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1.
Front Zool ; 21(1): 24, 2024 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-39327595

RESUMEN

BACKGROUND: Rapidly expanding human activities have profoundly changed the habitat use of both large carnivores and their prey, but whether and how human activities affect the interactions between them has received relatively less attention. In this study, we conducted a systematically designed camera-trapping survey on an endangered large carnivore (North Chinese leopard Panthera pardus japonensis) and its wild ungulate prey (Siberian roe deer Capreolus pygargus and wild boar Sus scrofa) in the Taihang Mountains of central North China. Using conditional two-species occupancy model based on data derived from the extensive sampling effort (15,654 camera-days at 102 camera sites), we examined the relationship of spatial use between leopards and each prey species under the effects of human presence, free-ranging cattle, roads and settlements. RESULTS: Humans and cattle had contrasting effects on the relationship of spatial use between leopard and roe deer, with higher and lower spatial segregation between them at human and cattle-frequented sites, respectively. Roads might create a shelter for wild boar from leopard predation, with less spatial segregation between them at sites close to the roads. CONCLUSIONS: Our findings demonstrate that human activities are reshaping the spatial overlap between large carnivores and their prey, and have non-equivalent effects among different types of human activity. Such effects may further alter the strength of interspecific interactions between predator and prey, with far-reaching influences on the community and ecosystem that require more research.

2.
Conserv Biol ; 34(4): 819-828, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32406975

RESUMEN

Former ranges of wild animals have been reestablished in many developed countries. However, this reestablishment has led to increasing human-wildlife conflict in agroforest ecosystems. In Japan, human-wildlife conflict, such as crop raiding by and ecological impacts of wild ungulates and primates, is a serious problem in depopulated rural areas due to these animal range expansions and increased abundances. Japan's human population is predicted to decline by 24% by 2050, and approximately 20% of agricultural settlements will become completely depopulated. In this scenario, anthropogenic pressures on wildlife (e.g., hunting and habitat alteration) will continue to decrease and human-wildlife conflict will increase due to increasing wildlife recovery. Japan's local governments plan to slow range recovery, prevent species reestablishment, or remove recolonizing large mammals through lethal control. This strategy, however, is not cost-effective, and workforce shortages in depopulated communities make it infeasible. Moreover, the suppression of wildlife prevents the recovery of ecological functions and thus would degrade regional biodiversity. The declining pressure on wildlife that accompanies human depopulation will prevent the restoration of any past states of human-wildlife interaction. We suggest human-used areas in rural landscapes be aggregated in compact cities and that in transition zones between human settlements and depopulated lands that land-sharing approaches be applied. Concentrating management efforts in compact cities may effectively decrease human-wildlife conflict, rather than intensifying human pressures. Reforestation of depopulated lands may lead to recovery of wildlife habitats, their ecosystem functions, and regional biodiversity due to minimization of negative anthropogenic effects (land-sparing approach). Balancing resolution of human-wildlife conflict and ecological rewilding could become a new, challenging task for regional wildlife managers.


