Publications

multiple environmental stressors induce complex transcriptomic responses indicative of phenotypic outcomes in western fence lizard.	the health and resilience of species in natural environments is increasingly challenged by complex anthropogenic stressor combinations including climate change, habitat encroachment, and chemical contamination. to better understand impacts of these stressors we examined the individual- and combined-stressor impacts of malaria infection, food limitation, and 2,4,6-trinitrotoluene (tnt) exposures on gene expression in livers of western fence lizards (wfl, sceloporus occidentalis) using custom wfl ...	2018	30518325
population history with invasive predators predicts innate immune function response to early-life glucocorticoid exposure in lizards.	early-life stress can suppress immune function, but it is unclear whether transgenerational stress exposure modulates the immune consequences of early stress. in populations where, historically, the immune system is frequently activated, e.g. persistent stressors that cause injury, it may be maladaptive to suppress immune function after early-life stress. thus, the relationship between early-life stress and immune function may vary with population-level historical stressor exposure. we collected ...	2019	30659082
glucocorticoids do not influence a secondary sexual trait or its behavioral expression in eastern fence lizards.	secondary sexual traits and associated behaviors can be influenced by environmental factors such as exposure to stressors. such effects may be mediated by the physiological stress response, which is typified by the release of glucocorticoid hormones. the effects of glucocorticoids on sexual traits such as plumage and display coloration have most commonly been studied in isolation rather than in conjunction with other pertinent aspects of signalling, such as behavior and habitat use, though these ...	2019	30914721
maternal corticosterone increases thermal sensitivity of heart rate in lizard embryos.	while it is well established that maternal stress hormones, such as corticosterone (cort), can induce transgenerational phenotypic plasticity, few studies have addressed the influence of maternal cort on pre-natal life stages. we tested the hypothesis that experimentally increased cort levels of gravid female eastern fence lizards ( sceloporus undulatus) would alter within-egg embryonic phenotype, particularly heart rates. we found that embryos from cort-treated mothers had heart rates that incr ...	2019	30958207
contrasting responses of lizards to divergent ecological stressors across biological levels of organization.	it is frequently hypothesized that animals employ a generalized "stress response," largely mediated by glucocorticoid (gc) hormones, such as corticosterone, to combat challenging environmental conditions. under this hypothesis, diverse stressors are predicted to have concordant effects across biological levels of an organism. we tested the generalized stress response hypothesis in two complementary experiments with juvenile and adult male eastern fence lizards (sceloporus undulatus). in both exp ...	2019	31127305
gestation alters the gut microbiota of an oviparous lizard.	mammalian pregnancy can alter the diversity, membership and structure of the maternal gut microbiota, but it is unclear whether this phenomenon occurs in vertebrates with different reproductive strategies. we conducted 16s rrna bacterial inventories to investigate whether oviparous lizards exhibit shifts in gut microbiota similar to those observed in mammals. using wild-caught eastern fence lizards from alabama, usa, we collected and extracted fecal dna from gravid and non-gravid individuals ove ...	2019	31210275
melanization, α-melanocyte stimulating hormone and steroid hormones in male western fence lizards from nine populations.	hormones can mediate suites of correlated traits. melanocortins regulate melanin synthesis and elements of the melanocortin system can directly, and indirectly, affect a number of other traits, such as stress reactivity. trait correlations within the melanocortin system have been studied mainly in birds and mammals but less so in reptiles. we examined adult male western fence lizards (sceloporus occidentalis) and if melanization was correlated with plasma levels of three hormones, including pept ...	2020	31563645
obtaining plasma to measure baseline corticosterone concentrations in reptiles: how quick is quick enough?	there is growing interest in the use of glucocorticoid (gc) hormones to understand how wild animals respond to environmental challenges. blood is the best medium for obtaining information about recent gc levels; however, obtaining blood requires restraint and can therefore be stressful and affect gc levels. there is a delay in gcs entering blood, and it is assumed that blood obtained within 3 min of first disturbing an animal reflects a baseline level of gcs, based largely on studies of birds an ...	2020	31733208
