| enterobacteriaceae isolated from iguanid lizards of west-central texas. | the prevalence of members of the family enterobacteriaceae in the intestines of seven species of iguanid lizards native to west-central texas was determined. of the 67 lizard specimens examined, 48.7% were infected with salmonella and 9% were infected with salmonella arizonae. two lizard species (sceloporus olivaceus and crotaphytus collaris) were shown to have a 100% prevalence of salmonella. | 1979 | 533273 |
| disrupting evolutionary processes: the effect of habitat fragmentation on collared lizards in the missouri ozarks. | humans affect biodiversity at the genetic, species, community, and ecosystem levels. this impact on genetic diversity is critical, because genetic diversity is the raw material of evolutionary change, including adaptation and speciation. two forces affecting genetic variation are genetic drift (which decreases genetic variation within but increases genetic differentiation among local populations) and gene flow (which increases variation within but decreases differentiation among local population ... | 2001 | 11344289 |
| the transition from isolated patches to a metapopulation in the eastern collared lizard in response to prescribed fires. | habitat fragmentation often arises from human-induced alterations to the matrix that reduce or eliminate dispersal between habitat patches. elimination of dispersal increases local extinction and decreases recolonization. these phenomena were observed in the eastern collared lizard (crotaphytus collaris collaris), which lives in the mid-continental highland region of the ozarks (missouri, usa) on glades: habitats of exposed bedrock that form desert-like habitats imbedded in a woodland matrix. wi ... | 2011 | 21939070 |
| changes in oviducal vascularity during the reproductive cycle of three oviparous lizards (eumeces obsoletus, sceloporus undulatus and crotaphytus collaris). | histologically derived estimates and ink suspension vascular casts were used to examine oviducal vascular changes. vascularity peaked during gravidity and was correlated with maximal plasma progesterone concentrations. the vascular increase in the oviducal tissue was attributed exclusively to increased capillary densities. the greatest change occurred in the anterior uterus where incubation and egg shell secretion occur. similar patterns of change in vascularity occurred in the infundibulum, alt ... | 2013 | 3656274 |
| luteal morphology, atresia, and plasma progesterone concentrations during the reproductive cycle of two oviparous lizards, crotaphytus collaris and eumeces obsoletus. | from ovulation to oviposition, the corpora lutea of the oviparous lizards crotaphytus collaris and eumeces obsoletus exhibit three stages of luteal development: 1) luteogenesis, 2) luteal maturity, and 3) luteal regression. each stage exhibits distinct characteristics, involving changes in: 1) luteal volume, 2) nuclear diameter of cells within the luteal cell mass, and 3) thecal development. plasma progesterone concentration is greatest during luteogenesis and is positively correlated with ovari ... | 2011 | 3661456 |
| 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 |
| extinction, reintroduction, and restoration of a lizard meta-population equilibrium in the missouri ozarks. | in this issue of molecular ecology, neuwald & templeton (2013) report on a 22-year study of natural populations of collared lizards (crotaphytus collaris) that evolved on isolated on rock outcrops (‘glades’) in the ozark mountains in eastern missouri. this ecosystem was originally maintained by frequent fires that kept the forest understory open, but fire-suppression was adopted as official policy in about 1945, which led to a loss of native biodiversity, including local extinctions of some liza ... | 2013 | 24003452 |
| tissue-carbon incorporation rates in lizards: implications for ecological studies using stable isotopes in terrestrial ectotherms. | carbon stable isotope (delta(13)c) analysis can be used to infer the origin and to estimate the flow of nutrient resources through animals and across ecological compartments. these applications require knowledge of the rates at which carbon is incorporated into animal tissues and diet-to-tissue discrimination factors (delta(13)c). studies of carbon dynamics in terrestrial vertebrates to date have focused almost solely on endothermic animals; ectotherms such as reptiles have received little atten ... | 2010 | 20441446 |
| 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 |
| mitochondrial introgression and incomplete lineage sorting through space and time: phylogenetics of crotaphytid lizards. | we investigate the roles of mitochondrial introgression and incomplete lineage sorting during the phylogenetic history of crotaphytid lizards. our bayesian phylogenetic estimate for crotaphytidae is based on analysis of mitochondrial dna sequence data for 408 individuals representing the 12 extant species of crotaphytus and gambelia. the mitochondrial phylogeny disagrees in several respects with a previously published morphological tree, as well as with conventional species designations, and we ... | 2007 | 17941840 |
| faster lizards sire more offspring: sexual selection on whole-animal performance. | sexual selection operates by acting on variation in mating success. however, since selection acts on whole-organism manifestations (i.e., performance) of underlying morphological traits, tests for phenotypic effects of sexual selection should consider whole-animal performance as a substrate for sexual selection. previous studies have revealed positive relationships between performance and survival, that is, natural selection, but none have explicitly tested whether performance may influence repr ... | 2006 | 17133868 |
| field use of maximal sprint speed by collared lizards (crotaphytus collaris): compensation and sexual selection. | to understand how selection acts on performance capacity, the ecological role of the performance trait being measured must be determined. knowing if and when an animal uses maximal performance capacity may give insight into what specific selective pressures may be acting on performance, because individuals are expected to use close to maximal capacity only in contexts important to survival or reproductive success. furthermore, if an ecological context is important, poor performers are expected t ... | 2006 | 17089973 |
| do female collared lizards change field use of maximal sprint speed capacity when gravid? | locomotor ability is well-documented to decrease in gravid female lizards. however, no studies have examined what proportion of maximal sprint speed capacity gravid females use in nature or how a reduction in maximal capacity translates to changes in sprint speeds used in nature. gravid females may compensate for reduced locomotor ability by increasing the proportion of their maximal capacity used in nature, or by changing their antipredator behaviour. i measured maximal sprint speed in the labo ... | 2006 | 16896766 |
