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The interpretation of morphometric data is relevant to understanding biological phenomena. Currently, little is known about the effect of body position on morphometric measurements in crocodylians as well as the extent to which these data are interchangeable. We investigated the effect of body position on snout-vent-length (SVL) and total-length (TL) measured ventrally (belly up) and dorsally (belly down) on 725 Crocodylus acutus (mean TL ventral and dorsal 68.49 cm and 69.82 cm, range = 33.1-185.4 cm and 33.8-185.4 cm) across South Florida, United States. We found evidence that body posture significantly influences SVL and TL measurements. However, regardless of body position, the variation found in SVL was less than 1 mm, and for TL was on average only 3 mm. We concluded that even though there is a difference when measuring American crocodiles belly up and belly down, there is a minimal effect on the outcome (less than half centimeter), which falls within the normal measurement instrument error (i.e., measurement tape) even more so under field conditions. If researchers concur that this is an acceptable error, then SVL and TL measurements taken belly up or belly down can be used interchangeably. [ABSTRACT FROM AUTHOR]

Nile Monitors (Varanus niloticus) are large (up to 2.4 m in length), semiaquatic, carnivorous lizards native to Sub-Saharan Africa. Nile Monitors are reported from southeastern Florida near the Homestead Air Reserve Base in Miami-Dade County, around Southwest Ranches in Broward County, and from a reproducing population along the C-51 canal in Palm Beach County. This study characterizes the diet of Nile Monitors removed from Palm Beach and Broward counties. In 2012, Florida Fish and Wildlife Conservation Commission staff and University of Florida researchers began conducting monthly boat surveys along the C-51 canal and driving and walking surveys in Southwest Ranches. We used Nile Monitors removed with firearms or live traps from southeastern Florida from 2012 to 2016. We extracted gastrointestinal (GI) tracts and collected gut contents when present. We rinsed, sorted, dried, examined, and identified gut contents to the lowest taxonomic level possible. We examined 68 GI tracts (30 males, 37 females, 1 of undetermined sex) and identified 1,484 prey items from 65 individuals. We categorized prey items as gastropod, diplopod, malacostracan, arachnid, insect, fish, amphibian, reptile, reptile egg, bird, and mammal. Adult Nile Monitors exhibited the highest dietary diversity and evenness among size classes, and there was no observable difference in diet between males and females. Our observations confirm Nile Monitors are active foragers, and the combination of broad diet and active foraging makes it unlikely that food availability will limit distribution of these invasive lizards in Florida. [ABSTRACT FROM AUTHOR]

Detection has been a long-standing challenge to monitoring populations of cryptic herpetofauna, which often have detection probabilities that are closer to zero than to one. Burmese Pythons (Python bivittatus [=Python molurus bivittatus]), a recent invader in the Greater Everglades Ecosystem of Florida, are cryptic snakes that have long periods of inactivity. In addition, management actions such as removal of every python encountered create challenges for estimating population size and quantifying effects of management using traditional statistical approaches. We used Bayesian analysis of data collected from 59 visual surveys (144 person-surveys) covering a total distance of 485.6 km (1,185.1 person-km) and radiotelemetry to estimate detection probability for Burmese Pythons. These estimates can improve interpretation of encounter and removal data. We found that detection probability ranged from 0.0001 to 0.0146 depending on whether effort units accounted for total human effort across multiple surveyors and statistical method used. On the basis of our surveys, detection probabilities for Burmese Pythons are therefore likely <0.05, but factors such as the number of searchers or time of day may improve detection probability. Traditional capture–recapture or visual surveys are, however, unlikely to yield accurate information on Burmese Python population size or trends across time without cost-prohibitive effort. Consequently, novel methods development to monitor or measure Burmese Python populations, including techniques better equipped to handle very low detection, are critically needed for informative and reliable inferences about population size or the management effects of python removal. [ABSTRACT FROM AUTHOR]

Highlights • Revealed an inverse correlation between relative density of crocodiles and salinity. • Everglades restoration will increase relative density. • Improved our understanding of how crocodiles will respond to Everglades restoration. Abstract The status of the American crocodile (Crocodylus acutus) has long been a matter of concern in Everglades National Park (ENP) due to its classification as a federal and state listed species, its recognition as a flagship species, and its function as an ecosystem indicator. Survival and recovery of American crocodiles has been linked with regional hydrological conditions, especially freshwater flow to estuaries, which affect water levels and salinities. We hypothesize that efforts to restore natural function to Everglades ecosystems by improving water delivery into estuaries within ENP will change salinities and water levels which in turn will affect relative density of crocodiles. Monitoring ecological responses of indicator species, such as crocodiles, with respect to hydrologic change is necessary to evaluate ecosystem responses to restoration projects. Our objectives were to monitor trends in crocodile relative density within ENP and to determine influences of salinity on relative density of crocodiles. We examined count data from 12 years of crocodile spotlight surveys in ENP (2004–2015) and used a hierarchical model of relative density that estimated relative density with probability of detection. The mean predicted value for relative density (λ) across all surveys was 2.9 individuals/km (95% CI: 2.0–4.2); relative density was estimated to decrease with increases in salinity. Routes in ENP's Flamingo/Cape Sable area had greater crocodile relative density than routes in the West Lake/Cuthbert Lake area and Northeast Florida Bay areas. These results are consistent with the hypothesis that restored flow and lower salinities will result in an increase in crocodile population size and provide support for the ecosystem management recommendations for crocodiles, which currently are to restore more natural patterns of freshwater flow to Florida Bay. Thus, monitoring relative density of American crocodiles will continue to be an effective indicator of ecological response to ecosystem restoration. [ABSTRACT FROM AUTHOR]

The 2013 Python Challenge® provided an opportunity to learn more about the ecology and management of Python molorus bivittatus (Burmese Python). Goals of the 2013 Python Challenge were to raise awareness about Burmese Pythons, remove pythons, increase public participation and agency cooperation in removal and reporting of pythons, increase knowledge of python ecology, and examine effectiveness of incentives to increase public participation in invasive wildlife management. Over 1500 participants registered for the competition. Sixty-eight Burmese Pythons were removed during the Challenge. Thirteen females (19%), 54 males (79%), and 1 young-of-the-year (1%) python of undetermined sex were captured. More pythons-73 (68 from the Challenge and 5 incidental)-were removed during the 2013 Python Challenge period than during similar time periods during 2008-2012. We found no evidence of unintended consequences such as removal of native species. We identified 13 prey species: 6 mammals (46%), 6 birds (46%), and 1 alligator (8%). The potential of recreational-harvest incentive programs to impact python populations is uncertain. Incentive programs are potential tools in invasive-species management programs, but they should be managed diligently and evaluated for effectiveness. [ABSTRACT FROM AUTHOR]

