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McCampbell M, Spencer M, Hart K, Link G, Watson A, McCleery R. Mammalian lures monitored with time-lapse cameras increase detection of pythons and other snakes. PeerJ 2024; 12:e17577. [PMID: 38938602 PMCID: PMC11210459 DOI: 10.7717/peerj.17577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 05/24/2024] [Indexed: 06/29/2024] Open
Abstract
Background Enhancing detection of cryptic snakes is critical for the development of conservation and management strategies; yet, finding methods that provide adequate detection remains challenging. Issues with detecting snakes can be particularly problematic for some species, like the invasive Burmese python (Python bivittatus) in the Florida Everglades. Methods Using multiple survey methods, we predicted that our ability to detect pythons, larger snakes and all other snakes would be enhanced with the use of live mammalian lures (domesticated rabbits; Oryctolagus cuniculus). Specifically, we used visual surveys, python detection dogs, and time-lapse game cameras to determine if domesticated rabbits were an effective lure. Results Time-lapse game cameras detected almost 40 times more snakes (n = 375, treatment = 245, control = 130) than visual surveys (n = 10). We recorded 21 independent detections of pythons at treatment pens (with lures) and one detection at a control pen (without lures). In addition, we found larger snakes, and all other snakes were 165% and 74% more likely to be detected at treatment pens compared to control pens, respectively. Time-lapse cameras detected almost 40 times more snakes than visual surveys; we did not detect any pythons with python detection dogs. Conclusions Our study presents compelling evidence that the detection of snakes is improved by coupling live mammalian lures with time-lapse game cameras. Although the identification of smaller snake species was limited, this was due to pixel resolution, which could be improved by changing the camera focal length. For larger snakes with individually distinctive patterns, this method could potentially be used to identify unique individuals and thus allow researchers to estimate population dynamics.
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Affiliation(s)
- Marina McCampbell
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America
| | - McKayla Spencer
- Florida Fish and Wildlife Conservation Commission, Gainesville, Florida, United States of America
| | - Kristen Hart
- Wetland and Aquatic Research Center, United States Geological Survey, Fort Lauderdale, Florida, United States of America
| | - Gabrielle Link
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America
| | - Andrew Watson
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America
| | - Robert McCleery
- Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida, United States of America
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Guzy JC, Falk BG, Smith BJ, Willson JD, Reed RN, Aumen NG, Avery ML, Bartoszek IA, Campbell E, Cherkiss MS, Claunch NM, Currylow AF, Dean T, Dixon J, Engeman R, Funck S, Gibble R, Hengstebeck KC, Humphrey JS, Hunter ME, Josimovich JM, Ketterlin J, Kirkland M, Mazzotti FJ, McCleery R, Miller MA, McCollister M, Parker MR, Pittman SE, Rochford M, Romagosa C, Roybal A, Snow RW, Spencer MM, Waddle JH, Yackel Adams AA, Hart KM. Burmese pythons in Florida: A synthesis of biology, impacts, and management tools. NEOBIOTA 2023. [DOI: 10.3897/neobiota.80.90439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Burmese pythons (Python molurus bivittatus) are native to southeastern Asia, however, there is an established invasive population inhabiting much of southern Florida throughout the Greater Everglades Ecosystem. Pythons have severely impacted native species and ecosystems in Florida and represent one of the most intractable invasive-species management issues across the globe. The difficulty stems from a unique combination of inaccessible habitat and the cryptic and resilient nature of pythons that thrive in the subtropical environment of southern Florida, rendering them extremely challenging to detect. Here we provide a comprehensive review and synthesis of the science relevant to managing invasive Burmese pythons. We describe existing control tools and review challenges to productive research, identifying key knowledge gaps that would improve future research and decision making for python control.
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Currylow AF, Falk BG, Yackel Adams AA, Romagosa CM, Josimovich JM, Rochford MR, Cherkiss MS, Nafus MG, Hart KM, Mazzotti FJ, Snow RW, Reed RN. Size distribution and reproductive phenology of the invasive Burmese python (Python molurus bivittatus) in the Greater Everglades Ecosystem, Florida, USA. NEOBIOTA 2022. [DOI: 10.3897/neobiota.78.93788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
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.
