Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 216
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
PLoS Biol ; 20(2): e3001500, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35113853

RESUMO

Nature experiences have been linked to mental and physical health. Despite the importance of understanding what determines individual variation in nature experience, the role of genes has been overlooked. Here, using a twin design (TwinsUK, number of individuals = 2,306), we investigate the genetic and environmental contributions to a person's nature orientation, opportunity (living in less urbanized areas), and different dimensions of nature experience (frequency and duration of public nature space visits and frequency and duration of garden visits). We estimate moderate heritability of nature orientation (46%) and nature experiences (48% for frequency of public nature space visits, 34% for frequency of garden visits, and 38% for duration of garden visits) and show their genetic components partially overlap. We also find that the environmental influences on nature experiences are moderated by the level of urbanization of the home district. Our study demonstrates genetic contributions to individuals' nature experiences, opening a new dimension for the study of human-nature interactions.


Assuntos
Natureza , Gêmeos/genética , Gêmeos/psicologia , Adulto , Fatores Etários , Meio Ambiente , Feminino , Jardins/estatística & dados numéricos , Humanos , Masculino , Inquéritos e Questionários , Reino Unido , População Urbana/estatística & dados numéricos
2.
Biol Lett ; 20(4): 20230518, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38593853

RESUMO

Only a few diurnal animals, such as bumblebees, extend their activity into the time around sunrise and sunset when illumination levels are low. Low light impairs viewing conditions and increases sensory costs, but whether diurnal insects use low light as a cue to make behavioural decisions is uncertain. To investigate how they decide to initiate foraging at these times of day, we observed bumblebee nest-departure behaviours inside a flight net, under naturally changing light conditions. In brighter light bees did not attempt to return to the nest and departed with minimal delay, as expected. In low light the probability of non-departures increased, as a small number of bees attempted to return after spending time on the departure platform. Additionally, in lower illumination bees spent more time on the platform before flying away, up to 68 s. Our results suggest that bees may assess light conditions once outside the colony to inform the decision to depart. These findings give novel insights into how behavioural decisions are made at the start and the end of a foraging day in diurnal animals when the limits of their vision impose additional costs on foraging efficiency.


Assuntos
Abelhas , Comportamento Animal , Luz , Animais , Abelhas/fisiologia
3.
Proc Biol Sci ; 290(2000): 20230725, 2023 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-37312543

RESUMO

Encroachment of artificial light at night (ALAN) into natural habitats is increasingly recognized as a major source of anthropogenic disturbance. Research focussed on variation in the intensity and spectrum of ALAN emissions has established physiological, behavioural and population-level effects across plants and animals. However, little attention has been paid to the structural aspect of this light, nor how combined morphological and behavioural anti-predator adaptations are affected. We investigated how lighting structure, background reflectance and the three-dimensional properties of the environment combined to affect anti-predator defences in the marine isopod Ligia oceanica. Experimental trials monitored behavioural responses including movement and background choice, and also colour change, a widespread morphological anti-predator mechanism little considered in relation to ALAN exposure. We found that behavioural responses of isopods to ALAN were consistent with classic risk-aversion strategies, being particularly exaggerated under diffuse lighting. However, this behaviour was disconnected from optimal morphological strategies, as diffuse light caused isopods to become lighter coloured while seeking out darker backgrounds. Our work highlights the potential for the structure of natural and artificial light to play a key role in behavioural and morphological processes likely to affect anti-predator adaptations, survival, and ultimately wider ecological effects.


