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Tim S Jessop - One of the best experts on this subject based on the ideXlab platform.
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Human activities associated with reduced Komodo Dragon habitat use and range loss on Flores
Biodiversity and Conservation, 2021Co-Authors: Achmad Ariefiandy, Deni Purwandana, Claudio Ciofi, Sanggar Abdil Nasu, Muhammad Azmi, Juna Mardani, Tim S JessopAbstract:Species restricted to archipelagos are often range-restricted, dispersal limited, and persist as disjunct populations. These attributes can make island populations especially vulnerable to extinction from natural or anthropogenic processes. Ascertaining causes of habitat use, population impact, and range loss is fundamental to guiding effective conservation actions. The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a highly restricted range distribution limited to a small number of islands in Eastern Indonesia. Flores Island is the largest island (13,540 km2) within the species distribution. However, with relatively few and small-protected areas, alongside a much higher incidence of human-related habitat use, Komodo Dragon habitat occupancy is suspected to decrease on Flores. Here over five years, we conducted systematic surveys to evaluate Komodo Dragon habitat occupancy at 346 camera monitoring stations (CMS) distributed along the Flores coastline. We successfully detected Komodo Dragons at 85 of the 346 CMS on Flores. The pattern of Komodo Dragon site presence indicated their distribution was confined to three isolated and highly restricted habitat areas on the west, northwestern, and northern coastal regions of Flores. Ranking of competing models indicated that proximity to farms and villages had the strongest negative effects on Komodo Dragon habitat occupancy. The current predicted Komodo Dragon range distribution appeared to have undergone significant range area contraction (~ 44%) at multiple coastal areas known to be occupied by the Komodo Dragon detected in previous decades (i.e., 1970–2000). We attribute decreased Komodo Dragon habitat use and range loss to multiple and cascading human activities. To address these threats, we advocate a range of land use planning and community conservation actions to avoid a potential Komodo Dragon extirpation on the largest island habitat within their distribution.
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Insights into the Nesting Ecology and Annual Hatchling Production of the Komodo Dragon
Copeia, 2020Co-Authors: Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, M. J. Imansyah, Heru Rudiharto, Tim S JessopAbstract:We studied annual trends and characteristics of nesting activities and hatchling production by female Komodo Dragons (Varanus Komodoensis) in Komodo National Park, Indonesia between 2002 and 2006. During this period, we recorded 12, 16, 15, 13, and 6 females nesting annually at 42 potential nesting sites. An average female nesting periodicity was estimated at 1.2±0.4 years. This result arose because most females bred annually and some biennially. Some females reused nest sites in successive years while others did not. Nesting females had significantly lower body mass compared to when they were recaptured again in a non-nesting state. All-female nesting activities were conducted within their resident valleys and suggested a strong tendency for spatial fidelity. Komodo Dragons were generally considered solitary nesters as only on one occasion were two nesting females observed to use the same nesting site. On average, 21.0±3.6 Komodo Dragon hatchlings emerged from each nest. We estimated that within the study area, nesting female Komodo Dragons produced between 129.0±21.8 and 344.0±58.16 hatchlings per annum. We discuss the ecological and evolutionary significance of these attributes. However, the main conservation management implications drawn from this study are that there are a low annual number of nesting females and associated hatchling production in Komodo National Park. Hence, a continuation of more extensive nesting surveys could provide a cost-effective and accurate way to gather important long-term demographic information for this species.
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Identifying island safe havens to prevent the extinction of the World's largest lizard from global warming.
Ecology and evolution, 2020Co-Authors: Alice R. Jones, Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, Tim S Jessop, Yunias Jackson Benu, Barry W. Brook, Stuart C. Brown, Tamen Sitorus, Tom M. L. WigleyAbstract:The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a naturally restricted distribution. Despite this, no previous studies have attempted to predict the effects of climate change on this iconic species. We used extensive Komodo Dragon monitoring data, climate, and sea-level change projections to build spatially explicit demographic models for the Komodo Dragon. These models project the species' future range and abundance under multiple climate change scenarios. We ran over one million model simulations with varying model parameters, enabling us to incorporate uncertainty introduced from three main sources: (a) structure of global climate models, (b) choice of greenhouse gas emission trajectories, and (c) estimates of Komodo Dragon demographic parameters. Our models predict a reduction in range-wide Komodo Dragon habitat of 8%-87% by 2050, leading to a decrease in habitat patch occupancy of 25%-97% and declines of 27%-99% in abundance across the species' range. We show that the risk of extirpation on the two largest protected islands in Komodo National Park (Rinca and Komodo) was lower than other island populations, providing important safe havens for Komodo Dragons under global warming. Given the severity and rate of the predicted changes to Komodo Dragon habitat patch occupancy (a proxy for area of occupancy) and abundance, urgent conservation actions are required to avoid risk of extinction. These should, as a priority, be focused on managing habitat on the islands of Komodo and Rinca, reflecting these islands' status as important refuges for the species in a warming world. Variability in our model projections highlights the importance of accounting for uncertainties in demographic and environmental parameters, structural assumptions of global climate models, and greenhouse gas emission scenarios when simulating species metapopulation dynamics under climate change.
