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Syafiq MF, Badli-Sham BH, Grismer LL, Ahmad AB. Uneven species occurrence and richness of lowland snakes (Serpentes, Squamata) in Terengganu, Peninsular Malaysia, with new locality records. Zookeys 2023; 1168:11-39. [PMID: 38328625 PMCID: PMC10848808 DOI: 10.3897/zookeys.1168.95833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 03/11/2023] [Indexed: 02/09/2024] Open
Abstract
This study documents information on the composition, diversity, richness, and temporal occurrence of snakes at Sekayu's lowland forest (SLF), Terengganu, Peninsular Malaysia for the first time. The snakes recorded within the SLF were sampled opportunistically from 2013 to 2019, employing the Visual Encounter Survey method (VES) and L-shape pitfall traps with drift fences. Forty-six snake species from 37 genera belonging to the nine families were recorded, of which 11 were new records to Terengganu. Individual-based rarefaction and extrapolation curves were not reaching asymptote, indicating that additional species can be recorded at the study area. Non-parametric species richness estimators estimated and produced a range between 51 and 57 species. ACE was the best estimator based on the quantitative evaluation. All species showed some variations of occurrence patterns across months. Fourteen species were only encountered once across the sampling years, and interestingly 11 of them were only detected during the rainy season (late October to January). In general, the number of species richness, abundance, and rare species were high during this season. Species richness of snakes is high at SLF but sampling effort should be intensified, especially during these rainy months, to obtain a robust estimated snake species richness in SLF. Terengganu harbor considerably high species richness of snakes with a total of 71 species to date (excluding marine snakes), but snake diversity is still underestimated as only a few localities were surveyed in the past years, primarily at the northern part. Future surveys should be commenced at the central and southern parts of Terengganu to complement the current investigation.
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Affiliation(s)
- Muhamad Fatihah Syafiq
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia
| | - Baizul Hafsyam Badli-Sham
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia
| | - Larry Lee Grismer
- Herpetology Laboratory, Department of Biology, La Sierra University, Riverwalk Parkway, Riverside, California 92505, USA
| | - Amirrudin B. Ahmad
- Faculty of Science and Marine Environment, Universiti Malaysia Terengganu, 21030, Kuala Nerus, Terengganu, Malaysia
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Maestresalas B, Piquet JC, López-Darias M. Spatial ecology to strengthen invasive snake management on islands. Sci Rep 2023; 13:6731. [PMID: 37185934 PMCID: PMC10130030 DOI: 10.1038/s41598-023-32483-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 03/28/2023] [Indexed: 05/17/2023] Open
Abstract
Knowledge on the spatial ecology of invasive predators positively contributes to optimizing their management, especially when involving cryptic and secretive species, such as snakes. However, this information is lacking for most invasive snakes, particularly on islands, where they are known to cause severe ecological and socio-economic impacts. This research is focused on assessing the spatial ecology of the California kingsnake (Lampropeltis californiae) on Gran Canaria to strengthen management actions. We monitored 15 radio-tagged individuals once per day on 9-11 days per month from July 2020 to June 2021 to calculate the species' home range and describe annual activity patterns in the invaded range. To account for the species' diel activity during the emergence period, we additionally monitored snakes from January to May 2021 during three consecutive days per month in four different time intervals each day. We detected movement (consecutive detections at least 6 m apart) in 31.68% of the 1146 detections during the whole monitoring period. Movements most frequently detected were shorter than 100 m (82.24%), and among them the range 0-20 m was the most recurrent (27.03%). The mean distance of movement was 62.57 ± 62.62 m in 1-2 days. Average home range was 4.27 ± 5.35 ha-calculated with the Autocorrelated Kernel Density Estimator (AKDE) at 95%-and did not significantly vary with SVL nor sex. We detected an extremely low value of motion variance (0.76 ± 2.62 σ2m) compared to other studies, with a general inactivity period from November to February, January being the less active month of the year. Diel activity was higher during central and evening hours than during early morning and night. Our results should be useful to improve control programs for this invasive snake (e.g., trap placement and visual survey guidance) on Gran Canaria. Our research highlights the importance of gathering spatial information on invasive snakes to enhance control actions, which can contribute to the management of secretive invasive snakes worldwide.
