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Invasive Burmese pythons (Python bivittatus) are extremely cryptic animals. Although their conservation status in their native range is Vulnerable, in the Greater Everglades Ecosystem (Florida, USA) they have become a dominant destructive force and usually are immediately removed whenever found. This poses a paradox where removals are occurring, yet the study and understanding of python ecology is needed to inform removal methods. An important component of life history includes the nesting season, but little is known about python nest site selection, nest brooding, thermogenesis, or hatching success in the wild. Here, we present the first complete and most detailed report of oviposition and brooding for this biologically significant time period of a female Burmese python. We describe anthropogenic nest site selection, document the extent of shivering thermogenesis, describe brooding behaviors, and provide photo‐documentation of complete hatching of the largest python clutch on record.

Diminishing natural resources and increasing climatic volatility are impacting agri-food systems, prompting the need for sustainable and resilient alternatives. Python farming is well established in Asia but has received little attention from mainstream agricultural scientists. We measured growth rates in two species of large pythons ( Malayopython reticulatus and Python bivittatus ) in farms in Thailand and Vietnam and conducted feeding experiments to examine production efficiencies. Pythons grew rapidly over a 12-month period, and females grew faster than males. Food intake and growth rates early in life were strong predictors of total lifetime growth, with daily mass increments ranging from 0.24 to 19.7 g/day for M. reticulatus and 0.24 to 42.6 g/day for P. bivittatus , depending on food intake. Pythons that fasted for up to 4.2 months lost an average of 0.004% of their body mass per day, and resumed rapid growth as soon as feeding recommenced. Mean food conversion rate for dressed carcasses was 4.1%, with useable products (dressed carcass, skin, fat, gall bladder) comprising 82% of the mass of live animals. In terms of food and protein conversion ratios, pythons outperform all mainstream agricultural species studied to date. The ability of fasting pythons to regulate metabolic processes and maintain body condition enhances food security in volatile environments, suggesting that python farming may offer a flexible and efficient response to global food insecurity.

The negative impacts of invasive Burmese pythons ( Python bivittatus ) on mammal communities in mainland South Florida are well-documented. However, few studies have examined the ecological effects of Burmese pythons along their southern invasion front in the Florida Keys. The establishment of Burmese pythons in the Keys could be devastating for island mammal communities and their ecosystem functions. We leveraged long-term data from camera trap surveys of endangered Key Largo woodrats ( Neotoma floridana smalli ) and free-ranging cats ( Felis catus ), as well as publicly available datasets to create time-dependent occupancy and generalized linear models to explore potential changes in the mammal community associated with increasing prevalence of Burmese pythons on Key Largo. Top occupancy models indicated that detection probabilities of endangered Key Largo cotton mice ( Peromyscus gossypinus allapaticola ), Key Largo woodrats, and invasive black rats ( Rattus rattus ) all decreased since the establishment of Burmese pythons in 2016 on North Key Largo, but the detection probability of Virginia opossums ( Didelphis virginiana ) might have increased. Additionally, top models indicated that increasing python prevalence was associated with high local extinction probabilities for woodrats and black rats. Generalized linear models indicated raccoon ( Procyon lotor ) and opossum counts decreased locally over time in areas where pythons were present, despite no broad-scale changes in occupancy. These results reveal a complex dynamic wherein Burmese pythons are likely having a stronger effect on rodent communities over mesopredator communities in North Key Largo—presumably due to demographics of a relatively new established python population. This study indicates that the python invasion in Key Largo has started to have ecological impacts. While these findings are cause for concern, evidence does suggest python removals are mitigating effects on certain mammal populations.