Burmese Pythons ( Python bivitattus) are large generalist predators that have established an expanding breeding population in Florida. As a first step in understanding current distributions, and therefore spread potential, we assessed diurnal habitat selection by Burmese Pythons in the southern Everglades using radiotelemetry. Sixteen individual pythons were radio-tracked between September 2006 and December 2009. Habitat variables included land cover, habitat edges, surface water depth, and change in water depth. Python locations were compared to available habitat, both within each snake's home range and across the entire study area, by calculating selection ratio intervals and developing resource selection functions. Habitat selection by Burmese Pythons in south Florida was nonrandom with clear selection of broad-leafed and coniferous forest and avoidance of open water and other habitats with deep water. We concluded that Burmese Pythons selected habitats with a substantial canopy overstory that was without deep flooding, with no strong selection for freshwater emergent macrophyte marsh habitats that dominate (∼ 43%) the study area. We will use these new quantitative insights into python habitat selection to model the potential for this invasive species to expand to new areas within Florida. [ABSTRACT FROM AUTHOR]

Here we present the remarkable movements of an individual Crocodylus acutus (American Crocodile) over a 14-year period. The crocodile was originally marked in Homestead, FL as a young-of-the-year in 1999, and was later recaptured multiple times more than 388 km away along the southwest coast of Florida. After several relocations and numerous sightings, this individual who has become known as Yellow Number 1 was found back within the same canal system in which it was first captured. [ABSTRACT FROM AUTHOR]

The Chiquibul/Maya Mountain Massif (CM3) is an approximately 1.25 million-acre area in southwestern Belize and is among the most intact tropical forests north of the Amazon. The CM3 has a variety of habitats that contribute to its valuable environmental services and high aesthetic value, but despite its protected area status, the CM3 is under increasing pressure from extraction of natural and cultural resources as a result of transboundary incursions on the western border and increased land-use changes from industrial activities that include agriculture, hydropower development, logging, and mining. Conceptual ecological models (CEM) are effective planning tools for organizing existing information about natural systems for determining gaps in knowledge and research priorities, and for developing objectives and measures of success for management and monitoring programs. The CEM of the CM3 describe ecological relationships among major stressors and attributes of the system and presents performance measures to quantify potential change to attributes. Attributes were derived from defining characteristics of the massif and chosen as valuable ecological and cultural components of the massif. Ecological linkages between stressors and attributes highlight priorities for conservation, management, and research that will ensure continued protection of the CM3. [ABSTRACT FROM PUBLISHER]

Abstract: Use of indicator species as a measure of ecosystem conditions is an established science application in environmental management. Because of its role in shaping wetland systems, the American alligator (Alligator mississippiensis) is one of the ecological indicators for wetland restoration in south Florida, USA. We conducted landscape-level aerial surveys of alligator holes in two different habitats in a wetland where anthropogenic modification of surface hydrology has altered the natural system. Alligator holes were scarcer in an area where modified hydrology caused draining and frequent dry-downs compared to another area that maintains a functional wetland system. Lower abundance of alligator holes indicates lack of alligator activities, lower overall species diversity, and lack of dry-season aquatic refugia for other organisms. The occupancy rate of alligator holes was lower than the current restoration target for the Everglades, and was variable by size class with large size-class alligators predominantly occupying alligator holes. This may indicate unequal size-class distribution, different habitat selection by size classes, or possibly a lack of recruitment. Our study provides pre-restoration baseline information about one indicator species for the Everglades. Success of the restoration can be assessed via effective synthesis of information derived by collective research efforts on the entire suite of selected ecological indicators. [Copyright &y& Elsevier]

Body condition factors have been used as an indicator of health and well-being of crocodilians. We evaluated body condition of Morelet's Crocodiles (Crocodylus moreletii) in northern Belize in relation to biotic (size, sex, and habitat) and abiotic (location, water level, and air temperature) factors. We also tested the hypothesis that high water levels and warm temperatures combine or interact to result in a decrease in body condition. Size class, temperature, and water level explained 20% of the variability in condition of Morelet's Crocodiles in this study. We found that adult crocodiles had higher condition scores than juveniles/subadults but that sex, habitat, and site had no effect. We confirmed our hypothesis that warm temperatures and high water levels interact to decrease body condition. We related body condition of Morelet's Crocodiles to natural fluctuations in air temperatures and water levels in northern Belize, providing baseline conditions for population and ecosystem monitoring. [ABSTRACT FROM AUTHOR]

When the American Crocodile (Crocodylus acutus) was declared endangered in 1975, scant data were available for making management decisions. Results of intensive studies conducted during the late 1970s and early 1980s by the National Park Service, Florida Game and Fresh Water Fish Commission, and Florida Power and Light Company resulted in an optimistic outlook for crocodiles. However, new issues face crocodiles today. Florida and Biscayne bays have undergone changes that have caused concern for the health of these ecosystems. The purpose of this paper is to review results of monitoring programs for C. acutus that have been used as a basis for consideration of reclassification of this endangered species and for restoration of its endangered ecosystem. More crocodiles and nests occur in more places today than in 1975. The maximum number of nesting females in Florida has increased from 20 in 1975 to 85 in 2004, and the number of concentrations of nesting effort from two to four. This evidence supports the proposed reclassification of the American Crocodile from endangered to threatened. However, crocodiles are still threatened by modification of habitat because of development adjacent to crocodile habitat and will benefit from restored freshwater flow into estuaries. As crocodiles continue to increase in number and expand into new areas, interactions with humans will occur more frequently. The challenge of integrating a recovering population of the American Crocodile with an ever-increasing use of coastal areas by humans will be the final challenge in successful recovery of this once critically endangered species. [ABSTRACT FROM AUTHOR]

