The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Tom V. Stehn - One of the best experts on this subject based on the ideXlab platform.
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ecological correlates of Whooping Crane use of fire treated upland habitats
Conservation Biology, 1996Co-Authors: Felipe Chavezramirez, Howard E. Hunt, Douglas R Slack, Tom V. StehnAbstract:The only remaining wild population of the endangered Whooping Crane (Grus americana) winters in salt marsh habitats of the Texas (U.S.) coast. Whooping Cranes are known to respond and utilize nearby upland habitats after a tire treatment has been applied. We investigated several factors that may attract Whooping Cranes to recently burned sites at Aransas National Wildlife Refuge between 1982 and 1994 and whether Cranes utilize upland habitats primarily in response to a recent fire treatment or whether they occur regularly on uplands regardless of burning. We evaluated the effect of different years, burn site location, date of burn, and acorn production on Crane use of specific burn sites. Crane use was determined with ground surveys from 1982 through 1985 and from weekly aerial surveys between 1986 and 1994. Whooping Cranes used fire-treated upland habitats to a significantly greater extent than unburned sites. The response of Cranes to recently burned sites was greatest immediately after fire treatment and declined with time. No significant difference was found in Crane use of burned sites among different years. Similarly, time of burn and acorn production had no significant effect on Crane use of fire-treated habitats. Crane use among specific burn units differed significantly. We suggest that Whooping Cranes may be using fire-treated upland habitats to feed on recently killed vertebrates and invertebrates plus recently exposed plant items. Because Cranes primarily inhabit salt marsh habitats, the availability of alternate food sources may be of considerable importance, particularly during years when marsh foods are scarce. But because it appears that areas must be burned to facilitate use by Whooping Cranes, we suggest that the extent of prescribed burning be based on reduced availability of marsh food resources and not on acorn production estimates alone. La unica poblacion silvestre de la Grulla Blanca (Grus americana) inverna en areas de marisma de la costa de Texas. Adicionalmente las grullas responden y utilizan areas de tierra firme con vegetacion arbustiva y pastizal a las que se ha aplicado fuego. De 1982 a 1994 investigamos varios factores que pudiesen atraer a las grullas a areas quemadas en Refugio Nacional de Vida Silvestre Aransas. Investigamos si la occurrencia de las grullas en tierra firme era una respuesta a las quemas o si occurrian regularmente en estas areas aun sin quemas. Evaluamos los efectos de diferentes anos, localidad especifica, fecha y temporada de quema y la produccion de bellota en la utilizacion de diferentes areas por las grullas. La utilizacion de areas quemadas por las grullas se determino mediante muestreos en tierra de 1982 a 1985 y con muestreos por avion llevados a cabo semanalmente de 1985 a 1994. Las grullas utilizaron areas recientemente quemadas con mayor frecuencia que areas sin quemar. Las grullas acudieron a areas immediatamente despues de las quemas y el uso de areas disminuyo con el tiempo. La utilizacion de areas tratadas con fuego no difirio significativamente entre los diferentes anos. La fecha de quema y la produccion de bellota en diferentes areas no afecto significativamente la utilizacion de areas por las grullas. La utilizacion de areas especificas difirio significativamente. Sugerimos posibles factores que puedan afectar la utilizacion de areas quemadas y posibles lineas de manejo e implicaciones para la conservacion de esta poblacion en peligro de extincion. Debido a que las grullas habitan principalmente las areas de marismas, la disponibilidad de areas alternas para alimentarse pueden ser sumamente importantes, particularmente durante anos cuando el alimento en las areas de marismas escasea. Pero debido a que parece que areas deben quemarse para facilitar el uso por la Grulla Blanca, sugerimos que las guemas se lleven a cabo en base a la reduccion en la disponibilidad de alimento en las mavismas y no en base a la estimacion de produccion de bellota.