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Ramsey DSL, Campbell KJ, Lavoie C, Macdonald N, Morrison SA. Quantifying the probability of detection of wild ungulates with the Judas technique. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2022; 36:e13898. [PMID: 35122326 DOI: 10.1111/cobi.13898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/16/2021] [Accepted: 12/17/2021] [Indexed: 06/14/2023]
Abstract
The Judas technique is often used in control or eradication of particular vertebrate pests. The technique exploits the tendency of individuals to form social groups. A radio collar is affixed to an individual and its subsequent monitoring facilitates the detection of other conspecifics. Efficacy of this technique would be improved if managers could estimate the probability that a Judas individual would detect conspecifics. To calculate this probability, we estimated association rates of Judas individuals with other Judas individuals, given the length of time the Judas has been deployed. We developed a simple model of space-use for individual Judas animals and constrained detection probabilities to those specific areas. We then combined estimates for individual Judas animals to infer the probability that a wild individual could be detected in an area of interest via Judas surveillance. We illustrated the method by using data from a feral goat eradication program on Isla Santiago, Galápagos, and a feral pig eradication program on Santa Cruz Island, California. Association probabilities declined as the proximity between individual areas of use of a Judas pair decreased. Unconditional probabilities of detection within individual areas of use averaged 0.09 per month for feral pigs and 0.11 per month for feral goats. Probabilities that eradication had been achieved, given no detections of wild conspecifics, and an uninformative prior probability of eradication were 0.79 (90% CI 0.22-0.99) for feral goats and 0.87 (90% CI 0.44-1.0) for feral pigs. We envisage several additions to the analyses used that could improve estimates of Judas detection probability. Analyses such as these can help managers increase the efficacy of eradication efforts, leading to more effective effects to restore native biodiversity.
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Affiliation(s)
- David S L Ramsey
- Department of Environment Land, Water and Planning, Arthur Rylah Institute, 3084, Heidelberg, Victoria, Australia
- School of Biological Sciences, University of Adelaide, 5005, Adelaide, North Terrace, Australia
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5
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Soto I, Cuthbert RN, Kouba A, Capinha C, Turbelin A, Hudgins EJ, Diagne C, Courchamp F, Haubrock PJ. Global economic costs of herpetofauna invasions. Sci Rep 2022; 12:10829. [PMID: 35902706 PMCID: PMC9334389 DOI: 10.1038/s41598-022-15079-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 06/17/2022] [Indexed: 11/24/2022] Open
Abstract
Biological invasions by amphibian and reptile species (i.e. herpetofauna) are numerous and widespread, having caused severe impacts on ecosystems, the economy and human health. However, there remains no synthesised assessment of the economic costs of these invasions. Therefore, using the most comprehensive database on the economic costs of invasive alien species worldwide (InvaCost), we analyse the costs caused by invasive alien herpetofauna according to taxonomic, geographic, sectoral and temporal dimensions, as well as the types of these costs. The cost of invasive herpetofauna totaled at 17.0 billion US$ between 1986 and 2020, divided split into 6.3 billion US$ for amphibians, 10.4 billion US$ for reptiles and 334 million US$ for mixed classes. However, these costs were associated predominantly with only two species (brown tree snake Boiga irregularis and American bullfrog Lithobates catesbeianus), with 10.3 and 6.0 billion US$ in costs, respectively. Costs for the remaining 19 reported species were relatively minor (< 0.6 billion US$), and they were entirely unavailable for over 94% of known invasive herpetofauna worldwide. Also, costs were positively correlated with research effort, suggesting research biases towards well-known taxa. So far, costs have been dominated by predictions and extrapolations (79%), and thus empirical observations for impact were relatively scarce. The activity sector most affected by amphibians was authorities-stakeholders through management (> 99%), while for reptiles, impacts were reported mostly through damages to mixed sectors (65%). Geographically, Oceania and Pacific Islands recorded 63% of total costs, followed by Europe (35%) and North America (2%). Cost reports have generally increased over time but peaked between 2011 and 2015 for amphibians and 2006 to 2010 for reptiles. A greater effort in studying the costs of invasive herpetofauna is necessary for a more complete understanding of invasion impacts of these species. We emphasise the need for greater control and prevention policies concerning the spread of current and future invasive herpetofauna.