Una Estrategia para el Manejo de Fauna en Áreas Rurales Despobladas de Japón Resumen Las distribuciones geográficas históricas de algunos animales silvestres se han reestablecido en muchos países desarrollados. Sin embargo, este restablecimiento ha derivado en un incremento del conflicto humano - fauna en los ecosistemas agroforestales. En Japón, el conflicto humano - fauna, como el asalto de cultivos y los impactos ecológicos de los primates y ungulados, es un problema serio en las áreas rurales despobladas debido a la expansión de la distribución y al incremento en abundancia de estos animales. Está pronosticado que la población humana de Japón decline en un 24% para 2050 y ∼20% de los establecimientos agrícolas estarán completamente despoblados. Bajo este escenario, las presiones antropogénicas sobre la fauna (como la caza y la alteración del hábitat) continuarán disminuyendo y el conflicto humano - fauna incrementará debido a la recuperación de la fauna. El gobierno local de Japón planea retrasar la recuperación de las distribuciones, prevenir el restablecimiento de las especies o remover a los mamíferos mayores en proceso de recolonización por medio del exterminio. Sin embargo, esta estrategia no es rentable y la escasez de mano de obra en las comunidades despobladas hace que no sea una estrategia factible. Además, la supresión de fauna impide la recuperación de las funciones ecológicas, por lo que terminaría por degradar la biodiversidad regional. La reducción de la presión sobre la fauna que va de la mano con la despoblación humana prevendrá la recuperación de cualquier estado pasado de la interacción humano - fauna. Sugerimos que las áreas usadas por humanos en los paisajes rurales queden agregadas en ciudades compactas y que se apliquen estrategias de tierras compartidas en las zonas de transición entre los asentamientos humanos y las tierras despobladas. La concentración de los esfuerzos de manejo en las ciudades compactas podría disminuir efectivamente el conflicto humano - fauna en lugar de intensificar las presiones humanas. La reforestación de las tierras despobladas podría derivar en la recuperación del hábitat de la fauna, sus funciones ambientales y de la biodiversidad regional debido a la minimización de los efectos antropogénicos (estrategia de tierra parsimoniosa). El balance entre la resolución del conflicto humano - fauna y el retorno ecológico a la vida silvestre podría convertirse en una tarea nueva y exigente para los administradores regionales de la fauna.


Asunto(s)
Animales Salvajes , Ecosistema , Animales , Biodiversidad , Conservación de los Recursos Naturales , Humanos , Japón
3.
Pediatr Cardiol ; 40(7): 1345-1358, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31346664

RESUMEN

The neonatal capacity for cardiac regeneration in mice is well studied and has been used to develop many potential strategies for adult cardiac regenerative repair following injury. However, translating these findings from rodents to designing regenerative therapeutics for adult human heart disease remains elusive. Large mammals including pigs, dogs, and sheep are widely used as animal models of humans in preclinical trials of new cardiac drugs and devices. However, very little is known about the fundamental cardiac cell biology and the timing of postnatal cardiac events that influence cardiomyocyte proliferation in these animals. There is emerging evidence that external physiological and environmental cues could be the key to understanding cardiomyocyte proliferative behavior. In this review, we survey available literature on postnatal development in various large mammal models to offer a perspective on the physiological and cellular characteristics that could be regulating cardiomyocyte proliferation. Similarities and differences between developmental milestones, cardiomyocyte maturational events, as well as environmental cues regulating cardiac development, are discussed for various large mammals, with a focus on postnatal cardiac regenerative potential and translatability to the human heart.


Asunto(s)
Proliferación Celular/fisiología , Corazón/fisiología , Regeneración/fisiología , Animales , Modelos Animales de Enfermedad , Perros , Humanos , Miocitos Cardíacos/fisiología , Ovinos , Porcinos
4.
Ecology ; 99(1): 172-183, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29065232

RESUMEN

Occupancy-abundance (OA) relationships are a foundational ecological phenomenon and field of study, and occupancy models are increasingly used to track population trends and understand ecological interactions. However, these two fields of ecological inquiry remain largely isolated, despite growing appreciation of the importance of integration. For example, using occupancy models to infer trends in abundance is predicated on positive OA relationships. Many occupancy studies collect data that violate geographical closure assumptions due to the choice of sampling scales and application to mobile organisms, which may change how occupancy and abundance are related. Little research, however, has explored how different occupancy sampling designs affect OA relationships. We develop a conceptual framework for understanding how sampling scales affect the definition of occupancy for mobile organisms, which drives OA relationships. We explore how spatial and temporal sampling scales, and the choice of sampling unit (areal vs. point sampling), affect OA relationships. We develop predictions using simulations, and test them using empirical occupancy data from remote cameras on 11 medium-large mammals. Surprisingly, our simulations demonstrate that when using point sampling, OA relationships are unaffected by spatial sampling grain (i.e., cell size). In contrast, when using areal sampling (e.g., species atlas data), OA relationships are affected by spatial grain. Furthermore, OA relationships are also affected by temporal sampling scales, where the curvature of the OA relationship increases with temporal sampling duration. Our empirical results support these predictions, showing that at any given abundance, the spatial grain of point sampling does not affect occupancy estimates, but longer surveys do increase occupancy estimates. For rare species (low occupancy), estimates of occupancy will quickly increase with longer surveys, even while abundance remains constant. Our results also clearly demonstrate that occupancy for mobile species without geographical closure is not true occupancy. The independence of occupancy estimates from spatial sampling grain depends on the sampling unit. Point-sampling surveys can, however, provide unbiased estimates of occupancy for multiple species simultaneously, irrespective of home-range size. The use of occupancy for trend monitoring needs to explicitly articulate how the chosen sampling scales define occupancy and affect the occupancy-abundance relationship.