ABSTRACT The Burmese python (Python bivittatus) is native to Southeast Asia and has an established invasive population throughout South Florida. As part of the effort to understand invasive python biology and potential impacts to the native ecosystem, we have been using radio‐telemetry to investigate feeding rates of adult female pythons. The body size and gape of adult Burmese pythons enable them to consume large native prey items including, but not limited to, white‐tailed deer (Odocoileus virginianus). As an ectothermic species, Burmese pythons' physiological processes, including digestion, are temperature dependent, which may limit their potential invasive range. The low temperature threshold for python digestion is thought to be 20°C within a laboratory setting. Here, we detail an observation of a radio‐telemetered female Burmese python that ingested an adult white‐tailed deer, retained the deer within the digestive tract for 10 days, and then vomited the deer coinciding with a drop in air temperature as low as 9.4°C. The python survived the vomiting and was alive at the time of publication. To our knowledge, this is the first observation of a free‐ranging Burmese python vomiting a deer within the invasive range without direct disturbance from humans at the time of vomiting. This observation provides additional evidence regarding the limits of thermal tolerance, digestion, and feeding habits of invasive Burmese pythons. The Burmese python (Python bivittatus) has an established invasive population throughout South Florida. Here, we detail an observation of a radio‐telemetered female Burmese python that ingested an adult white‐tailed deer, retained the deer within the digestive tract for 10 days, and then vomited the deer coinciding with a drop in air temperature as low as 9.4°C. To our knowledge, this is the first observation of a free‐ranging Burmese python vomiting a deer within the invasive range without direct disturbance from humans at the time of vomiting.

The invasive Burmese python (Python molurus bivittatus) is causing declines in the numbers and diversity of native mammals in the Greater Everglades Ecosystem (GEE). However, limited evidence suggests that some species may be less susceptible to pythons than others. This difference in susceptibility may be a function of different life-history traits. We analysed incidence data with a multi-species hierarchical occupancy model to evaluate the influence of pythons on native mammals and examine the association between python’s influence on species occurrence and life-history traits. We also used our traits-based model to predict the effects of pythons on occupancy probabilities of five mammalian species of conservation or management concern known to occur in the GEE but not detected in our study. Ten of 18 observed mammals showed significant negative effects from pythons, while one responded positively. We found that three of the six species traits evaluated (mass, fecundity, and habitat breadth) moderated the negative effects of pythons on mammal occurrence and were, thus, useful for predicting species responses. Our results suggest larger, fecund and/or species with wide habitat breadths were less susceptible to increasing relative densities of pythons. Our results also suggest a positive and neutral associations between rodents and relative python density, likely due to wide habitat breadths, high fecundity rates, and the reduction of mammalian predators in areas with higher relative python densities. These trait relationships predicted a negative response of all five unobserved species of management concern included in our analysis. Our study provides a broader understanding of wildlife community vulnerability to invasive predators and demonstrates how trait-based models can be used to elucidate generalizable patterns and generate predictions for rare and/or undetected species.

Global pet trade demand has led to the introduction of large constrictor snakes into new environments either intentionally or accidentally. Brazil has the third-highest reptile species diversity globally, with snakes representing the predominant reptilian group, including 12 constrictor species. The potential for competition and predation between invasive and native snakes underscores the need for comprehensive assessment of the risks faced by endemic herpetofauna. This study aimed to identify potential areas for the establishment of invasive Python and assess their impact on native constrictors in Brazil. Environmental Niche Models were employed to predict suitable habitats for invasive pythons and the four endemic Brazilian snake species. By overlapping Python spp. records with those of endemic serpents, this study sought to understand the resource availability for potentially invasive species and the vulnerability of native species to Python invasion. These results highlight Python sebae and Python bivittatus as potentially invasive species that threaten native constrictors. Conversely, Eunectes murinus , with its semi-aquatic behavior, exhibited lower vulnerability. Endemic serpents, including Boa constrictor , Corallus hortulanus , and Epicrates cenchria , were identified as being highly susceptible to potential competition from invasive pythons. These findings emphasize the importance of understanding the potential ecological impacts of introducing invasive species into native ecosystems.

Invasive Burmese pythons (Python bivittatus) have introduced a nonnative pentastomid parasite (Raillietiella orientalis) to southern Florida that has spilled over to infect native snakes. However, the extent of spillover, regarding prevalence and intensity, is unknown. We examined native snakes (n = 523) and invasive pythons (n = 1003) collected from Florida to determine the degree to which parasite spillover is occurring. We found R. orientalis has infected 13 species of native snakes collected from areas of sympatry with pythons. Prevalence and infection intensity of R. orientalis were significantly higher among native snakes compared with pythons. Moreover, adult female pentastomes achieved larger sizes and represented a greater proportion of the overall parasite population in native snakes vs. pythons, indicating native snakes are more competent hosts of R. orientalis than pythons. We also examined native snakes from regions of allopatry with pythons to determine how far R. orientalis has spread. We found an infected native snake 348 km north of the northernmost infected python. Our data show that native snakes are highly competent hosts of R. orientalis and have facilitated the rapid spread of this nonnative pentastome beyond the range of its invasive host.