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Knee deep in trouble: rusa deer use an aquatic escape behaviour to delay attack by Komodo Dragons
Australian Mammalogy, 2020Co-Authors: Achmad Ariefiandy, Deni Purwandana, Yunias Jackson Benu, Mike Letnic, Tim S JessopAbstract:We document six observations of an aquatic behaviour used by rusa deer (Rusa timorensis) to delay an imminent attack from Komodo Dragons (Varanus Komodoensis). This unusual behaviour arose after rusa deer fled into the nearby seawater following an attack from a solitary Komodo Dragon. Once in the sea, rusa deer remained relatively stationary by standing in shallow water (
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Knee deep in trouble: rusa deer use an aquatic escape behaviour to delay attack by Komodo Dragons
Australian Mammalogy, 2020Co-Authors: Achmad Ariefiandy, Deni Purwandana, Yunias Jackson Benu, Mike Letnic, Tim S JessopAbstract:We document six observations of an aquatic behaviour used by rusa deer (Rusa timorensis) to delay an imminent attack from Komodo Dragons (Varanus Komodoensis). This unusual behaviour arose after rusa deer fled into the nearby seawater following an attack from a solitary Komodo Dragon. Once in the sea, rusa deer remained relatively stationary by standing in shallow water (<1 m deep) for up to 4 h. This behaviour generally allowed rusa deer to avoid an in-water attack from Komodo Dragons. However, if rusa did not die from injuries, they moved back onto land and were subsequently killed by Komodo Dragons. The aquatic behaviour delays subsequent attacks on rusa deer by Komodo Dragons, but this appears only to postpone, rather than prevent, the deer’s death.
Claudio Ciofi - One of the best experts on this subject based on the ideXlab platform.
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Human activities associated with reduced Komodo Dragon habitat use and range loss on Flores
Biodiversity and Conservation, 2021Co-Authors: Achmad Ariefiandy, Deni Purwandana, Claudio Ciofi, Sanggar Abdil Nasu, Muhammad Azmi, Juna Mardani, Tim S JessopAbstract:Species restricted to archipelagos are often range-restricted, dispersal limited, and persist as disjunct populations. These attributes can make island populations especially vulnerable to extinction from natural or anthropogenic processes. Ascertaining causes of habitat use, population impact, and range loss is fundamental to guiding effective conservation actions. The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a highly restricted range distribution limited to a small number of islands in Eastern Indonesia. Flores Island is the largest island (13,540 km2) within the species distribution. However, with relatively few and small-protected areas, alongside a much higher incidence of human-related habitat use, Komodo Dragon habitat occupancy is suspected to decrease on Flores. Here over five years, we conducted systematic surveys to evaluate Komodo Dragon habitat occupancy at 346 camera monitoring stations (CMS) distributed along the Flores coastline. We successfully detected Komodo Dragons at 85 of the 346 CMS on Flores. The pattern of Komodo Dragon site presence indicated their distribution was confined to three isolated and highly restricted habitat areas on the west, northwestern, and northern coastal regions of Flores. Ranking of competing models indicated that proximity to farms and villages had the strongest negative effects on Komodo Dragon habitat occupancy. The current predicted Komodo Dragon range distribution appeared to have undergone significant range area contraction (~ 44%) at multiple coastal areas known to be occupied by the Komodo Dragon detected in previous decades (i.e., 1970–2000). We attribute decreased Komodo Dragon habitat use and range loss to multiple and cascading human activities. To address these threats, we advocate a range of land use planning and community conservation actions to avoid a potential Komodo Dragon extirpation on the largest island habitat within their distribution.