Assuntos
Isópodes , Animais , Poluição Luminosa , Aclimatação , Afeto , Efeitos Antropogênicos
4.
Bioscience ; 73(4): 280-290, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37091747

RESUMO

How the relative impacts of anthropogenic pressures on the natural environment vary between different taxonomic groups, habitats, and geographic regions is increasingly well established. By contrast, the times of day at which those pressures are most forcefully exerted or have greatest influence are not well understood. The impact on the nighttime environment bears particular scrutiny, given that for practical reasons (e.g., researchers themselves belong to a diurnal species), most studies on the impacts of anthropogenic pressures are conducted during the daytime on organisms that are predominantly day active or in ways that do not differentiate between daytime and nighttime. In the present article, we synthesize the current state of knowledge of impacts of anthropogenic pressures on the nighttime environment, highlighting key findings and examples. The evidence available suggests that the nighttime environment is under intense stress across increasing areas of the world, especially from nighttime pollution, climate change, and overexploitation of resources.

5.
Proc Biol Sci ; 287(1918): 20191882, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31937219

RESUMO

The direct interactions between people and nature are critically important in many ways, with growing attention particularly on their impacts on human health and wellbeing (both positive and negative), on people's attitudes and behaviour towards nature, and on the benefits and hazards to wildlife. A growing evidence base is accelerating the understanding of different forms that these direct human-nature interactions take, novel analyses are revealing the importance of the opportunity and orientation of individual people as key drivers of these interactions, and methodological developments are increasingly making apparent their spatial, temporal and socio-economic dynamics. Here, we provide a roadmap of these advances and identify key, often interdisciplinary, research challenges that remain to be met. We identified several key challenges, including the need to characterize individual people's nature interactions through their life course, to determine in a comparable fashion how these interactions vary across much more diverse geographical, cultural and socio-economic contexts that have been explored to date, and to quantify how the relative contributions of people's opportunity and orientation vary in shaping their nature interactions. A robust research effort, guided by a focus on such unanswered questions, has the potential to yield high-impact insights into the fundamental nature of human-nature interactions and contribute to developing strategies for their appropriate management.


Assuntos
Ecologia , Animais , Humanos , Natureza
6.
Glob Chang Biol ; 26(12): 7099-7111, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32998181

RESUMO

The impacts of the changing climate on the biological world vary across latitudes, habitats and spatial scales. By contrast, the time of day at which these changes are occurring has received relatively little attention. As biologically significant organismal activities often occur at particular times of day, any asymmetry in the rate of change between the daytime and night-time will skew the climatic pressures placed on them, and this could have profound impacts on the natural world. Here we determine global spatial variation in the difference in the mean annual rate at which near-surface daytime maximum and night-time minimum temperatures and mean daytime and mean night-time cloud cover, specific humidity and precipitation have changed over land. For the years 1983-2017, we derived hourly climate data and assigned each hour as occurring during daylight or darkness. In regions that showed warming asymmetry of >0.5°C (equivalent to mean surface temperature warming during the 20th century) we investigated corresponding changes in cloud cover, specific humidity and precipitation. We then examined the proportional change in leaf area index (LAI) as one potential biological response to diel warming asymmetry. We demonstrate that where night-time temperatures increased by >0.5°C more than daytime temperatures, cloud cover, specific humidity and precipitation increased. Conversely, where daytime temperatures increased by >0.5°C more than night-time temperatures, cloud cover, specific humidity and precipitation decreased. Driven primarily by increased cloud cover resulting in a dampening of daytime temperatures, over twice the area of land has experienced night-time warming by >0.25°C more than daytime warming, and has become wetter, with important consequences for plant phenology and species interactions. Conversely, greater daytime relative to night-time warming is associated with hotter, drier conditions, increasing species vulnerability to heat stress and water budgets. This was demonstrated by a divergent response of LAI to warming asymmetry.