The southernmost population of Gopherus polyphemus (Gopher Tortoises) occurs at Cape Sable, FL. The burrows of this population were surveyed in 1979 using strip transects to estimate Gopher Tortoise burrow density. We present data from a 1990 strip-transect survey and a 2001 line-transect survey of burrows for comparison. We found a significantly lower density of active burrows and a significantly higher density of abandoned burrows in 2001 compared to 1979 and 1990, but the overall density of burrows did not differ significantly over time. The distribution of burrow widths in 2001 was not significantly different from the 1982 distribution, and the bimodal pattern suggests that reproduction has occurred at the site. The 76% decline of active burrows at the site suggests that Gopher Tortoises have been subject to mortality. Reduction of habitat quality and tropical storms are possible explanations for the apparent decline in the Gopher Tortoise population at Cape Sable, but more monitoring is required to understand the long-term trends in this coastal population. [ABSTRACT FROM AUTHOR]

American Alligators (Alligator mississippiensis Daudin) are ecological engineers who alter the Everglades landscape through creation and maintenance of small ponds, called alligator holes, that play a key ecological role by providing both drier and wetter habitats for other organisms. The objective of this study was to compare morphology, vegetation. and activity of alligators in twenty natural and nine man-made alligator holes in ridge and slough wetlands of the central Everglades. All alligator holes were circular in shape and excavated to flat limestone substrate. Nine natural alligator holes were associated with tree islands and 11 were surrounded by sawgrass marsh. Man-made alligator holes were adjacent to islands constructed as high water refugia for deer. Marsh alligator holes were smaller and shallower than alligator holes associated with tree islands. Alligator hole size was correlated with water depth. Alligator holes surrounded by marsh had less diversified surroundings and lower species richness than alligator holes associated with tree islands. Alligator holes contained species of vegetation not found in the surrounding marsh. Seventy-nine percent of the alligator holes had signs of recent activity by alligators. Larger alligator holes associated with tree islands had adult and hatchling alligators and smaller marsh alligator holes contained juvenile alligators. Understanding the ecological role of alligator holes will be critical to planning and evaluating restoration of the Everglades ecosystem. [ABSTRACT FROM AUTHOR]

Body condition is used as an indicator of the degree of body fat in an animal but evidence of its actual relationship with health diagnostics (e.g., blood parameters) is usually lacking across species. In American alligators (Alligator mississippiensis), body condition has been used as a performance metric within the Greater Everglades ecosystem to provide insight on hydrological and landscape changes on alligator populations. However, there is no clear evidence that spatial body condition changes relate to different health conditions (low food intake vs sickness) and whether this link can be made when relating body condition values with blood parameters. We assessed the relationship between alligator body condition and 36 hematological and biochemistry (blood) parameters in four areas across two physiographic regions (Everglades and Big Cypress) of the Greater Everglades (sample size = 120). We found very strong to weak evidence of linearity between 7 (Big Cypress) and 19 (Everglades) blood parameters and relative condition factor index, from which cholesterol (38%) and uric acid (41%) for the former and phosphorus (up to 52%) and cholesterol (up to 45%) for the latter (mean absolute error MAE = 0.18 each) were the predictors that individually explain most of the body condition variation. The best combination of blood parameters for the Everglades were cholesterol, phosphorus, osmolality, total protein, albumin, alpha 2, beta, and gamma globulins, and corticosterone accounting for 40% (37 ± 21%, MAE = 0.16) of the variation found in alligator body condition for this region. We found better predictability power in models when analyzed at smaller rather than larger scales showing a potential habitat effect on the body condition—blood parameters relationship. Overall, Everglades alligators in poorer condition are likely dehydrated or have an inadequate diet and the spatial differences found between physiographic regions suggest that these areas differ in prey availability/quality. [ABSTRACT FROM AUTHOR]

Background: Hurricanes can have catastrophic effects on coastal ecosystems. To minimize negative impacts of storms, animals may seek shelter in place, move to a nearby refuge, or evacuate long-distances. Crocodilians can be important predators in estuarine habitats, but little is known about how they respond to extreme weather events. We investigated the movement behaviors of eight acoustically tracked American alligators (Alligator mississippiensis) before, during, and after Hurricane Irma in 2017 within the Shark River Estuary of Everglades National Park, USA. Using tracking data, we compared their movements and habitat use before and after the hurricane to similar timeframes in other years without major storms. Results: We observed considerable variation in movement tactics and responses to the hurricane. Of eight animals that we tracked, two showed no changes in movement or habitat use throughout the study. Two animals ceased upstream excursions that they were regularly making before the hurricane with one of these animals reducing the distance ranged across the river system. Another animal moved upstream from the lower river to the mid-estuary immediately after the hurricane despite having not done this in the 60 days prior. Two other animals moved from the marsh and mangrove forest habitats to river channels several days after the hurricane. One animal shifted to commuting downstream from its upstream habitat shortly before the storm and continued this behavior for the rest of the 2017 and 2018 wet seasons. Conclusions: We found considerable variability in behavioral responses to the hurricane, ranging from no discernable changes in movements to one animal exhibiting a complete shift in movement tactics not observed by any animal in the long-term tracking of this population. Our research provides insight into alligator movement behavior and ecology in the context of a major hurricane disturbance. [ABSTRACT FROM AUTHOR]

Spectacled caimans (Caiman crocodilus Linnaeus, 1758) are established invaders in the United States, Cuba, and San Andres Island, Colombia. They have been established in South Florida since the 1970s and are found primarily within Comprehensive Everglades Restoration Plan (CERP) projects. These projects provide suitable habitat and may provide dispersal pathways via water management activities. Caiman presence in these areas directly conflicts with the CERP’s goals, and as a generalist species with a broad diet, they can impact biological resources. Past removal efforts failed to extirpate caimans, but their efficacy has not been well evaluated. We addressed caimans via removal surveys during 2012–2021 with the goal of evaluating extirpation or maximum species control within South Florida’s CERP projects. Documented opportunistic removals for this study began in December 2012, and systematic efforts have been ongoing since October 2017. We evaluated efficacy of caiman removals by analyzing 10 years of opportunistic and systematic survey data, plus associated removal data, along 11 survey routes during 2012–2021. We also conducted necropsies to collect biological information which could be used to improve removal efforts. We removed 251 caimans during 2012 to 2021, and the rate of caiman removals per year increased from 5 animals during 2012 to a peak of 47 animals during 2020. Necropsies revealed reproductive information (nesting/hatching timelines) that we applied to improve our removal rates. Caiman encounter rates declined from a peak of 1.55 ± 0.66 caiman/hr and 0.72 ± 0.38 caiman/km during 2013 to a low of 0.18 ± 0.09 caiman/hr and 0.03 ± 0.02 caiman/km during 2020 and slightly increased during 2020–2021, likely because of a change in search effort. We evaluated and discussed the potential for extirpating caiman from CERP projects and provide a data-driven prescription for removal efforts. [ABSTRACT FROM AUTHOR]