| weapon performance, not size, determines mating success and potential reproductive output in the collared lizard (crotaphytus collaris). | in territorial polygynous taxa, reproductive success reflects phenotypic variation. using crotaphytus collaris, a sexually dimorphic lizard in which males use the head (i.e., jaws and associated musculature) as a weapon when territorial interactions escalate to fights, we tested the hypothesis that weapon performance (i.e., bite force) is a better predictor of fitness than body or weapon size. bite-force performance predicted the number of female home ranges overlapped, estimated mating success, ... | 2005 | 16224696 |
| correlation of pairwise genetic and geographic distance measures: inferring the relative influences of gene flow and drift on the distribution of genetic variability. | attempts to relate estimates of regional fstto gene flow and drift via wright's (1931) equation fst≈ 1/ (4nm + 1) are often inappropriate because most natural sets of populations probably are not at equilibrium (mccauley 1993), as assumed by the island model upon which the equation is based, or ineffective because the influences of gene flow and drift are confounded in the product nm. evaluations of the association between genetic (fst) and geographic distances separating all pairwise population ... | 1999 | 28565459 |
| social inhibition of territorial behaviour in yearling male collared lizards, crotaphytus collaris. | in central oklahoma, collared lizard males display age-dependent differences in social behaviour, whereby sexually mature first-year (yearling) males adopt subordinate tactics, and males 2 years and older establish and defend all-purpose territories. we tested the hypothesis that the social activities of adult males inhibit the expression of territorial tactics in yearling males by recording the behaviour of yearlings in the presence of adult males, when all adult males were removed from study p ... | 1998 | 9790710 |
| feeding evoked by electrical stimulation in collared lizards. | feeding was evoked in collared lizards, crotaphytus collaris, using electrical stimulation of the brain (esb). stimulation sites were tested in the forebrain and midbrain of 39 animals. six stimulation loci were localized in the septal, preoptic, hypothalamic, and thalamic areas from which esb feeding was evoked. feeding could be elicited by esb over several test days, but the number of feeding bouts per test session was usually low. however, several animals ate or approached food consistently w ... | 1988 | 3368529 |
| helminths of collared lizards (crotaphytus collaris) from the pedro armendariz lava field, new mexico. | | 1986 | 3806338 |
| independent effects of the pineal and a bacterial pyrogen in behavioural thermoregulation in lizards. | the pineal complex of lizards is comprised of an extracranial photoreceptive structure known as the parietal eye, and an intracranial pineal organ which is homologous to the pineal gland of birds and mammals. studies have shown that removing the parietal eye or severing the parietal nerve causes lizards to select higher temperatures when allowed to thermoregulate behaviourally in thermal or photothermal laboratory gradients. although comparable studies involving removal of the lizard pineal orga ... | 1980 | 7383158 |
| agonistic behavior elicited by electrical stimulation of the brain in western collared lizards, crotaphytus collaris. | western collared lizards, crotaphytus collaris, were tested in three experiments using electrical stimulation of the brain. in experiment 1, agonistic behavior (defensive, aggressive and escape) responses were elicited in free-moving unanesthetized lizards. in experiment 2, areas were localized from which gular extension, a common component of defensive and aggressive behavior, could be evoked in anesthetized animals. experiment 3 was carried out to demonstrate that defensive and aggressive beha ... | 1978 | 570079 |
| steroids and color change during gravidity in the lizard crotaphytus collaris. | | 1972 | 5009679 |
| the function of the middle ear in lizards: crotaphytus collaris (iguanidae). | | 1970 | 5478938 |
| classical conditioning of skeletal and autonomic responses in the lizard (crotaphytus collaris). | | 1970 | 5535515 |
| the somatic chromosomes of 3 lizard species: gekko gecko, iguana iguana, and crotaphytus collaris. | | 1967 | 6062904 |
| femoral glands of the lizard, crotaphytus collaris. | | 1966 | 5906908 |
| integrating bioenergetics and conservation biology: thermal sensitivity of digestive performance in eastern collared lizards (crotaphytus collaris) may affect population persistence. | information on bioenergetics can provide valuable insight into the ecology, life history and population dynamics of organisms. for ectothermic animals, thermal sensitivity of digestion is an important determinant of net assimilated energy budgets. a recent study in the ozark mountains indicated that eastern collared lizards (crotaphytus collaris) restricted to encroached glades (characterized by woody vegetation encroachment) experience reduced environmental heat loads and have reduced age-speci ... | 2020 | 32274065 |
| the effect of body posture on available habitat and activity-time in a lizard: implications for thermal ecology studies. | ectothermic animals contend with variable environmental temperature through behavioral thermoregulation, including selection of activity-times and microhabitat spaces with suitable operative temperatures. thus, an important component to understanding the influence of temperature on animals is through the assessment of thermal constraints on time and space usage. thermal ecologists have recognized that postural adjustments are an important part of behavioral thermoregulation. however, the impact ... | 2019 | 31128637 |
| oviductal morphology and egg shelling in the oviparous lizards crotaphytus collaris and eumeces obsoletus. | morphological changes occurring in the oviduct and epithelial cells of the lizards crotaphytus collaris and eumeces obsoletus during the natural reproductive cycle were examined and quantified. additionally, development of the eggshell at different stages of gravidity was described. the anterior uterus of each species has a distinct glandular type which differs between species: in e. obsoletus, the glands are tubular and in c. collaris, branched saccular. the branched saccular glands in the ante ... | 1989 | 29865655 |