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Affiliation(s)
- Borja Maestresalas
- Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), 38206, La Laguna, Tenerife, Canary Islands, Spain
| | - Julien C Piquet
- Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), 38206, La Laguna, Tenerife, Canary Islands, Spain
| | - Marta López-Darias
- Island Ecology and Evolution Research Group, Instituto de Productos Naturales y Agrobiología (IPNA-CSIC), 38206, La Laguna, Tenerife, Canary Islands, Spain.
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3
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The Reptile Relocation Industry in Australia: Perspectives from Operators. DIVERSITY 2023. [DOI: 10.3390/d15030343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Thousands of reptiles are relocated annually in Australia, yet there has been relatively little research aimed at understanding how the reptile relocation industry operates. An online questionnaire was distributed to anyone who had relocated a reptile between April 2019 and April 2020, including wildlife relocators, wildlife rehabilitators and the general public. The questionnaire explored demographics, decision-making and concerns about how the industry functions, through 24 questions and two opportunities to provide open-ended comments. We received 125 responses and 123 comments from operators in all Australian states and territories. Beliefs about appropriate times and places for reptile releases were not reflected in practice for the majority of operators. Confidence about reptiles remaining at recipient sites was low regardless of how many years’ experience an operator had. Escaped captive native reptiles were encountered by most operators, and a quarter of operators were called out to exotic non-native snakes. Operators across all levels of experience indicated a need for changes within the industry, including increased training and professionalism, and more scientific studies on the outcomes of relocations to address concerns about the impacts that the industry has on the wildlife that it is trying to protect.
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Tipton AF, Vázquez-Diosdado JA, DeSantis DL. Scale-dependent effects of roadways on the movement behavior of a large-bodied pit viper (Crotalus horridus). Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1007743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
Roadways are among the most widespread and disruptive anthropogenic land use features that influence the behavior and movement of wildlife. Negative impacts of roadways have been well documented, but the behavioral impact of roadways on smaller, cryptic species has yet to be thoroughly examined. Using a novel integration of radio telemetry and tri-axial accelerometry, we evaluated the effects of roadways on the movement behavior of 26 adult Timber Rattlesnakes (Crotalus horridus) at coarse and fine time scales in central Georgia between June 2020 and November 2021. To interpret the effect of roads at a coarse time scale, we modeled the effect of mean annual distance to roadways (DTR) on annual measures of movement and space use by C. horridus using both radio telemetry and accelerometry derived metrics (RT and ACT metrics). To explore the fine-scale impact of roadways, we quantified RT and ACT metrics during confirmed road interactions (i.e., instances when individual snakes crossed a road or encountered a road but did not cross) and compared these instances to the RT and ACT metrics calculated across the remainder of the active season within this subset of snakes. Relating the annual RT and ACT metrics to DTR revealed no significant associations at a coarse time scale. However, the evaluation of C. horridus movement behavior during punctuated road encounters revealed that snakes increased RT and ACT metrics during the road interactions compared to metrics calculated across the remainder of the active season. This might indicate that the abundance of contiguous habitat adjacent to roadways at our study site is serving as an adequate buffer to any long-term shifts in movement behavior, but the potential hidden cost of increasing movement when snakes encounter roads could have negative implications for populations that encounter roads more frequently, even in the absence of significant direct road mortality. Overall, integrating radio telemetry and accelerometry and adopting a scale-dependent approach to quantifying movement allowed for a more detailed evaluation of the response of C. horridus to roadways. This approach holds promise for detecting and interpreting previously overlooked short-term alterations in snake movement behavior with potentially significant fitness consequences.