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Ecological Correlates of Whooping Crane Use of Fire‐Treated Upland Habitats
Conservation Biology, 1996Co-Authors: Felipe Chavez-ramirez, Howard E. Hunt, R. Douglas Slack, Tom V. StehnAbstract:The only remaining wild population of the endangered Whooping Crane (Grus americana) winters in salt marsh habitats of the Texas (U.S.) coast. Whooping Cranes are known to respond and utilize nearby upland habitats after a tire treatment has been applied. We investigated several factors that may attract Whooping Cranes to recently burned sites at Aransas National Wildlife Refuge between 1982 and 1994 and whether Cranes utilize upland habitats primarily in response to a recent fire treatment or whether they occur regularly on uplands regardless of burning. We evaluated the effect of different years, burn site location, date of burn, and acorn production on Crane use of specific burn sites. Crane use was determined with ground surveys from 1982 through 1985 and from weekly aerial surveys between 1986 and 1994. Whooping Cranes used fire-treated upland habitats to a significantly greater extent than unburned sites. The response of Cranes to recently burned sites was greatest immediately after fire treatment and declined with time. No significant difference was found in Crane use of burned sites among different years. Similarly, time of burn and acorn production had no significant effect on Crane use of fire-treated habitats. Crane use among specific burn units differed significantly. We suggest that Whooping Cranes may be using fire-treated upland habitats to feed on recently killed vertebrates and invertebrates plus recently exposed plant items. Because Cranes primarily inhabit salt marsh habitats, the availability of alternate food sources may be of considerable importance, particularly during years when marsh foods are scarce. But because it appears that areas must be burned to facilitate use by Whooping Cranes, we suggest that the extent of prescribed burning be based on reduced availability of marsh food resources and not on acorn production estimates alone. La unica poblacion silvestre de la Grulla Blanca (Grus americana) inverna en areas de marisma de la costa de Texas. Adicionalmente las grullas responden y utilizan areas de tierra firme con vegetacion arbustiva y pastizal a las que se ha aplicado fuego. De 1982 a 1994 investigamos varios factores que pudiesen atraer a las grullas a areas quemadas en Refugio Nacional de Vida Silvestre Aransas. Investigamos si la occurrencia de las grullas en tierra firme era una respuesta a las quemas o si occurrian regularmente en estas areas aun sin quemas. Evaluamos los efectos de diferentes anos, localidad especifica, fecha y temporada de quema y la produccion de bellota en la utilizacion de diferentes areas por las grullas. La utilizacion de areas quemadas por las grullas se determino mediante muestreos en tierra de 1982 a 1985 y con muestreos por avion llevados a cabo semanalmente de 1985 a 1994. Las grullas utilizaron areas recientemente quemadas con mayor frecuencia que areas sin quemar. Las grullas acudieron a areas immediatamente despues de las quemas y el uso de areas disminuyo con el tiempo. La utilizacion de areas tratadas con fuego no difirio significativamente entre los diferentes anos. La fecha de quema y la produccion de bellota en diferentes areas no afecto significativamente la utilizacion de areas por las grullas. La utilizacion de areas especificas difirio significativamente. Sugerimos posibles factores que puedan afectar la utilizacion de areas quemadas y posibles lineas de manejo e implicaciones para la conservacion de esta poblacion en peligro de extincion. Debido a que las grullas habitan principalmente las areas de marismas, la disponibilidad de areas alternas para alimentarse pueden ser sumamente importantes, particularmente durante anos cuando el alimento en las areas de marismas escasea. Pero debido a que parece que areas deben quemarse para facilitar el uso por la Grulla Blanca, sugerimos que las guemas se lleven a cabo en base a la reduccion en la disponibilidad de alimento en las mavismas y no en base a la estimacion de produccion de bellota.
Felipe Chavez-ramirez - One of the best experts on this subject based on the ideXlab platform.
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Potential Impact of Climate Change Scenarios on Whooping Crane Life History
Wetlands, 2012Co-Authors: Felipe Chavez-ramirez, Walter WehtjeAbstract:Whooping Crane ( Grus americana ), a rare and critically endangered species, are wetland dependent throughout their life cycle. The Whooping Crane’s small population size, limited distribution, and wetland habitat requirements make them vulnerable to potential climate changes. Climate change predictions suggest overall temperature increases and significant changes in precipitation regimes throughout North America. At the individual level, temperature changes should have neutral to positive effects on thermoregulation and overall energy expenditure throughout the Whooping Crane’s range. In the breeding grounds, earlier snow melt and increasing temperatures should improve food resources. However, increased precipitation and more extreme rainfall events could impact chick survival if rainfall occurs during hatching. Increased precipitation may also alter fire regimes leading to increased woody plant abundance thus reducing nesting habitat quality. During winter, higher temperatures will lead to a northward shifting of the freeze line, which will decrease habitat quality via invasion of black mangrove. Large portions of current winter habitat may be lost if predicted sea level changes occur. Stopover wetland availability during migration may decrease due to drier conditions in the Great Plains. Current and future conservation actions should be planned in light of not only current needs but also considering future expectations.