Assuntos
Ecossistema , Folhas de Planta , Mudança Climática , Temperatura Alta , Umidade , Temperatura
7.
PLoS Biol ; 15(1): e2000942, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28081142

RESUMO

Alien species are a major component of human-induced environmental change. Variation in the numbers of alien species found in different areas is likely to depend on a combination of anthropogenic and environmental factors, with anthropogenic factors affecting the number of species introduced to new locations, and when, and environmental factors influencing how many species are able to persist there. However, global spatial and temporal variation in the drivers of alien introduction and species richness remain poorly understood. Here, we analyse an extensive new database of alien birds to explore what determines the global distribution of alien species richness for an entire taxonomic class. We demonstrate that the locations of origin and introduction of alien birds, and their identities, were initially driven largely by European (mainly British) colonialism. However, recent introductions are a wider phenomenon, involving more species and countries, and driven in part by increasing economic activity. We find that, globally, alien bird species richness is currently highest at midlatitudes and is strongly determined by anthropogenic effects, most notably the number of species introduced (i.e., "colonisation pressure"). Nevertheless, environmental drivers are also important, with native and alien species richness being strongly and consistently positively associated. Our results demonstrate that colonisation pressure is key to understanding alien species richness, show that areas of high native species richness are not resistant to colonisation by alien species at the global scale, and emphasise the likely ongoing threats to global environments from introductions of species.


Assuntos
Biodiversidade , Aves/fisiologia , Internacionalidade , Espécies Introduzidas , Animais , Produto Interno Bruto , Especificidade da Espécie , Fatores de Tempo
8.
PLoS Biol ; 15(3): e2001656, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28350825

RESUMO

The Strategic Plan for Biodiversity, adopted under the auspices of the Convention on Biological Diversity, provides the basis for taking effective action to curb biodiversity loss across the planet by 2020-an urgent imperative. Yet, Antarctica and the Southern Ocean, which encompass 10% of the planet's surface, are excluded from assessments of progress against the Strategic Plan. The situation is a lost opportunity for biodiversity conservation globally. We provide such an assessment. Our evidence suggests, surprisingly, that for a region so remote and apparently pristine as the Antarctic, the biodiversity outlook is similar to that for the rest of the planet. Promisingly, however, much scope for remedial action exists.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais/tendências , Regiões Antárticas , Conservação dos Recursos Naturais/métodos
9.
J Anim Ecol ; 89(11): 2508-2516, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32858779

RESUMO

Many organisms are experiencing changing daily light regimes due to latitudinal range shifts driven by climate change and increased artificial light at night (ALAN). Activity patterns are often driven by light cycles, which will have important consequences for species interactions. We tested whether longer photoperiods lead to higher parasitism rates by a day-active parasitoid on its host using a laboratory experiment in which we independently varied daylength and the presence of ALAN. We then tested whether reduced nighttime temperature tempers the effect of ALAN. We found that parasitism rate increased with daylength, with ALAN intensifying this effect only when the temperature was not reduced at night. The impact of ALAN was more pronounced under short daylength. Increased parasitoid activity was not compensated for by reduced life span, indicating that increased daylength leads to an increase in total parasitism effects on fitness. To test the significance of increased parasitism rate for population dynamics, we developed a host-parasitoid model. The results of the model predicted an increase in time-to-equilibrium with increased daylength and, crucially, a threshold daylength above which interactions are unstable, leading to local extinctions. Here we demonstrate that ALAN impact interacts with daylength and temperature by changing the interaction strength between a common day-active consumer species and its host in a predictable way. Our results further suggest that range expansion or ALAN-induced changes in light regimes experienced by insects and their natural enemies will result in unstable dynamics beyond key tipping points in daylength.


Assuntos
Mudança Climática , Fotoperíodo , Animais , Insetos , Luz , Dinâmica Populacional , Estações do Ano
10.
Am Nat ; 193(4): 481-502, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30912975

RESUMO

The existence of a synthetic program of research on what was then termed the "nocturnal problem" and that we might now call "nighttime ecology" was declared more than 70 years ago. In reality, this failed to materialize, arguably as a consequence of practical challenges in studying organisms at night and instead concentrating on the existence of circadian rhythms, the mechanisms that give rise to them, and their consequences. This legacy is evident to this day, with consideration of the ecology of the nighttime markedly underrepresented in ecological research and literature. However, several factors suggest that it would be timely to revive the vision of a comprehensive research program in nighttime ecology. These include (i) that the study of the ecology of the night is being revolutionized by new and improved technologies; (ii) suggestions that, far from being a minor component of biodiversity, a high proportion of animal species are active at night; (iii) that fundamental questions about differences and connections between the ecology of the daytime and the nighttime remain largely unanswered; and (iv) that the nighttime environment is coming under severe anthropogenic pressure. In this article, I seek to reestablish nighttime ecology as a synthetic program of research, highlighting key focal topics and questions and providing an overview of the current state of understanding and developments.


