Robin Warne

• PhD
• Research Director at University of Illinois Urbana-Champaign

The comprehensive study of organisms is often hindered by the difficulty of consistently capturing, detecting, and tracking all life stages and age classes. This challenge is particularly pronounced for aquatic amphibians such as Siren intermedia (lesser siren), which can aestivate underground in dry burrows during extended droughts. In addition, o...

The complete study of semiaquatic ectothermic animals is often limited by the researchers' ability to detect them in their nonbreeding habitat. This is particularly challenging for semiaquatic amphibians whose detectability is greatest during the breeding season as they engage in visual and or auditory reproductive behaviors within specific aquatic...

Background Objectives PIT Tag Retention Results Figure 1. A large, fishless, and semi-permanent wetland located within a remnant Tupelo-Cypress Swamp complex in southern Illinois. Retained Tag Movement Results Figures 2. T-test results among siren with retained and dropped PIT tags. Figure 3. Significant linear regressions of redetections and total...

The gut microbiota is known to influence and have regulatory effects in diverse physiological functions of host animals, but only recently has the relationship between host thermal biology and gut microbiota been explored. Here, we examined how early-life manipulations of the gut microbiota in larval amphibians influenced their critical thermal max...

The gut microbiota is known to influence and have regulatory effects in diverse physiological functions of host animals, but only recently has the relationship between host thermal biology and gut microbiota been explored. Here, we examined how early-life manipulations of the gut microbiota in larval amphibians influenced their critical thermal max...

Greater knowledge of how host–microbiome interactions vary with anthropogenic environmental change and influence pathogenic infections is needed to better understand stress-mediated disease outcomes. We investigated how increasing salinization in freshwaters (e.g. due to road de-icing salt runoff) and associated increases in growth of nutritional a...

Extreme heat events and emerging infectious diseases negatively impact wildlife populations, but the interacting effects of infection and host heat tolerance remain understudied. The few studies covering this subject have demonstrated that pathogens lower the heat tolerance of their hosts, which places infected hosts at a greater risk experiencing...

Plasticity in heat tolerance provides ectotherms the ability to reduce overheating risk during thermal extremes. However, the tolerance-plasticity trade-off hypothesis states that individuals acclimated to warmer environments have a reduced plastic response, including hardening, limiting their ability to further adjust their thermal tolerance. Heat...

The thermal tolerance–plasticity trade-off hypothesis states that acclimation to warmer environments increases basal thermal tolerance in ectotherms but reduces plasticity in coping with acute thermal stress characterized as heat hardening. We examined the potential trade-off between basal heat tolerance and hardening plasticity, measured as critic...

During the ongoing biodiversity crisis, captive conservation and breeding programs offer a refuge for species to persist and provide source populations for reintroduction efforts. Unfortunately, captive animals are at a higher disease risk and reintroduction efforts remain largely unsuccessful. One potential factor in these outcomes is the host mic...

Invasive herpetofauna are a significant threat to native wildlife and when colonizing higher latitudes, they must cope with greater seasonality that likely exposes them to temperatures below their preferred temperature range and reduced physiological performance. Therefore, it is important to understand the ecology of invasive herpetofauna along th...

Disease results from interactions among the host, pathogen, and environment. Inoculation trials can quantify interactions among these players and explain aspects of disease ecology to inform management in variable and dynamic natural environments. White-nose Syndrome, a disease caused by the fungal pathogen, Pseudogymnoascus destructans ( Pd ), has...

The regulatory pathways by which gut microbiota potentially shape host life histories remain largely untested, however, a constellation of research suggests that gut bacteria likely have significant effects on their hosts via metabolites. In this article we review known and hypothesized pathways by which gut microbiota influence host life histories...

Environmental and biotic pressures impose homeostatic costs on all organisms. The energetic costs of maintaining high body temperatures (Tb) render endotherms sensitive to pressures that increase foraging costs. In response, some mammals become more heterothermic to conserve energy. We measured Tb in banner-tailed kangaroo rats (Dipodomys spectabil...