Asunto(s)
Ecología , Ecosistema , Animales
5.
Ecol Appl ; 28(1): 106-118, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28944528

RESUMEN

In animal surveys, detectability can vary widely across species. We hypothesized that detectability of animals should be a function of species traits such as mass, color, and mean herd size. We also hypothesized that models of detectability based on species traits can be used to predict detectability for new species not in the original data set, leading to substantial benefits for ecology and conservation. We tested these hypotheses with double-observer aerial surveys of 10 mammal species in northern Botswana. We combined all 10 species and modeled their detectability with species traits (mass, mean herd size, color) as predictors while controlling for observer effects, vegetation, and herd size. We found support for effects of mass and an interaction between herd size and mean herd size on detectability. This model accurately predicted the ratio of herds detected by two observers vs. one observer for 8 of 10 species. To test whether a model based on species traits could be applied to a new species, we serially deleted each species from the data set, fit a trait-based model to the remaining nine species, and used this model to predict detectability for the deleted species. The model was able to reproduce the species-trait model for seven species and accurately predicted the ratio of detections by one or two observers for a different set of seven species; the model was successful by both measures for five species. To our knowledge, this represents the first time that a mechanistic model for detectability of animals has been used to predict detectability for new species. Prediction failed for species with extreme values of traits, suggesting that predicting detectability is not possible near or beyond the boundaries of one's data set. The approach taken in this paper can potentially be used with a variety of taxa and may provide new opportunities to apply detectability corrections where they have not been possible before.


Asunto(s)
Ecología/métodos , Mamíferos , Modelos Teóricos , Aeronaves , Animales , Botswana
6.
Conserv Biol ; 32(3): 672-684, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29068083

RESUMEN

Land-use change is the largest proximate threat to biodiversity yet remains one of the most complex to manage. In British Columbia (BC), where large mammals roam extensive tracts of intact habitat, continued land-use development is of global concern. Extant mammal diversity in BC is unrivalled in North America owing, in part, to its unique position at the intersection of alpine, boreal, and temperate biomes. Despite high conservation values, understanding of cumulative ecological impacts from human development is limited. Using cumulative-effects-assessment (CEA) methods, we assessed the current human footprint over 16 regional ecosystems and 7 large mammal species. Using historical and current range estimates of the mammals, we investigated impacts of human land use on species' persistence. For ecosystems, we found that bunchgrass, coastal Douglas fir, and ponderosa pine have been subjected to over 50% land-use conversion, and over 85% of their spatial extent has undergone either direct or estimated indirect impacts. Of the mammals we considered, wolves were the least affected by land conversion, yet all species had reduced ranges compared with historical estimates. We found evidence of a hard trade-off between development and conservation, most clearly for mammals with large distributions and ecosystems with high levels of conversion. Rather than serve as a platform to monitor species decline, we strongly advocate these data be used to inform land-use planning and to assess current conservation efforts. More generally, CEAs offer a robust tool to inform wildlife and habitat conservation at scale.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Animales , Biodiversidad , Colombia Británica , Humanos , América del Norte
7.
J Environ Manage ; 217: 690-699, 2018 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-29654972