Ctenosaura similis (Black Spiny-tailed Iguana) is native to Mexico and Central America, where it is a wide-ranging habitat-generalist that is well adapted to human-altered environments. Black Spiny-tailed Iguana is considered one of the larger, heavier iguanid species, identified by its coloration and a series of enlarged whorls of spiny scales on the tail. Despite harvest rates for human consumption and the pet trade, Black Spiny-tailed Iguana is currently considered a species of least concern in their native range. There have been several introductions outside of their native range, many of which have become established due to their generalist nature. In Florida, Black Spiny-tailed Iguana was first introduced in 1979 and has been reported in 24 counties. Early removal efforts of other introduced iguanids such as Ctenosaura pectinata (Mexican Spiny-tailed Iguana) and Iguana iguana (Green Iguana) could serve as case studies to develop and implement eradication and management plans for this species. We provide a comprehensive summary of natural history findings on Black Spiny-tailed Iguana, including management methods and potential ecological impacts as an invasive species in the southeastern United States. [ABSTRACT FROM AUTHOR]

The range of the threatened American crocodile (Crocodylus acutus) in the United States is limited to the southernmost parts of Florida. As this species has recovered concurrently with an increasing human population, human–crocodile conflicts have also increased. Resolving conflicts can involve translocating crocodiles; however, they often return to the site from which they were removed. We examined the effects of translocation on crocodile movements, habitat use, body condition, and survival in Florida, USA, in 2018–2019 to refine recommendations for managers considering translocation to resolve human–crocodile conflict. We captured and attached global positioning system (GPS) units to 17 crocodiles, 10 of which served as a reference group (free‐ranging crocodiles released at their capture site) and 7 served as a treatment group (crocodiles that were translocated 14–158 km from their capture site). We collected location data from individual crocodiles for 34–661 days (x¯ $\mathop{x}\limits^{̅}$ ~ 250 days for each group). Body condition was similar for both groups. Corticosterone levels measured periodically during handling indicated that crocodiles experienced increasing stress levels during handling. Three crocodiles translocated ≤45 km from their original capture site returned to that location within 13 days. Three crocodiles translocated ≥110 km did not return. One female translocated 152 km was recaptured 0.42 km from its original capture site 965 days after its release. We identified 2 states of characteristic movement patterns: state 1 indicated individuals moving slowly and somewhat randomly, and state 2 indicated individuals exhibiting fast, active directional movement. Translocated individuals were more likely than reference individuals to switch to, and stay in, state 2. Because of concerns regarding return rates and heightened stress as a result of capture and translocation, we suggest crocodile translocations have limited conservation value and may only be worth considering once all other reasonable options are exhausted. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discuss the theme of the issue, the 2015 Greater Everglades Ecosystem Restoration Science Conference focused on advances in research and management of invasive exotic species in the Greater Everglades Ecosystem.

The potential for animals to modify spatial patterns of nutrient limitation for autotrophs and habitat availability for other members of their communities is increasingly recognized. However, net trophic effects of consumers acting as ecosystem engineers remain poorly known. The American Alligator Alligator mississippiensis is an abundant predator capable of dramatic modifications of physical habitat through the creation and maintenance of pond‐like basins, but its role in influencing community structure and nutrient dynamics is less appreciated.We investigated if alligators engineer differences in nutrient availability and changes to community structure by their creation of 'alligator ponds' compared to the surrounding phosphorus (P)‐limited oligotrophic marsh.We used a halo sampling design of three distinct habitats extending outward from 10 active alligator ponds across a hydrological gradient in the Everglades, USA. We performed nutrient analysis on basal food‐web resources and quantitative community analyses, and stoichiometric analyses on plants and animals.Our findings demonstrate that alligators act as ecosystem engineers and enhance food‐web heterogeneity by increasing nutrient availability, manipulating physical structure and altering algal, plant and animal communities. Flocculent detritus, an unconsolidated layer of particulate organic matter and soil, showed strong patterns of P enrichment in ponds. Higher P availability in alligator ponds also resulted in bottom‐up trophic transfer of nutrients as evidenced by higher growth rates (lower N:P) for plants and aquatic consumers. Edge habitats surrounding alligator ponds contained the most diverse communities of invertebrates and plants, but low total abundance of fishes, likely driven by high densities of emergent macrophytes. Pond communities exhibited higher abundance of fish compared to edge habitat and were dominated by compositions of small invertebrates that track high nutrient availability in the water column. Marshes contained high numbers of animals that are closely tied to periphyton mats, which were absent from other habitats.Alligator‐engineered habitats are ecologically important by providing nutrient‐enriched 'hotspots' in an oligotrophic system, habitat heterogeneity to marshes, and refuges for other fauna during seasonal disturbances. This work adds to growing evidence that efforts to model community dynamics should routinely consider animal‐mediated bottom‐up processes like ecosystem engineering. [ABSTRACT FROM AUTHOR]

Background: GPS telemetry has revolutionized the study of animal spatial ecology in the last two decades. Until recently, it has mainly been deployed on large mammals and birds, but the technology is rapidly becoming miniaturized, and applications in diverse taxa are becoming possible. Large constricting snakes are top predators in their ecosystems and accordingly they are often a management priority, whether their populations are threatened or invasive. Fine-scale GPS tracking datasets could greatly improve our ability to understand and manage these snakes, but the ability of this new technology to deliver high-quality data in this system is unproven. In order to evaluate GPS technology in large constrictors, we GPS-tagged 13 Burmese pythons (Python bivittatus) in Everglades National Park and deployed an additional 7 GPS tags on stationary platforms to evaluate habitat-driven biases in GPS locations. Both python and test platform GPS tags were programmed to attempt a GPS fix every 90 min. Results: While overall fix rates for the tagged pythons were low (18.1%), we were still able to obtain an average of 14.5 locations/animal/week, a large improvement over once-weekly VHF tracking. We found overall accuracy and precision to be very good (mean accuracy = 7.3 m, mean precision = 12.9 m), but a very few imprecise locations were still recorded (0.2% of locations with precision > 1.0 km). We found that dense vegetation did decrease fix rate, but we concluded that the low observed fix rate was also due to python microhabitat selection underground or underwater. Half of our recovered pythons were either missing their tag or the tag had malfunctioned, resulting in no data being recovered. Conclusions: GPS biologging technology is a promising tool for obtaining frequent, accurate and precise locations of large constricting snakes. We recommend future studies couple GPS telemetry with frequent VHF locations in order to reduce bias and limit the impact of catastrophic failures on data collection and we recommend improvements to GPS tag design to lessen the frequency of these failures. [ABSTRACT FROM AUTHOR]