Assuntos
Ritmo Circadiano , Ecologia , Animais , Ecossistema
11.
Conserv Biol ; 33(2): 369-376, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30039592

RESUMO

Knowing how much biodiversity is captured by protected areas (PAs) is important to meeting country commitments to international conservation agreements, such as the Convention on Biological Diversity, and analyzing gaps in species coverage by PAs contributes greatly to improved locating of new PAs and conservation of species. Regardless of their importance, global gap analyses have been conducted only for a few taxonomic groups (e.g., mangroves, corals, amphibians, birds, mammals). We conducted the first global gap analysis for a complete specious plant group, the highly threatened Cactaceae. Using geographic distribution data of 1438 cactus species, we assessed how well the current PA network represents them. We also systematically identified priority areas for conservation of cactus species that met and failed to meet conservation targets accounting for their conservation status. There were 261 species with no coverage by PAs (gap species). A greater percentage of cacti species (18%) lacked protection than mammals (9.7%) and birds (5.6%), and also a greater percentage of threatened cacti species (32%) were outside protected areas than amphibians (26.5%), birds (19.9%), or mammals (16%). The top 17% of the landscape that best captured covered species represented on average 52.9% of species ranges. The priority areas for gap species and the unprotected portion of the ranges of species that only partially met their conservation target (i.e., partial gap) captured on average 75.2% of their ranges, of which 100 were threatened gap species. These findings and knowledge of the threats affecting species provide information that can be used to improve planning for cacti conservation and highlight the importance of assessing the representation of major groups, such as plants, in PAs to determining the performance of the current PA network.


Análisis del Vacío Mundial de Especies de Cactáceas y Sitios Prioritarios para su Conservación Resumen El conocimiento sobre cuánta biodiversidad es captada por las áreas protegidas (AP) es importante para cumplir los compromisos de cada país con los acuerdos internacionales sobre conservación, como la Convención sobre la Diversidad Biológica, y el análisis de los vacíos en la cobertura de especies por las AP contribuye enormemente a una ubicación mejorada de AP nuevas y a la conservación de especies. Sin considerar su importancia, los análisis de vacío global se han realizado solamente para unos cuantos grupos taxonómicos (p. ej.: mangles, corales, anfibios, aves, mamíferos). Realizamos el primer análisis de vacío global para un grupo completo de especies de plantas, las Cactaceae, que se encuentran bajo seria amenaza. Evaluamos que tan bien representa la red actual de AP a las cactáceas con datos de distribución geográfica de 1438 especies de cactus. También identificamos sistemáticamente las áreas prioritarias de conservación para especies de cactus que cumplieron o fallaron los objetivos de conservación considerando el estado de conservación de las cactáceas. Hubo 261 especies sin cobertura en las AP (especies vacío). Un mayor porcentaje de especies de cactus (18%) careció de protección comparado con los mamíferos (9.7%) y las aves (5.6%), y también encontramos un mayor porcentaje de especies amenazadas de cactus (32%) fuera de las áreas protegidas comparado con los anfibios (26.5%), aves (19.9%) o mamíferos (16%). El 17% máximo del paisaje que mejor capturó a las especies cubiertas representó el 52.9% de la extensión de las especies. Las áreas prioritarias para las especies vacío y la porción desprotegida de la extensión de las especies que sólo cumplieron parcialmente con sus objetivos de conservación (es decir, el vacío parcial) capturaron en promedio el 75.2% de la extensión de las cactáceas, de las cuales 100 eran especies vacío amenazadas. Estos hallazgos y conocimiento sobre las amenazas que afectan a las especies proporcionan información que puede usarse para mejorar la planeación de la conservación de cactáceas y también resalta la importancia de la evaluación de la representación de grupos importantes, como las plantas, en AP para determinar el desempeño de la red contemporánea de AP.