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A LANDSCAPE PERSPECTIVE OF Whooping Crane MIGRATION THROUGH NEBRASKA: CONSERVATION AND MANAGEMENT IMPLICATIONS
2008Co-Authors: Felipe Chavez-ramirez, Chris Helzer, Paul TebbelAbstract:Past and current discussions of conservation of Whooping Crane (Grus americana) stopover habitat in Nebraska have long been focused on the Platte River. We evaluated the distribution of Whooping Crane stopover sites in Nebraska in a broader context to (a) determine the distribution of Whooping Crane stopover sites on the Platte River relative to other landscapes and (b) use Whooping migratory behavior data to systematically define and explain patterns of stopover clusters. The distribution of stopover clusters suggests rainwater basin wetlands and the Platte River may be used interchangeably by migrating Whooping Cranes. The Rainwater Basin and Platte River appear to be particularly significant for spring north migrating Cranes as there appears to be a void of wetlands between Cheyenne Bottoms and quivira National Wildlife Refuges in Kansas. We propose that Whooping Crane conservation and management actions in Nebraska must take a broader landscape perspective to include the Platte River plus the entire area required for Whooping Cranes to travel during a day. This perspective suggests that we focus conservation and management activities on a 320-km wide and approximately 240-km long area centered on the Central Valley of the Platte River. We present a strategy to focus conservation and management actions to maximize the availability of Whooping Crane stopover habitat in south-central Nebraska. ProcEEDINGS of thE North AmErIcAN Crane WorkShoP 10:160
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Refining the Whooping Crane Studbook by Incorporating Microsatellite DNA and Leg‐Banding Analyses
Conservation Biology, 2002Co-Authors: Kenneth L. Jones, Travis C. Glenn, Robert C. Lacy, James R. Pierce, Natalie C. Unruh, Claire M. Mirande, Felipe Chavez-ramirezAbstract:We sought to refine genetic management of the endangered Whooping Crane (Grus americana) population by developing comprehensive genetic pedigrees for the captive population. Improvements to the studbook were accomplished by addition of pedigree information derived from leg-banding data on wild ju- venile andfounder similarity coefficients calculatedfrom microsatellite DNA profiles to the original studbook pedigree. Incorporation of pedigrees derived from data on leg-banding of wild juveniles did not greatly alter the previous relatedness structure of the captive population, but incorporation of microsatellite similarity co- efficients produced a substantially different view of the population structure. Microsatellite data provided new information on shared founder genotypes and provided a new DNA-based studbook pedigree that will assist in genetic management of the Whooping Crane population.
