperm from smaller sires to produce daughters. this cryptic sperm choice had significant effects on progeny survival to maturity that were ... | 2004 | 15009280 |
| social competition, corticosterone and survival in female lizard morphs. | we examined the selective consequences of variation in behaviour and endocrine physiology in two female throat-colour morphs of the lizard, uta stansburiana in the wild. female morphs differed in home-range distribution patterns and corticosterone levels in relation to the density and frequency of their female neighbours. levels of plasma corticosterone of yellow-throated females increased with increased density of both morphs. in contrast, orange-throated females had reduced levels of corticost ... | 2003 | 14635910 |
| lizard threat display handicaps endurance. | honest-signalling theory asserts that threat displays reliably advertise attributes that influence fighting success. endurance, as measured by treadmill performance, predicts the outcome of agonistic interactions among lizards. if threat displays in lizards function to advertise endurance capacity then variation in threat displays should correlate with endurance. i tested this prediction for the duration of threat posturing in male side-blotched lizards (uta stansburiana) and examined whether th ... | 2003 | 12803896 |
| uncoupling direct and indirect components of female choice in the wild. | one of the most controversial debates in evolutionary biology concerns the fitness consequences of female choice in nature. discriminating females may benefit from high-quality territories and/or sires with high-quality genes. here we experimentally dissociate female preferences for high-quality territories and male body size in a wild population of side-blotched lizards, uta stansburiana. females preferred experimentally improved territories but still chose high-quality sires for their progeny. ... | 2002 | 12417752 |
| correlational selection and the evolution of genomic architecture. | we review and discuss the importance of correlational selection (selection for optimal character combinations) in natural populations. if two or more traits subject to multivariate selection are heritable, correlational selection builds favourable genetic correlations through the formation of linkage disequilibrium at underlying loci governing the traits. however, linkage disequilibria built up by correlational selection are expected to decay rapidly (ie, within a few generations), unless correl ... | 2002 | 12399990 |
| the ontogeny of territoriality during maturation. | territoriality drives the evolution of many mating systems, yet has remained an extremely difficult trait to measure in the wild. classic studies rely on the theoretical framework of resource holding potential (rhp) as a predictor of success in territory acquisition. however, mounting evidence suggests that an individual's rhp may change over short time scales. previous studies suggest that rhp is best understood by considering two categories of territoriality, resource defending and resource us ... | 2002 | 28547426 |
| sexual selection and alternative mating behaviours generate demographic stochasticity in small populations. | recent theory predicts that environmental variation and small population size facilitate the coexistence of alternative phenotypes despite unequal mean fitness. however, traditional studies of reproductive strategies often assume that the stability of alternative mating behaviours relies on equal male fitness. we present results from field observations and experimental manipulations of thermal resources on territories demonstrating the coexistence of alternative reproductive behaviours with uneq ... | 2002 | 11798431 |
| condition, genotype-by-environment interaction, and correlational selection in lizard life-history morphs. | we compared reproductive allocation and variation in condition and survivorship of two heritable female throat color morphs (orange and yellow) in a free-living population of side-blotched lizards (uta stansburiana). using path analysis and structural equation modeling, we investigated how variation in the social environment affected clutch size and egg mass and two condition traits (postlaying mass, immunological condition) and how these traits in turn affected female field survival. in the pre ... | 2001 | 11761065 |
| social causes of correlational selection and the resolution of a heritable throat color polymorphism in a lizard. | when selection acts on social or behavioral traits, the fitness of an individual depends on the phenotypes of its competitors. here, we describe methods and statistical inference for measuring natural selection in small social groups. we measured selection on throat color alleles that arises from microgeographic variation in allele frequency at natal sites of side-blotched lizards (uta stansburiana). previous game-theoretic analysis indicates that two color morphs of female side-blotched lizards ... | 2001 | 11761064 |
