Terrestrial Frog Research Articles

Does greater thermal plasticity facilitate range expansion of an invasive terrestrial anuran into higher latitudes?

Temperature has pervasive effects on physiological processes and is critical in setting species distribution limits. Since invading Australia, cane toads have spread rapidly across low latitudes, but slowly into higher latitudes. Low temperature is the likely factor limiting high-latitude advancement. Several previous attempts have been made to predict future cane toad distributions in Australia, but understanding the potential contribution of phenotypic plasticity and adaptation to future range expansion remains challenging. Previous research demonstrates the considerable thermal metabolic plasticity of the cane toad, but suggests limited thermal plasticity of locomotor performance. Additionally, the oxygen-limited thermal tolerance hypothesis predicts that reduced aerobic scope sets thermal limits for ectotherm performance. Metabolic plasticity, locomotor performance and aerobic scope are therefore predicted targets of natural selection as cane toads invade colder regions. We measured these traits at temperatures of 10, 15, 22.5 and 30°C in low- and high-latitude toads acclimated to 15 and 30°C, to test the hypothesis that cane toads have adapted to cooler temperatures. High-latitude toads show increased metabolic plasticity and higher resting metabolic rates at lower temperatures. Burst locomotor performance was worse for high-latitude toads. Other traits showed no regional differences. We conclude that increased metabolic plasticity may facilitate invasion into higher latitudes by maintaining critical physiological functions at lower temperatures.

Toe Clipping Does Not Affect the Survival of Leopard Frogs (Rana pipiens)

Toe clipping is commonly used to identify individual frogs in mark–recapture studies. However, Institutional Animal Care and Use Committees (IACUCs) often have reservations about approving studies that include toe clipping as a way to mark animals. Previous studies indicate that recapture rates of terrestrial frogs and toads decrease with increasing numbers of toes clipped. It is not known whether these decreases are due to decreased survival rates, increased avoidance of recapture, or some other reason. The goal of this paper is to provide IACUCs with a quantitative analysis of the effects of toe clipping on survival so that they can make informed, data-based decisions when approving studies using this method, rather than basing decisions on anthropomorphic biases. We conducted a large (n = 100) laboratory experiment to determine the effects of toe clipping on the frog Rana pipiens. We found no evidence that the number of toes clipped affected either the survival rate of Leopard Frogs or the number of ...

Reduction in site fidelity with smaller spatial scale may suggest scale-dependent information use

Animals change the strategy that they use to select breeding sites at the spatial scales of habitat, patch, and microhabitat. In this regard, breeding site fidelity is expected to vary according to environmental predictability, which, in turn, is expected to differ between each spatial scale. However, whether or not animals change their degree of site fidelity at different spatial scales remains unclear. We captured and released males of the terrestrial frog Pseudophryne bibronii into alternative patches within a breeding habitat and determined the extent to which site fidelity influenced individual nest-site choice. We found that males tended to return to their original patch rather than resettle in an alternative patch. However, males were unlikely to return to their original nest sites within the patch. We suggest that site fidelity in this species may be scale dependent because information from previous breeding seasons can predict the quality of patches, but not nest sites. This behavioral variation is consistent with a hypothetical relationship between spatial scale and environmental predictability, which may have important implications for decision-making processes that extend over multiple spatial scales.

Tres nuevas especies de ranas terrestres <em>Pristimantis</em> (Anura: Craugastoridae) de lacuenca alta del Río Pastaza, Ecuador

Describimos tres nuevas especies de ranas terrestres Pristimantis de los bosques siempreverde montanos circundantes al Volcán Tungurahua en la cuenca alta del Rio Pastaza, estribaciones orientales de Ecuador. La primera especie se diferencia por la distintiva forma de sus dígitos (alargados, estrechos y con discos solo un poco más anchos que los dedos); la segunda exhibe cresta craneal y presenta tamaño corporal menor a 31 mm; y la tercera es espinosa y exhibe un distintivo patrón de coloración rojo-vino finamente delineado con crema.