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Ecological Correlates of Whooping Crane Use of Fire‐Treated Upland Habitats
Conservation Biology, 1996Co-Authors: Felipe Chavez-ramirez, Howard E. Hunt, R. Douglas Slack, Tom V. StehnAbstract:The only remaining wild population of the endangered Whooping Crane (Grus americana) winters in salt marsh habitats of the Texas (U.S.) coast. Whooping Cranes are known to respond and utilize nearby upland habitats after a tire treatment has been applied. We investigated several factors that may attract Whooping Cranes to recently burned sites at Aransas National Wildlife Refuge between 1982 and 1994 and whether Cranes utilize upland habitats primarily in response to a recent fire treatment or whether they occur regularly on uplands regardless of burning. We evaluated the effect of different years, burn site location, date of burn, and acorn production on Crane use of specific burn sites. Crane use was determined with ground surveys from 1982 through 1985 and from weekly aerial surveys between 1986 and 1994. Whooping Cranes used fire-treated upland habitats to a significantly greater extent than unburned sites. The response of Cranes to recently burned sites was greatest immediately after fire treatment and declined with time. No significant difference was found in Crane use of burned sites among different years. Similarly, time of burn and acorn production had no significant effect on Crane use of fire-treated habitats. Crane use among specific burn units differed significantly. We suggest that Whooping Cranes may be using fire-treated upland habitats to feed on recently killed vertebrates and invertebrates plus recently exposed plant items. Because Cranes primarily inhabit salt marsh habitats, the availability of alternate food sources may be of considerable importance, particularly during years when marsh foods are scarce. But because it appears that areas must be burned to facilitate use by Whooping Cranes, we suggest that the extent of prescribed burning be based on reduced availability of marsh food resources and not on acorn production estimates alone. La unica poblacion silvestre de la Grulla Blanca (Grus americana) inverna en areas de marisma de la costa de Texas. Adicionalmente las grullas responden y utilizan areas de tierra firme con vegetacion arbustiva y pastizal a las que se ha aplicado fuego. De 1982 a 1994 investigamos varios factores que pudiesen atraer a las grullas a areas quemadas en Refugio Nacional de Vida Silvestre Aransas. Investigamos si la occurrencia de las grullas en tierra firme era una respuesta a las quemas o si occurrian regularmente en estas areas aun sin quemas. Evaluamos los efectos de diferentes anos, localidad especifica, fecha y temporada de quema y la produccion de bellota en la utilizacion de diferentes areas por las grullas. La utilizacion de areas quemadas por las grullas se determino mediante muestreos en tierra de 1982 a 1985 y con muestreos por avion llevados a cabo semanalmente de 1985 a 1994. Las grullas utilizaron areas recientemente quemadas con mayor frecuencia que areas sin quemar. Las grullas acudieron a areas immediatamente despues de las quemas y el uso de areas disminuyo con el tiempo. La utilizacion de areas tratadas con fuego no difirio significativamente entre los diferentes anos. La fecha de quema y la produccion de bellota en diferentes areas no afecto significativamente la utilizacion de areas por las grullas. La utilizacion de areas especificas difirio significativamente. Sugerimos posibles factores que puedan afectar la utilizacion de areas quemadas y posibles lineas de manejo e implicaciones para la conservacion de esta poblacion en peligro de extincion. Debido a que las grullas habitan principalmente las areas de marismas, la disponibilidad de areas alternas para alimentarse pueden ser sumamente importantes, particularmente durante anos cuando el alimento en las areas de marismas escasea. Pero debido a que parece que areas deben quemarse para facilitar el uso por la Grulla Blanca, sugerimos que las guemas se lleven a cabo en base a la reduccion en la disponibilidad de alimento en las mavismas y no en base a la estimacion de produccion de bellota.
Tarla Rai Peterson - One of the best experts on this subject based on the ideXlab platform.
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engaging active stakeholders in implementation of community based conservation Whooping Crane management in texas usa
Wildlife Society Bulletin, 2015Co-Authors: Leigh Bernacchi, Chara J Ragland, Tarla Rai PetersonAbstract:Engaging a variety of wildlife stakeholders in the implementation of conservation plans is an increasingly frequent activity of wildlife managers. In some cases, stakeholders develop interdependent relationships with a species being managed by the wildlife agency, usually when the species is economically important. We studied the potential for engaging stakeholders in the implementation of community-based conservation in the winter habitat of the federally endangered Whooping Crane (Grus americana) to better understand the relationships between stakeholders (including landowners and nongovernmental organizations) and wildlife managers when working with charismatic species that provide local economic value. In May–September 2010, we interviewed 35 Texas individuals interested in Crane conservation, and then analyzed transcripts using both a priori and emergent coding techniques. We found that active stakeholders were eager to work with wildlife managers because of the charismatic and economic values they attributed to the Whooping Crane. We also found that these stakeholders responded positively to agency intervention for the purpose of sharing expert knowledge and providing stakeholders with standing in the dynamically complex management practices surrounding the species and ecosystem. By recognizing the interests of active stakeholders, wildlife managers can expand opportunities for positive public participation in efforts to conserve and restore endangered species populations. They can improve community relations by building on already existing positive perceptions of relationships between humans and wildlife. © 2015 The Authors. Wildlife Society Bulletin published by The Wildlife Society.
