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1.
Animals (Basel) ; 14(8)2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38672360

RESUMEN

Perceived risk associated with hunters can cause white-tailed deer (Odocoileus virginianus) to shift their activity away from key foraging areas or alter normal movements, which are important considerations in managing hunting and its effects on a population. We studied the effects of seven firearms hunts on the movements of 20 female deer in two Wildlife Management Areas within the Chattahoochee National Forest of northern Georgia, USA, during the 2018-2019 and 2019-2020 hunting seasons. Deer populations and the number of hunters in our study area have declined significantly since the 1980s. In response, hunting regulations for the 2019-2020 hunting season eliminated opportunities for harvesting female deer. To evaluate the indirect effects of antlered deer hunting on non-target female deer, we calculated 90% utilization distributions (UDs), 50% UDs, and step lengths for pre-hunt, hunt, and post-hunt periods using the dynamic Brownian bridge movement model. Data included 30 min GPS locations for 44 deer-hunt combinations. Pre-hunt 50% UDs (x- = 7.0 ha, SE = 0.4 ha) were slightly greater than both hunt (x- = 6.0 ha, SE = 0.3 ha) and post-hunt (x- = 6.0 ha, SE = 0.2 ha) 50% UDs (F = 3.84, p = 0.03). We did not detect differences in step length, nor did we detect differences in size or composition of 90% UDs, among the periods. Overall, our results suggest that the low level of hunting pressure in our study area and lack of exposure to hunters led to no biologically significant changes in female deer movements. To the extent of the findings presented in this paper, adjustments to the management of hunting in our study area do not appear to be necessary to minimize hunting-related disturbances for female deer. However, managers should continue to consider female deer behavior when evaluating future changes to hunting regulations.

2.
Animals (Basel) ; 13(23)2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-38067026

RESUMEN

Although generally abundant, white-tailed deer (Odocoileus virginianus) populations in the southeastern United States have recently experienced several localized declines attributed to reduced fawn recruitment following the establishment of coyotes (Canis latrans). The Southern Appalachians is a mountainous region suggested to be experiencing white-tailed deer declines, as harvest numbers and hunter success rates have substantially decreased in northern Georgia since 1979. Low fawn survival (16%) was also recently documented in the Chattahoochee National Forest (CNF) in northern Georgia, necessitating further examination. We radio-collared 14 yearling and 45 adult female white-tailed deer along with 71 fawns during 2018-2020 in the CNF to estimate field-based vital rates (i.e., survival and fecundity) and parameterize stage-structured population models. We projected population growth rates (λ) over 10 years to evaluate the current rate of decline and various other management scenarios. Our results indicated that the observed population would decline by an average of 4.0% annually (λ = 0.960) under current conditions. Only scenarios including antlerless harvest restrictions in addition to improved fawn survival resulted in positive growth (λ = 1.019, 1.085), suggesting these measures are likely necessary for population recovery in the region. This approach can be applied by wildlife managers to inform site-specific management strategies.