RESUMEN

A rapidly expanding human footprint - comprised of anthropogenic land-use change and infrastructure - is profoundly affecting wildlife distributions worldwide. Cumulative effects management (CEM) is a regional approach that seeks to manage combined effects of the human footprint on biodiversity across large spatial scales. Challenges to implementing this approach include a lack of ecological data at large spatial scales, the high cost of monitoring multiple indicators, and the need to manage multiple footprints across industries. To inform development of effective CEM, we used large mammals as indicators to address the following questions: a) do species respond more strongly to individual footprint features or to cumulative effects (combined area of all footprint types, measured as total footprint), b) which features elicit the strongest responses across species, and c) are the direction of responses to footprint consistent? We used data from 12 years of snowtrack surveys (2001-2013) in the boreal forest of Alberta, coupled with regional footprint and landcover data, to develop generalized linear mixed-effects models relating the relative abundance of five boreal mammals [gray wolf (Canis lupus), Canada lynx (Lynx canadensis), coyote (Canis latrans), white-tailed deer (Odocoileus virginianus) and moose (Alces alces)] to individual and cumulative effects of the human footprint. We found that across species the strongest responses were to agriculture, roads, and young cutblocks (<10 years), suggesting these as potential priority stressors to address within CEM. Most species also responded to total footprint, indicating that in the absence of detailed information on individual features, this coarse measure can serve as an index of cumulative effects. There was high variability in direction and magnitude of responses across species, indicating that community-level responses are likely and should be considered within CEM planning.


Asunto(s)
Biodiversidad , Ciervos , Actividades Humanas , Alberta , Animales , Animales Salvajes , Ecología , Humanos , Dinámica Poblacional
8.
Ecology ; 97(4): 1058-1068, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28792596

RESUMEN

Autumn has to a large extent been neglected in the climate effect literature, yet autumn events, e.g., plant senescence and animal migration, affect fitness of animals differently than spring events. Understanding how variables including plant phenology influence timing of autumn migrations is important to gain a comprehensive understanding of the full annual cycle of migratory species. Here we use 13 yr of data from 60 male and 168 female red deer (Cervus elaphus) to identify triggers of autumn migration. We relate the timing of autumn migration to environmental variables like snow fall, temperature, and plant phenology (NDVI), and to onset of hunting, sex, and migration distance. Severe weather has been suggested as the main trigger of autumn migration, but we found that the majority of the individuals had left the summer range well before snow fall (80.3%) and frost (70.5%), and also before the peak deterioration in forage quality (71.9%). Declining temperatures were associated with a higher daily migration potential. Onset of hunting showed the largest effect on migration potential, with a marked increase during the first days of hunting. Individuals still present in the summer range when snow fall, frost, or peak forage deterioration occurred showed a significantly higher migration potential around these events. Males were less responsive to environmental cues, suggesting rutting activity, starting earlier in males, initiate movement prior to such conditions. Also, individuals with longer migration distances had a higher migration potential late in the season than individuals with shorter migration distances. Our study shows that factors beyond weather and plant phenology, such as onset of hunting, may be important triggers of autumn migration. Severe weather and forage deterioration were important triggers for the individuals experiencing this, which suggests a hierarchical response to environmental cues. The trade-off between staying longer in the summer range and increased energy expenditures if surprised by severe weather is asymmetric, and leaving well in advance can be seen as a risk-averse tactic.


Asunto(s)
Migración Animal , Ciervos/fisiología , Monitoreo del Ambiente , Animales , Clima , Femenino , Masculino , Estaciones del Año , Nieve
9.
J Hum Evol ; 95: 1-12, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27260171

RESUMEN

The dispersal of Homo erectus out of Africa at some 1.9 million years ago is one of the most important, crucial, and yet controversial events in human evolution. Current opinions about this episode expose the contrast between those who see H. erectus as a highly social, cooperative species seeking out new ecological opportunities to exploit, and those preferring a passive, climate driven explanation for such an event. By using geostatistics techniques and probabilistic models, we characterised the ecological context of H. erectus dispersal, from its East African origin to the colonization of Eurasia, taking into account both the presence of other large mammals and the physical characteristics of the landscape as potential factors. Our model indicated that H. erectus followed almost passively the large herbivore fauna during its dispersal. In Africa, the dispersal was statistically associated with the presence of large freshwater bodies (Rift Valley Lakes). In Eurasia, the presence of H. erectus was associated with the occurrence of geological outcrops likely yielding unconsolidated flint. During the early phase of dispersal, our model indicated that H. erectus actively avoided areas densely populated by large carnivores. This pattern weakened as H. erectus dispersed over Europe, possibly because of the decreasing presence of carnivores there plus the later acquisition of Acheulean technology. During this later phase, H. erectus was associated with limestone and shaley marl, and seems to have been selecting for high-elevation sites. While our results do not directly contradict the idea that H. erectus may have been an active hunter, they clearly point to the fact that predator avoidance may have conditioned its long-distance diffusion as it moved outside Africa. The modelled dispersal route suggests that H. erectus remained preferentially associated with low/middle latitude (i.e., comparatively warm) sites throughout its colonization history.