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Affiliation(s)
- Ismael Soto
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České Budějovice, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - Ross N Cuthbert
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Antonín Kouba
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České Budějovice, Zátiší 728/II, 389 25, Vodňany, Czech Republic
| | - César Capinha
- Centro de Estudos Geográficos, Instituto de Geografia e Ordenamento do Território-IGOT, Universidade de Lisboa, Rua Branca Edmée Marques, 1600-276, Lisbon, Portugal
- Laboratório Associado Terra, Lisbon, Portugal
| | - Anna Turbelin
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, 91405, Orsay, France
| | - Emma J Hudgins
- Department of Biology, Carleton University, Ottawa, Canada
| | - Christophe Diagne
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, 91405, Orsay, France
| | - Franck Courchamp
- Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, 91405, Orsay, France
| | - Phillip J Haubrock
- Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, University of South Bohemia in České Budějovice, Zátiší 728/II, 389 25, Vodňany, Czech Republic.
- Department of River Ecology and Conservation, Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, Germany.
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Claunch NM, Bartoszek IA, Tillis S, Stacy NI, Ossiboff RJ, Oakey S, Schoenle LA, Wellehan JFX, Romagosa CM. Physiological effects of capture and short-term captivity in an invasive snake species, the Burmese python (Python bivittatus) in Florida. Comp Biochem Physiol A Mol Integr Physiol 2022; 267:111162. [PMID: 35149178 DOI: 10.1016/j.cbpa.2022.111162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/04/2022] [Accepted: 02/04/2022] [Indexed: 02/05/2023]
Abstract
It is important to evaluate the role of captivity as a potential stressor. An understanding of stress responses to capture and transition to captivity may inform the limitations of laboratory studies on wild animals, aid in understanding the consequences of introducing animals into captive environments, and help predict which species may be successful invasives. We investigated physiological effects of captivity by comparing at-capture blood variables in wild Burmese pythons (Python bivittatus) in Florida to pythons recently brought into captivity (1-109 days). We conducted an acute restraint test by collecting samples at baseline (immediately at handling) and one hour post-restraint across wild field-sampled (n = 19) and recently-captive (n = 33) pythons to evaluate fluctuations in plasma corticosterone, bacterial killing ability, antibody response, leukogram, and serpentovirus infection. We observed higher baseline plasma corticosterone and monocytes in recently captive compared to wild snakes, which both subsided in snakes held for a longer time in captivity, and a mild decrease in lymphocytes in the middle of the captivity period. Functional immunity and viral infection were not affected by captivity, and pythons maintained restraint-induced responses in corticosterone, heterophil to lymphocyte ratio, and monocyte counts throughout captivity. Prevalence for serpentovirus was 50%, though infection status was related to sampling date rather than captivity, indicating that viral infection may be seasonal. The history of Burmese python as a common captive animal for research and pet trade, as well as its general resilience to effects of capture and short-term captivity, may contribute to its invasion success in Florida.
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Affiliation(s)
- Natalie M Claunch
- School of Natural Resources and Environment, University of Florida, USA.
| | | | - Steve Tillis
- College of Veterinary Medicine, University of Florida, USA
| | - Nicole I Stacy
- College of Veterinary Medicine, University of Florida, USA
| | | | - Samantha Oakey
- College of Veterinary Medicine, University of Georgia, USA
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7
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Spatial ecology, activity patterns, and habitat use by giant pythons (Simalia amethistina) in tropical Australia. Sci Rep 2022; 12:5274. [PMID: 35347214 PMCID: PMC8960824 DOI: 10.1038/s41598-022-09369-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 03/21/2022] [Indexed: 11/09/2022] Open
Abstract
Although giant snakes are abundant in some tropical forests, their ecology is far less well-known than for smaller species of snakes in cooler climates. Information on spatial ecology can clarify management issues such as the sizes and types of habitats needed for conservation. We radio-tracked 27 scrub pythons (Simalia amethistina; snout-vent lengths 2.02 to 3.70 m) in Cape York, near the northeastern tip of Australia, for a mean period of 426 days (up to 1001 days) per snake. Home ranges were larger in males than females (means 0.60 vs. 0.28 km2) and overlapped considerably among individuals. All snakes used rainforest habitat, but seasonal shifts into open woodland were common. Snakes were active primarily by night, with larger snakes hunting less of the time overall, and more often by day. Hunting behaviour was seen more often during the wet season than the dry season. Average daily displacement was < 10 m, typically involving a shift from diurnal refuge to nocturnal ambush-site. A reliance on sit-and-wait predation results in small home ranges and limited movements, despite the large body size of this species.