Carnivores are valued by conservationists globally but protecting them can impose direct costs on rural, livestock-dependent communities. Financial incentives are increasingly used with the goal of increasing people's tolerance of predators, but the definition of tolerance has been vague and inconsistent. Empirical correlations between attitudinal and behavioural measures of tolerance imply that attitudes may be a valid proxy for behaviours. However, theoretical differences between the concepts suggest that attitudinal tolerance and behavioural intention to kill cats would have different underlying determinants. We surveyed 112 residents within a forest–farm mosaic in northern Belize inhabited by jaguars Panthera onca and four other species of wild cats. A conservation payment programme pays local landowners when camera traps record cat presence on their land. Results indicated that tolerance was associated with gender and participation in the camera-trapping programme, whereas intention to kill cats was associated with cultural group (Mennonites vs Mestizos), presence of children in the home and, to a lesser extent, tolerance. Neither dependent variable was significantly related to depredation losses or economic factors. Results suggest that monetary payments alone are unlikely to affect attitudes and behaviours towards carnivores. Payment programmes may be enhanced by accentuating non-monetary incentives, leveraging social norms and targeting specific groups with information about risks and benefits associated with carnivores. By empirically separating two concepts commonly conflated as ‘tolerance’ we clarify understanding of how social forces interact with financial incentives to shape people's relationships with predators. [ABSTRACT FROM AUTHOR]

Body condition is a measure of the health and fitness of an organism represented by available energy stores, typically fat. Direct measurements of fat are difficult to obtain non-invasively, thus body condition is usually estimated by calculating body condition indices (BCIs) using mass and length. The utility of BCIs is contingent on the relationship of BCIs and fat, thereby validation studies should be performed to select the best performing BCI before application in ecological investigations. We evaluated 11 BCIs in 883 Argentine black and white tegus (Salvator merianae) removed from their non-native range in South Florida, United States. Because the length-mass relationship in tegus is allometric, a segmented linear regression model was fit to the relationship between mass and length to define size classes. We evaluated percent, residual, and scaled fat and determined percent fat was the best measure of fat, because it was the least-associated with snout-vent length (SVL). We evaluated performance of BCIs with the full dataset and within size classes and identified Fulton's K as the best performing BCI for our sampled population, explaining up to 19% of the variation in fat content. Overall, we found that BCIs: 1) maintained relatively weak relationships with measures of fat and 2) splitting data into size classes reduced the strength of the relationship (i.e., bias) between percent fat and SVL but did not improve the performance of BCIs. We postulate that the weak performance of BCIs in our dataset was likely due to the weak association of fat with SVL, the body plan and life-history traits of tegus, and potentially inadequate accounting of available energy resources. We caution against assuming that BCIs are strong indicators of body condition across species and suggest that validation studies be implemented, or that alternative or complimentary measures of health or fitness should be considered. [ABSTRACT FROM AUTHOR]

The spectacled caiman (Caiman crocodilus) is currently considered to be a species complex due to the relatively high morphological and molecular diversity expressed across its range. One of the populations of interest, inhabiting the Apaporis River (Colombia), was described based on skull features as an incipient species (C. c. apaporiensis) and has been treated by some authors as a full species. Recent molecular work challenged this hypothesis, because relatively low mitochondrial molecular differentiation was found between the morphologically described Apaporis caiman and C. crocodilus (s.s.) Amazonian populations. Here, we present an update on the topic based on a larger molecular sample size and on analysis of expanded geometric morphometric data that include six newly collected skulls. Morphometric data support the existence of previously recognized morphotypes within the complex in Colombia and demonstrate that the newly collected material can be assigned to the classic Apaporis caiman morphotype. However, our expanded genetic analysis fails to find appreciable mitochondrial molecular divergence of the Apaporis caiman population from the C. c. crocodilus population (COI-CytB : Amazon Peru 0.17 ± 0.06%, CytB -only: Caquetá River Colombia 0.08 ± 0.07%). The Apaporis caiman is interpreted to be a phenotypically distinct member of the cis -Andean C. crocodilus metapopulation that has not yet achieved (or may not be undergoing at all) appreciable genetic differentiation. Thus, it should not be considered a fully independent evolutionary lineage, nor given full species rank. [ABSTRACT FROM AUTHOR]

Abstract: Alligators and crocodiles integrate biological impacts of hydrological operations, affecting them at all life stages through three key aspects of Everglades ecology: (1) food webs, (2) diversity and productivity, and (3) freshwater flow. Responses of crocodilians are directly related to suitability of environmental conditions and hydrologic change. Correlations between biological responses and environmental conditions contribute to an understanding of species’ status and trends over time. Positive or negative trends of crocodilian populations relative to hydrologic changes permit assessment of positive or negative trends in restoration. The crocodilian indicator uses monitoring parameters (performance measures) that have been shown to be both effective and efficient in tracking trends. The alligator component uses relative density (reported as an encounter rate), body condition, and occupancy rates of alligator holes; the crocodile component uses juvenile growth and hatchling survival. We hypothesize that these parameters are correlated with hydrologic conditions including depth, duration, timing, spatial extent and water quality. Salinity is a critical parameter in estuarine habitats. Assessments of parameters defined for crocodilian performance measures support these hypotheses. Alligators and crocodiles are the charismatic megafauna of the Everglades. They are both keystone and flagship species to which the public can relate. In addition, the parameters used to track trends are easy to understand. They provide answers to the following questions: How has the number of alligators or crocodiles changed? Are the animals fatter or thinner than they should be? Are the animals in the places (in terms of habitat and geography) where they should be? As surely as there is no other Everglades, no other single species defines the Everglades as does the American alligator. The Everglades is the only place in the world where both alligators and crocodiles exist. Crocodilians clearly respond to changes in hydrologic parameters of management interest. These relationships are easy to communicate and mean something to managers, decision makers, and the public. Having crocodilians on the list of system-wide, general indicators provides us with one of the most powerful tools we have to communicate progress of ecosystem restoration in Greater Everglades ecosystems to diverse audiences. [Copyright &y& Elsevier]