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Hodges CW, Marshall BM, Hill JG, Strine CT. Malayan kraits (Bungarus candidus) show affinity to anthropogenic structures in a human dominated landscape. Sci Rep 2022; 12:7139. [PMID: 35504946 PMCID: PMC9065047 DOI: 10.1038/s41598-022-11255-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 04/07/2022] [Indexed: 11/22/2022] Open
Abstract
Animal movement can impact human-wildlife conflict by influencing encounter and detection rates. We assess the movement and space use of the highly venomous and medically important Malayan krait (Bungarus candidus) on a suburban university campus. We radio-tracked 14 kraits for an average of 114 days (min: 19, max: 218), during which we located individuals an average of 106 times (min: 21, max: 229) each. Most individuals displayed some level of attraction to buildings (n = 10) and natural areas (n = 12); we identified a similar unambiguous pattern of attraction to buildings and natural areas at the population level (of our sample). Snakes remained in shelter sites for long durations (max: 94 days) and revisited sites on average every 15.45 days. Over 50% of locations were within human settlements and 37.1% were associated with buildings. We found generally seasonal patterns of activity, with higher activity in wet seasons, and lower activity in the hot season. These results show frequent proximity between Malayan kraits and humans at the university; thereby, suggesting a near constant potential for human-wildlife conflict. Despite the fact that no snakebites from this species occurred at the university during our study period, substantial education and awareness training should be considered to ensure continued coexistence on campus.
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Affiliation(s)
- Cameron Wesley Hodges
- School of Biology, Institute of Science, Suranaree University of Technology, Muang Nakhon Ratchasima, Nakhon Ratchasima, 30000, Thailand.
| | - Benjamin Michael Marshall
- School of Biology, Institute of Science, Suranaree University of Technology, Muang Nakhon Ratchasima, Nakhon Ratchasima, 30000, Thailand
- Biological and Environmental Sciences, University of Stirling, Stirling, UK
| | - Jacques George Hill
- Science and Math Division, Northwest Arkansas Community College, Bentonville, AR, 72703, USA
| | - Colin Thomas Strine
- School of Biology, Institute of Science, Suranaree University of Technology, Muang Nakhon Ratchasima, Nakhon Ratchasima, 30000, Thailand.
- Department of Natural Science, Dickinson State University, North Dakota, 58601, USA.
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Goodheart B, Creel S, Vinks MA, Banda K, Reyes de Merkle J, Kusler A, Dart C, Banda K, Becker MS, Indala P, Simukonda C, Kaluka A. African wild dog movements show contrasting responses to long and short term risk of encountering lions: analysis using dynamic Brownian bridge movement models. MOVEMENT ECOLOGY 2022; 10:16. [PMID: 35361272 PMCID: PMC8974231 DOI: 10.1186/s40462-022-00316-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 03/17/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Prey depletion is a threat to the world's large carnivores, and is likely to affect subordinate competitors within the large carnivore guild disproportionately. African lions limit African wild dog populations through interference competition and intraguild predation. When lion density is reduced as a result of prey depletion, wild dogs are not competitively released, and their population density remains low. Research examining distributions has demonstrated spatial avoidance of lions by wild dogs, but the effects of lions on patterns of movement have not been tested. Movement is one of the most energetically costly activities for many species and is particularly costly for cursorial hunters like wild dogs. Therefore, testing how top-down, bottom-up, and anthropogenic variables affect movement patterns can provide insight into mechanisms that limit wild dogs (and other subordinate competitors) in resource-depleted ecosystems. METHODS We measured movement rates using the motion variance from dynamic Brownian Bridge Movement Models (dBBMMs) fit to data from GPS-collared wild dogs, then used a generalized linear model to test for effects on movement of predation risk from lions, predictors of prey density, and anthropogenic and seasonal variables. RESULTS Wild dogs proactively reduced movement in areas with high lion density, but reactively increased movement when lions were immediately nearby. Predictors of prey density had consistently weaker effects on movement than lions did, but movements were reduced in the wet season and when dependent offspring were present. CONCLUSION Wild dogs alter their patterns of movement in response to lions in ways that are likely to have important energetic consequences. Our results support the recent suggestion that competitive limitation of wild dogs by lions remains strong in ecosystems where lion and wild dog densities are both low as a result of anthropogenic prey depletion. Our results reinforce an emerging pattern that movements often show contrasting responses to long-term and short-term variation in predation risk.