Ranas terrestres de los Andes Surorientales de Ecuador II: Una nueva especie de <em>Pristimantis</em> verde espinosa de los bosques montanos del Parque Nacional Sangay (Anura: Craugastoridae)

Describimos una nueva especie de rana verde espinosa del género Pristimantis diagnosticada por presentar tímpano, cresta craneal, tubérculos cónicos grandes en las extremidades posteriores y anteriores y por su coloración ventral crema. Se presenta información acústica sobre los llamados de advertencia y cortejo y comparaciones detalladas de la especie nueva con algunas especies similares de los Andes de Ecuador. La nueva especie forma parte de un particular ecotipo de aproximadamente 12 especies de ranas terrestres de los bosques montanos de Ecuador agrupadas en por lo menos cuatro grupos parafíléticos de Pristimantis. La condición de cresta craneal con bordes frontoparietales elevados, sugiere una relación cercana de la nueva especie con el grupo-de-especies P. devillei.

Conservation and historical biogeography: How did the mountain chicken frog get to the Caribbean?

Leptodactylus fallax, commonly known as the mountain chicken frog, is a large terrestrial frog currently found on two islands in the Caribbean. Habitat destruction, overhunting and disease outbreaks have contributed to declining population numbers. In order to identify appropriate conservation strategies, the historic geographic distribution of this frog must first be determined. Because no archeological evidence exists, this was accomplished by reviewing historical documents and inspecting museum collections. Inaccuracies in location and species names were identified in documents as well as in the mislabeling of museum specimens. Two means for natural immigration (dispersal and vicariance) and the artificial introduction by humans were considered. The authors concluded that the Amerindians transported L. fallax to eight islands throughout the Lesser Antilles as potential food resources as they colonized this area. The implication that 75% of the historical distribution is currently unoccupied by this species is considered in light of future reintroduction projects. Key words: Leptodactylus fallax, Amerindians, dispersal, vicariance.

Goal orientation by geometric and feature cues: spatial learning in the terrestrial toad Rhinella arenarum.

Although of crucial importance in vertebrate evolution, amphibians are rarely considered in studies of comparative cognition. Using water as reward, we studied whether the terrestrial toad, Rhinella arenarum, is also capable of encoding geometric and feature information to navigate to a goal location. Experimental toads, partially dehydrated, were trained in either a white rectangular box (Geometry-only, Experiment 1) or in the same box with a removable colored panel (Geometry-Feature, Experiment 2) covering one wall. Four water containers were used, but only one (Geometry-Feature), or two in geometrically equivalent corners (Geometry-only), had water accessible to the trained animals. After learning to successfully locate the water reward, probe trials were carried out by changing the shape of the arena or the location of the feature cue. Probe tests revealed that, under the experimental conditions used, toads can use both geometry and feature to locate a goal location, but geometry is more potent as a navigational cue. The results generally agree with findings from other vertebrates and support the idea that at the behavioral-level geometric orientation is a conserved feature shared by all vertebrates.

The anuran vocal sac: a tool for multimodal signalling

Although in anurans the predominant mode of intra- and intersexual communication is vocalization, modalities used in addition to or instead of acoustic signals range from seismic and visual to chemical. In some cases, signals of more than one modality are produced through or by the anuran vocal sac. However, its role beyond acoustics has been neglected for some time and nonacoustic cues such as vocal sac movement have traditionally been seen as an epiphenomenon of sound production. The diversity in vocal sac coloration and shape found in different species is striking and recently its visual properties have been given a more important role in signalling. Chemosignals seem to be the dominant communication mode in newts, salamanders and caecilians and certainly play a role in the aquatic life phase of anurans, but airborne chemical signalling has received less attention. There is, however, increasing evidence that at least some terrestrial anuran species integrate acoustic, visual and chemical cues in species recognition and mate choice and a few secondarily mute anuran species seem to fully rely on volatile chemical cues produced in glands on the vocal sac. Within vertebrates, frogs in particular are suitable organisms for investigating multimodal communication by means of experiments, since they are tolerant of disturbance by observers and can be easily manipulated under natural conditions. Thus, the anuran vocal sac might be of great interest not only to herpetologists, but also to behavioural biologists studying communication systems.

Expression of G proteins in the olfactory receptor neurons of the newt Cynops pyrrhogaster: their unique projection into the olfactory bulbs.