The American crocodile Crocodylus acutus occurs across the Americas, with its northernmost distribution being in South Florida, USA. This species has undergone severe declines across its range and is categorized globally as Vulnerable on the IUCN Red List and as Threatened on the U.S. Federal Endangered Species List. Long-term monitoring studies in the USA have documented a shift in American crocodile nesting activity and an expansion of its range throughout the southern and eastern coasts of South Florida. However, no successful American crocodile nests have been recorded until now on the west coast of South Florida. Here we document the American crocodile nest monitoring conducted during 1997–2021 at Rookery Bay National Estuarine Research Reserve and the first successful nest from the west coast of South Florida for C. acutus. Marco Airport and McIlvane Marsh are the two main American crocodile nesting areas identified at the Reserve, with 92 nests and 3,586 eggs recorded during 1997–2021. We found most nests at Marco Airport (95.7%) and only four nests (4.3%) at McIlvane Marsh. To date, none of the nests found at Marco Airport have produced successful hatchlings. In contrast, hatchlings have been produced at McIlvane Marsh since nests were first documented there in 2020. We discuss the implications of our findings in terms of the future conservation of the species. [ABSTRACT FROM AUTHOR]

Varanus salvator (Asian Water Monitor) is the second largest species of lizard in the world and is a member of the Varanidae Family. This highly aquatic species can also be found in arboreal environments and is an active predator and scavenger. Originating from southeastern Asia, including parts of India, this species is common in the international pet trade. Its popularity in the pet trade has led to multiple introductions outside of their native range, making this a species of concern as potentially invasive to the southeastern US with ready access to the Caribbean and Latin America. As a generalist species that has already been identified in Florida, there is a high likelihood for establishment as an invasive species. In cases such as these, implementing early detection and rapid response for successful management of invasive species is critical. Here, we provide a comprehensive summary of natural history findings on the Asian Water Monitor, including management methods and potential ecological impacts as an invasive species. [ABSTRACT FROM AUTHOR]

The design of successful invasive species control programs is often hindered by the absence of basic demographic data on the targeted population. Establishment of invasive Burmese pythons (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida USA has led to local precipitous declines (> 90%) of mesomammal populations and is also a major threat to native populations of reptiles and birds. Efforts to control this species are ongoing but are hampered by the lack of access to and information on the expected biological patterns of pythons in southern Florida. We present data from more than 4,000 wild Burmese pythons that were removed in southern Florida over 26 years (1995-2021), the most robust dataset representing this invasive population to date. We used these data to characterize Burmese python size distribution, size at maturity, clutch size, and seasonal demographic and reproductive trends. We broadened the previously described size ranges by sex and, based on our newly defined size-stage classes, showed that males are smaller than females at sexual maturity, confirmed a positive correlation between maternal body size and potential clutch size, and developed predictive equations to facilitate demographic predictions. We also refined the annual breeding season (approx.100 days December into March), oviposition timing (May), and hatchling emergence and dispersal period (July through October) using correlations of capture morphometrics with observations of seasonal gonadal recrudescence (resurgence) and regression. Determination of reproductive output and timing can inform population models and help managers arrest population growth by targeting key aspects of python life history. These results define characteristics of the species in Florida and provide an enhanced understanding of the ecology and reproductive biology of Burmese pythons in their invasive Everglades range. [ABSTRACT FROM AUTHOR]

Public engagement is important to invasive species management, and recreational harvest programs are one way agencies seek to involve the public and raise awareness. We surveyed participants (n= 660) and non-participants (n= 77) in the 2013 Python ChallengeTMto understand whether this event achieved its primary goal of raising awareness of the ecological impact of Burmese pythons (Python molurus bivittatus) in south Florida. Respondents indicated a high level of ‘concern’ about the seriousness of the python problem and the need for management actions. Concern was affected positively by environmental motivations, experience of seeing pythons in the wild, older age, and female sex, but negatively by level of Python Challenge involvement. Results suggest that ‘proximate’ experience ofnotseeing a python may reduce concern, whereas ‘ongoing’ experience may temper concern without diminishing involvement. This research highlights the role of experience in shaping beliefs and advises diligence in public participation programs. [ABSTRACT FROM PUBLISHER]

Ecological associations where one species enhances habitat for another nearby species (facilitations) shape fundamental community dynamics and can promote niche expansion, thereby influencing how and where species persist and coexist. For the many breeding birds facing high nest-predation pressure, enemy-free space can be gained by nesting near more formidable animals for physical protection. While the benefits to protected species seem well documented, very few studies have explored whether and how protector species are affected by nest protection associations. Long-legged wading birds (Pelecaniformes and Ciconiiformes) actively choose nesting sites above resident American alligators (Alligator mississippiensis), apparently to take advantage of the protection from mammalian nest predators that alligator presence offers. Previous research has shown that wading bird nesting colonies could provide substantial food for alligators in the form of dropped chicks. We compared alligator body condition in similar habitat with and without wading bird nesting colonies present. Alligator morphometric body condition indices were significantly higher in colony than in non-colony locations, an effect that was statistically independent of a range of environmental variables. Since colonially nesting birds and crocodilians co-occur in many tropical and subtropical wetlands, our results highlight a potentially widespread keystone process between two ecologically important species-groups. These findings suggest the interaction is highly beneficial for both groups of actors, and illustrate how selective pressures may have acted to form and reinforce a strongly positive ecological interaction. [ABSTRACT FROM AUTHOR]

Understanding perceptual and situational factors underlying nuisance complaints can help managers maintain carnivore populations while mitigating conflicts with people. Our study uses data from a mail survey (n = 467 complainants about nuisance alligators, and n = 669 random Florida residents) and a three-step binary logistic regression analysis to examine how general attitudes, specific beliefs, and situational factors influence the behavior of reporting nuisance alligators. Residence adjacent to fresh water, the presence of outdoor pets, higher risk belief scores, higher nuisance belief scores, higher education, and older age were all related to complaining about an alligator, whereas general attitude toward alligators was not. Results are consistent with the "specificity principle" for attitude-behavior correspondence and emphasize the importance of situational factors as behavioral determinants. Targeted harvest areas can help to manage complaints in marginal habitats where risk from alligators is persistent. Information about protective behaviors and benefits of alligators can motivate residents to avoid dangerous encounters. [ABSTRACT FROM AUTHOR]