endocrine stress response of eastern fence lizards in fire-disturbed landscapes.	landscape disturbances can alter habitat structure and resource availability, often inducing physiological responses by organisms to cope with the changing conditions. quantifying the endocrine stress response through measurement of glucocorticoids has become an increasingly common method for determining how organisms physiologically respond to challenges imposed by their environment. we tested the hypothesis that eastern fence lizards cope with fire disturbance effects by modulating their secre ...	2019	31857811
establishment of brown anoles (anolis sagrei) across a southern california county and potential interactions with a native lizard species.	the brown anole, anolis sagrei, is a native species to the caribbean; however, a. sagrei has invaded multiple parts of the usa, including florida, louisiana, hawai'i and more recently california. the biological impacts of a. sagrei invading california are currently unknown. evidence from the invasion in taiwan shows that they spread quickly and when immediate action is not taken eradication stops being a viable option. in orange county, california, five urban sites, each less than 100 ha, were s ...	2020	32296613
plastic sexual ornaments: assessing temperature effects on color metrics in a color-changing reptile.	conspicuous coloration is an important subject in social communication and animal behavior, and it can provide valuable insight into the role of visual signals in social selection. however, animal coloration can be plastic and affected by abiotic factors such as temperature, making its quantification problematic. in such cases, careful consideration is required so that metric choices are consistent across environments and least sensitive to abiotic factors. a detailed assessment of plastic trait ...	2020	32433700
transcriptome sequencing reveals signatures of positive selection in the spot-tailed earless lizard.	the continual loss of threatened biodiversity is occurring at an accelerated pace. high-throughput sequencing technologies are now providing opportunities to address this issue by aiding in the generation of molecular data for many understudied species of high conservation interest. our overall goal of this study was to begin building the genomic resources to continue investigations and conservation of the spot-tailed earless lizard. here we leverage the power of high-throughput sequencing to ge ...	2020	32542006
the lizard gut microbiome changes with temperature and is associated with heat tolerance.	vertebrates harbor trillions of microorganisms in the gut, collectively termed the gut microbiota, which affect a wide range of host functions. recent experiments in lab-reared vertebrates have shown that changes in environmental temperature can induce shifts in the gut microbiota, and in some cases these shifts have been shown to affect host thermal physiology. however, there is a lack of information about the effects of temperature on the gut microbiota of wild-caught vertebrates. moreover, in ...	2020	32591376
downsizing for downtown: limb lengths, toe lengths, and scale counts decrease with urbanization in western fence lizards (sceloporus occidentalis).	urbanization induced habitat loss and alteration causes significant challenges for the survival of many species. identifying how species respond to urbanization can yield insights for the conservation of wildlife, but research on reptiles has been narrowly-focused. we compared morphology among four populations of western fence lizards (sceloporus occidentalis) to determine whether a common native species affected by urbanization exhibits morphological differences consistent with habitat use. we ...	2019	32774080
effects of temperature on plasma corticosterone in a native lizard.	the glucocorticoid stress response is frequently used to indicate vertebrate response to the environment. body temperature may affect glucocorticoid concentrations, particularly in ectotherms. we conducted lab manipulations and field measurements to test the effects of body temperature on plasma corticosterone (predominant glucocorticoid in reptiles) in eastern fence lizards (sceloporus undulatus). first, we acclimated lizards to one of 4 treatments: 22 °c, 29 °c, 33 °c, or 36 °c, and measured c ...	2020	33004871
ecoimmune reallocation in a native lizard in response to the presence of invasive, venomous fire ants in their shared environment.	exposure to stressors over prolonged periods can have fitness-relevant consequences, including suppression of immune function. we tested for effects of presence of an invasive species threat on a broad panel of immune functions of a coexisting lizard. eastern fence lizards (sceloporus undulatus) have been exposed to invasive fire ants (solenopsis invicta) for over 80 years. fire ants sting and envenomate lizards, causing physiological stress, but we do not have a comprehensive understanding of t ...	2020	33038069