Assuntos
Cactaceae , Anfíbios , Animais , Biodiversidade , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção
12.
Bioscience ; 68(4): 264-272, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29686433

RESUMO

Although there is a diversity of concerns about recent persistent declines in the abundances of many species, the implications for the associated delivery of ecosystem services to people are surprisingly poorly understood. In principle, there are a broad range of potential functional relationships between the abundance of a species or group of species and the magnitude of ecosystem-service provision. Here, we identify the forms these relationships are most likely to take. Focusing on the case of birds, we review the empirical evidence for these functional relationships, with examples of supporting, regulating, and cultural services. Positive relationships between abundance and ecosystem-service provision are the norm (although seldom linear), we found no evidence for hump-shaped relationships, and negative ones were limited to cultural services that value rarity. Given the magnitude of abundance declines among many previously common species, it is likely that there have been substantial losses of ecosystem services, providing important implications for the identification of potential tipping points in relation to defaunation resilience, biodiversity conservation, and human well-being.

13.
PLoS Biol ; 13(12): e1002324, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26680314

RESUMO

Phytoplankton are key components of aquatic ecosystems, fixing CO2 from the atmosphere through photosynthesis and supporting secondary production, yet relatively little is known about how future global warming might alter their biodiversity and associated ecosystem functioning. Here, we explore how the structure, function, and biodiversity of a planktonic metacommunity was altered after five years of experimental warming. Our outdoor mesocosm experiment was open to natural dispersal from the regional species pool, allowing us to explore the effects of experimental warming in the context of metacommunity dynamics. Warming of 4°C led to a 67% increase in the species richness of the phytoplankton, more evenly-distributed abundance, and higher rates of gross primary productivity. Warming elevated productivity indirectly, by increasing the biodiversity and biomass of the local phytoplankton communities. Warming also systematically shifted the taxonomic and functional trait composition of the phytoplankton, favoring large, colonial, inedible phytoplankton taxa, suggesting stronger top-down control, mediated by zooplankton grazing played an important role. Overall, our findings suggest that temperature can modulate species coexistence, and through such mechanisms, global warming could, in some cases, increase the species richness and productivity of phytoplankton communities.


Assuntos
Biodiversidade , Mudança Climática , Modelos Biológicos , Fitoplâncton/crescimento & desenvolvimento , Regulação para Cima , Animais , Aquicultura , Inglaterra , Temperatura Alta/efeitos adversos , Fitoplâncton/isolamento & purificação , Distribuição de Poisson , Estações do Ano , Zooplâncton/crescimento & desenvolvimento , Zooplâncton/isolamento & purificação
14.
Sensors (Basel) ; 18(2)2018 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-29462912

RESUMO

The monitoring of invasive grasses and vegetation in remote areas is challenging, costly, and on the ground sometimes dangerous. Satellite and manned aircraft surveys can assist but their use may be limited due to the ground sampling resolution or cloud cover. Straightforward and accurate surveillance methods are needed to quantify rates of grass invasion, offer appropriate vegetation tracking reports, and apply optimal control methods. This paper presents a pipeline process to detect and generate a pixel-wise segmentation of invasive grasses, using buffel grass (Cenchrus ciliaris) and spinifex (Triodia sp.) as examples. The process integrates unmanned aerial vehicles (UAVs) also commonly known as drones, high-resolution red, green, blue colour model (RGB) cameras, and a data processing approach based on machine learning algorithms. The methods are illustrated with data acquired in Cape Range National Park, Western Australia (WA), Australia, orthorectified in Agisoft Photoscan Pro, and processed in Python programming language, scikit-learn, and eXtreme Gradient Boosting (XGBoost) libraries. In total, 342,626 samples were extracted from the obtained data set and labelled into six classes. Segmentation results provided an individual detection rate of 97% for buffel grass and 96% for spinifex, with a global multiclass pixel-wise detection rate of 97%. Obtained results were robust against illumination changes, object rotation, occlusion, background cluttering, and floral density variation.