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Insights into the Nesting Ecology and Annual Hatchling Production of the Komodo Dragon
Copeia, 2020Co-Authors: Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, M. J. Imansyah, Heru Rudiharto, Tim S JessopAbstract:We studied annual trends and characteristics of nesting activities and hatchling production by female Komodo Dragons (Varanus Komodoensis) in Komodo National Park, Indonesia between 2002 and 2006. During this period, we recorded 12, 16, 15, 13, and 6 females nesting annually at 42 potential nesting sites. An average female nesting periodicity was estimated at 1.2±0.4 years. This result arose because most females bred annually and some biennially. Some females reused nest sites in successive years while others did not. Nesting females had significantly lower body mass compared to when they were recaptured again in a non-nesting state. All-female nesting activities were conducted within their resident valleys and suggested a strong tendency for spatial fidelity. Komodo Dragons were generally considered solitary nesters as only on one occasion were two nesting females observed to use the same nesting site. On average, 21.0±3.6 Komodo Dragon hatchlings emerged from each nest. We estimated that within the study area, nesting female Komodo Dragons produced between 129.0±21.8 and 344.0±58.16 hatchlings per annum. We discuss the ecological and evolutionary significance of these attributes. However, the main conservation management implications drawn from this study are that there are a low annual number of nesting females and associated hatchling production in Komodo National Park. Hence, a continuation of more extensive nesting surveys could provide a cost-effective and accurate way to gather important long-term demographic information for this species.
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Identifying island safe havens to prevent the extinction of the World's largest lizard from global warming.
Ecology and evolution, 2020Co-Authors: Alice R. Jones, Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, Tim S Jessop, Yunias Jackson Benu, Barry W. Brook, Stuart C. Brown, Tamen Sitorus, Tom M. L. WigleyAbstract:The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a naturally restricted distribution. Despite this, no previous studies have attempted to predict the effects of climate change on this iconic species. We used extensive Komodo Dragon monitoring data, climate, and sea-level change projections to build spatially explicit demographic models for the Komodo Dragon. These models project the species' future range and abundance under multiple climate change scenarios. We ran over one million model simulations with varying model parameters, enabling us to incorporate uncertainty introduced from three main sources: (a) structure of global climate models, (b) choice of greenhouse gas emission trajectories, and (c) estimates of Komodo Dragon demographic parameters. Our models predict a reduction in range-wide Komodo Dragon habitat of 8%-87% by 2050, leading to a decrease in habitat patch occupancy of 25%-97% and declines of 27%-99% in abundance across the species' range. We show that the risk of extirpation on the two largest protected islands in Komodo National Park (Rinca and Komodo) was lower than other island populations, providing important safe havens for Komodo Dragons under global warming. Given the severity and rate of the predicted changes to Komodo Dragon habitat patch occupancy (a proxy for area of occupancy) and abundance, urgent conservation actions are required to avoid risk of extinction. These should, as a priority, be focused on managing habitat on the islands of Komodo and Rinca, reflecting these islands' status as important refuges for the species in a warming world. Variability in our model projections highlights the importance of accounting for uncertainties in demographic and environmental parameters, structural assumptions of global climate models, and greenhouse gas emission scenarios when simulating species metapopulation dynamics under climate change.
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Isolating Chromosomes of the Komodo Dragon: New Tools for Comparative Mapping and Sequence Assembly.
Cytogenetic and genome research, 2019Co-Authors: Alessio Iannucci, Claudio Ciofi, Marie Altmanová, Michail Rovatsos, Petr Velenský, Ivan Rehák, Malcolm A. Ferguson-smith, Jorge C. Pereira, Roscoe Stanyon, Lukáš KratochvílAbstract:We developed new tools to build a high-quality chromosomal map of the Komodo Dragon (Varanus Komodoensis) available for cross-species phylogenomic analyses. First, we isolated chromosomes by flow sorting and determined the chromosome content of each flow karyotype peak by FISH. We then isolated additional Komodo Dragon chromosomes by microdissection and amplified chromosome-specific DNA pools. The chromosome-specific DNA pools can be sequenced, assembled, and mapped by next-generation sequencing technology. The chromosome-specific paint probes can be used to investigate karyotype evolution through cross-species chromosome painting. Overall, the set of chromosome-specific DNA pools of V. Komodoensis provides new tools for detailed phylogenomic analyses of Varanidae and squamates in general.
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Exploring mechanisms and origins of reduced dispersal in island Komodo Dragons.
Proceedings. Biological sciences, 2018Co-Authors: Tim S Jessop, Jeri Imansyah, Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, David M. Forsyth, Yunias Jackson Benu, Damien A. Fordham, Raoul A. Mulder, Benjamin L. PhillipsAbstract:Loss of dispersal typifies island biotas, but the selective processes driving this phenomenon remain contentious. This is because selection via, both indirect (e.g. relaxed selection or island syndromes) and direct (e.g. natural selection or spatial sorting) processes may be involved, and no study has yet convincingly distinguished between these alternatives. Here, we combined observational and experimental analyses of an island lizard, the Komodo Dragon (Varanus Komodoensis, the world's largest lizard), to provide evidence for the actions of multiple processes that could contribute to island dispersal loss. In the Komodo Dragon, concordant results from telemetry, simulations, experimental translocations, mark-recapture, and gene flow studies indicated that despite impressive physical and sensory capabilities for long-distance movement, Komodo Dragons exhibited near complete dispersal restriction: individuals rarely moved beyond the valleys they were born/captured in. Importantly, lizard site-fidelity was insensitive to common agents of dispersal evolution (i.e. indices of risk for inbreeding, kin and intraspecific competition, and low habitat quality) that consequently reduced survival of resident individuals. We suggest that direct selection restricts movement capacity (e.g. via benefits of spatial philopatry and increased costs of dispersal) alongside use of dispersal-compensating traits (e.g. intraspecific niche partitioning) to constrain dispersal in island species.
