Hits Close to Home: Repeated Persecution of King Cobras ( Ophiophagus hannah ) in Northeastern Thailand

Crane

Silva

et al. 2020

Preprint

Self Cite

13Studying animal movement provides insights into how animals react to land-use changes, specifically 14 how animals can change their behaviour in agricultural areas. Recent reviews show a tendency for 15 species to reduce movements in response to increased human landscape modification, but the study of 16 movement has not been extensively explored in reptiles. We examined movements of a large reptilian 17 predator, the King Cobra (Ophiophagus hannah), in Northeast Thailand. We used a consistent regime 18 of radio-telemetry tracking to document movements across protected forest and adjacent agricultural 19 areas. We then adapted GPS-targeting analytic methods to examine the movement using metrics of site 20 reuse and dynamic Brownian Bridge Movement Model derived motion variance. Examination of 21 motion variance demonstrated that King Cobra movements increased in forested areas and tended to 22 decrease in agricultural areas. Our Integrated Step-Selection Functions indicated that when moving in 23 agricultural areas King Cobras restricted their movements, thereby remaining within vegetated semi-24 natural areas, often located along the banks of irrigation canals. Site reuse metrics of residency time and 25 number of revisits remained unaffected by distance to landscape features. Neither motion variance nor 26 reuse metrics were consistently affected by the presence of threatening landscape features (e.g. roads, 27 human settlements); suggesting that King Cobras will remain in close proximity to threats, provided 28 habitat patches are available. Although King Cobras displayed heterogeneity in their response to 29 agricultural landscapes, the overall trend suggested a reduction in movements when faced with 30 fragmented habitat patches embedded in an otherwise inhospitable land-use matrix. Reductions in 31 movements are consistent with findings for mammals and forest specialist species. 32

Section: Introduction 35mentioning

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No room to roam: King Cobras reduce movement in agriculture

Crane

Silva

et al. 2020

Preprint

Self Cite

“…The nature of these captures serves as evidence that Burmese pythons do initiate humanwildlife conflict via consumption of livestock in our study site. We were fortunate that none of these instances led to the persecution of Burmese pythons, as direct human-snake conflict results in snake mortality for other species in our study site (Crane et al, 2016;Marshall et al, 2018). It is difficult to determine whether Burmese pythons fall victim to persecution in our study site as we suspect that people would hesitate to notify us about killing or harming a protected species.…”

Section: Discussionmentioning

confidence: 92%

Restricted constrictors: Space use and habitat selection of native Burmese pythons in Northeast Thailand

Smith

Jones

et al. 2020

Preprint

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Animal movement and resource use are tightly linked. Investigating these links to understand how animals utilize space and select habitats is especially relevant in areas that have been 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 patchy land use matrix dominated by agricultural crops and human settlements. We used radio telemetry to record daily locations of seven Burmese pythons over the course of our study period of approximately 22 months. We created dynamic Brownian Bridge Movement Models (dBBMMs) for all individuals, using occurrence distributions to estimate extent of movements and motion variance to reveal temporal patterns. Then we used integrated step selection functions to determine whether individual movements were associated with particular landscape features (aquatic agriculture, forest, roads, settlements, terrestrial agriculture, water), and whether there were consistent associations at the population level. Our dBBMM estimates suggested that Burmese pythons made use of small areas (98.97 ± 35.42 ha), with low mean individual motion variance characterized by infrequent moves and long periods at a single location. At both the individual and population level, Burmese pythons in the agricultural matrix were associated with aquatic environments. Only one individual showed a strong avoidance for human settlements which is troublesome from a human-wildlife conflict angle, especially as Burmese pythons have been observed entering human settlements and consuming livestock in our study site. Our study is one of the first to contribute to the knowledge of Burmese python ecology in their native range as the majority of studies have focused on invasive populations.

How do King Cobras move across a major highway? Unintentional wildlife crossing structures may facilitate movement

Jones

Smith

et al. 2022

Ecology and Evolution

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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.