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Engaging active stakeholders in implementation of community‐based conservation: Whooping Crane management in Texas, USA
Wildlife Society Bulletin, 2015Co-Authors: Leigh Bernacchi, Chara J Ragland, Tarla Rai PetersonAbstract:Engaging a variety of wildlife stakeholders in the implementation of conservation plans is an increasingly frequent activity of wildlife managers. In some cases, stakeholders develop interdependent relationships with a species being managed by the wildlife agency, usually when the species is economically important. We studied the potential for engaging stakeholders in the implementation of community-based conservation in the winter habitat of the federally endangered Whooping Crane (Grus americana) to better understand the relationships between stakeholders (including landowners and nongovernmental organizations) and wildlife managers when working with charismatic species that provide local economic value. In May–September 2010, we interviewed 35 Texas individuals interested in Crane conservation, and then analyzed transcripts using both a priori and emergent coding techniques. We found that active stakeholders were eager to work with wildlife managers because of the charismatic and economic values they attributed to the Whooping Crane. We also found that these stakeholders responded positively to agency intervention for the purpose of sharing expert knowledge and providing stakeholders with standing in the dynamically complex management practices surrounding the species and ecosystem. By recognizing the interests of active stakeholders, wildlife managers can expand opportunities for positive public participation in efforts to conserve and restore endangered species populations. They can improve community relations by building on already existing positive perceptions of relationships between humans and wildlife. © 2015 The Authors. Wildlife Society Bulletin published by The Wildlife Society.
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engaging active stakeholders in implementation of community based conservation Whooping Crane management
2015Co-Authors: Leigh Bernacchi, Chara J Ragland, Tarla Rai PetersonAbstract:Engaging a variety of wildlife stakeholders in the implementation of conservation plans is an increasingly frequent activity of wildlife managers. In some cases, stakeholders develop interdependent relationships with a species being managed by the wildlife agency, usually when the species is economically important. We studied the potential for engaging stakeholders in the implementation of community-based conservation in the winter habitat of the federally endangered Whooping Crane (Grus americana) to better understand the relationships between stakeholders (including landowners and nongovernmental organizations) and wildlife managers when working with charismatic species that provide local economic value. In May-September 2010, we interviewed 35 Texas individuals interested in Crane conservation, and then analyzed transcripts using both a priori and emergent coding techniques. We found that active stakeholders were eager to work with wildlife managers because of the charismatic and economic values they attributed to the Whooping Crane. We also found that these stakeholders responded positively to agency intervention for the purpose of sharing expert knowledge and providing stakeholders with standing in the dynamically complex management practices surrounding the species and ecosystem. By recognizing the interests of active stakeholders, wildlife managers can expand opportunities for positive public participation in efforts to conserve and restore endangered species populations. They can improve community relations by building on already existing positive perceptions of relationships between humans and wildlife. 2015 The Authors. Wildlife Society Bulletin published by The Wildlife Society
Felipe Chavezramirez - One of the best experts on this subject based on the ideXlab platform.
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an individual Whooping Crane s family history
2010Co-Authors: Karine Gil, Thomas V. Stehn, Brian W. Johns, Felipe Chavezramirez, Robin SilvaAbstract:Between 1977 and 1988, 12 cohorts (134 individuals) of Whooping Cranes (Grus americana) were banded in Wood Buffalo National Park (WBNP, Canada-breeding ground) and monitored from Canada to Aransas National Wildlife Refuge (ANWR, Texas-wintering ground). During 2004, historical data on banded individuals was analyzed to estimate population parameters and life table of the wild population. This study used information from one of the few banded Cranes known to be alive in 2008 since 1978. A genealogy tree (Family Tree Maker software) was developed from individual RwR-nil to represent its descendents and relatives, as well as a map (GIS) for geographic distribution. We found that his descendents were: 4 in the first generation, at least 13 in the second generation, and 4 in the fourth generation. In total 21 descendents arrived to ANWR, and 3 of them are still alive. We identified that all males in the family selected nesting and winter territories and did not change territories with new mates. Banded females did. All nests were established in the Sass River nesting area of WBNP, and all wintering territories were in Matagorda Island, which are close to their parents' territories. History of mates, nesting fate (success, failures, no nest), number of eggs, chicks, and juveniles were analyzed, as were territory distribution and use of stopovers. Years of nesting success and failure occurred in synchrony among members of the family. Evidence of potential inbreeding, adoption, and extended family migration was collected. Information from this family will contribute to studies of kin selection and inclusive fitness. PROCEEDINGS OF THE NORTH AMERICAN Crane WORKSHOP 11:201