Deni Purwandana - One of the best experts on this subject based on the ideXlab platform.
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Human activities associated with reduced Komodo Dragon habitat use and range loss on Flores
Biodiversity and Conservation, 2021Co-Authors: Achmad Ariefiandy, Deni Purwandana, Claudio Ciofi, Sanggar Abdil Nasu, Muhammad Azmi, Juna Mardani, Tim S JessopAbstract:Species restricted to archipelagos are often range-restricted, dispersal limited, and persist as disjunct populations. These attributes can make island populations especially vulnerable to extinction from natural or anthropogenic processes. Ascertaining causes of habitat use, population impact, and range loss is fundamental to guiding effective conservation actions. The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a highly restricted range distribution limited to a small number of islands in Eastern Indonesia. Flores Island is the largest island (13,540 km2) within the species distribution. However, with relatively few and small-protected areas, alongside a much higher incidence of human-related habitat use, Komodo Dragon habitat occupancy is suspected to decrease on Flores. Here over five years, we conducted systematic surveys to evaluate Komodo Dragon habitat occupancy at 346 camera monitoring stations (CMS) distributed along the Flores coastline. We successfully detected Komodo Dragons at 85 of the 346 CMS on Flores. The pattern of Komodo Dragon site presence indicated their distribution was confined to three isolated and highly restricted habitat areas on the west, northwestern, and northern coastal regions of Flores. Ranking of competing models indicated that proximity to farms and villages had the strongest negative effects on Komodo Dragon habitat occupancy. The current predicted Komodo Dragon range distribution appeared to have undergone significant range area contraction (~ 44%) at multiple coastal areas known to be occupied by the Komodo Dragon detected in previous decades (i.e., 1970–2000). We attribute decreased Komodo Dragon habitat use and range loss to multiple and cascading human activities. To address these threats, we advocate a range of land use planning and community conservation actions to avoid a potential Komodo Dragon extirpation on the largest island habitat within their distribution.
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Insights into the Nesting Ecology and Annual Hatchling Production of the Komodo Dragon
Copeia, 2020Co-Authors: Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, M. J. Imansyah, Heru Rudiharto, Tim S JessopAbstract:We studied annual trends and characteristics of nesting activities and hatchling production by female Komodo Dragons (Varanus Komodoensis) in Komodo National Park, Indonesia between 2002 and 2006. During this period, we recorded 12, 16, 15, 13, and 6 females nesting annually at 42 potential nesting sites. An average female nesting periodicity was estimated at 1.2±0.4 years. This result arose because most females bred annually and some biennially. Some females reused nest sites in successive years while others did not. Nesting females had significantly lower body mass compared to when they were recaptured again in a non-nesting state. All-female nesting activities were conducted within their resident valleys and suggested a strong tendency for spatial fidelity. Komodo Dragons were generally considered solitary nesters as only on one occasion were two nesting females observed to use the same nesting site. On average, 21.0±3.6 Komodo Dragon hatchlings emerged from each nest. We estimated that within the study area, nesting female Komodo Dragons produced between 129.0±21.8 and 344.0±58.16 hatchlings per annum. We discuss the ecological and evolutionary significance of these attributes. However, the main conservation management implications drawn from this study are that there are a low annual number of nesting females and associated hatchling production in Komodo National Park. Hence, a continuation of more extensive nesting surveys could provide a cost-effective and accurate way to gather important long-term demographic information for this species.
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Identifying island safe havens to prevent the extinction of the World's largest lizard from global warming.