| density-dependent competition and selection on immune function in genetic lizard morphs. | density-dependent territorial interactions have been suggested to cause immunosuppression and thereby decrease fitness, but empirical support from natural populations is lacking. data from a natural lizard population (uta stansburiana) showed that breeding females surrounded by many territorial neighbors had suppressed immune function. furthermore, variation in immunological condition had different effects on the fitness of the two heritable female throat-color morphs in this population. these i ... | 2001 | 11592973 |
| the evolution of alternative reproductive strategies: fitness differential, heritability, and genetic correlation between the sexes. | paternity analyses using molecular markers have become standard in studies of mating systems, parentage, and kinship. in systems where individuals exhibit alternative mating strategies, molecular analyses have been productively used to estimate the reproductive success of each behavioral type and hence the fitness consequences to each individual. here we review the fitness results in a system of five alternative mating strategies present in one population of side-blotched lizards (uta stansburia ... | 2007 | 11396579 |
| testosterone, endurance, and darwinian fitness: natural and sexual selection on the physiological bases of alternative male behaviors in side-blotched lizards. | the mechanistic bases of natural and sexual selection on physiological and behavioral traits were examined in male morphs of three colors of the side-blotched lizard, uta stansburiana. orange-throated males are aggressive and defend large territories with many females. blue-throated males defend smaller territories with fewer females; however, blue-throated males assiduously mate guard females on their territory. yellow-throated males do not defend a territory, but patrol a large home range. the ... | 2000 | 11104640 |
| experimental excursions on adaptive landscapes: density-dependent selection on egg size. | theories of density-dependent natural selection suggest that intraspecific competition will favor juveniles of high competitive ability. empirical evidence has been provided from laboratory selection experiments, but field studies are lacking due to the logistical difficulties of experimentally manipulating population densities in natural settings. here, we present data from a decade-long experimental field study of side-blotched lizards, uta stansburiana that overcomes these difficulties. we te ... | 2000 | 11005305 |
| reproductive burden, locomotor performance, and the cost of reproduction in free ranging lizards. | a reduction in the locomotor capacity of gravid females is considered to be a cost of reproduction if it leads to an increased risk of mortality. in this study, we measured the change in endurance between gravid and postgravid female side-blotched lizards (uta stansburiana) as a test of the cost of reproduction. we also altered reproductive investment in some females by direct ovarian manipulation (yolkectomy), which decreased reproductive burden by 30%. regardless of experimental treatment, all ... | 2000 | 11005304 |
| the effects of tail loss on survival, growth, reproduction, and sex ratio of offspring in the lizard uta stansburiana in the field. | tail autotomy is a defense against predators used by many lizard species but is associated with various costs, most of which have been measured only in the laboratory. we conducted a field experiment in which we induced tail autotomy to approximately half (58%) of a marked sample (n=326) of uta stansburiana from western texas in the fall, and left the other half with intact tails. the following spring we determined survival, measured growth, and brought females to the laboratory to allow them to ... | 2000 | 28308283 |
| phylogeny of the side-blotched lizards (phrynosomatidae:uta) based on mtdna sequences: support for midpeninsular seaway in baja california. | we investigated the phylogenetic relationships of western north american side-blotched lizards, genus uta, using mitochondrial dna partial gene sequences from cytochorme b and atpase 6. uta stejnegeri appeared basal in our tree followed by u. palmeri. uta stansburiana from the islands of angel de la guarda, mejia, and raza formed the next clade, followed by u. antiqua and other populations of u. stansburiana. these relationships suggest that the populations on the angel de la guarda island block ... | 1997 | 9242598 |
| the effects of tail autotomy on survivorship and body growth of uta stansburiana under conditions of high mortality. | we examined the effects of tail autotomy on survivorship and body growth of both adult and juvenile uta stansburiana by directly manipulating tail condition. tail loss decreased neither survivorship nor rate of body growth for individuals in two natural populations. lack of an influence of tail loss on survivorship in these two populations may be the result of high mortality. under high mortality any differential effects of tail loss will be lower than in populations facing lower mortality. grow ... | 1994 | 28307008 |