Asunto(s)
Distribución Animal , Evolución Biológica , Hominidae/fisiología , África , Animales , Migración Humana , Modelos Biológicos
10.
J Anim Ecol ; 85(4): 857-68, 2016 07.
Artículo en Inglés | MEDLINE | ID: mdl-27007672

RESUMEN

Indirect effects of large mammalian herbivores (LMH), while much less studied than those of apex predators, are increasingly recognized to exert powerful influences on communities and ecosystems. The strength of these effects is spatiotemporally variable, and several sets of authors have suggested that they are governed in part by primary productivity. However, prior theoretical and field studies have generated conflicting results and predictions, underscoring the need for a synthetic global analysis. We conducted a meta-analysis of the direction and magnitude of large mammalian herbivore-initiated indirect interactions using 67 published studies comprising 456 individual responses. We georeferenced 41 of these studies (comprising 253 responses from 33 locations on five continents) to a satellite-derived map of primary productivity. Because predator assemblages might also influence the impact of large herbivores, we conducted a similar analysis using a global map of large carnivore species richness. In general, LMH reduced the abundance of other consumer species and also tended to reduce consumer richness, although the latter effect was only marginally significant. There was a pronounced reduction in the strength of negative (i.e. suppressive, due e.g., to competition) indirect effects of LMH on consumer abundance in more productive ecosystems. In contrast, positive (facilitative) indirect effects were not significantly correlated with productivity, likely because these comprised a more heterogeneous array of mechanisms. We found no effect of carnivore species richness on herbivore-initiated indirect effect strength. Our findings help to resolve the fundamental problem of ecological contingency as it pertains to the strength of an understudied class of multitrophic interactions. Moreover, these results will aid in predicting the indirect effects of anthropogenic wildlife declines and irruptions, and how these effects might be mediated by climatically driven shifts in resource availability. To the extent that intact ungulate guilds help to suppress populations of small animals that act as agricultural pests and disease reservoirs, the negative impacts of large mammal declines on human well-being may be relatively stronger in low-productivity areas.


Asunto(s)
Cadena Alimentaria , Herbivoria , Fenómenos Fisiológicos de las Plantas , Animales , Carnivoría , Ecosistema , Mamíferos
11.
PNAS Nexus ; 3(9): pgae382, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39282006

RESUMEN

Large mammals respond to human hunting via proactive and reactive responses, which can induce subsequent nonconsumptive effects (NCEs). Thus, there is evidence that large mammals exhibit considerable behavioral plasticity in response to human hunting risk. Currently, however, it is unclear which cues of human hunting large mammals may be responding to. We conducted a literature review to quantify the large mammal behavioral responses induced by the cues of human hunting. We detected 106 studies published between 1978 and 2022 of which 34 (32%) included at least one measure of cue, typically visual (n = 26 of 106, 25%) or auditory (n = 11 of 106, 10%). Space use (n = 37 of 106, 35%) and flight (n = 31 of 106, 29%) were the most common behavioral responses studied. Among the 34 studies that assessed at least one cue, six (18%) measured large mammal behavioral responses in relation to proxies of human hunting (e.g. hunting site or season). Only 14% (n = 15 of 106) of the studies quantified an NCE associated with an animal's response to human hunting. Moreover, the association between cues measured and antipredator behaviors is unclear due to a consistent lack of controls. Thus, while human hunting can shape animal populations via consumptive effects, the cues triggering these responses are poorly understood. There hence remains a need to link cues, responses, NCEs, and the dynamics of large mammal populations. Human activities can then be adjusted accordingly to prevent both overexploitation and unintended NCEs in animal populations.