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refining the Whooping Crane studbook by incorporating microsatellite dna and leg banding analyses
Conservation Biology, 2002Co-Authors: Kenneth L. Jones, Travis C. Glenn, Robert C. Lacy, James R. Pierce, Claire M. Mirande, Natalie Unruh, Felipe ChavezramirezAbstract:We sought to refine genetic management of the endangered Whooping Crane (Grus americana) population by developing comprehensive genetic pedigrees for the captive population. Improvements to the studbook were accomplished by addition of pedigree information derived from leg-banding data on wild ju- venile andfounder similarity coefficients calculatedfrom microsatellite DNA profiles to the original studbook pedigree. Incorporation of pedigrees derived from data on leg-banding of wild juveniles did not greatly alter the previous relatedness structure of the captive population, but incorporation of microsatellite similarity co- efficients produced a substantially different view of the population structure. Microsatellite data provided new information on shared founder genotypes and provided a new DNA-based studbook pedigree that will assist in genetic management of the Whooping Crane population.
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ecological correlates of Whooping Crane use of fire treated upland habitats
Conservation Biology, 1996Co-Authors: Felipe Chavezramirez, Howard E. Hunt, Douglas R Slack, Tom V. StehnAbstract:The only remaining wild population of the endangered Whooping Crane (Grus americana) winters in salt marsh habitats of the Texas (U.S.) coast. Whooping Cranes are known to respond and utilize nearby upland habitats after a tire treatment has been applied. We investigated several factors that may attract Whooping Cranes to recently burned sites at Aransas National Wildlife Refuge between 1982 and 1994 and whether Cranes utilize upland habitats primarily in response to a recent fire treatment or whether they occur regularly on uplands regardless of burning. We evaluated the effect of different years, burn site location, date of burn, and acorn production on Crane use of specific burn sites. Crane use was determined with ground surveys from 1982 through 1985 and from weekly aerial surveys between 1986 and 1994. Whooping Cranes used fire-treated upland habitats to a significantly greater extent than unburned sites. The response of Cranes to recently burned sites was greatest immediately after fire treatment and declined with time. No significant difference was found in Crane use of burned sites among different years. Similarly, time of burn and acorn production had no significant effect on Crane use of fire-treated habitats. Crane use among specific burn units differed significantly. We suggest that Whooping Cranes may be using fire-treated upland habitats to feed on recently killed vertebrates and invertebrates plus recently exposed plant items. Because Cranes primarily inhabit salt marsh habitats, the availability of alternate food sources may be of considerable importance, particularly during years when marsh foods are scarce. But because it appears that areas must be burned to facilitate use by Whooping Cranes, we suggest that the extent of prescribed burning be based on reduced availability of marsh food resources and not on acorn production estimates alone. La unica poblacion silvestre de la Grulla Blanca (Grus americana) inverna en areas de marisma de la costa de Texas. Adicionalmente las grullas responden y utilizan areas de tierra firme con vegetacion arbustiva y pastizal a las que se ha aplicado fuego. De 1982 a 1994 investigamos varios factores que pudiesen atraer a las grullas a areas quemadas en Refugio Nacional de Vida Silvestre Aransas. Investigamos si la occurrencia de las grullas en tierra firme era una respuesta a las quemas o si occurrian regularmente en estas areas aun sin quemas. Evaluamos los efectos de diferentes anos, localidad especifica, fecha y temporada de quema y la produccion de bellota en la utilizacion de diferentes areas por las grullas. La utilizacion de areas quemadas por las grullas se determino mediante muestreos en tierra de 1982 a 1985 y con muestreos por avion llevados a cabo semanalmente de 1985 a 1994. Las grullas utilizaron areas recientemente quemadas con mayor frecuencia que areas sin quemar. Las grullas acudieron a areas immediatamente despues de las quemas y el uso de areas disminuyo con el tiempo. La utilizacion de areas tratadas con fuego no difirio significativamente entre los diferentes anos. La fecha de quema y la produccion de bellota en diferentes areas no afecto significativamente la utilizacion de areas por las grullas. La utilizacion de areas especificas difirio significativamente. Sugerimos posibles factores que puedan afectar la utilizacion de areas quemadas y posibles lineas de manejo e implicaciones para la conservacion de esta poblacion en peligro de extincion. Debido a que las grullas habitan principalmente las areas de marismas, la disponibilidad de areas alternas para alimentarse pueden ser sumamente importantes, particularmente durante anos cuando el alimento en las areas de marismas escasea. Pero debido a que parece que areas deben quemarse para facilitar el uso por la Grulla Blanca, sugerimos que las guemas se lleven a cabo en base a la reduccion en la disponibilidad de alimento en las mavismas y no en base a la estimacion de produccion de bellota.