| effects of steroid hormone interaction on activity and home-range size of male lizards. | steroid hormones play a major role in influencing the physiology and behavior of all animals, including reptiles. oftentimes, it is an interaction between two or more hormones that is ultimately responsible for the observed response or behavior. we designed a pair of field studies on adjacent communities of side-blotched lizards (uta stansburiana) to provide insight into the interrelationship of testosterone (t) and corticosterone (b) in regulating aggressive behavior. on one site, males were im ... | 1994 | 7814007 |
| effects of corticosterone on activity and home-range size of free-ranging male lizards. | the purpose of our study was to examine whether corticosterone (b) affects the spacing behavior of free-ranging male side-blotched lizards (uta stansburiana). furthermore, we wanted to determine if the density, reflected in seasonal changes in population size, or behavior, as a result of hormonal manipulation, of "neighboring" males influences these effects. field studies were conducted on four naturally isolated "neighborhoods" of lizards. half of the males on three of the sites were randomly i ... | 1994 | 8034282 |
| effects of corticosterone on social behavior of male lizards. | adrenal corticoid release is a major component of the stress response which can affect many body functions including behavior. the purpose of our studies was to examine the effects of corticosterone (b) on both the agonistic and courtship components of social behavior in male side-blotched lizards (uta stansburiana). of particular interest was the effect of b on plasma testosterone (t), a hormone known to influence aggression, and the importance of this action on the behavioral effects of b. exp ... | 1993 | 8349278 |
| tail injuries increase the risk of mortality in free-living lizards (uta stansburiana). | caudal autotomy is an effective anti-predator mechanism used by many lizard species. fitness benefits of surviving a predatory attack are obvious, although lizards that autotomize their tails may be at greater risk during subsequent encounters with predators than lizards with complete tails. in previous laboratory studies, tail-less lizards were more vulnerable to capture by predators, but little is known about the relative survival of tailed versus tail-less lizards in nature. this study report ... | 1992 | 28311825 |
| serotonin and dopamine in the retina of a lizard. | the objective of this paper is to report the presence and localization of serotonin and dopamine in the retina of the lizard uta stansburiana. high performance liquid chromatography and electrochemical detection were used to identify and quantitate the two amines. both compounds are present as endogenous molecules in this retina and are found in concentrations similar to those reported in other non-mammalian retinas. the same methods were employed to confirm, in the isolated retina, the synthesi ... | 1987 | 3571518 |
| altered energy metabolism in an irradiated population of lizards at the nevada test site. | field metabolic rates (via doubly labeled water), body compartmentalization of energy stores, and energy assimilation efficiencies were measured to assess all avenues of energy utilization in uta stansburiana living in a low-level gamma-irradiated plot in rock-valley, nevada. comparison of energy budgets for radiation-sterilized females with those of nonirradiated control lizards revealed several substantial differences. sterile females were heavier, mainly because they had extraordinarily large ... | 1985 | 4070562 |
| annual variation of survival advantage of large juvenile side-blotched lizards, uta stansburiana: its causes and evolutionary significance. | | 1984 | 28555919 |
| the effect of supplemental feeding on home range size and activity patterns in the lizard uta stansburiana. | there was no difference in home range size between supplementally fed and unfed lizards even though supplementally fed lizards gained significantly more body mass than did unfed lizards. a logistic growth model was fit to curves of accumulative home range size against days of observation for fed and unfed lizards. an analysis of these curves showed that supplementally fed lizards's home range estimates grew at a slower rate than did unfed lizards. thus, fed lizards utilized the habitat at a slow ... | 1983 | 28310148 |
| social cost of tail loss in uta stansburiand. | tail removal from dominant juvenile uta stansburiana resulted in a decrease in social status in dyadic encounters. most lizards were affected after removal of two-thirds of their tails. in some pairs, dominant lizards lost status after removal of one-third of their tails but regained dominance after the other member of the pair lost two-thirds of its tail. tail loss in nature may impose a social handicap to successful home range acquisition and thereby increase risk of death. | 1982 | 17791590 |