12.
Ecol Evol ; 14(10): e70395, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39385838

RESUMEN

Human fatalities and injury from wildlife attacks often result in a negative attitude toward conservation. This research was undertaken to investigate the patterns and conflict-causing factors of human killing and injury by large mammals, especially by Asian elephant (Elephas maximus), common leopard (Panthera pardus), and Bengal tiger (Panthera tigris tigris) in the Bardia-Banke Complex of western Nepal. We collected human death and injury records caused by wildlife in the Bardia-Banke Complex between 2019 and 2023, based on relief applications submitted by the victim's family. Additionally, camera trap monitoring was conducted following incidents of human-tiger and human-leopard conflicts. A total of 76 incidents involving human casualties and injuries were considered for analysis. Incidents of livestock depredation, crop raiding, and property damage were excluded from the analysis. Most of the attacks on humans were caused by tigers (75%), followed by elephants (16%) and leopards (9%). Almost all incidents occurred in daytime (97%). The highest number of conflicts were recorded in 2021, with 20 incidents. Most of the cases (84%) occurred within 1 km of forest edge. Khata corridor and the western side of the Bardia National Park, i.e., Karnali River corridor, were identified as high-conflict areas. The primary causes of the conflict manifested in cattle grazing (28%), grass cutting (28%), firewood collection (11%), fishing (8%), vegetable collection (5%), sand collection (4%), during rescuing friends (3%), grazing captive elephants (3%), highway rides (3%), sleeping in Chaupadi Goth (3%), walking nearby forest areas (3%), playing nearby forest areas (1%), while feeding pig (1%), and working in agricultural lands (1%). To promote human-wildlife coexistence, community-based patrols (33%), habitat restoration (26%), electric fencing (26%), and insurance (7%) were identified as the preferred strategies. Therefore, we recommend that stakeholders and concerned bodies increase awareness among local community about the use of forest resources, wildlife behavior, and human-wildlife conflict mitigation strategies.

13.
R Soc Open Sci ; 11(9): 240574, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39323555

RESUMEN

Wild bovids provide important ecosystem functions as seed dispersers and vegetation modifiers. Five wild bovids remain in Thailand: gaur (Bos gaurus), banteng (Bos javanicus), wild water buffalo (Bubalus arnee), mainland serow (Capricornis sumatraensis) and Chinese goral (Naemorhedus griseus). Their populations and habitats have declined substantially and become fragmented by land-use change. We use ecological niche models to quantify how much potential suitable habitat for these species remains within protected areas in Asia and then specifically Thailand. We combined species occurrence data from several sources (e.g. mainly camera traps and direct observation) with environmental variables and species-specific and single, large accessible areas in ensemble models to generate suitability maps, using out-of-sample predictions to validate model performance against new independent data. Gaur, banteng and buffalo models showed reasonable model accuracy throughout the entire distribution (greater than or equal to 62%) and in Thailand (greater than or equal to 80%), whereas serow and goral models performed poorly for the entire distribution and in Thailand, though 5 km movement buffers markedly improved the performance for serow. Large suitable areas were identified in Thailand and India for gaur, Cambodia and Thailand for banteng and India for buffalo. Over 50% of suitable habitat is located outside protected areas, highlighting the need for habitat management and conflict mitigation outside protected areas.