Ecology and evolution, 2020Co-Authors: Alice R. Jones, Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, Tim S Jessop, Yunias Jackson Benu, Barry W. Brook, Stuart C. Brown, Tamen Sitorus, Tom M. L. WigleyAbstract:The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a naturally restricted distribution. Despite this, no previous studies have attempted to predict the effects of climate change on this iconic species. We used extensive Komodo Dragon monitoring data, climate, and sea-level change projections to build spatially explicit demographic models for the Komodo Dragon. These models project the species' future range and abundance under multiple climate change scenarios. We ran over one million model simulations with varying model parameters, enabling us to incorporate uncertainty introduced from three main sources: (a) structure of global climate models, (b) choice of greenhouse gas emission trajectories, and (c) estimates of Komodo Dragon demographic parameters. Our models predict a reduction in range-wide Komodo Dragon habitat of 8%-87% by 2050, leading to a decrease in habitat patch occupancy of 25%-97% and declines of 27%-99% in abundance across the species' range. We show that the risk of extirpation on the two largest protected islands in Komodo National Park (Rinca and Komodo) was lower than other island populations, providing important safe havens for Komodo Dragons under global warming. Given the severity and rate of the predicted changes to Komodo Dragon habitat patch occupancy (a proxy for area of occupancy) and abundance, urgent conservation actions are required to avoid risk of extinction. These should, as a priority, be focused on managing habitat on the islands of Komodo and Rinca, reflecting these islands' status as important refuges for the species in a warming world. Variability in our model projections highlights the importance of accounting for uncertainties in demographic and environmental parameters, structural assumptions of global climate models, and greenhouse gas emission scenarios when simulating species metapopulation dynamics under climate change.
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anthropomorphic and factual approaches in Komodo Dragon conservation awareness program for elementary school students initial study
Applied Environmental Education & Communication, 2020Co-Authors: Puspita Insan Kamil, Deni Purwandana, Harry Susianto, Achmad AriefiandyAbstract:Increasing wildlife awareness is a commonly used approach in community conservations programs. However, in Indonesia, this approach has rarely been quantitatively evaluated for its effectiveness. I...
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Knee deep in trouble: rusa deer use an aquatic escape behaviour to delay attack by Komodo Dragons
Australian Mammalogy, 2020Co-Authors: Achmad Ariefiandy, Deni Purwandana, Yunias Jackson Benu, Mike Letnic, Tim S JessopAbstract:We document six observations of an aquatic behaviour used by rusa deer (Rusa timorensis) to delay an imminent attack from Komodo Dragons (Varanus Komodoensis). This unusual behaviour arose after rusa deer fled into the nearby seawater following an attack from a solitary Komodo Dragon. Once in the sea, rusa deer remained relatively stationary by standing in shallow water (
Achmad Ariefiandy - One of the best experts on this subject based on the ideXlab platform.
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Human activities associated with reduced Komodo Dragon habitat use and range loss on Flores
Biodiversity and Conservation, 2021Co-Authors: Achmad Ariefiandy, Deni Purwandana, Claudio Ciofi, Sanggar Abdil Nasu, Muhammad Azmi, Juna Mardani, Tim S JessopAbstract:Species restricted to archipelagos are often range-restricted, dispersal limited, and persist as disjunct populations. These attributes can make island populations especially vulnerable to extinction from natural or anthropogenic processes. Ascertaining causes of habitat use, population impact, and range loss is fundamental to guiding effective conservation actions. The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a highly restricted range distribution limited to a small number of islands in Eastern Indonesia. Flores Island is the largest island (13,540 km2) within the species distribution. However, with relatively few and small-protected areas, alongside a much higher incidence of human-related habitat use, Komodo Dragon habitat occupancy is suspected to decrease on Flores. Here over five years, we conducted systematic surveys to evaluate Komodo Dragon habitat occupancy at 346 camera monitoring stations (CMS) distributed along the Flores coastline. We successfully detected Komodo Dragons at 85 of the 346 CMS on Flores. The pattern of Komodo Dragon site presence indicated their distribution was confined to three isolated and highly restricted habitat areas on the west, northwestern, and northern coastal regions of Flores. Ranking of competing models indicated that proximity to farms and villages had the strongest negative effects on Komodo Dragon habitat occupancy. The current predicted Komodo Dragon range distribution appeared to have undergone significant range area contraction (~ 44%) at multiple coastal areas known to be occupied by the Komodo Dragon detected in previous decades (i.e., 1970–2000). We attribute decreased Komodo Dragon habitat use and range loss to multiple and cascading human activities. To address these threats, we advocate a range of land use planning and community conservation actions to avoid a potential Komodo Dragon extirpation on the largest island habitat within their distribution.
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Insights into the Nesting Ecology and Annual Hatchling Production of the Komodo Dragon
Copeia, 2020Co-Authors: Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, M. J. Imansyah, Heru Rudiharto, Tim S JessopAbstract:We studied annual trends and characteristics of nesting activities and hatchling production by female Komodo Dragons (Varanus Komodoensis) in Komodo National Park, Indonesia between 2002 and 2006. During this period, we recorded 12, 16, 15, 13, and 6 females nesting annually at 42 potential nesting sites. An average female nesting periodicity was estimated at 1.2±0.4 years. This result arose because most females bred annually and some biennially. Some females reused nest sites in successive years while others did not. Nesting females had significantly lower body mass compared to when they were recaptured again in a non-nesting state. All-female nesting activities were conducted within their resident valleys and suggested a strong tendency for spatial fidelity. Komodo Dragons were generally considered solitary nesters as only on one occasion were two nesting females observed to use the same nesting site. On average, 21.0±3.6 Komodo Dragon hatchlings emerged from each nest. We estimated that within the study area, nesting female Komodo Dragons produced between 129.0±21.8 and 344.0±58.16 hatchlings per annum. We discuss the ecological and evolutionary significance of these attributes. However, the main conservation management implications drawn from this study are that there are a low annual number of nesting females and associated hatchling production in Komodo National Park. Hence, a continuation of more extensive nesting surveys could provide a cost-effective and accurate way to gather important long-term demographic information for this species.