| seasonal shifts in clutch size and egg size in the side-blotched lizard, uta stansburiana baird and girard. | there is evidence that the side-blotched lizard, uta stansburiana, and some other organisms of temperate latitudes produce fewer and larger eggs as the reproductive season progresses. there are at least two models that could explain this phenomenon.proponents of the parental investment model claim that females are selected to increase egg size, at the cost of clutch size, late in the season in order to produce larger and competitively superior hatchlings at a time when food for hatchlings is in ... | 1981 | 28309442 |
| endocrine function and reproductive impairment in an irradiated population of the lizard uta stansburiana. | | 1978 | 734058 |
| sterility among female lizards (uta stansburiana) exposed to continuous gamma irradiation. | | 1977 | 850729 |
| natural selection on morphological phenotypes of the lizard uta stansburiana. | | 1975 | 28563292 |
| genetic variation in irradiated and nonirradiated populations of the lizard, uta stansburiana. | | 1971 | 5561941 |
| a demographic analysis of continuously irradiated and nonirradiated populations of the lizard, uta stansburiana. | | 1969 | 5771802 |
| estradiol-induced vitellinogenesis and concomitant fat mobilization in the lizard uta stansburiana. | | 1967 | 6075170 |
| acute gamma irradiation experiments with the lizard uta stansburiana. | | 1967 | 6024363 |
| releasers of courtship and territorial behaviour in the side blotched lizard uta stansburiana. | | 1966 | 5918254 |
| effects of radiation on the natality, density and breeding structure of a natural population of lizards, uta stansburiana. | | 1965 | 5894394 |
| lizard reproduction: refractory period and response to warmth in uta stansburiana females. | photoperiod does not affect timing of the female reproductive cycle in uta stansburiana. this lizard is refractory to reproduction until early december. later, prolonged warmth under laboratory conditions initiates the reproductive cycle in some lizards regardless of photoperiod. | 1965 | 14287608 |
| fat body cycling and experimental evidence for its adaptive significance to ovarian follicle development in the lizard uta stansburiana. | | 1965 | 14299684 |
| effects of x-radiation on the testes of the lizard, uta stansburiana stejnegeri. | | 1965 | 14309656 |
| seasonal changes in testicular and epididymal histology and spermatogenic rate in the lizard uta stansburiana stejnegeri. | | 1964 | 14234869 |
| hierarchical distance sampling to estimate population sizes of common lizards across a desert ecoregion. | multispecies wildlife monitoring across large geographical regions is important for effective conservation planning in response to expected impacts from climate change and land use. unlike many species of birds, mammals, and amphibians which can be efficiently sampled using automated sensors including cameras and sound recorders, reptiles are often much more challenging to detect, in part because of their typically cryptic behavior and generally small body sizes. although many lizard species are ... | 2019 | 30962880 |
| novel and bizarre abnormalities of the tooth row in side-blotched lizards (uta) and rock lizards (petrosaurus). | multiple tooth rows along the dentary or maxilla are present in many bony and cartilaginous fishes but occur infrequently in amniotes. although two partially overlapping rows of teeth or a few doubled tooth positions were both previously reported in extant and extinct lizards, multiple rows of teeth across the entire dental or maxillary shelf were not previously documented in any lizard taxon. here, we report one specimen of the side-blotched lizard uta stansburiana and two specimens of the rock ... | 2020 | 31587495 |
| no evidence for differential sociosexual behavior and space use in the color morphs of the european common wall lizard (podarcis muralis). | explaining the evolutionary origin and maintenance of color polymorphisms is a major challenge in evolutionary biology. such polymorphisms are commonly thought to reflect the existence of alternative behavioral or life-history strategies under negative frequency-dependent selection. the european common wall lizard podarcis muralis exhibits a striking ventral color polymorphism that has been intensely studied and is often assumed to reflect alternative reproductive strategies, similar to the icon ... | 2020 | 33144943 |
| glucocorticoids, energy metabolites, and immunity vary across allostatic states for plateau side-blotched lizards (uta stansburiana uniformis) residing in a heterogeneous thermal environment. | reptiles rely on thermal heat exchange to achieve body temperatures (tbody ) conducive to maintaining homeostasis. diurnal changes in the thermal environment are therefore liable to influence allostatic mediation of survival processes (e.g., immunity) during environmental challenges or stressors. however, the extent to which tbody prompts individual variation in physiology remains largely unexplored in reptiles. our study tested how circulating energy-mobilizing hormone, energy metabolites, and ... | 2020 | 32959993 |