Background The gut microbiota is an emerging frontier in wildlife research and its importance to vertebrate health and physiology is becoming ever more apparent. Reptiles, in particular snakes, have not received the same attention given to other vertebrates and the composition of their wild gut microbiome remains understudied. The primary goal of t...

Thermal performance of immunity has been relatively understudied in ectotherms, especially in the context of invasive species or in relation to other fitness-related traits and thermoregulatory patterns in the field. For reptiles, thermal biology is a primary factor determining physiological performance and population viability, and suboptimal ther...

Rationale Nitrogen stable isotope ratio (δ¹⁵N) processes are not well described in reptiles, which limits reliable inference of trophic and nutrient dynamics. In this study we detailed δ¹⁵N turnover and discrimination (Δ¹⁵N) in diverse tissues of two lizard species, and compared these results with previously published carbon data (δ¹³C) to inform e...

Immune function is a complex collection of responses that often trade-off with one another and with other life history traits, because of the high costs of mounting and maintaining immune responses. Animals, even those from the same populations, may emphasize different aspects of immune function depending on their habitat and phenotype. For example...

Colonization of gut microbiomes during early life can shape metabolism and immunity of adult animals. However, most data are derived from antibiotic‐treated or germ‐free laboratory mammals. Furthermore, few studies have explored how microbial colonization during critical windows influences a suite of other fitness‐related traits in wild animals. Th...

The effects of animal homeostatic function on ecological interactions have not been well-integrated into community ecology. Animals mediate environmental change and stressors through homeostatic shifts in physiology and behavior, which likely shape ecological interactions and plant communities. Animal responses to stressors can alter their habitat...

1. Ubiquitous environmental stressors are often thought to alter animal susceptibility to pathogens and contribute to disease emergence. However, duration of exposure to a stressor is likely critical, because while chronic stress is often immunosuppressive, acute stress can temporarily enhance immune function. Furthermore, host susceptibility to st...

Subsidies across aquatic–terrestrial boundaries can alter consumer distributions and physiology. The importance of subsidies is a function of export quantity and of their physiological significance and relative scarcity in the recipient system. Aquatically derived long-chain polyunsaturated fatty acids (LC-PUFAs) are physiologically essential, rela...

Exploration of the importance of developmental windows for microbial colonization in diverse animal taxa, and tests of how these shape both animal microbiomes as well as host phenotypes promise to shed needed light on host-microbe interactions. The aims of this study were to explore how gut microbiota diversity of larval amphibians varies among spe...

Variation in environmental conditions during larval life stages can shape development during critical windows and have lasting effects on the adult organism. Changes in larval developmental rates in response to environmental conditions, for example, can trade-off with growth to determine body size and condition at metamorphosis, which can affect ad...

Immune function is often involved in physiological trade-offs because of the energetic costs of maintaining constitutive immunity and mounting responses to infection. However, immune function is a collection of discrete immunity factors and animals should allocate towards factors that combat the parasite threat with the highest fitness cost. For ex...

Marsupial frogs have a unique reproductive mode in which females carry eggs enclosed in a sealed dorsal brood pouch. While most anurans are considered to be oviparous with lecithotrophic eggs, the extensively vascularized membrane of the brood pouch in marsupial frogs suggests potential opportunities for nutrient transfer. We tested for matrotrophy...

Behavioural phenotypes may provide a means for identifying individuals that disproportionally contribute to disease spread and epizootic outbreaks. For example, bolder phenotypes may experience greater exposure and susceptibility to pathogenic infection because of distinct interactions with conspecifics and their environment. We tested the value of...

Exposure to environmental stressors alters animal phenotypes as well as nutrient metabolism, assimilation, and excretion. While stress-induced shifts in nutrient processes are known to alter organismal carbon (C) and nitrogen (N) stoichiometry, there has been little exploration of how environmental factors influence phosphorous (P). A better unders...

While global amphibian declines are associated with the spread of Batrachochytrium dendrobatidis (Bd), undetected concurrent co-infection by other pathogens may be little recognized threats to amphibians. Emerging viruses in the genus Ranavirus (Rv) also cause die-offs of amphibians and other ectotherms, but the extent of their distribution globall...