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Affiliation(s)
- Ben Goodheart
- Department of Ecology, Montana State University, 310 Lewis Hall, Bozeman, MT, 59717, USA.
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia.
| | - Scott Creel
- Department of Ecology, Montana State University, 310 Lewis Hall, Bozeman, MT, 59717, USA
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
- Insitutioned För Vilt, Fisk Och Miljö, Sveriges lantbruksuniversitet, Umeå, Sweden
| | - Milan A Vinks
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
- Montana Fish Wildlife and Parks, 490 North Meridian Road, Kalispell, MT, 59901, USA
| | - Kambwiri Banda
- Department of Ecology, Montana State University, 310 Lewis Hall, Bozeman, MT, 59717, USA
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
| | - Johnathan Reyes de Merkle
- Department of Ecology, Montana State University, 310 Lewis Hall, Bozeman, MT, 59717, USA
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
| | - Anna Kusler
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
| | - Chase Dart
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
| | - Kachama Banda
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
| | - Matthew S Becker
- Department of Ecology, Montana State University, 310 Lewis Hall, Bozeman, MT, 59717, USA
- Zambian Carnivore Programme, PO Box 80, Mfuwe, Eastern Province, Zambia
| | - Peter Indala
- Zambia Department of National Parks and Wildlife, Private Bag 80, Lusaka, Zambia
| | - Chuma Simukonda
- Zambia Department of National Parks and Wildlife, Private Bag 80, Lusaka, Zambia
| | - Adrian Kaluka
- Zambia Department of National Parks and Wildlife, Private Bag 80, Lusaka, Zambia
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Jones MD, Marshall BM, Smith SN, Crane M, Silva I, Artchawakom T, Suwanwaree P, Waengsothorn S, Wüster W, Goode M, Strine CT. How do King Cobras move across a major highway? Unintentional wildlife crossing structures may facilitate movement. Ecol Evol 2022; 12:e8691. [PMID: 35342558 PMCID: PMC8928851 DOI: 10.1002/ece3.8691] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 02/04/2022] [Accepted: 02/11/2022] [Indexed: 11/08/2022] Open
Abstract
Global road networks continue to expand, and the wildlife responses to these landscape-level changes need to be understood to advise long-term management decisions. Roads have high mortality risk to snakes because snakes typically move slowly and can be intentionally targeted by drivers.We investigated how radio-tracked King Cobras (Ophiophagus hannah) traverse a major highway in northeast Thailand, and if reproductive cycles were associated with road hazards.We surveyed a 15.3 km stretch of Highway 304 to determine if there were any locations where snakes could safely move across the road (e.g., culverts and bridges). We used recurse analyses to detect possible road-crossing events, and used dynamic Brownian Bridge Movement Models (dBBMMs) to show movement pathways association with possible unintentional crossing structures. We further used Integrated Step Selection Functions (ISSF) to assess seasonal differences in avoidance of major roads for adult King Cobras in relation to reproductive state.We discovered 32 unintentional wildlife crossing locations capable of facilitating King Cobra movement across the highway. While our dBBMMs broadly revealed underpasses as possible crossing points, they failed to identify specific underpasses used by telemetered individuals; however, the tracking locations pre- and post-crossing and photographs provided strong evidence of underpass use. Our ISSF suggested a lower avoidance of roads during the breeding season, although the results were inconclusive. With the high volume of traffic, large size of King Cobras, and a 98.8% success rate of crossing the road in our study (nine individuals: 84 crossing attempts with one fatality), we strongly suspect that individuals are using the unintentional crossing structures to safely traverse the road.Further research is needed to determine the extent of wildlife underpass use at our study site. We propose that more consistent integration of drainage culverts and bridges could help mitigate the impacts of roads on some terrestrial wildlife.