3.
PLoS One ; 18(8): e0288449, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37651350

RESUMEN

In the Southern Appalachian region of the United States, harvest data has indicated the occurrence of low deer densities while exposing a trend of declining white-tailed deer (Odocoileus virginianus) populations over the past several decades in northern Georgia. A triumvirate of increasing fawn predator populations reside in the Southern Appalachian Mountains including coyotes (Canis latrans), black bears (Ursus americanus) and bobcats (Lynx rufus). This region is also characterized by a homogenous landscape composed of mature forests and sparse understory vegetation, likely lacking adequate cover to offer fawns refugia from predators. Our objectives were to estimate survival and cause-specific mortality rates of fawns while assessing a possible link between mortality risk, intrinsic fawn characteristics (i.e., birth mass, Julian birth date, sibling status), and landscape features within fawn usage areas. During 2018-2020, we radio-collared 71 fawns within the Chattahoochee National Forest of northern Georgia, USA and monitored survival to 12 weeks of age. We observed low fawn survival (cumulative = 0.157, 95% CI = 0.091-0.273; vaginal implant transmitter = 0.196, 95% CI = 0.096-0.403) with predation as the leading cause of all known mortalities (45 of 55 mortalities; 82%) due primarily to coyotes (n = 22), black bears (n = 12), and bobcats (n = 7). Relationships between landscape features and fawn predation risk were minimal with only one informative covariate. Increasing amounts of early successional land cover within fawn usage areas decreased fawn mortality risk within the first 20 days of life, but elevated mortality risk thereafter. All fawns with any amount of early successional land cover in their usage areas died of predation (n = 13) at various time intervals, suggesting limited areas of potential fawning cover may be targeted by predators. However, fawn predation risk seemed to be high regardless of landscape covariates due to the limited number of surviving fawns. Coyote-caused mortality occurred over a longer period at a consistently higher magnitude than all other forms of mortality, indicating possible delayed prey-switching behavior and coyote predation as an important factor of fawn survival. The low recruitment of fawns influenced by high predation rates and homogenous habitat conditions is likely the cause of deer population declines in the region.


Asunto(s)
Coyotes , Ciervos , Saltamontes , Lynx , Ursidae , Animales , Femenino , Conducta Predatoria , Región de los Apalaches
4.
Conserv Biol ; 37(3): e14028, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36317723

RESUMEN

Citizen science (CS) is gaining recognition as a valuable approach to meet data needs for environmental projects while fostering collaboration between scientists and members of the public. Despite increasing implementation of CS by natural resource entities, organizations' motivations for engaging in CS remain poorly understood. We examined the utility of the theory of planned behavior (TPB) and social exchange theory (SET) in identifying factors influencing support of CS by scientific organizations. To test predictions of the TPB and SET theories, we surveyed (quantitative, web based) state wildlife agency staff in the United States on their perceptions of organizational engagement in CS. We divided questions that measured TPB items into individual and organizational components to address the influence of personal- and organization-level decision-making on staff perceptions and attitudes. We used structural equation modeling to identify key constructs that influence staff support of CS in state wildlife agencies. The survey yielded 627 responses across 44 states. Both TPB and SET constructs accurately predicted staff support of CS; however, measures from SET (e.g., public engagement benefits and costs of CS to scientific credibility) were most influential (i.e., TPB constructs had less impact). Our findings indicate that organizational support for CS is primarily influenced by assessment of trade-offs among perceived costs and benefits. Indicators of support for CS were further elucidated by including measures from the TPB model. Based on our results, we suggest that natural resource entities give careful consideration to CS project design, develop thorough communication and data management plans, and practice iterative evaluation of CS project productivity.


Impulsores del apoyo a la ciencia ciudadana entre las agencias estatales de gestión de fauna en los Estados Unidos Resumen Cada vez se reconoce más a la ciencia ciudadana (CC) como una estrategia valiosa para cumplir con las necesidades informativas de los proyectos ambientales, a la vez que promueve la colaboración entre los científicos y el público. Aunque es cada vez mayor la implementación de la CC por parte de las entidades de recursos naturales, todavía hay poca información sobre la motivación de las organizaciones para participar en la CC. Analizamos la utilidad de la teoría del comportamiento planeado (TCP) y la teoría del intercambio social (TIS) en la identificación de los factores que influyen sobre el apoyo de las organizaciones científicas a la CC. Sondeamos (cuantitativamente y en línea) al personal de las agencias estatales de los Estados Unidos sobre sus percepciones de la participación organizacional en la CC para evaluar las predicciones de ambas teorías. Dividimos las preguntas que medían los objetos de la TCP en componentes individuales y organizacionales para abordar la influencia de la toma de decisiones a nivel personal y organizacional sobre las actitudes y percepciones del personal. Usamos modelos de ecuación estructural para identificar los constructos clave que influyen sobre el apoyo a la CC por parte del personal de las agencias estatales de fauna. El sondeo aportó 627 respuestas de 44 estados. Los constructos de ambas teorías pronosticaron correctamente el apoyo a la CC por parte del personal; sin embargo, las medidas de la TIS (por ejemplo, los beneficios de la participación del público y los costos de la CC en la credibilidad científica) tuvieron la mayor influencia (los constructos de la TCP tuvieron un menor impacto). Nuestros resultados indican que el apoyo organizacional hacia la CC está influenciado principalmente por la valoración de las compensaciones entre los costos y beneficios percibidos. Los indicadores del apoyo a la CC se esclarecieron más con la inclusión de las medidas del modelo de la TCP. Con base en nuestros resultados, sugerimos que las entidades de recursos naturales consideren cuidadosamente el diseño de proyectos de CC, desarrollen una comunicación minuciosa y planes de manejo de datos y practiquen la evaluación iterativa de la productividad de los proyectos de CC.