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Identifying island safe havens to prevent the extinction of the World's largest lizard from global warming.
Ecology and evolution, 2020Co-Authors: Alice R. Jones, Deni Purwandana, Achmad Ariefiandy, Claudio Ciofi, Tim S Jessop, Yunias Jackson Benu, Barry W. Brook, Stuart C. Brown, Tamen Sitorus, Tom M. L. WigleyAbstract:The Komodo Dragon (Varanus Komodoensis) is an endangered, island-endemic species with a naturally restricted distribution. Despite this, no previous studies have attempted to predict the effects of climate change on this iconic species. We used extensive Komodo Dragon monitoring data, climate, and sea-level change projections to build spatially explicit demographic models for the Komodo Dragon. These models project the species' future range and abundance under multiple climate change scenarios. We ran over one million model simulations with varying model parameters, enabling us to incorporate uncertainty introduced from three main sources: (a) structure of global climate models, (b) choice of greenhouse gas emission trajectories, and (c) estimates of Komodo Dragon demographic parameters. Our models predict a reduction in range-wide Komodo Dragon habitat of 8%-87% by 2050, leading to a decrease in habitat patch occupancy of 25%-97% and declines of 27%-99% in abundance across the species' range. We show that the risk of extirpation on the two largest protected islands in Komodo National Park (Rinca and Komodo) was lower than other island populations, providing important safe havens for Komodo Dragons under global warming. Given the severity and rate of the predicted changes to Komodo Dragon habitat patch occupancy (a proxy for area of occupancy) and abundance, urgent conservation actions are required to avoid risk of extinction. These should, as a priority, be focused on managing habitat on the islands of Komodo and Rinca, reflecting these islands' status as important refuges for the species in a warming world. Variability in our model projections highlights the importance of accounting for uncertainties in demographic and environmental parameters, structural assumptions of global climate models, and greenhouse gas emission scenarios when simulating species metapopulation dynamics under climate change.
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anthropomorphic and factual approaches in Komodo Dragon conservation awareness program for elementary school students initial study
Applied Environmental Education & Communication, 2020Co-Authors: Puspita Insan Kamil, Deni Purwandana, Harry Susianto, Achmad AriefiandyAbstract:Increasing wildlife awareness is a commonly used approach in community conservations programs. However, in Indonesia, this approach has rarely been quantitatively evaluated for its effectiveness. I...
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Invasive toads are close to but absent from Komodo National Park
BIO Web of Conferences, 2020Co-Authors: Umar F Kennedi, Achmad Ariefiandy, Mirza Dikari Kusrini, Ani MardiastutiAbstract:The islands of Komodo National Park in the Wallacea region are the habitats of Komodo Dragon (Varanus Komodoensis ). Although the Wallacea islands have lower species richness compared to the other large islands in Indonesia, they are rich in endemics, and the occurrence of invasive species would therefore threatened the ecological, economic and social balance of the regions. Several papers have hinted at the possibility of the invasion of Komodo National Parks by Asian toads, a situation which would potentially affect the survival of the Komodo Dragon. To detect the presence of the invansive toad Duttaphrynus melanostictus in Komodo National Park and its surroundings areas we carried out an amphibian survey using a Visual Encounter Survey method during February to April 2018. The surveyed location consisted of two main islands within Komodo National Park (Rinca island and Komodo island), Flores island (Labuan Bajo and Cumbi village) and Sumbawa island (Sape). Two species of amphibians were found in Komodo National Park (Rinca island and Komodo island), while seven species of amphibians were found across all four locations. No D. melanostictus toads were found in Flores (including in Komodo National Park), however the toad was found to be abundant in Sape (Sumbawa island).
Monique L. Van Hoek - One of the best experts on this subject based on the ideXlab platform.
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Komodo-Dragon cathelicidin-inspired peptides are antibacterial against carbapenem-resistant Klebsiella pneumoniae.