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Affiliation(s)
- Max Dolton Jones
- School of BiologySuranaree University of TechnologyNakhon RatchasimaThailand
| | | | | | - Matt Crane
- School of Bioresources and TechnologyKing Mongkut’s University of Technology ThonburiBangkokThailand
| | - Inês Silva
- School of Bioresources and TechnologyKing Mongkut’s University of Technology ThonburiBangkokThailand
- Center for Advanced Systems Understanding (CASUS)GörlitzGermany
- Helmholtz‐Zentrum Dresden‐Rossendorf (HZDR)DresdenGermany
| | - Taksin Artchawakom
- Thailand Institute of Science and Technological ResearchNakhon RatchasimaThailand
| | - Pongthep Suwanwaree
- School of BiologySuranaree University of TechnologyNakhon RatchasimaThailand
| | | | - Wolfgang Wüster
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Natural SciencesBangor UniversityBangorUK
| | - Matt Goode
- School of Natural Resources and EnvironmentUniversity of ArizonaTucsonArizonaUSA
| | - Colin Thomas Strine
- School of BiologySuranaree University of TechnologyNakhon RatchasimaThailand
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Ochoa C, Pittavino M, Babo Martins S, Alcoba G, Bolon I, Ruiz de Castañeda R, Joost S, Sharma SK, Chappuis F, Ray N. Estimating and predicting snakebite risk in the Terai region of Nepal through a high-resolution geospatial and One Health approach. Sci Rep 2021; 11:23868. [PMID: 34903803 PMCID: PMC8668914 DOI: 10.1038/s41598-021-03301-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/01/2021] [Indexed: 11/09/2022] Open
Abstract
Most efforts to understand snakebite burden in Nepal have been localized to relatively small areas and focused on humans through epidemiological studies. We present the outcomes of a geospatial analysis of the factors influencing snakebite risk in humans and animals, based on both a national-scale multi-cluster random survey and, environmental, climatic, and socio-economic gridded data for the Terai region of Nepal. The resulting Integrated Nested Laplace Approximation models highlight the importance of poverty as a fundamental risk-increasing factor, augmenting the snakebite odds in humans by 63.9 times. For animals, the minimum temperature of the coldest month was the most influential covariate, increasing the snakebite odds 23.4 times. Several risk hotspots were identified along the Terai, helping to visualize at multiple administrative levels the estimated population numbers exposed to different probability risk thresholds in 1 year. These analyses and findings could be replicable in other countries and for other diseases.
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Affiliation(s)
- Carlos Ochoa
- Institute of Global Health (IGH), Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Chemin des Mines 9, 1202, Geneva, Switzerland.
- Institute for Environmental Sciences (ISE), University of Geneva, Geneva, Switzerland.
| | - Marta Pittavino
- Research Center for Statistics (RCS), Geneva School of Economics and Management (GSEM), University of Geneva, Geneva, Switzerland
| | - Sara Babo Martins
- Institute of Global Health (IGH), Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Chemin des Mines 9, 1202, Geneva, Switzerland
| | - Gabriel Alcoba
- Institute of Global Health (IGH), Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Chemin des Mines 9, 1202, Geneva, Switzerland
- Médecins Sans Frontières (MSF), Geneva, Switzerland
- Division of Tropical and Humanitarian Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland
| | - Isabelle Bolon
- Institute of Global Health (IGH), Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Chemin des Mines 9, 1202, Geneva, Switzerland
| | - Rafael Ruiz de Castañeda
- Institute of Global Health (IGH), Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Chemin des Mines 9, 1202, Geneva, Switzerland
| | - Stéphane Joost
- Laboratory of Geographic Information Systems (LASIG), School of Architecture, Civil and Environmental Engineering (ENAC), École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | | | - François Chappuis
- Division of Tropical and Humanitarian Medicine, Geneva University Hospitals (HUG), Geneva, Switzerland
- Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Nicolas Ray
- Institute of Global Health (IGH), Department of Community Health and Medicine, Faculty of Medicine, University of Geneva, Chemin des Mines 9, 1202, Geneva, Switzerland
- Institute for Environmental Sciences (ISE), University of Geneva, Geneva, Switzerland
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Space use and activity of Boiga cyanea – A major songbird nest predator in a seasonal tropical forest in Thailand. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01875] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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10