15.
Sensors (Basel) ; 18(7)2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29941801

RESUMO

Recent advances in unmanned aerial system (UAS) sensed imagery, sensor quality/size, and geospatial image processing can enable UASs to rapidly and continually monitor coral reefs, to determine the type of coral and signs of coral bleaching. This paper describes an unmanned aerial vehicle (UAV) remote sensing methodology to increase the efficiency and accuracy of existing surveillance practices. The methodology uses a UAV integrated with advanced digital hyperspectral, ultra HD colour (RGB) sensors, and machine learning algorithms. This paper describes the combination of airborne RGB and hyperspectral imagery with in-water survey data of several types in-water survey of coral under diverse levels of bleaching. The paper also describes the technology used, the sensors, the UAS, the flight operations, the processing workflow of the datasets, the methods for combining multiple airborne and in-water datasets, and finally presents relevant results of material classification. The development of the methodology for the collection and analysis of airborne hyperspectral and RGB imagery would provide coral reef researchers, other scientists, and UAV practitioners with reliable data collection protocols and faster processing techniques to achieve remote sensing objectives.


Assuntos
Antozoários , Recifes de Corais , Tecnologia de Sensoriamento Remoto/métodos , Máquina de Vetores de Suporte , Animais , Processamento de Imagem Assistida por Computador
16.
Glob Chang Biol ; 23(7): 2641-2648, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28139040

RESUMO

White light-emitting diodes (LEDs) are rapidly replacing conventional outdoor lighting technologies around the world. Despite rising concerns over their impact on the environment and human health, the flexibility of LEDs has been advocated as a means of mitigating the ecological impacts of globally widespread outdoor night-time lighting through spectral manipulation, dimming and switching lights off during periods of low demand. We conducted a three-year field experiment in which each of these lighting strategies was simulated in a previously artificial light naïve grassland ecosystem. White LEDs both increased the total abundance and changed the assemblage composition of adult spiders and beetles. Dimming LEDs by 50% or manipulating their spectra to reduce ecologically damaging wavelengths partially reduced the number of commoner species affected from seven to four. A combination of dimming by 50% and switching lights off between midnight and 04:00 am showed the most promise for reducing the ecological costs of LEDs, but the abundances of two otherwise common species were still affected. The environmental consequences of using alternative lighting technologies are increasingly well established. These results suggest that while management strategies using LEDs can be an effective means of reducing the number of taxa affected, averting the ecological impacts of night-time lighting may ultimately require avoiding its use altogether.


Assuntos
Ecossistema , Pradaria , Iluminação , Animais , Besouros , Humanos , Luz , Dinâmica Populacional , Aranhas
17.
Proc Natl Acad Sci U S A ; 111(38): 13727-32, 2014 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-25225371

RESUMO

Many animals regulate their activity over a 24-h sleep-wake cycle, concentrating their peak periods of activity to coincide with the hours of daylight, darkness, or twilight, or using different periods of light and darkness in more complex ways. These behavioral differences, which are in themselves functional traits, are associated with suites of physiological and morphological adaptations with implications for the ecological roles of species. The biogeography of diel time partitioning is, however, poorly understood. Here, we document basic biogeographic patterns of time partitioning by mammals and ecologically relevant large-scale patterns of natural variation in "illuminated activity time" constrained by temperature, and we determine how well the first of these are predicted by the second. Although the majority of mammals are nocturnal, the distributions of diurnal and crepuscular species richness are strongly associated with the availability of biologically useful daylight and twilight, respectively. Cathemerality is associated with relatively long hours of daylight and twilight in the northern Holarctic region, whereas the proportion of nocturnal species is highest in arid regions and lowest at extreme high altitudes. Although thermal constraints on activity have been identified as key to the distributions of organisms, constraints due to functional adaptation to the light environment are less well studied. Global patterns in diversity are constrained by the availability of the temporal niche; disruption of these constraints by the spread of artificial lighting and anthropogenic climate change, and the potential effects on time partitioning, are likely to be critical influences on species' future distributions.