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Currylow AF, McCollister MF, Anderson GE, Josimovich JM, Fitzgerald AL, Romagosa CM, Yackel Adams AA. Face-off: Novel depredation and nest defense behaviors between an invasive and a native predator in the Greater Everglades Ecosystem, Florida, USA. Ecol Evol 2022; 12:e8639. [PMID: 35222984 PMCID: PMC8858213 DOI: 10.1002/ece3.8639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/20/2022] [Accepted: 01/27/2022] [Indexed: 11/09/2022] Open
Abstract
We describe several photo-documented novel interactions between intraguild predators in southern Florida-the native bobcat (Lynx rufus) and the invasive Burmese python (Python bivittatus). Over several days we documented a bobcat's depredation of an unguarded python nest and subsequent python nest defense behavior following the return of both animals to the nest. This is the first documentation of any animal in Florida preying on python eggs, and the first evidence or description of such antagonistic interactions at a python nest.
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Affiliation(s)
- Andrea F. Currylow
- U.S. Geological SurveyFort Collins Science Center ‐ South Florida Field Station in Everglades National ParkHomesteadFloridaUSA
| | | | - Gretchen E. Anderson
- U.S. Geological SurveyFort Collins Science Center ‐ South Florida Field Station in Everglades National ParkHomesteadFloridaUSA
| | - Jillian M. Josimovich
- U.S. Geological SurveyFort Collins Science Center ‐ South Florida Field Station in Everglades National ParkHomesteadFloridaUSA
- Present affiliation: U.S. Fish and Wildlife ServiceAvon Park Air Force RangeAvon ParkFloridaUSA
| | - Austin L. Fitzgerald
- U.S. Geological SurveyFort Collins Science Center ‐ South Florida Field Station in Everglades National ParkHomesteadFloridaUSA
| | - Christina M. Romagosa
- Department of Wildlife Ecology and ConservationUniversity of FloridaGainesvilleFloridaUSA
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Pittman SE, Bartoszek IA. Initial dispersal behavior and survival of non-native juvenile Burmese pythons (Python bivittatus) in South Florida. BMC ZOOL 2021; 6:33. [PMID: 37170339 PMCID: PMC10124209 DOI: 10.1186/s40850-021-00098-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 11/10/2021] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Dispersal behavior is a critical component of invasive species dynamics, impacting both spatial spread and population density. In South Florida, Burmese pythons (Python bivittatus) are an invasive species that disrupt ecosystems and have the potential to expand their range northward. Control of python populations is limited by a lack of information on movement behavior and vital rates, especially within the younger age classes. We radio-tracked 28 Burmese pythons from hatching until natural mortality for approximately 3 years. Pythons were chosen from 4 clutches deposited by adult females in 4 different habitats: forested wetland, urban interface, upland pine, and agricultural interface.
Results
Known-fate survival estimate was 35.7% (95% CI = 18% - 53%) in the first 6 months, and only 2 snakes survived 3 years post hatching. Snakes moving through ‘natural’ habitats had higher survival than snakes dispersing through ‘modified’ habitats in the first 6- months post-hatching. Predation was the most common source of mortality. Snakes from the agricultural interface utilized canals and displayed the largest net movements.
Conclusions
Our results suggest that pythons may have lower survival if clutches are deposited in or near urbanized areas. Alternatively, juvenile pythons could quickly disperse to new locations by utilizing canals that facilitate linear movement. This study provides critical information about behavioral and life history characteristics of juvenile Burmese pythons that will inform management practices.