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Malhotra A, Wüster W, Owens JB, Hodges CW, Jesudasan A, Ch G, Kartik A, Christopher P, Louies J, Naik H, Santra V, Kuttalam SR, Attre S, Sasa M, Bravo-Vega C, Murray KA. Promoting co-existence between humans and venomous snakes through increasing the herpetological knowledge base. Toxicon X 2021; 12:100081. [PMID: 34522881 PMCID: PMC8426276 DOI: 10.1016/j.toxcx.2021.100081] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 11/23/2022] Open
Abstract
Snakebite incidence at least partly depends on the biology of the snakes involved. However, studies of snake biology have been largely neglected in favour of anthropic factors, with the exception of taxonomy, which has been recognised for some decades to affect the design of antivenoms. Despite this, within-species venom variation and the unpredictability of the correlation with antivenom cross-reactivity has continued to be problematic. Meanwhile, other aspects of snake biology, including behaviour, spatial ecology and activity patterns, distribution, and population demography, which can contribute to snakebite mitigation and prevention, remain underfunded and understudied. Here, we review the literature relevant to these aspects of snakebite and illustrate how demographic, spatial, and behavioural studies can improve our understanding of why snakebites occur and provide evidence for prevention strategies. We identify the large gaps that remain to be filled and urge that, in the future, data and relevant metadata be shared openly via public data repositories so that studies can be properly replicated and data used in future meta-analyses.
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Affiliation(s)
- Anita Malhotra
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
| | - Wolfgang Wüster
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
| | - John Benjamin Owens
- Molecular Ecology and Evolution @ Bangor, School of Natural Sciences, Bangor University, 3rd floor ECW, Deiniol Road, Bangor, LL57 2UW, UK
- Captive & Field Herpetology Ltd, Wales, 13 Hirfron, Holyhead, Llaingoch, Anglesey, LL65 1YU, UK
| | - Cameron Wesley Hodges
- School of Biology, Institute of Science, Suranaree University of Technology, Muang Nakhon Ratchasima, Thailand
| | - Allwin Jesudasan
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Gnaneswar Ch
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Ajay Kartik
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | - Peter Christopher
- Madras Crocodile Bank Trust, Centre for Herpetology, Post bag No.4, Vadanamelli Village, East Coast Road, Mamallapuram, 603 104, Tamil Nadu, India
| | | | - Hiral Naik
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Johannesburg. P. O. Wits, 2050, Gauteng, South Africa
- Save the Snakes, R527, Blyderus, Hoedspruit, 1380, South Africa
| | - Vishal Santra
- Captive & Field Herpetology Ltd, Wales, 13 Hirfron, Holyhead, Llaingoch, Anglesey, LL65 1YU, UK
- Society for Nature Conservation, Research and Community Engagement (CONCERN), Nalikul, Hooghly, West Bengal 712407, India
| | - Sourish Rajagopalan Kuttalam
- Society for Nature Conservation, Research and Community Engagement (CONCERN), Nalikul, Hooghly, West Bengal 712407, India
| | - Shaleen Attre
- Durrell Institute of Conservation and Ecology, School of Anthropology and Conservation, Marlowe Building, University of Kent, Canterbury, Kent, CT2 7NR, UK
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica
- Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
| | - Carlos Bravo-Vega
- Research Group in Mathematical and Computational Biology (BIOMAC), Department of Biomedical Engineering, University of the Andes, Bogotá, Colombia
| | - Kris A. Murray
- MRC Centre for Global Infectious Disease Analysis, Imperial College London, UK
- MRC Unit The Gambia at London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, Gambia
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11
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Crane M, Silva I, Marshall BM, Strine CT. Lots of movement, little progress: a review of reptile home range literature. PeerJ 2021; 9:e11742. [PMID: 34322323 PMCID: PMC8300531 DOI: 10.7717/peerj.11742] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 06/17/2021] [Indexed: 11/20/2022] Open
Abstract