Chadwin B. Smith - One of the best experts on this subject based on the ideXlab platform.
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Whooping Crane use of riverine stopover sites
PloS one, 2019Co-Authors: David Baasch, Patrick Farrell, Shay Howlin, Aaron T. Pearse, Jason M. Farnsworth, Chadwin B. SmithAbstract:Migratory birds like endangered Whooping Cranes (Grus americana) require suitable nocturnal roost sites during twice annual migrations. Whooping Cranes primarily roost in shallow surface water wetlands, ponds, and rivers. All these features have been greatly impacted by human activities, which present threats to the continued recovery of the species. A portion of one such river, the central Platte River, has been identified as critical habitat for the survival of the endangered Whooping Crane. Management intervention is now underway to rehabilitate habitat form and function on the central Platte River to increase use and thereby contribute to the survival of Whooping Cranes. The goal of our analyses was to develop habitat selection models that could be used to direct riverine habitat management activities (i.e., channel widening, tree removal, flow augmentation, etc.) along the central Platte River and throughout the species' range. As such, we focused our analyses on two robust sets of Whooping Crane observations and habitat metrics the Platte River Recovery Implementation Program (Program or PRRIP) and other such organizations could influence. This included channel characteristics such as total channel width, the width of channel unobstructed by dense vegetation, and distance of forest from the edge of the channel and flow-related metrics like wetted width and unit discharge (flow volume per linear meter of wetted channel width) that could be influenced by flow augmentation or reductions during migration. We used 17 years of systematic monitoring data in a discrete-choice framework to evaluate the influence these various metrics have on the relative probability of Whooping Crane use and found the width of channel unobstructed by dense vegetation and distance to the nearest forest were the best predictors of Whooping Crane use. Secondly, we used telemetry data obtained from a sample of 38 birds of all ages over the course of seven years, 2010-2016, to evaluate Whooping Crane use of riverine habitat within the North-central Great Plains, USA. For this second analysis, we focused on the two metrics found to be important predictors of Whooping Crane use along the central Platte River, unobstructed channel width and distance to nearest forest or wooded area. Our findings indicate resource managers, such as the Program, have the potential to influence Whooping Crane use of the central Platte River through removal of in-channel vegetation to increase the unobstructed width of narrow channels and through removal of trees along the bank line to increase unforested corridor widths. Results of both analyses also indicated that increases in relative probability of use by Whooping Cranes did not appreciably increase with unobstructed views ≥200 m wide and unforested corridor widths that were ≥330 m. Therefore, managing riverine sites for channels widths >200 m and removing trees beyond 165 m from the channel's edge would increase costs associated with implementing management actions such as channel and bank-line disking, removing trees, augmenting flow, etc. without necessarily realizing an additional appreciable increase in use by migrating Whooping Cranes.
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In-channel riverine a priori model list evaluated for Whooping Crane roosting habitat use along the central Platte River.
2019Co-Authors: David Baasch, Shay Howlin, Aaron T. Pearse, Jason M. Farnsworth, Patrick D. Farrell, Chadwin B. SmithAbstract:The interpretation assumes an a priori direction (positive or negative) in the relationship between Whooping Crane habitat use and metrics, but actual model fit based on data could have been in the opposite direction.
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Example of how unobstructed channel width (UOCW; yellow lines), nearest forest (NF; red lines) and unforested channel width (UFCW; blue lines) were measured at Whooping Crane use and available locations.