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Fitzgerald AL, Josimovich JM, Robinson CJ, Reed RN, Currylow AF. Identifying negative sentiment polarity in the Judas technique. CONSERVATION SCIENCE AND PRACTICE 2021. [DOI: 10.1111/csp2.532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Austin L. Fitzgerald
- U.S. Geological Survey, Fort Collins Science Center – Invasive Species Science 2150 Centre Avenue, Building C Fort Collins Colorado USA
| | - Jillian M. Josimovich
- U.S. Geological Survey, Fort Collins Science Center – Invasive Species Science 2150 Centre Avenue, Building C Fort Collins Colorado USA
| | - Charlotte J. Robinson
- U.S. Geological Survey, Fort Collins Science Center – Invasive Species Science 2150 Centre Avenue, Building C Fort Collins Colorado USA
| | - Robert N. Reed
- U.S. Geological Survey, Fort Collins Science Center – Invasive Species Science 2150 Centre Avenue, Building C Fort Collins Colorado USA
- U.S. Geological Survey, Pacific Island Ecosystems Research Center Hawaii National Park Hawaii USA
| | - Andrea F. Currylow
- U.S. Geological Survey, Fort Collins Science Center – Invasive Species Science 2150 Centre Avenue, Building C Fort Collins Colorado USA
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Genome-Wide SNP Analysis Reveals Multiple Paternity in Burmese Pythons Invasive to the Greater Florida Everglades. J HERPETOL 2021. [DOI: 10.1670/20-104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Bartoszek IA, Smith BJ, Reed RN, Hart KM. Spatial ecology of invasive Burmese pythons in southwestern Florida. Ecosphere 2021. [DOI: 10.1002/ecs2.3564] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
| | - Brian J. Smith
- Department of Wildland Resources and Conservation Center Utah State University 5230 Old Main Hill Logan Utah84322USA
| | - Robert N. Reed
- Pacific Island Ecosystems Research Center U.S. Geological Survey Hawaii Volcanoes National Park Hawaii96718USA
| | - Kristen M. Hart
- Wetland and Aquatic Research Center U.S. Geological Survey 3321 College Avenue Davie Florida33314USA
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McCollister MF, Josimovich JM, Fitzgerald AL, Jansen DK, Currylow AF. Native Mammalian Predators Can Depredate Adult Burmese Pythons in Florida. SOUTHEAST NAT 2021. [DOI: 10.1656/058.020.0205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Matthew F. McCollister
- National Park Service, Big Cypress National Preserve, 33100 Tamiami Trail East, Ochopee, FL 34141
| | - Jillian M. Josimovich
- US Geological Survey, Fort Collins Science Center, South Florida Field Station in Everglades National Park, 40001 SR 9336, Homestead, FL 33034
| | - Austin L. Fitzgerald
- US Geological Survey, Fort Collins Science Center, South Florida Field Station in Everglades National Park, 40001 SR 9336, Homestead, FL 33034
| | - Deborah K. Jansen
- National Park Service, Big Cypress National Preserve, 33100 Tamiami Trail East, Ochopee, FL 34141
| | - Andrea F. Currylow
- US Geological Survey, Fort Collins Science Center, South Florida Field Station in Everglades National Park, 40001 SR 9336, Homestead, FL 33034
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Native Burmese pythons exhibit site fidelity and preference for aquatic habitats in an agricultural mosaic. Sci Rep 2021; 11:7014. [PMID: 33782524 PMCID: PMC8007826 DOI: 10.1038/s41598-021-86640-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 03/04/2021] [Indexed: 11/08/2022] Open
Abstract
Animal movement and resource use are tightly linked. Investigating these links to understand how animals use space and select habitats is especially relevant in areas affected by habitat fragmentation and agricultural conversion. We set out to explore the space use and habitat selection of Burmese pythons (Python bivittatus) in a heterogenous, agricultural landscape within the Sakaerat Biosphere Reserve, northeast Thailand. We used VHF telemetry to record the daily locations of seven Burmese pythons and created dynamic Brownian Bridge Movement Models to produce occurrence distributions and model movement extent and temporal patterns. To explore relationships between movement and habitat selection we used integrated step selection functions at both the individual and population level. Burmese pythons had a mean 99% occurrence distribution contour of 98.97 ha (range 9.05–285.56 ha). Furthermore, our results indicated that Burmese pythons had low mean individual motion variance, indicating infrequent moves and long periods at a single location. In general, Burmese pythons restricted movement and selected aquatic habitats but did not avoid potentially dangerous land use types like human settlements. Although our sample is small, we suggest that Burmese pythons are capitalizing on human disturbed landscapes.