Reptiles are the most species-rich terrestrial vertebrate group with a broad diversity of life history traits. Biotelemetry is an essential methodology for studying reptiles as it compensates for several limitations when studying their natural history. We evaluated trends in terrestrial reptile spatial ecology studies focusing upon quantifying home ranges for the past twenty years. We assessed 290 English-language reptile home range studies published from 2000-2019 via a structured literature review investigating publications' study location, taxonomic group, methodology, reporting, and analytical techniques. Substantial biases remain in both location and taxonomic groups in the literature, with nearly half of all studies (45%) originating from the USA. Snakes were most often studied, and crocodiles were least often studied, while testudines tended to have the greatest within study sample sizes. More than half of all studies lacked critical methodological details, limiting the number of studies for inclusion in future meta-analyses (55% of studies lacked information on individual tracking durations, and 51% lacked sufficient information on the number of times researchers recorded positions). Studies continue to rely on outdated methods to quantify space-use (including Minimum Convex Polygons and Kernel Density Estimators), often failing to report subtleties regarding decisions that have substantial impact on home range area estimates. Moving forward researchers can select a suite of appropriate analytical techniques tailored to their research question (dynamic Brownian Bridge Movement Models for within sample interpolation, and autocorrelated Kernel Density Estimators for beyond sample extrapolation). Only 1.4% of all evaluated studies linked to available and usable telemetry data, further hindering scientific consensus. We ultimately implore herpetologists to adopt transparent reporting practices and make liberal use of open data platforms to maximize progress in the field of reptile spatial ecology.
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Affiliation(s)
- Matthew Crane
- Conservation Ecology Program, King Mongkut’s Institute of Technology Thonburi, Bangkok, Bangkhuntien / Bangkok, Thailand
| | - Inês Silva
- (CASUS), Center for Advanced Systems Understanding, Görlitz, Germany
- (HZDR), Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Benjamin M. Marshall
- School of Biology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Colin T. Strine
- School of Biology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
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12
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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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13
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Rutz C, Webster MM. Ethology
adopts the STRANGE framework for animal behaviour research, to improve reporting standards. Ethology 2021. [DOI: 10.1111/eth.13118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Christian Rutz
- Centre for Biological Diversity, School of Biology University of St Andrews St Andrews UK
| | - Mike M. Webster
- Centre for Biological Diversity, School of Biology University of St Andrews St Andrews UK
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14
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Jones MD, Marshall BM, Smith SN, Christie JT, Waengsothorn S, Artchawakom T, Suwanwaree P, Strine CT. Can post-capture photographic identification as a wildlife marking technique be undermined by observer error? A case study using King Cobras in northeast Thailand. PLoS One 2020; 15:e0242826. [PMID: 33296389 PMCID: PMC7725303 DOI: 10.1371/journal.pone.0242826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 11/09/2020] [Indexed: 11/18/2022] Open
Abstract
Identifying individuals with natural markings is increasing in popularity to non-invasively support population studies. However, applying natural variation among individuals requires careful evaluation among target species, snakes for example have little validation of such methods. Here we introduce a mark-free identification method for King Cobras (Ophiophagus hannah) from the Sakaerat Biosphere Reserve, in northeast Thailand using both subcaudal scale pholidosis (scale arrangement and number) and unique ventral body markings to distinguish individuals. This project aims to evaluate the impact of observer error on individual identification. Observers of varying expertise, will distinguish between King Cobra individuals using identifying photographs from a previous study. We will ask randomly assigned observers to distinguish individuals via: 1) subcaudal pholidosis, 2) ventral body markings, and 3) combination of both measures. Using Bayesian logistic regression, we will assess the probability observers correctly distinguish individuals. Based on exploratory observations, we hypothesise that there will be a high probability of correct identifications using subcaudal pholidosis and ventral body markings. We aim to stimulate other studies implementing identification techniques for scrutinous assessment of such methods, in order to avoid subsequent errors during long-term population studies.