Reptiles exhibit a wide diversity of social systems, and while not very common, exclusive and consensual mating relationships have been documented in several lizard species including lizards from the Teiidae family. Here, we document dyadic movement behavior between an adult male and female Salvator merianae (Argentine Black and White Tegu), a large, omnivorous lizard native to Brazil, Uruguay, eastern Paraguay, and Argentina that became established as an invasive species in Florida, in the southeastern United States. Using global positioning system and very high frequency telemetry data, we documented 8–9 days of joint movement between a reproductively active male and female Tegu in Miami-Dade County, FL. [ABSTRACT FROM AUTHOR]

Wetlands are dynamic environments where aquatic organisms are affected by both predictable and unpredictable changes in hydrology. Understanding how abundant large-bodied predators respond to these changes is especially important in context of wetland restoration. We used satellite telemetry to investigate how individual (e.g., sex, size, body condition) and environmental factors influenced movement behaviors of American Alligators [Alligator mississippiensis (Daudin, 1801)] in a managed freshwater marsh ecosystem of the Florida Everglades. We quantified space use, movement activity, and habitat selection of animals (n = 18) across hydrological seasons and the breeding period and performed stable isotope analyses to infer seasonal dietary changes. Though individual animals did not change space use across seasons, movement activity was lower for some individuals and δ15 Nitrogen isotopic values were higher in the dry season possibly reflecting greater foraging opportunities when marsh dry down concentrates prey. Alligators may be using canals as foraging sites which have abundant prey year-round and shallow sawgrass habitats as spots for basking. Based on our findings, ongoing restoration of water inflow will likely change the distribution and movement behavior of alligators. [ABSTRACT FROM AUTHOR]

Abstract: Movement and habitat use patterns are fundamental components of the behaviors of mobile animals and help determine the scale and types of interactions they have with their environments. These behaviors are especially important to quantify for top predators because they can have strong effects on lower trophic levels as well as the wider ecosystem. Many studies of top predator movement and habitat use focus on general population level trends, which may overlook important intra-population variation in behaviors that now appear to be common. In an effort to better understand the prevalence of intra-population variation in top predator movement behaviors and the potential effects of such variation on ecosystem dynamics, we examined the movement and habitat use patterns of a population of adult American alligators (Alligator mississippiensis) in a subtropical estuary for nearly four years. We found that alligators exhibited divergent behaviors with respect to activity ranges, movement rates, and habitat use, and that individualized behaviors were stable over multiple years. We also found that the variations across the three behavioral metrics were correlated such that consistent behavioral types emerged, specifically more exploratory individuals and more sedentary individuals. Our study demonstrates that top predator populations can be characterized by high degrees of intra-population variation in terms of movement and habitat use behaviors that could lead to individuals filling different ecological roles in the same ecosystem. By extension, one-size-fits-all ecosystem and species-specific conservation and management strategies that do not account for potential intra-population variation in top predator behaviors may not produce the desired outcomes in all cases. [Copyright &y& Elsevier]

Reptiles exhibit a wide diversity of social systems, and while not very common, exclusive and consensual mating relationships have been documented in several lizard species including lizards from the Teiidae family. Here, we document dyadic movement behavior between an adult male and female Salvator merianae (Argentine Black and White Tegu), a large, omnivorous lizard native to Brazil, Uruguay, eastern Paraguay, and Argentina that became established as an invasive species in Florida, in the southeastern United States. Using global positioning system and very high frequency telemetry data, we documented 8-9 days of joint movement between a reproductively active male and female Tegu in Miami-Dade County, FL. [ABSTRACT FROM AUTHOR]

The round-tailed muskrat (Neofiber alleni) is a nocturnal rodent restricted to Florida and southeastern Georgia and is dependent on wetlands for survival. The status of Everglades round-tailed muskrat populations is unknown; however, they are known to occur at the Arthur R. Marshall Loxahatchee National Wildlife Refuge (LNWR). Walking transects and aerial surveys have been used to survey the species at other locations but are not feasible in LNWR. We conducted preliminary surveys by airboat and collected data on house location and habitat characteristics that can be used to develop specific protocols for addressing questions about round-tailed muskrat site occupancy and responses to environmental change. Methods developed in LNWR are applicable to other large wetland areas of the Everglades. [ABSTRACT FROM AUTHOR]

Alligator holes are a key feature of Everglades marshes that provide refugia and foraging sites for a wide range of species. We investigated the spatial pattern of alligator holes in Water Conservation Area 3, a part of the central Everglades, and examined associations among alligator holes, canals, and hydrology. There were fewer alligator holes within 1000 m of canals than expected, supporting the hypothesis that Alligator mississippiensis (American Alligator) are using canals as aquatic refugia rather than creating or maintaining alligator holes in the marsh. In addition, density of holes was associated with hydrology; specifically, areas that were drier had more than twice as many alligator holes than areas that were wetter. Analyses from this study provide a baseline for evaluating changes in location and density of alligator holes in response to canal removal and hydrologic changes that will occur as part of Everglades restoration. [ABSTRACT FROM AUTHOR]

The article focuses on predation of Nerodia clarkii and a suspected hybrid by Crocodylus acutus (American Crocodile) in South Florida, USA, providing a rare observation of predation on this species, with only two previously published instances documented.

The federally threatened American crocodile (Crocodylus acutus) is a flagship species and ecological indicator of hydrologic restoration in the Florida Everglades. We conducted a long-term capture-recapture study on the South Florida population of American crocodiles from 1978 to 2015 to evaluate the effects of restoration efforts to more historic hydrologic conditions. The study produced 10,040 crocodile capture events of 9,865 individuals and more than 90% of captures were of hatchlings. Body condition and growth rates of crocodiles were highly age-structured with younger crocodiles presenting with the poorest body condition and highest growth rates. Mean crocodile body condition in this study was 2.14±0.35 SD across the South Florida population. Crocodiles exposed to hypersaline conditions (> 40 psu) during the dry season maintained lower body condition scores and reduced growth rate by 13% after one year, by 24% after five years, and by 29% after ten years. Estimated hatchling survival for the South Florida population was 25% increasing with ontogeny and reaching near 90% survival at year six. Hatchling survival was 34% in NE Florida Bay relative to a 69% hatchling survival at Crocodile Lake National Wildlife Refuge and 53% in Flamingo area of Everglades National Park. Hypersaline conditions negatively affected survival, growth and body condition and was most pronounced in NE Florida Bay, where the hydrologic conditions have been most disturbed. The American crocodile, a long-lived animal, with relatively slow growth rate provides an excellent model system to measure the effects of altered hydropatterns in the Everglades landscape. These results illustrate the need for continued long-term monitoring to assess system-wide restoration outcomes and inform resource managers. [ABSTRACT FROM AUTHOR]