Burmese python (Python bivittatus) is an invasive snake that has significantly affected ecosystems in southern Florida, United States. Aside from direct predation and competition, invasive species can also introduce nonnative pathogens that can adversely affect native species. The subfamily Serpentovirinae (order Nidovirales) is composed of positive-sense RNA viruses primarily found in reptiles. Some serpentoviruses, such as shingleback nidovirus, are associated with mortalities in wild populations, while others, including ball python nidovirus and green tree python nidovirus can be a major cause of disease and mortality in captive animals. To determine if serpentoviruses were present in invasive Burmese pythons in southern Florida, oral swabs were collected from both free-ranging and long-term captive snakes. Swabs were screened for the presence of serpentovirus by reverse transcription PCR and sequenced. A total serpentovirus prevalence of 27.8% was detected in 318 python samples. Of the initial swabs from 172 free-ranging pythons, 42 (24.4%) were positive for multiple divergent viral sequences comprising four clades across the sampling range. Both sex and snout-vent length were statistically significant factors in virus prevalence, with larger male snakes having the highest prevalence. Sampling location was statistically significant in circulating virus sequence. Mild clinical signs and lesions consistent with serpentovirus infection were observed in a subset of sampled pythons. Testing of native snakes (n = 219, 18 species) in part of the python range found no evidence of python virus spillover; however, five individual native snakes (2.3%) representing three species were PCR positive for unique, divergent serpentoviruses. Calculated pairwise uncorrected distance analysis indicated the newly discovered virus sequences likely represent three novel genera in the subfamily Serpentovirinae. This study is the first to characterize serpentovirus in wild free-ranging pythons or in any free-ranging North America reptile. Though the risk these viruses pose to the invasive and native species is unknown, the potential for spillover to native herpetofauna warrants further investigation.

The oral microbiota has a diversity of microorganisms that together maintain the homeostasis of the oral cavity. Disruptions in the balance of these microbial populations can lead to the development of oral and dental diseases. To characterize the normal oral microbiota of captive ophidians, samples were obtained from the oral cavity of eight Burmese pythons (Python bivittatus) and 11 royal pythons (Python regius), using oral swab, during routine evaluations. In the Laboratory-Antimicrobials, Biocides and Biofilms Unit at University of Trás-os-Montes e Alto Douro, the identification and antimicrobial susceptibility profile was determined using the Vitek® 2 Compact automated device (bioMérieux, Marcy-l’Étoile, France). Of the 106 bacterial isolates obtained, 69% were Gram-negative species and 31% were Gram-positive bacteria. The genus Pseudomonas was the most frequently isolated. Chryseobacterium indologenes, Escherichia coli and Pseudomonas aeruginosa were the most isolated species. Antimicrobial susceptibility testing revealed that the phenotypic resistance was highest for nitrofurans (47.2%), beta-lactams (45.8%) and sulfonamides (30.6%). Twenty-one multidrug-resistant isolates (58.3%) were identified with Acinetobacter baumannii, Serratia plymuthica, Chryseobacterium indologenes, Providencia rettgeri and Pseudomonas aeruginosa showing the highest resistance frequencies.

Invasive Burmese pythons have been shown to have population-level effects on native mammals in southern Florida. Tens of thousands of long-legged wading birds (of multiple species in Ciconiiformes, Pelecaniformes) breed in aggregations, known as colonies, on tree islands in the Everglades. Burmese pythons may pose a threat to these colonies because pythons are semi-aquatic and commonly use tree islands and arboreal habitat. However, python predation on nests of wading birds has not previously been documented or quantified. We used trail cameras to monitor nests at colonies in Everglades National Park and Water Conservation Area 3 in 2014, and 2016–2017. We did not detect Burmese python predation at monitored nests in 2014 (23 nests in 2 colonies) or 2016 (59 nests in 4 colonies). In 2017 (125 nests in 7 colonies), we detected three individual pythons consuming nestlings, fledglings, and eggs in a minimum of 7.9% (5 nests, n = 63) of monitored nests at a colony in Everglades National Park. In 2017, the overall predation rate of Burmese pythons at all monitored nests (5 of 125 nests, or 4%), was five times the native predator rate (1 of 125 nests, or 0.8%). Our study confirms that Burmese pythons are acting as predators in wading bird colonies at nontrivial rates and provides a baseline to which future studies can refer.