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Affiliation(s)
- Max Dolton Jones
- School of Biology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
- * E-mail: (MDJ); (CTS)
| | | | | | - Jack Taylor Christie
- Thailand Institute of Science and Technological Research, Nakhon Ratchasima, Thailand
| | - Surachit Waengsothorn
- Thailand Institute of Science and Technological Research, Nakhon Ratchasima, Thailand
| | | | - Pongthep Suwanwaree
- School of Biology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Colin Thomas Strine
- School of Biology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
- * E-mail: (MDJ); (CTS)
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15
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Silva I, Crane M, Marshall BM, Strine CT. Reptiles on the wrong track? Moving beyond traditional estimators with dynamic Brownian Bridge Movement Models. MOVEMENT ECOLOGY 2020; 8:43. [PMID: 33133609 PMCID: PMC7592577 DOI: 10.1186/s40462-020-00229-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Accepted: 10/12/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND Animal movement expressed through home ranges or space-use can offer insights into spatial and habitat requirements. However, different classes of estimation methods are currently instinctively applied to answer home range, space-use or movement-based research questions regardless of their widely varying outputs, directly impacting conclusions. Recent technological advances in animal tracking (GPS and satellite tags), have enabled new methods to quantify animal space-use and movement pathways, but so far have primarily targeted mammal and avian species. METHODS Most reptile spatial ecology studies only make use of two older home range estimation methods: Minimum Convex Polygons (MCP) and Kernel Density Estimators (KDE), particularly with the Least Squares Cross Validation (LSCV) and reference (h ref ) bandwidth selection algorithms. These methods are frequently applied to answer space-use and movement-based questions. Reptile movement patterns are unique (e.g., low movement frequency, long stop-over periods), prompting investigation into whether newer movement-based methods -such as dynamic Brownian Bridge Movement Models (dBBMMs)- apply to Very High Frequency (VHF) radio-telemetry tracking data. We simulated movement data for three archetypical reptile species: a highly mobile active hunter, an ambush predator with long-distance moves and long-term sheltering periods, and an ambush predator with short-distance moves and short-term sheltering periods. We compared traditionally used estimators, MCP and KDE, with dBBMMs, across eight feasible VHF field sampling regimes for reptiles, varying from one data point every four daylight hours, to once per month. RESULTS Although originally designed for GPS tracking studies, dBBMMs outperformed MCPs and KDE h ref across all tracking regimes in accurately revealing movement pathways, with only KDE LSCV performing comparably at some higher frequency sampling regimes. However, the LSCV algorithm failed to converge with these high-frequency regimes due to high site fidelity, and was unstable across sampling regimes, making its use problematic for species exhibiting long-term sheltering behaviours. We found that dBBMMs minimized the effect of individual variation, maintained low error rates balanced between omission (false negative) and commission (false positive), and performed comparatively well even under low frequency sampling regimes (e.g., once a month). CONCLUSIONS We recommend dBBMMs as a valuable alternative to MCP and KDE methods for reptile VHF telemetry data, for research questions associated with space-use and movement behaviours within the study period: they work under contemporary tracking protocols and provide more stable estimates. We demonstrate for the first time that dBBMMs can be applied confidently to low-resolution tracking data, while improving comparisons across regimes, individuals, and species. SUPPLEMENTARY INFORMATION Supplementary information accompanies this paper at 10.1186/s40462-020-00229-3.
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Affiliation(s)
- Inês Silva
- Conservation Ecology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkhunthien, Bangkok, Thailand
| | - Matt Crane
- Conservation Ecology Program, School of Bioresources and Technology, King Mongkut’s University of Technology Thonburi, Bangkhunthien, Bangkok, Thailand
| | - Benjamin Michael Marshall
- School of Biology, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Colin Thomas Strine
- School of Biology, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand
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