We analyzed the expression of G protein α subunits and the axonal projection into the brain in the olfactory system of the semiaquatic newt Cynops pyrrhogaster by immunostaining with antibodies against Gαolf and Gαo , by in situ hybridization using probes for Gαolf , Gαo , and Gαi2 , and by neuronal tracing with DiI and DiA. The main olfactory epithelium (OE) consists of two parts, the ventral OE and dorsal OE. In the ventral OE, the Gαolf - and Gαo -expressing neurons are located in the apical and basal zone of the OE, respectively. This zonal expression was similar to that of the OE in the middle cavity of the fully aquatic toad Xenopus laevis. However, the Gαolf - and Gαo -expressing neurons in the newt ventral OE project their axons toward the main olfactory bulb (MOB) and the accessory olfactory bulb (AOB), respectively, whereas in Xenopus, the axons of both neurons project solely toward the MOB. In the dorsal OE of the newt, as in the principal cavity of Xenopus, the majority of the neurons express Gαolf and extend their axons into the MOB. In the vomeronasal organ (VNO), the neurons mostly express Gαo . These neurons and quite a few Gαolf -expressing neurons project their axons toward the AOB. This feature is similar to that in the terrestrial toad Bufo japonicus and is different from that in Xenopus, in which VNO neurons express solely Gαo , although their axons invariably project toward the AOB. We discuss the findings in the light of diversification and evolution of the vertebrate olfactory system.

Susceptibility to the amphibian chytrid fungus varies with ontogeny in the direct-developing frog, Eleutherodactylus coqui.

Age-related differences in susceptibility to infectious disease are known from a wide variety of plant and animal taxonomic groups. For example, the immature immune systems of young vertebrates, along with limited prior exposure to pathogens and behavioral factors, can place juveniles at greater risk of acquiring and succumbing to a pathogen. We studied the ontogenetic susceptibility of terrestrial direct-developing frogs (Eleutherodactylus coqui) to the fungal pathogen, Batrachochytrium dendrobatidis (Bd), which is responsible for the decline of amphibian species worldwide. By exposing juvenile and adult frogs to the same dose and strain of Bd, we uncovered ontogenetic differences in susceptibility. Froglets exposed to the pathogen had significantly lower survival rates compared with control froglets, while adult frogs largely cleared infection and had survival rates indistinguishable from control frogs, even when exposed to a much higher dose of Bd. The high disease-induced mortality rate of juveniles may explain ongoing population declines in eastern Puerto Rico, where Bd is endemic and juveniles experience higher prevalence and infection intensity compared to adults. Our results have important implications for understanding and modeling the decline, possibly to extinction, of amphibian populations and species.

Pulmonary Compliance and Lung Volume Are Related to Terrestriality in Anuran Amphibians

Dehydration tolerance of anuran amphibians is directly related to their ability to mobilize lymphatic reserves, with more terrestrial species having more effective lymph mobilization dependent on specialized skeletal muscles acting directly on the lymph sacs and via pulmonary ventilation. Consequently, we tested the hypothesis that pulmonary compliance, lung volume, and femoral lymphatic sac volume were related to terrestriality-and, hence, lymph mobilization-for 18 species of aquatic, semiaquatic, or terrestrial anuran amphibians. Lung compliance and volume were significantly related to body mass, but there was no significant phylogenetic pattern. There were significant habitat-related patterns for mass-corrected and phylogenetically corrected residuals for these pulmonary variables. Femoral lymph volume was significantly related to body mass, with no significant phylogenetic pattern, and there was only a weak correlation for habitat with mass-corrected and phylogenetically corrected residuals. These results suggest that pulmonary volume and compliance are strongly related to terrestriality in anuran amphibians and are under significant selection pressure to enhance lymph mobilization, but lymph sac volume does not appear to have a major role in adaptation to terrestriality.

The biogeographical boundaries of northern Australia: evidence from ecological niche models and a multi‐locus phylogeny of Uperoleia toadlets (Anura: Myobatrachidae)