Sampling locations for wild caught frogs in the Kosnipata valley, near Manu National Park, Cusco, Peru. (KML)

Table S1. Nitrogen (δ15N‰ Air) and carbon (δ13C‰ VPDB) stable isotope values for insects and the tissues of G. excubitor frogs. Control frogs (n = 3) were fed insects with background isotope values, while labelled frogs (n = 5) were fed insects labelled with δ15N-leucine and δ13C-palmitic acid.; Supplemental Figure. Association of developmental sta...

Table S1. Nitrogen (δ15N‰ Air) and carbon (δ13C‰ VPDB) stable isotope values for insects and the tissues of G. excubitor frogs. Control frogs (n = 3) were fed insects with background isotope values, while labelled frogs (n = 5) were fed insects labelled with δ15N-leucine and δ13C-palmitic acid.; Supplemental Figure. Association of developmental sta...

The extent to which interactions between environmental stressors and phenotypic variation during larval life stages impose carry-over effects on adult phenotypes in wildlife are not clear. Using semi-natural mesocosms, we examined how chronically low food availability and size-specific phenotypes in larval amphibians interact and carry over to infl...

Diverse biomarkers including stable isotope, hormonal, and ecoimmunological assays are powerful tools to assess animal condition. However, an integrative approach is necessary to provide the context essential to understanding how biomarkers reveal animal health in varied ecological conditions. A barrier to such integration is a general lack of awar...

During the past decade, we have gained new insights into the profound effects that essential micronutrients and macronutrients have on biological processes ranging from cellular function, to whole-organism performance, to dynamics in ecological communities, as well as to the structure and function of ecosystems. For example, disparities between int...

Size variance among similarly aged individuals within populations is a pattern common to many organisms that is a result of interactions between intrinsic and extrinsic traits of individuals. While genetic and maternal effects, as well as physiological and behavioral traits have been shown to contribute to size variation in animal populations, teas...

Exposure to adverse environmental conditions during early development can shape life-history traits and have lasting effects on physiological function in later life. Although findings within the biomedical literature have shown that environmentally induced elevations in glucocorticoids (GCs) during critical developmental windows can cause persisten...

The use of stored resources to fuel reproduction, growth, and self-maintenance in the face of uncertain nutrient availability is a tactic common to many organisms. The degree to which organisms rely on stored resources in response to varied nutrients, however, is not well quantified. In this study, we used stable isotope methods to quantify the use...

Background: In organisms with indeterminate growth, the average size (W̄ in mass, L̄ in length) of an adult is a problem in life-history evolution because it involves the size at first reproduction, W α (or Lα), as well as the additional growth thereafter, which reflects the balance between allocation of personal production to reproduction versus g...

1. Animal populations exhibit considerable variation in their susceptibility to infection by emerging diseases, yet it is poorly understood how environmental and intrinsic factors contribute to these patterns. Considering that intrinsic factors (e.g. life history stage, nutritional state) can impact immune function, knowledge of the physiological m...

Pathogens may induce different immune responses in hosts contingent on pathogen characteristics, host characteristics, or interactions between the two. We investigated whether the broadly effective acute-phase response (APR), a whole body immune response that occurs in response to constitutive immune receptor activation and includes fever, secretio...

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...

In many ecosystems, seasonal shifts in temperature and precipitation induce pulses of primary productivity that vary in phenology, abundance, and nutritional quality. Variation in these resource pulses could strongly influence community composition and ecosystem function, because these pervasive bottom-up forces play a primary role in determining t...

Fundamental to life-history theory is the assumed inverse proportionality between the number of offspring and the resource allocation per offspring. Lizards have been model organisms for empirical tests of this theory for decades; however, the expected negative relationship between clutch size and offspring size is often not detected. Here we use t...

In a 1966 American Naturalist article, G. C. Williams initiated the study of reproductive effort (RE) with the prediction that longer-lived organisms ought to expend less in reproduction per unit of time. We can multiply RE, often measured in fractions of adult body mass committed to reproduction per unit time, by the average adult life span to get...