Asunto(s)
Ciencia Ciudadana , Conservación de los Recursos Naturales , Animales , Estados Unidos , Humanos , Animales Salvajes , Recursos Naturales , Organizaciones
5.
Animals (Basel) ; 11(8)2021 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-34438790

RESUMEN

Bait is often used to increase wildlife harvest susceptibility, enhance viewing opportunities, and survey wildlife populations. The effects of baiting depend on how bait influences space use and resource selection at multiple spatial scales. Although telemetry studies allow for inferences about resource selection within home ranges (third-order selection), they provide limited information about spatial variation in density, which is the result of second-order selection. Recent advances in spatial capture-recapture (SCR) techniques allow exploration of second- and third-order selection simultaneously using non-invasive methods such as camera traps. Our objectives were to describe how short-term baiting affects white-tailed deer (Odocoileus virginianus) behavior and distribution. We fit SCR models to camera data from baited and unbaited locations in southwestern Georgia to assess the effects of short-term baiting on second- and third-order selection of deer during summer and winter surveys. We found little evidence of second-order selection during late summer or early winter surveys when camera surveys using bait are typically conducted. However, we found evidence for third-order selection, indicating that resource selection within home ranges is affected. Concentrations in space use resulting from baiting may enhance disease transmission, change harvest susceptibility, and potentially bias the outcome of camera surveys using bait.

6.
PLoS One ; 13(10): e0203703, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30303970

RESUMEN

To ensure reproductive success, Canis species establish contiguous mosaics of territories in suitable habitats to partition space and defend limiting resources. Consequently, Canis species can exert strong effects on prey populations locally because of their year-round maintenance of territories. We assessed prey use by coyotes (Canis latrans) by sampling scats from within known territories in southeastern Alabama and the Savannah River area of Georgia and South Carolina. We accounted for the size and habitat composition of coyote home ranges to investigate the influence of space use, vegetation density, and habitat type on coyote diets. Coyote use of prey was influenced by a combination of mean monthly temperature, home range size, vegetation density, and hardwood forests. For example, coyote use of adult white-tailed deer (Odocoileus virginianus) was associated with cooler months and smaller home ranges, whereas use of rabbits (Sylvilagus spp.) was associated with cooler months, larger home ranges, and less vegetation density. Coyotes in our study relied primarily on nutritionally superior mammalian prey and supplemented their diet with fruit when available, as their use of mammalian prey did not appreciably decrease with increasing use of fruit. We suggest that differential use of prey by coyotes is influenced by habitat heterogeneity within their home ranges, and prey-switching behaviors may stabilize local interactions between coyotes and their food resources to permit stable year-round territories. Given that habitat composition affects coyote prey use, future studies should also incorporate effects of habitat composition on coyote distribution and abundance to further identify coyote influences on prey communities.


Asunto(s)
Coyotes/fisiología , Fenómenos de Retorno al Lugar Habitual/fisiología , Conducta Predatoria/fisiología , Animales , Ciervos/fisiología , Ecosistema , Mamíferos/fisiología , Conejos , Estaciones del Año
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