AbstractAimOur aim was to test hypothesized biogeographical barriers using small‐bodied terrestrial Uperoleia frogs, to identify Pleistocene refugia and to define biogeographical units.LocationThe Australian Monsoonal Tropics, defined as the open woodlands and savanna north of the inland arid and eastern winter‐rainfall zones.MethodsA multi‐locus molecular phylogeny of the Uperoleia lithomoda, U. trachyderma and U. minima species complex, with supporting morphological and acoustic data, was generated to test species boundaries and clarify distributions. Ecological niche modelling with current climate and Last Glacial Maximum climate data was used to identify biogeographical units, barriers to dispersal, and regions of stability that may have served as Pleistocene refugia.ResultsOur combined data supported five clades that comprise four allopatric species. Ecological niche models of the resolved species suggest that the Kimberley Plateau represents a distinct bioregion, the Top End extends from the edge of the Kimberley Plateau to the Carpentarian Gap, and the transition from sandstone escarpments to flat, sandy soils represents a major barrier to dispersal between the Top End and the Northern Deserts. The Northern Deserts were found to comprise two distinct subregions. Population‐ and species‐level divergences were evident in a north–south line in the Northern Territory, representing a newly identified biogeographical break. Putative Pleistocene refugia were predicted in the north‐west Kimberley Plateau, the western half of the Top End, the Selwyn Range and western Cape York.Main conclusionsBy combining detailed genetic, morphological and acoustic data with newly developed statistical methods, we have delineated species boundaries, identified cryptic species and provided a region‐wide assessment of the biogeography of northern Australia. We have identified previously unrecognized biogeographical barriers, better defined biogeographical regions, and proposed new hypotheses about the effects of Pleistocene climate cycles on the present‐day diversity of northern Australia. Our work provides a solid foundation for the investigation of biogeographical patterns in other taxa.

Spatial and temporal distribution of call activities of two Gephyromantis species (Mantellidae) along forest–farmbush habitat in Ranomafana, Madagascar

Understanding how changes in land use affect the distribution, abundance and behaviour of organisms is an increasingly important question in ecology. We investigated the distribution and the differential calling behaviour of two diurnal terrestrial frogs, Gephyromantis decaryi (Near Threatened) and Gephyromantis enki (Data Deficient) (Mantellidae), across a disturbed forest and farmbush area at the border of Ranomafana National Park (Madagascar), in a selectively logged forest. We used five transects of 300 m that encompass habitats of equal length. We found that G. enki is rather a forest species while G. decaryi occurs more abundantly in farmbush. While detection was relatively constant inside forest, it depended on time of sampling in secondary vegetation: more G. enki calls were recorded in the morning while more G. decaryi calls were recorded in the afternoon outside forest. These findings bring new information to the habitat requirement and the calling behaviour of the two species. Results suggest the need for different study design recognising that the two species may have different calling behaviour. It also implies the importance of secondary vegetation around protected areas for threatened species.

Effects of fuel reduction treatments on movement and habitat use of American toads in a southern Appalachian hardwood forest

Prescribed fire is a commonly used management technique for maintaining fire-adapted ecosystems, yet empirical data regarding its effects on amphibians are limited and contradictory. Anurans (frogs and toads) may be the amphibian taxa most negatively affected by fire due to their extensive use of the forest floor; however, short-term abundance studies suggest that terrestrial toads (e.g., Anaxyrus [Bufo] americanus) may benefit from fire-based ecosystem management. We used radio-telemetry to examine the effects of prescribed fire on movements, home range characteristics, mortality, and habitat selection of A. americanus in a southern Appalachian upland hardwood forest. We tracked 26 adult A. americanus between 27 January and 30 May 2012. Toads exhibited high non-breeding site fidelity and traveled 993.5m (±265.9m) mean (±SD) route distance between the breeding ponds and the last recorded location within their summer habitat. We found no evidence of direct mortality of A. americanus from a prescribed fire that occurred on 13 February 2012. Forward stepwise discriminant analysis (DA) revealed that the availability of coarse woody debris (CWD) was a significant discriminator between microhabitats used (i.e., location plots) and random plots (Wilk’s lambda=0.9852, F1, 661=9.9414, p=0.002). Forward stepwise DA revealed that burned and unburned location plots were significantly different (Wilk’s lambda=0.2713, F1, 221=593.6863, p<0.001) based on the percent of plot ground cover comprised of charred material (%char). When %char was excluded from the analysis due to its short-term nature, the percent of plot ground cover comprised of deciduous leaves, a cover item commonly used by toads in unburned locations, was the variable with the most discriminatory power (Wilk’s lambda=0.4243, F1, 221=299.8741, p<0.001). Toads maintained greater distances from CWD in the unburned (mean±SD=119.50±109.64cm) than in the burned locations (mean±SD=86.05±104.81cm; χ12=9.7055, p=0.002). Our results indicate that prescribed fire as implemented in this study did not cause direct mortality, nor did it appear to inhibit migratory movements of adult A. americanus. However, fire reduced the diversity and availability of refugia, especially deciduous leaves, though the availability of alternative cover objects (e.g., CWD) in burned treatments allowed toads to inhabit those areas, suggesting the importance of noncombustible or semi-permanent refugia for A. americanus in fire-managed forests.