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Vanek JP, Burke RL. Insular dwarfism in female Eastern Hog-nosed Snakes ( Heterodon platirhinos; Dipsadidae) on a barrier island. CAN J ZOOL 2020. [DOI: 10.1139/cjz-2019-0137] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The island rule postulates that the special ecological conditions on islands, such as limited resource availability, can cause populations of large-bodied animals to evolve smaller sizes and small-bodied populations to evolve larger sizes. Although support for the island rule is well documented (with notable exceptions and debate) in mammals and birds, similar trends are poorly explored in ectothermic vertebrates. As part of a larger study investigating the ecology of Eastern Hog-nosed Snakes (Heterodon platirhinos Latreille, 1801), we compared the mean and maximum sizes of a population from a barrier island (∼4 000 ha) to snakes on an adjacent larger island (∼363 000 ha) and two mainland sites (450 total snakes across all study sites). We did not observe a difference between the small and the large islands, but we did find differences between the smallest island and the mainland. Female snakes on the barrier island were 8% smaller than those on the mainland, and the female from the largest barrier island was 35% smaller than the largest documented H. platirhinos. In addition, we found that males did not exhibit dwarfism. We hypothesize that the observed dwarfism is a result of limited availability of large prey items and recommend that future studies distinguish between sexes in their analyses.
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Affiliation(s)
- John P. Vanek
- Department of Biology, Hofstra University, Hempstead, NY 11549–1140, USA
- Department of Biology, Hofstra University, Hempstead, NY 11549–1140, USA
| | - Russell L. Burke
- Department of Biology, Hofstra University, Hempstead, NY 11549–1140, USA
- Department of Biology, Hofstra University, Hempstead, NY 11549–1140, USA
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Nafus MG, Yackel Adams AA, Boback SM, Siers SR, Reed RN. Behavior, size, and body condition predict susceptibility to management and reflect post-treatment frequency shifts in an invasive snake. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2019.e00834] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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17
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Estimating Detection Probability for Burmese Pythons with Few Detections and Zero Recaptures. J HERPETOL 2020. [DOI: 10.1670/18-154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Richard SA, Tillman EA, Humphrey JS, Avery ML, Parker MR. Male Burmese pythons follow female scent trails and show sex-specific behaviors. Integr Zool 2019; 14:460-469. [PMID: 30585425 DOI: 10.1111/1749-4877.12376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Animals communicate with potential mates using species-specific signals, and pheromones are powerful sexual signals that modify conspecific behavior to facilitate mate location. Among the vertebrates, snakes are especially adept in mate searching via chemical trailing, which is particularly relevant given that many snake species are invasive outside their native ranges. Chemical signals used in mate choice are, thus, potentially valuable tools for management of invasive snake species. The Burmese python (Python bivittatus) is an invasive snake in the Florida Everglades where it is negatively impacting native fauna. In this study, we sought to: (i) determine if males can follow conspecific chemical trails in a Y-maze; and (ii) describe the mate searching behaviors exhibited by males while trailing. All males consistently followed a single female scent trail in the maze, but when only a male scent trail was present they did not discriminate between the male and blank arms. Rate of tongue-flicking, a proxy for chemosensory sampling, was also marginally higher when males were following female versus male scent trails. However, when both female and male scent trails were simultaneously present in the Y-maze, males did not show a preference for the female arm, although the tongue-flick rate was higher in the female-only trial compared to female versus male. Analyses of multiple male behaviors individually and using an ethogram revealed that behaviors were more frequent and complex in the female-only trials compared to male-only trials. Additional behavioral trials are needed to determine if an effective pheromonal approach to Burmese python management is possible.
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Affiliation(s)
- Shannon A Richard
- Department of Biology, James Madison University, Harrisonburg, Virginia, USA
| | - Eric A Tillman
- National Wildlife Research Center, Florida Field Station, U.S. Department of Agriculture, Gainesville, Florida, USA
| | - John S Humphrey
- National Wildlife Research Center, Florida Field Station, U.S. Department of Agriculture, Gainesville, Florida, USA
| | - Michael L Avery
- National Wildlife Research Center, Florida Field Station, U.S. Department of Agriculture, Gainesville, Florida, USA
| | - M Rockwell Parker
- Department of Biology, James Madison University, Harrisonburg, Virginia, USA
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Hunter ME, Johnson NA, Smith BJ, Davis MC, Butterfield JSS, Snow RW, Hart KM. Cytonuclear discordance in the Florida Everglades invasive Burmese python ( Python bivittatus) population reveals possible hybridization with the Indian python ( P. molurus). Ecol Evol 2018; 8:9034-9047. [PMID: 30271564 PMCID: PMC6157680 DOI: 10.1002/ece3.4423] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 06/08/2018] [Accepted: 06/22/2018] [Indexed: 12/04/2022] Open
Abstract
The invasive Burmese python (Python bivittatus) has been reproducing in the Florida Everglades since the 1980s. These giant constrictor snakes have caused a precipitous decline in small mammal populations in southern Florida following escapes or releases from the commercial pet trade. To better understand the invasion pathway and genetic composition of the population, two mitochondrial (mtDNA) loci across 1,398 base pairs were sequenced on 426 snakes and 22 microsatellites were assessed on 389 snakes. Concatenated mtDNA sequences produced six haplotypes with an average nucleotide and haplotype diversity of π = 0.002 and h = 0.097, respectively. Samples collected in Florida from morphologically identified P. bivittatus snakes were similar to published cytochrome oxidase 1 and cytochrome b sequences from both P. bivittatus and Python molurus and were highly divergent (genetic distances of 5.4% and 4.3%, respectively). The average number of microsatellite alleles and expected heterozygosity were N A = 5.50 and H E = 0.60, respectively. Nuclear Bayesian assignment tests supported two genetically distinct groups and an admixed group, not geographically differentiated. The effective population size (N E = 315.1) was lower than expected for a population this large, but reflected the low genetic diversity overall. The patterns of genetic diversity between mtDNA and microsatellites were disparate, indicating nuclear introgression of separate mtDNA lineages corresponding to cytonuclear discordance. The introgression likely occurred prior to the invasion, but genetic information on the native range and commercial trade is needed for verification. Our finding that the Florida python population is comprised of distinct lineages suggests greater standing variation for adaptation and the potential for broader areas of suitable habitat in the invaded range.
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Affiliation(s)
- Margaret E. Hunter
- U.S. Geological SurveyWetland and Aquatic Research CenterGainesvilleFlorida
| | - Nathan A. Johnson
- U.S. Geological SurveyWetland and Aquatic Research CenterGainesvilleFlorida
| | - Brian J. Smith
- Wetland and Aquatic Research CenterCherokee Nation TechnologiesDavieFlorida
| | - Michelle C. Davis
- U.S. Geological SurveyWetland and Aquatic Research CenterGainesvilleFlorida
| | | | - Ray W. Snow
- U.S. National Park ServiceEverglades National ParkHomesteadFlorida
| | - Kristen M. Hart
- U.S. Geological SurveyWetland and Aquatic Research CenterDavieFlorida
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Reichert BE, Sovie AR, Udell BJ, Hart KM, Borkhataria RR, Bonneau M, Reed R, McCleery R. Urbanization may limit impacts of an invasive predator on native mammal diversity. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12531] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Affiliation(s)
- Brian E. Reichert
- Department of Wildlife Ecology and Conservation University of Florida Gainesville FL 32611‐0485 USA
| | - Adia R. Sovie
- Department of Wildlife Ecology and Conservation University of Florida Gainesville FL 32611‐0485 USA
| | - Brad J. Udell
- Department of Wildlife Ecology and Conservation University of Florida Gainesville FL 32611‐0485 USA
| | - Kristen M. Hart
- U.S. Geological Survey Wetland and Aquatic Research Center Davie FL 33314 USA
| | - Rena R. Borkhataria
- Everglades Research and Education Center University of Florida 3200 E. Palm Beach Rd. Belle Glade FL 33430 USA
| | - Mathieu Bonneau
- Department of Wildlife Ecology and Conservation University of Florida Gainesville FL 32611‐0485 USA
| | - Robert Reed
- U.S. Geological Survey Invasive Species Branch Fort Collins CO 80526 USA
| | - Robert McCleery
- Department of Wildlife Ecology and Conservation University of Florida Gainesville FL 32611‐0485 USA
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