Journal of medical microbiology, 2020Co-Authors: Samantha J Hitt, Barney Bishop, Monique L. Van HoekAbstract:Introduction. The rise of carbapenem-resistant enterobacteriaceae (CRE) is a growing crisis that requires development of novel therapeutics.Hypothesis. To this end, cationic antimicrobial peptides (CAMPs) represent a possible source of new potential therapeutics to treat difficult pathogens such as carbapenem-resistant Klebsiella pneumoniae (CRKP), which has gained resistance to many if not all currently approved antibiotics, making treatment difficult.Aim. To examine the anti-CRKP antimicrobial activity of the predicted cathelicidins derived from Varanus Komodoensis (Komodo Dragon) as well as synthetic antimicrobial peptides that we created.Methodology. We determined the minimum inhibitory concentrations of the peptides against CRKP. We also characterized the abilities of these peptides to disrupt the hyperpolarization of the bacterial membrane as well as their ability to form pores in the membrane.Results. We did not observe significant anti-CRKP activity for the predicted native Komodo cathelicidin peptides. We found that the novel peptides DRGN-6,-7 and -8 displayed significant antimicrobial activity against CRKP with MICs of 4-8 µg ml-1. DRGN-6 peptide was the most effective peptide against CRKP. Unfortunately, these peptides showed higher than desired levels of hemolysis, although in vivo testing in the waxworm Galleria mellonella showed no mortality associated with treatment by the peptide; however, CRKP-infected waxworms treated with peptide did not show an improvement in survival.Conclusion. Given the challenges of treating CRKP, identification of peptides with activity against it represents a promising avenue for further research. Given DRGN-6's similar level of activity to colistin, DRGN-6 is a promising template for the development of novel antimicrobial peptide-based therapeutics.
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The Komodo Dragon (Varanus Komodoensis) genome and identification of innate immunity genes and clusters.
BMC genomics, 2019Co-Authors: Monique L. Van Hoek, M. Dennis Prickett, Robert E. Settlage, Lin Kang, Pawel Michalak, Kent A. Vliet, Barney BishopAbstract:We report the sequencing, assembly and analysis of the genome of the Komodo Dragon (Varanus Komodoensis), the largest extant lizard, with a focus on antimicrobial host-defense peptides. The Komodo Dragon diet includes carrion, and a complex milieu of bacteria, including potentially pathogenic strains, has been detected in the saliva of wild Dragons. They appear to be unaffected, suggesting that Dragons have robust defenses against infection. While little information is available regarding the molecular biology of reptile immunity, it is believed that innate immunity, which employs antimicrobial host-defense peptides including defensins and cathelicidins, plays a more prominent role in reptile immunity than it does in mammals. . High molecular weight genomic DNA was extracted from Komodo Dragon blood cells. Subsequent sequencing and assembly of the genome from the collected DNA yielded a genome size of 1.6 Gb with 45x coverage, and the identification of 17,213 predicted genes. Through further analyses of the genome, we identified genes and gene-clusters corresponding to antimicrobial host-defense peptide genes. Multiple β-defensin-related gene clusters were identified, as well as a cluster of potential Komodo Dragon ovodefensin genes located in close proximity to a cluster of Komodo Dragon β-defensin genes. In addition to these defensins, multiple cathelicidin-like genes were also identified in the genome. Overall, 66 β-defensin genes, six ovodefensin genes and three cathelicidin genes were identified in the Komodo Dragon genome. Genes with important roles in host-defense and innate immunity were identified in this newly sequenced Komodo Dragon genome, suggesting that these organisms have a robust innate immune system. Specifically, multiple Komodo antimicrobial peptide genes were identified. Importantly, many of the antimicrobial peptide genes were found in gene clusters. We found that these innate immunity genes are conserved among reptiles, and the organization is similar to that seen in other avian and reptilian species. Having the genome of this important squamate will allow researchers to learn more about reptilian gene families and will be a valuable resource for researchers studying the evolution and biology of the endangered Komodo Dragon.