Expression Profiling of Intestinal Tissues Implicates Tissue-Specific Genes and Pathways Essential for Thyroid Hormone-Induced Adult Stem Cell Development

The study of the epithelium during development in the vertebrate intestine touches upon many contemporary aspects of biology: to name a few, the formation of the adult stem cells (ASCs) essential for the life-long self-renewal and the balance of stem cell activity for renewal vs cancer development. Although extensive analyses have been carried out on the property and functions of the adult intestinal stem cells in mammals, little is known about their formation during development due to the difficulty of manipulating late-stage, uterus-enclosed embryos. The gastrointestinal tract of the amphibian Xenopus laevis is an excellent model system for the study of mammalian ASC formation, cell proliferation, and differentiation. During T3-dependent amphibian metamorphosis, the digestive tract is extensively remodeled from the larval to the adult form for the adaptation of the amphibian from its aquatic herbivorous lifestyle to that of a terrestrial carnivorous frog. This involves de novo formation of ASCs that requires T3 signaling in both the larval epithelium and nonepithelial tissues. To understand the underlying molecular mechanisms, we have characterized the gene expression profiles in the epithelium and nonepithelial tissues by using cDNA microarrays. Our results revealed that T3 induces distinct tissue-specific gene regulation programs associated with the remodeling of the intestine, particularly the formation of the ASCs, and further suggested the existence of potentially many novel stem cell-associated genes, at least in the intestine during development.

Separating the contributions of vascular anatomy and blood viscosity to peripheral resistance and the physiological implications of interspecific resistance variation in amphibians

Amphibian pulmonary and systemic vascular circuits are arranged in parallel, with potentially important consequences for resistance (R) to blood flow. The contribution of the parallel anatomic arrangement to total vascular R (R T), independent of blood viscosity, is unknown. We measured pulmonary (R P) and systemic (R S) vascular R with an in situ Ringer's solution perfusion technique using anesthetized anuran and urodele species to determine: (1) relative contributions of vascular anatomy and blood viscosity to R T; (2) distensibility index (%ΔflowkPa(-1)) of the pulmonary and systemic vascular circuits; and (3) interspecific correlates of variation in these parameters with red blood cell size, cardiac power output, and aerobic capacities. R P was lower than R S in anurans, while R P of the urodeles was greater than R S and significantly greater than anuran R P. Anuran R T was lowest and did not vary interspecifically, whereas urodele R T was significantly greater than anuran, and varied interspecifically. Pulmonary and systemic circuit distensibility differences may explain cardiac shunt patterns in toads with changes in cardiac output from rest to activity. When blood viscosity was taken into account, vascular resistance accounted for about 25% of R T while blood viscosity accounted for the remaining 75%. Owing to lower R T, terrestrial anuran species required lower cardiac power outputs when moving fluid through their vasculature compared to aquatic species. These results indicate that physical characteristics of the vasculature can account for interspecific differences in cardiovascular physiology and suggest a co-evolution of cardiac and vascular anatomy among amphibians.

Road use by the Iriomote Cat (Prionailurus bengalensis iriomotensis) on Iriomote-Jima Island in Relation to its Herpetile Prey

The Iriomote cat is an endangered subspecies (CR on the Japanese Red List) found only on Iriomote-jima Island in the Ryukyu Archipelago, Japan. One of the main factors threatening the Iriomote cat is the main paved road that contributes to traffic mortality of this wildcat and also alters its preferred lowland habitats with abundant prey. One of the reasons why the Iriomote cat appears on the road may be due to the presence of prey; therefore, we investigated road use by this wildcat in relation to its prey. In 2009, scat surveys were conducted to assess road use by the Iriomote cat, and prey surveys were undertaken in the morning and at night, mainly targeting terrestrial frogs and reptiles. To analyse the importance of factors related to road use by the Iriomote cat, the influences of prey density along road types, habitat types, presence or absence of road construction activities, and survey regions on number of scats were examined using nested generalised linear models (GLM), assuming Poisson error and a log-link function. Diurnal lizard density was strongly correlated with scat along roads, and the density of road-killed Fejervarya sakishimensis was positively correlated with scat presence along roads.