2019Co-Authors: David Baasch, Shay Howlin, Aaron T. Pearse, Jason M. Farnsworth, Patrick D. Farrell, Chadwin B. SmithAbstract:Example of how unobstructed channel width (UOCW; yellow lines), nearest forest (NF; red lines) and unforested channel width (UFCW; blue lines) were measured at Whooping Crane use and available locations.
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Investigating Whooping Crane habitat in relation to hydrology, channel morphology and a water-centric management strategy on the central Platte River, Nebraska.
Heliyon, 2018Co-Authors: Jason M. Farnsworth, David Baasch, Chadwin B. Smith, Patrick D. Farrell, Kevin L. WerbyloAbstract:The Flow-Sediment-Mechanical approach is one of two management strategies presented in the Platte River Recovery Implementation Program's (Program) Adaptive Management Plan to create and maintain suitable riverine habitat (≥200 m wide unobstructed channels) for Whooping Cranes (Grus americana). The Program's Flow-Sediment-Mechanical management strategy consists of sediment augmentation, mechanical vegetation clearing and channel widening, channel consolidation, and short duration high flow releases of 142-227 m3/s for three to five days in two out of three years in order to increase the unvegetated width of the main channel and, by extension, create and maintain suitable habitat for Whooping Crane use. We examined the influence of a range of hydrologic and physical metrics on total unvegetated channel width (TUCW) and maximum unobstructed channel width (MUOCW) during the period of 2007-2015 and applied those findings to assess the performance of the Flow-Sediment-Mechanical management strategy for creating and maintaining Whooping Crane roosting habitat. Our investigation highlights uncertainties that are introduced when exploring the relationship between physical process drivers and species habitat metrics. We identified a strong positive relationship between peak flows and TUCW and MUOCW within the Associated Habitat Reach of the central Platte River. However, the peak discharge magnitude and duration needed to create highly favorable Whooping Crane roosting habitat within our study area are much greater than short duration high flow releases, as currently envisioned. We also found disking in combination with herbicide application to vegetated portions of the channel are effective for creating and maintaining highly favorable unobstructed channel widths for Whooping Cranes in all but the very driest years. As such, resource managers could prioritize the treatment of mid-channel islands that are vegetated to increase the suitability of roosting habitat for Whooping Cranes.
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Investigating Whooping Crane habitat in relation to hydrology, channel morphology and a water-centric management strategy on the central Platte River, Nebraska
Elsevier, 2018Co-Authors: Jason M. Farnsworth, David Baasch, Chadwin B. Smith, Patrick D. Farrell, Kevin L. WerbyloAbstract:The Flow-Sediment-Mechanical approach is one of two management strategies presented in the Platte River Recovery Implementation Program's (Program) Adaptive Management Plan to create and maintain suitable riverine habitat (≥200 m wide unobstructed channels) for Whooping Cranes (Grus americana). The Program's Flow-Sediment-Mechanical management strategy consists of sediment augmentation, mechanical vegetation clearing and channel widening, channel consolidation, and short duration high flow releases of 142–227 m3/s for three to five days in two out of three years in order to increase the unvegetated width of the main channel and, by extension, create and maintain suitable habitat for Whooping Crane use. We examined the influence of a range of hydrologic and physical metrics on total unvegetated channel width (TUCW) and maximum unobstructed channel width (MUOCW) during the period of 2007–2015 and applied those findings to assess the performance of the Flow-Sediment-Mechanical management strategy for creating and maintaining Whooping Crane roosting habitat. Our investigation highlights uncertainties that are introduced when exploring the relationship between physical process drivers and species habitat metrics. We identified a strong positive relationship between peak flows and TUCW and MUOCW within the Associated Habitat Reach of the central Platte River. However, the peak discharge magnitude and duration needed to create highly favorable Whooping Crane roosting habitat within our study area are much greater than short duration high flow releases, as currently envisioned. We also found disking in combination with herbicide application to vegetated portions of the channel are effective for creating and maintaining highly favorable unobstructed channel widths for Whooping Cranes in all but the very driest years. As such, resource managers could prioritize the treatment of mid-channel islands that are vegetated to increase the suitability of roosting habitat for Whooping Cranes. Keywords: Ecology, Environmental science, Hydrolog