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Komodo Dragon-inspired synthetic peptide DRGN-1 promotes wound-healing of a mixed-biofilm infected wound
npj Biofilms and Microbiomes, 2017Co-Authors: Ezra M. C. Chung, Scott N. Dean, Crystal N. Propst, Barney M. Bishop, Monique L. Van HoekAbstract:Cationic antimicrobial peptides are multifunctional molecules that have a high potential as therapeutic agents. We have identified a histone H1-derived peptide from the Komodo Dragon ( Varanus Komodoensis) , called VK25. Using this peptide as inspiration, we designed a synthetic peptide called DRGN-1. We evaluated the antimicrobial and anti-biofilm activity of both peptides against Pseudomonas aeruginosa and Staphylococcus aureus . DRGN-1, more than VK25, exhibited potent antimicrobial and anti-biofilm activity, and permeabilized bacterial membranes. Wound healing was significantly enhanced by DRGN-1 in both uninfected and mixed biofilm ( Pseudomonas aeruginosa and Staphylococcus aureus )-infected murine wounds. In a scratch wound closure assay used to elucidate the wound healing mechanism, the peptide promoted the migration of HEKa keratinocyte cells, which was inhibited by mitomycin C (proliferation inhibitor) and AG1478 (epidermal growth factor receptor inhibitor). DRGN-1 also activated the EGFR-STAT1/3 pathway. Thus, DRGN-1 is a candidate for use as a topical wound treatment. Wound infections are a major concern; made increasingly complicated by the emerging, rapid spread of bacterial resistance. The novel synthetic peptide DRGN-1 (inspired by a peptide identified from Komodo Dragon) exhibits pathogen-directed and host-directed activities in promoting the clearance and healing of polymicrobial ( Pseudomonas aeruginosa & Staphylococcus aureus ) biofilm infected wounds. The effectiveness of this peptide cannot be attributed solely to its ability to act upon the bacteria and disrupt the biofilm, but also reflects the peptide’s ability to promsote keratinocyte migration. When applied in a murine model, infected wounds treated with DRGN-1 healed significantly faster than did untreated wounds, or wounds treated with other peptides. The host-directed mechanism of action was determined to be via the EGFR-STAT1/3 pathway. The pathogen-directed mechanism of action was determined to be via anti-biofilm activity and antibacterial activity through membrane permeabilization. This novel peptide may have potential as a future therapeutic for treating infected wounds. A synthetic peptide based on a natural molecule found in the Komodo Dragon promotes healing of biofilm-infected wounds. Peptides are small protein-like molecules. Monique van Hoek, Barney Bishop and colleagues at George Mason University in Virginia, USA, isolated a natural peptide with some antimicrobial properties from Komodo Dragon plasma. They designed a modified synthetic version with rearranged amino acids, named DRGN-1 in recognition of the “Komodo Dragon” peptide that inspired it. In preliminary trials, DRGN-1 enhanced the healing of biofilm-infected wounds in mice, and was more effective than the natural peptide. This may be due to both bacterial- and host-directed effects. DRGN-1 reduced biofilm and bacterial number while increasing wound closure. The authors suggest DRGN-1 could be developed into a therapeutic agent that may treat the biofilm-infected wounds that are increasingly resistant to conventional antibiotics.
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Komodo Dragon-inspired synthetic peptide DRGN-1 promotes wound-healing of a mixed-biofilm infected wound.
NPJ biofilms and microbiomes, 2017Co-Authors: Ezra M. C. Chung, Barney Bishop, Scott N. Dean, Crystal N. Propst, Monique L. Van HoekAbstract:Cationic antimicrobial peptides are multifunctional molecules that have a high potential as therapeutic agents. We have identified a histone H1-derived peptide from the Komodo Dragon (Varanus Komodoensis), called VK25. Using this peptide as inspiration, we designed a synthetic peptide called DRGN-1. We evaluated the antimicrobial and anti-biofilm activity of both peptides against Pseudomonas aeruginosa and Staphylococcus aureus. DRGN-1, more than VK25, exhibited potent antimicrobial and anti-biofilm activity, and permeabilized bacterial membranes. Wound healing was significantly enhanced by DRGN-1 in both uninfected and mixed biofilm (Pseudomonas aeruginosa and Staphylococcus aureus)-infected murine wounds. In a scratch wound closure assay used to elucidate the wound healing mechanism, the peptide promoted the migration of HEKa keratinocyte cells, which was inhibited by mitomycin C (proliferation inhibitor) and AG1478 (epidermal growth factor receptor inhibitor). DRGN-1 also activated the EGFR-STAT1/3 pathway. Thus, DRGN-1 is a candidate for use as a topical wound treatment. Wound infections are a major concern; made increasingly complicated by the emerging, rapid spread of bacterial resistance. The novel synthetic peptide DRGN-1 (inspired by a peptide identified from Komodo Dragon) exhibits pathogen-directed and host-directed activities in promoting the clearance and healing of polymicrobial (Pseudomonas aeruginosa & Staphylococcus aureus) biofilm infected wounds. The effectiveness of this peptide cannot be attributed solely to its ability to act upon the bacteria and disrupt the biofilm, but also reflects the peptide's ability to promsote keratinocyte migration. When applied in a murine model, infected wounds treated with DRGN-1 healed significantly faster than did untreated wounds, or wounds treated with other peptides. The host-directed mechanism of action was determined to be via the EGFR-STAT1/3 pathway. The pathogen-directed mechanism of action was determined to be via anti-biofilm activity and antibacterial activity through membrane permeabilization. This novel peptide may have potential as a future therapeutic for treating infected wounds.