14.
J Mammal ; 105(1): 122-133, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-39070117

RESUMEN

Large mammals in temperate climates typically display seasonal patterns of habitat use. However, these patterns are often overlooked because large mammals are usually surveyed at annual intervals. In addition, most studies focus on a single species and ignore other species with which the focal species could interact. Knowing seasonal patterns of habitat use in multiple species and understanding factors that cause these patterns can provide further detail on population dynamics and guide effective conservation planning. Here, using dynamic occupancy modeling, we analyze 11 years of camera-trap data collected in northwestern Anatolia, Turkey, to investigate seasonal habitat use of 8 large-mammal species: Brown Bear (Ursus arctos), Eurasian Lynx (Lynx lynx), Gray Wolf (Canis lupus), Red Fox (Vulpes vulpes), Wild Boar (Sus scrofa), Roe Deer (Capreolus capreolus), European Hare (Lepus europaeus), and Red Deer (Cervus elaphus). For each species, we study the strength of seasonality in habitat use and its dependence on human population density and elevation, which have been shown to affect distributions of species in the region. Although all species exhibited seasonality in habitat use, the strength of this seasonality varied among species; it was strongest in Wild Boar, Roe Deer, and Brown Bear. Moreover, except for Brown Bear, all species tended to avoid sites close to humans. The species responded differently to changing elevation; increasing elevation had both positive and negative effects on species-specific colonization and desertion probabilities, and these effects were likely related to either feeding habits or tendency to avoid humans. These results indicate that seasonality should be taken into consideration in population studies. However, because species differ, seasonality patterns should be identified separately for each species of interest, as differences in these patterns can explain the underlying dynamics of habitat-use patterns more accurately.

15.
J Neurol Sci ; 446: 120564, 2023 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-36731358

RESUMEN

Alzheimer's disease (AD) is the most common form of dementia found in the elderly and disease progression is associated with accumulation of Amyloid beta 1-42 (Aß42) in brain. An immune-mediated approach as a preventive intervention to reduce amyloid plaques without causing brain inflammation is highly desirable for future clinical use. Genetic immunization, in which the immunizing agent is DNA encoding Aß42, has great potential because the immune response to DNA delivered into the skin is generally non-inflammatory, and thus differs quantitatively and qualitatively from immune responses elicited by peptides, which are inflammatory with production of IFNγ and IL-17 cytokines by activated T cells. DNA immunization has historically been proven difficult to apply to larger mammals. A potential barrier to use DNA immunization in large mammals is the method for delivery of the DNA antigen. We tested jet injection in mice and rabbits and found good antibody production and safe immune responses (no inflammatory cytokines). We found significant reduction of amyloid plaques and Aß peptides in brains of the DNA Aß42 immunized 3xTg-AD mouse model. This study was designed to optimize DNA delivery for possible testing of the DNA Aß42 vaccine for AD prevention in a clinical trial.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Ratones , Conejos , Animales , Péptidos beta-Amiloides/metabolismo , Placa Amiloide , Fragmentos de Péptidos , Inmunoterapia , Encéfalo/metabolismo , Citocinas , Inmunización/métodos , Inyecciones a Chorro , ADN , Ratones Transgénicos , Modelos Animales de Enfermedad , Mamíferos/genética , Mamíferos/metabolismo
16.
Ecol Evol ; 12(2): e8529, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35169447

RESUMEN

Medium and large-sized mammals of Jorgo-Wato Protected Forest have not yet been documented though the forest established before four decades. Hence, this study aims to document medium and large mammals and the behavioral responses of selected mammals toward anthropogenic activities in the study area. The study was conducted from February 2015 to June 2016, encompassing the wet and dry seasons. Data were collected mainly through camera traps, indirect and direct evidence. The study revealed about 23 medium and large-sized mammals that belong to seven orders namely Bovidae, Carnivora, Primates, Rodentia, Tubulidentata, Lagomorpha, and Hyracoidea. Papio anubis, C. guereza, and C. aethiops were the most abundant large mammals in JWPF. Because of high anthropogenic activities, African buffalo shifted its activity period from diurnal into crepuscular and nocturnal. African buffalo traveled longer distances during the wet season (mean = 14.33 km, SD = 1.25 km) than during the dry season (mean = 9.00 km, SD = 2.16 km). This could be due to the fact that the local people were less likely to go to the forest for resource exploitation during the wet season as they are fully engaged in agricultural activities. However, low agricultural activities during the dry season allow the local people to extract resources and involve in bushmeat hunting which could limit the movement of mammals to their refugia. African buffalo preferred to rest on and adjacent to a gravel road (22.1%) in the forest, followed by on open rocky hilltops (14.7%) at night time, but rest in the bottomland thicket vegetation during the dry daytime. Regardless of high human pressure in the area, this study has revealed a good number of medium and large-sized mammals that could be used as baseline information to design a sound conservation and management action plan of large mammals and their habitat in Jorgo-Wato Protected Forest.