Background: The establishment of Burmese pythons (Python bivittatus) in Everglades National Park, Florida, USA, has been connected to a > 90% decline in the mesomammal population in the park and is a major threat to native reptile and bird populations. Efforts to control this population are underway, but are hampered by a lack of information about fine-scale activity cycles and ecology of these cryptic animals in the wild. We aimed to establish a technique for monitoring the activity of Burmese pythons in the wild using acceleration data loggers (ADLs), while attempting to identify any behavioral patterns that could be used to help manage this invasive species in the Greater Everglades and South Florida. Results: We obtained continuous acceleration and temperature data from four wild snakes over periods of 19 to 95 days (mean 54 ± 33 days). Snakes spent 86% of their time at rest and 14% of their time active, including transiting between locations. All snakes showed at least one period of continuous transiting lasting 10 h or more, with one animal transiting continuously for a period of 58.5 h. Acceleration data logger-derived transiting bout duration was significantly correlated with the distance snakes traveled per hour for two snakes that also carried GPS loggers. Snakes were most active in midday or early-night depending on individual and time of year, but all snakes were least likely to be active in the early mornings (0400–0700 h local time). Very little movement took place at temperatures below 14 °C or above 24 °C, with most movement taking place between 15° and 20 °C. One animal showed a highly unusual rolling event that may be indicative of a predation attempt, but this could not be confirmed. Conclusions: Fine-scale activity and some behaviors were apparent from ADL data, making ADLs a potentially valuable, unbiased tool for monitoring large-bodied snakes in the wild. Snakes spent the majority of their time resting, but also moved continuously for several hours at a time during bouts of transiting. Results suggest that individuals may shift their diel activity pattern based on season. Understanding seasonal differences in activity levels can improve the accuracy of population estimates, help detect range expansion, and improve managers' ability to find and capture individuals. [ABSTRACT FROM AUTHOR]

The article focuses on Crocodylus acutus, the American Crocodile, and the phenomenon of tail regeneration, documenting two cases of caudal regeneration in this species in south Florida, U.S.

Large‐bodied predators are well represented among the world's threatened and endangered species. A significant body of literature shows that in terrestrial and marine ecosystems large predators can play important roles in ecosystem structure and functioning. By contrast, the ecological roles and importance of large predators within freshwater ecosystems are poorly understood, constraining the design and implementation of optimal conservation strategies for freshwater ecosystems. Conservationists and environmentalists frequently promulgate ecological roles that crocodylians are assumed to fulfil, but often with limited evidence supporting those claims. Here, we review the available information on the ecological importance of crocodylians, a widely distributed group of predominantly freshwater‐dwelling, large‐bodied predators. We synthesise information regarding the role of crocodylians under five criteria within the context of modern ecological concepts: as indicators of ecological health, as ecosystem engineers, apex predators, keystone species, and as contributors to nutrient and energy translocation across ecosystems. Some crocodylians play a role as indicators of ecosystem health, but this is largely untested across the order Crocodylia. By contrast, the role of crocodylian activities in ecosystem engineering is largely anecdotal, and information supporting their assumed role as apex predators is currently limited to only a few species. Whether crocodylians contribute significantly to nutrient and energy translocation through cross‐ecosystem movements is unknown. We conclude that most claims regarding the importance of crocodylians as apex predators, keystone species, ecosystem engineers, and as contributors to nutrient and energy translocation across ecosystems are mostly unsubstantiated speculation, drawn from anecdotal observations made during research carried out primarily for other purposes. There is a paucity of biological research targeted directly at: understanding population dynamics; trophic interactions within their ecological communities; and quantifying the short‐ and long‐term ecological impacts of crocodylian population declines, extirpations, and recoveries. Conservation practices ideally need evidence‐based planning, decision making and justification. Addressing the knowledge gaps identified here will be important for achieving effective conservation of crocodylians. [ABSTRACT FROM AUTHOR]

The Central American river turtle, Dermatemys mawii, is a critically endangered species with declines in its population caused by human harvest. Previous knowledge of nesting behaviour is minimal, and communal nesting of D. mawii has not been described previously. Here we report the first observations of communal nesting of D. mawii and provide recommendations to researchers and conservationists on how to find D. mawii nests, based on observed communal nesting conditions, proximity to water, hydro-period, and vegetative cover. [ABSTRACT FROM AUTHOR]

The article focuses on the reproduction of the American crocodile (Crocodylus acutus) and specifically addresses the occurrence of twinning, highlighting previous documentation but noting the lack of detailed information regarding the origin and development conditions.

The article reports first observation of polydactyly in Crocodylus Acutus hatchlings in south Florida, where the extra digits appeared on the ventral side of the foot and may have been caused by various factors including genetics, abnormal incubation conditions and teratogen exposure.

The article informs that observations confirm that the American crocodile or Crocodylus acutus preys on the Northern raccoon or Procom lotor, adding to its already diverse diet of insects, crustaceans, fish, reptiles and mammals.

Invasive species provide powerful in situ experimental systems for studying evolution in response to selective pressures in novel habitats. While research has shown that phenotypic evolution can occur rapidly in nature, few examples exist of genomewide adaptation on short "ecological" timescales. Burmese pythons (Python molurus bivittatus) have become a successful and impactful invasive species in Florida over the last 30 years despite major freeze events that caused high python mortality. We sampled Florida Burmese pythons before and after a major freeze event in 2010 and found evidence for directional selection in genomic regions enriched for genes associated with thermosensation, behaviour and physiology. Several of these genes are linked to regenerative organ growth, an adaptive response that modulates organ size and function with feeding and fasting in pythons. Independent histological and functional genomic data sets provide additional layers of support for a contemporary shift in invasive Burmese python physiology. In the Florida population, a shift towards maintaining an active digestive system may be driven by the fitness benefits of maintaining higher metabolic rates and body temperature during freeze events. Our results suggest that a synergistic interaction between ecological and climatic selection pressures has driven adaptation in Florida Burmese pythons, demonstrating the often‐overlooked potential of rapid adaptation to influence the success of invasive species. [ABSTRACT FROM AUTHOR]