| stoichiometric and stable isotope ratios of wild lizards in an urban landscape vary with reproduction, physiology, space and time. | spatial and temporal variation in stoichiometric and stable isotope ratios of animals contains ecological information that we are just beginning to understand. in both field and lab studies, stoichiometric or isotopic ratios are related to physiological mechanisms underlying nutrition or stress. conservation and ecosystem ecology may be informed by isotopic data that can be rapidly and non-lethally collected from wild animals, especially where human activity leaves an isotopic signature (e.g. vi ... | 2020 | 32082575 |
| investment of both essential fatty and amino acids to immunity varies depending on reproductive stage. | trade-offs among the key life-history traits of reproduction and immunity have been widely documented. however, the currency in use is not well-understood. we investigated how reproducing female side-blotched lizards, uta stansburiana, allocate lipids versus proteins when given an immune challenge. we tested whether lizards would invest more in reproduction or immunity depending on reproductive stage. females were given stable isotopes (15 n-leucine and 13 c-1-palmitic acid), maintained on a reg ... | 2019 | 31625280 |
| life-history differences across latitude in common side-blotched lizards (uta stansburiana). | life-history strategies are known to shift with latitude in many species. while life-history variation related to body size, reproductive investment, and behavior has been studied for years, another crucial life-history component is the immune system, which can influence an animal's survival.we measured selected life-history traits in side-blotched lizards in southern utah and oregon in the field for two consecutive years and conducted a common-garden experiment in the laboratory to determine ho ... | 2019 | 31160995 |
| integration of genotype, physiological performance, and survival in a lizard (uta stansburiana) with alternative mating strategies. | covariation among behavioral and physiological traits is thought to enhance reproductive success and darwinian fitness. species that exhibit alternative mating strategies provide excellent opportunities to assess the relative contributions of physiological and behavioral traits to fitness. male side-blotched lizards (uta stansburiana) exhibit three heritable throat color morphs that are associated with alternative mating behaviors. the three morphs differ in resource holding potential, mate attr ... | 2019 | 30924718 |
| genital morphology associated with mating strategy in the polymorphic lizard, uta stansburiana. | sexual selection can lead to rapid evolution of sexual traits and striking morphological diversity across taxa. in populations where competition for mates is intense, males sometimes evolve distinct behavioral strategies along with morphological differences that help them secure mating opportunities. strong postcopulatory selection and differential resource allocation across male strategy type can result in strategy-specific differences in sexual traits, such as sperm morphology, ejaculate compo ... | 2019 | 30592530 |
| the genetic basis of adaptation following plastic changes in coloration in a novel environment. | phenotypic plasticity has been hypothesized to precede and facilitate adaptation to novel environments [1-8], but examples of plasticity preceding adaptation in wild populations are rare (but see [9, 10]). we studied a population of side-blotched lizards, uta stansburiana, living on a lava flow that formed 22,500 years ago [11] to understand the origin of their novel melanic phenotype that makes them cryptic on the black lava. we found that lizards living on and off of the lava flow exhibited ph ... | 2018 | 30197088 |
| molecular survey of coccidian infections of the side-blotched lizard uta stansburiana on san benito oeste island, mexico. | blood parasites are found in many vertebrates, but the research on blood parasites of lizards is still at its onset. we analyzed blood samples from side-blotched lizards uta stansburiana from san benito oeste island, mexico, to test for the presence of hemoparasites. we found a high prevalence (23 out of 27 samples) of a blood parasite of the genus lankesterella (coccidia, eimeriorina, lankesterellidae) according to phylogenetic analyses of the parasite 18s rrna gene. similar parasites (97-99% s ... | 2018 | 30109981 |
| mechanistic analysis of natural selection and a refinement of lack's and williams's principles. | results from several physiologically based manipulations were synthesized to investigate two selective trade-offs involving offspring number versus offspring quality and costs of reproduction in an annual lizard uta stansburiana. lifetime reproductive success of experimentally size-altered progeny was studied to address the offspring number and offspring quality trade-off. causes of natural selection on adult reproductive costs were assessed with three complementary manipulations of clutch size, ... | 1999 | 29586707 |