17.
Sci Total Environ ; 853: 158679, 2022 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-36099955

RESUMEN

Large forested landscapes often harbour significant amount of biodiversity and support mankind by rendering various livelihood opportunities and ecosystem services. Their periodic assessment for health and ecological integrity is essential for timely mitigation of any negative impact of human use due to over harvesting of natural resources or unsustainable developmental activities. In this context, monitoring of mega fauna may provide reasonable insights about the connectivity and quality of forested habitats. In the present study, we conducted a largest non-invasive genetic survey to explore mammalian diversity and genetically characterized 13 mammals from the Indian Himalayan Region (IHR). We analyzed 4806 faecal samples using 103 autosomal microsatellites and with three mitochondrial genes, we identified 37 species of mammal. We observed low to moderate level of genetic variability and most species exhibited stable demographic history. We estimated an unbiased population genetic account (PGAunbias) for 13 species that may be monitored after a fixed time interval to understand species performance in response to the landscape changes. The present study has been evident to show pragmatic permeability with the representative sampling in the IHR in order to facilitate the development of species-oriented conservation and management programmes.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Animales , Humanos , Biodiversidad , Mamíferos/genética
18.
Sci Total Environ ; 758: 144000, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33338787

RESUMEN

With climate change, terrestrial fauna in riparian floodplain ecosystems must adapt to a predicted increase in frequency and magnitude of fluvial perturbations. Seasonal migration to seek refuge from floodwaters represents a central adaptation strategy, but may entail risky navigation of anthropogenic spaces in heterogeneous landscapes. Here, we demonstrate the opportunities and constraints large-bodied mammalian herbivores face during an adaptive response of obligatory flood-driven refuge migration, across a human-dominated environment. Our study system, centred around a productive protected area--Kaziranga National Park in Assam, Northeast India--on the floodplains of the Brahmaputra River, is home to an abundance of large herbivores that undertake seasonal migrations in response to floods. We contrast species distribution data during a major flood event with those from the dry season to illustrate season-specific movement and space use decisions of large herbivores ranging in body mass from the 3000-kg Asian elephant Elephas maximus to the 20-kg muntjac Muntiacus muntjak. In the dry season, most large herbivores--a majority of which are endangered and threatened by anthropogenic pressures--avoided areas with a strong human footprint, while preferring spaces with high land-use diversity. During the floods, such species were pushed out of inundated habitats within the protected area, and they chose to move through woodlands and areas under bamboo cover on private lands, as they migrated to forested refugia on higher ground. Our results show how seasonal environmental constraints shaped by floods determine the internal motivation of animals to risk traversing a human-dominated space to seek refuge, which contextually defines how animals view and navigate the landscape. Such insights underscore the importance of dynamic and adaptive planning, and participatory conservation efforts, to facilitate connectivity in the changing environment and climate of the present Anthropocene.


Asunto(s)
Ecosistema , Inundaciones , Animales , Cambio Climático , Conservación de los Recursos Naturales , Humanos , India , Ríos
19.
Sci Total Environ ; 742: 140712, 2020 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-32721759

RESUMEN

Tropical forests inhabited by endangered orangutans, rhinos, tigers, and elephants in South-east Asia are threatened by deforestation, including oil palm expansion. Certification has been proposed to label sustainable palm oil production. However, from a remotely sensed time-series and imagery analysis (1984-2020), we discovered that most of the currently certified grower supply bases and concessions in Sumatra and Borneo are located in the 1990s large mammals habitat and in areas that were biodiverse tropical forests less than 30 years ago. In light of this dramatic evidence, we suggest that certification schemes claim for the "sustainable" production of palm oil just because they neglect a very recent past of deforestation and habitat degradation.


Asunto(s)
Conservación de los Recursos Naturales , Bosques , Animales , Asia Sudoriental , Borneo , Certificación , Ecosistema , Indonesia , Aceite de Palma
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