Repeatability of baseline corticosterone and short-term corticosterone stress responses, and their correlation with testosterone and body condition in a terrestrial breeding anuran (Platymantis vitiana)

Repeatability of physiological response variables, such as the stress hormone corticosterone, across numerous sampling occasions is an important assumption for their use as predictors of behaviour, reproduction and fitness in animals. Very few studies have actually tested this assumption in free-living animals under uncontrolled natural conditions. Non-invasive urine sampling and standard capture handling protocol have enabled the rapid quantification of baseline corticosterone and short-term corticosterone stress responses in anuran amphibians. In this study, established non-invasive methods were used to monitor physiological stress and urinary testosterone levels in male individuals of the terrestrial breeding Fijian ground frog (Platymantis vitiana). Adult male frogs (n=20) were sampled at nighttime on three repeated occasions at intervals of 14days during their annual breeding season on Viwa Island, Fiji. All frogs expressed urinary corticosterone metabolite responses to the capture and handling stressor, with some frogs showing consistently higher urinary corticosterone responses than others. Ranks of corticosterone values at 0, 4 and 8h, and the corrected rank were highly significant (r=0.75–0.99) between the three repeated sampling occasions. Statistical repeatabilities were high for baseline corticosterone (r=0.973) and for corticosterone values at 2h (r=0.862), 4h (r=0.861), 6h (r=0.820) and 8h (r=0.926), and also for the total (inclusive of baseline corticosterone values) and the corrected integrated responses (index of the acute response) [r=0.867 and r=0.870]. Urinary testosterone levels also showed high statistical repeatability (r=0.78). Furthermore, variation in baseline and short-term corticosterone stress responses was greater between individuals than within individuals. Baseline urinary corticosterone was significantly negatively correlated with the corrected integrated corticosterone response (r=−0.3, p<0.001) but non-significantly with body-condition (r=−0.04) and baseline urinary testosterone (r=−0.07). In contrast, the corrected integrated corticosterone response was positively correlated (non-significantly) with baseline urinary testosterone (r=+0.04) and body-condition (r=+0.08). Urinary testosterone levels and body-condition were significantly negatively correlated (r=−0.23, p<0.001). The results suggest that male frogs with higher levels of testosterone could have depleted energy reserve during the breeding period. The acute corticosterone responses help in replenishing energy that is needed for breeding and survival. The results also provide some support to the ‘cort-fitness’ hypothesis as highlighted by the negative correlation between baseline corticosterone and body-condition. It is most likely that the acute corticosterone response is adaptive and linked positively with reproductive fitness and survival in male anurans.

Lability in Host Defenses: Terrestrial Frogs Die from Chytridiomycosis under Enzootic Conditions

Chytridiomycosis-induced mortalities often occur upon the emergence of Batrachochytrium dendrobatidis (Bd) in naïve amphibian populations. We report chytridiomycosis-associated mortalities in the wild of the coqui (Eleutherodactylus coqui), a declining direct-developing frog with persistent Bd infections. These findings provide additional evidence of decreased host defenses during cool-dry seasons in Puerto Rico.

Disease in a dynamic landscape: Host behavior and wildfire reduce amphibian chytrid infection

Disturbances are often expected to magnify effects of disease, but these effects may depend on the ecology, behavior, and life history of both hosts and pathogens. In many ecosystems, wildfire is the dominant natural disturbance and thus could directly or indirectly affect dynamics of many diseases. To determine how probability of infection by the aquatic fungus Batrachochytrium dendrobatidis (Bd) varies relative to habitat use by individuals, wildfire, and host characteristics, we sampled 404 boreal toads (Anaxyrus boreas boreas) across Glacier National Park, Montana (USA). Bd causes chytridiomycosis, an emerging infectious disease linked with widespread amphibian declines, including the boreal toad. Probability of infection was similar for females and the combined group of males and juveniles. However, only 9% of terrestrial toads were infected compared to >30% of aquatic toads, and toads captured in recently burned areas were half as likely to be infected as toads in unburned areas. We suspect these large differences in infection reflect habitat choices by individuals that affect pathogen exposure and persistence, especially in burned forests where warm, arid conditions could limit Bd growth. Our results show that natural disturbances such as wildfire and the resulting diverse habitats can influence infection across large landscapes, potentially maintaining local refuges and host behaviors that facilitate evolution of disease resistance.