Assuntos
Ciclos de Atividade/fisiologia , Adaptação Fisiológica , Comportamento Animal/fisiologia , Mudança Climática , Mamíferos/fisiologia , Animais , Filogeografia
18.
Biol Lett ; 12(4)2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27072401

RESUMO

The identification of species at risk of extinction is a central goal of conservation. As the use of data compiled for IUCN Red List assessments expands, a number of misconceptions regarding the purpose, application and use of the IUCN Red List categories and criteria have arisen. We outline five such classes of misconception; the most consequential drive proposals for adapted versions of the criteria, rendering assessments among species incomparable. A key challenge for the future will be to recognize the point where understanding has developed so markedly that it is time for the next generation of the Red List criteria. We do not believe we are there yet but, recognizing the need for scrutiny and continued development of Red Listing, conclude by suggesting areas where additional research could be valuable in improving the understanding of extinction risk among species.


Assuntos
Espécies em Perigo de Extinção , Extinção Biológica , Medição de Risco/métodos , Animais , Conservação dos Recursos Naturais , Eucariotos , Dinâmica Populacional
19.
Sensors (Basel) ; 16(1)2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26784196

RESUMO

Surveying threatened and invasive species to obtain accurate population estimates is an important but challenging task that requires a considerable investment in time and resources. Estimates using existing ground-based monitoring techniques, such as camera traps and surveys performed on foot, are known to be resource intensive, potentially inaccurate and imprecise, and difficult to validate. Recent developments in unmanned aerial vehicles (UAV), artificial intelligence and miniaturized thermal imaging systems represent a new opportunity for wildlife experts to inexpensively survey relatively large areas. The system presented in this paper includes thermal image acquisition as well as a video processing pipeline to perform object detection, classification and tracking of wildlife in forest or open areas. The system is tested on thermal video data from ground based and test flight footage, and is found to be able to detect all the target wildlife located in the surveyed area. The system is flexible in that the user can readily define the types of objects to classify and the object characteristics that should be considered during classification.


Assuntos
Animais Selvagens/fisiologia , Inteligência Artificial , Monitoramento Ambiental/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Gravação em Vídeo/instrumentação , Aeronaves , Algoritmos , Animais , Espécies em Perigo de Extinção , Monitoramento Ambiental/métodos , Desenho de Equipamento , Florestas , Sistemas de Informação Geográfica/instrumentação , Humanos , Espécies Introduzidas , Interface Usuário-Computador , Gravação em Vídeo/métodos
20.
Ecol Lett ; 18(1): 28-36, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25363472

RESUMO

Biodiversity is undergoing unprecedented global decline. Efforts to slow this rate have focused foremost on rarer species, which are at most risk of extinction. Less interest has been paid to more common species, despite their greater importance in terms of ecosystem function and service provision. How rates of decline are partitioned between common and less abundant species remains unclear. Using a 30-year data set of 144 bird species, we examined Europe-wide trends in avian abundance and biomass. Overall, avian abundance and biomass are both declining with most of this decline being attributed to more common species, while less abundant species showed an overall increase in both abundance and biomass. If overall avian declines are mainly due to reductions in a small number of common species, conservation efforts targeted at rarer species must be better matched with efforts to increase overall bird numbers, if ecological impacts of birds are to be maintained.


Assuntos
Biodiversidade , Aves , Conservação dos Recursos Naturais/métodos , Animais , Biomassa , Europa (Continente) , Modelos Biológicos , Densidade Demográfica , Dinâmica Populacional
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA