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1.
Sci Rep ; 10(1): 8199, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424226

RESUMO

Invasive species present a major conservation threat globally and nowhere are their affects more pronounced than in island ecosystems. Determining how native island populations respond demographically to invasive species can provide information to mitigate the negative effects of invasive species. Using 20 years of mark-recapture data from three sympatric species of albatrosses (black-browed Thalassarche melanophris, grey-headed T. chrysostoma, and light-mantled albatrosses Phoebetria palpebrata), we quantified the influence of invasive European rabbits Oryctolagus cuniculus and extreme weather patterns on breeding probability and success. Temporal variability in rabbit density explained 33-76% of the variability in breeding probability for all three species, with severe decreases in breeding probability observed after a lag period following highest rabbit numbers. For black-browed albatrosses, the combination of extreme rainfall and high rabbit density explained 33% of total trait variability and dramatically reduced breeding success. We showed that invasive rabbits and extreme weather events reduce reproductive output in albatrosses and that eliminating rabbits had a positive effect on albatross reproduction. This illustrates how active animal management at a local breeding site can result in positive population outcomes even for wide ranging animals like albatrosses where influencing vital rates during their at-sea migrations is more challenging.


Assuntos
Aves/genética , Aves/fisiologia , Espécies Introduzidas , Simpatria , Tempo (Meteorologia) , Animais , Clima , Coelhos , Reprodução
2.
J Anim Ecol ; 88(9): 1366-1378, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31187479

RESUMO

Many animal taxa exhibit sex-specific variation in ecological traits, such as foraging and distribution. These differences could result in sex-specific responses to change, but such demographic effects are poorly understood. Here, we test for sex-specific differences in the demography of northern (NGP, Macronectes halli) and southern (SGP, M. giganteus) giant petrels - strongly sexually size-dimorphic birds that breed sympatrically at South Georgia, South Atlantic Ocean. Both species feed at sea or on carrion on land, but larger males (30% heavier) are more reliant on terrestrial foraging than the more pelagic females. Using multi-event mark-recapture models, we examine the impacts of long-term changes in environmental conditions and commercial fishing on annual adult survival and use two-sex matrix population models to forecast future trends. As expected, survival of male NGP was positively affected by carrion availability, but negatively affected by zonal winds. Female survival was positively affected by meridional winds and El Niño-Southern Oscillation (ENSO), and negatively affected by sea ice concentration and pelagic longline effort. Survival of SGPs did not differ between sexes; however, survival of males only was positively correlated with the Southern Annular Mode (SAM). Two-sex population projections indicate that future environmental conditions are likely to benefit giant petrels. However, any potential increase in pelagic longline fisheries could reduce female survival and population growth. Our study reveals that sex-specific ecological differences can lead to divergent responses to environmental drivers (i.e. climate and fisheries). Moreover, because such effects may not be apparent when all individuals are considered together, ignoring sex differences could underestimate the relative influence of a changing environment on demography.


Assuntos
Aves , Pesqueiros , Animais , Oceano Atlântico , Demografia , Feminino , Ilhas , Masculino
3.
Proc Natl Acad Sci U S A ; 114(50): E10829-E10837, 2017 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-29158390

RESUMO

Environmental and anthropogenic factors often drive population declines in top predators, but how their influences may combine remains unclear. Albatrosses are particularly threatened. They breed in fast-changing environments, and their extensive foraging ranges expose them to incidental mortality (bycatch) in multiple fisheries. The albatross community at South Georgia includes globally important populations of three species that have declined by 40-60% over the last 35 years. We used three steps to deeply understand the drivers of such dramatic changes: (i) describe fundamental demographic rates using multievent models, (ii) determine demographic drivers of population growth using matrix models, and (iii) identify environmental and anthropogenic drivers using ANOVAs. Each species was affected by different processes and threats in their foraging areas during the breeding and nonbreeding seasons. There was evidence for two kinds of combined environmental and anthropogenic effects. The first was sequential; in wandering and black-browed albatrosses, high levels of bycatch have reduced juvenile and adult survival, then increased temperature, reduced sea-ice cover, and stronger winds are affecting the population recovery potential. The second was additive; in gray-headed albatrosses, not only did bycatch impact adult survival but also this impact was exacerbated by lower food availability in years following El Niño events. This emphasizes the need for much improved implementation of mitigation measures in fisheries and better enforcement of compliance. We hope our results not only help focus future management actions for these populations but also demonstrate the power of the modelling approach for assessing impacts of environmental and anthropogenic drivers in wild animal populations.


Assuntos
Aves , Mudança Climática , Pesqueiros , Animais , Espécies em Perigo de Extinção , Feminino , Masculino , Modelos Biológicos , Dinâmica Populacional , Reprodução
4.
Philos Trans R Soc Lond B Biol Sci ; 372(1723)2017 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-28483873

RESUMO

Climate changes include concurrent changes in environmental mean, variance and extremes, and it is challenging to understand their respective impact on wild populations, especially when contrasted age-dependent responses to climate occur. We assessed how changes in mean and standard deviation of sea surface temperature (SST), frequency and magnitude of warm SST extreme climatic events (ECE) influenced the stochastic population growth rate log(λs) and age structure of a black-browed albatross population. For changes in SST around historical levels observed since 1982, changes in standard deviation had a larger (threefold) and negative impact on log(λs) compared to changes in mean. By contrast, the mean had a positive impact on log(λs). The historical SST mean was lower than the optimal SST value for which log(λs) was maximized. Thus, a larger environmental mean increased the occurrence of SST close to this optimum that buffered the negative effect of ECE. This 'climate safety margin' (i.e. difference between optimal and historical climatic conditions) and the specific shape of the population growth rate response to climate for a species determine how ECE affect the population. For a wider range in SST, both the mean and standard deviation had negative impact on log(λs), with changes in the mean having a greater effect than the standard deviation. Furthermore, around SST historical levels increases in either mean or standard deviation of the SST distribution led to a younger population, with potentially important conservation implications for black-browed albatrosses.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'.


Assuntos
Aves/fisiologia , Mudança Climática , Características de História de Vida , Oceanos e Mares , Temperatura , Animais , Regiões Antárticas , Oceano Índico , Modelos Biológicos , Dinâmica Populacional
5.
Subst Abus ; 38(2): 157-160, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28166464

RESUMO

BACKGROUND: The dangers of co-administration of opioid pain relievers (OPRs) and benzodiazepines (BZDs) are well documented. The combination of OPRs and BZDs make up the majority of medications involved in prescription drug-related overdose and are often used concomitantly. This pattern is consistent among the veteran population where mental health illness and substance abuse are prominent. The Veterans Health Administration implemented the Opioid Safety Initiative (OSI) aimed at improving patient safety surrounding OPRs. In alignment with OSI, the study facility implemented a prior authorization pharmacy consult in an effort to reduce OPR and BZD co-prescribing and optimize patient safety. The purpose of this article is to report the frequency of co-prescribing before and after implementation of the consult. Secondary aims include reporting the emergency room visits and hospitalizations, prescribers' actions in the setting of disapproved consults, patient characteristics associated with co-prescribing, and frequency of co-prescribing without a consult. METHODS: This was a single-center, retrospective chart review study. Microsoft Structured Query Language server database and Veterans Health Information Systems and Technology Architecture were used to extract data and identify study patients. The Computerized Patient Record System was used to collect patient data. Microsoft Access and Excel were utilized to organize, query, and analyze the extracted data. RESULTS: There was a 34.6% reduction in patients on chronic OPR therapy co-prescribed a BZD, and the total number of overdose-related events decreased after implementation of the consult. In the event of disapproved consults, pharmacists' evidence-based recommendations were implemented 63% of the time. Patients for whom co-prescribing consults were placed were more likely to have mental health diagnoses. CONCLUSIONS: Following implementation of a pharmacy consult, there was a reduction in co-prescribing and overdose-related events at the study facility.


Assuntos
Analgésicos Opioides/efeitos adversos , Benzodiazepinas/efeitos adversos , Overdose de Drogas/prevenção & controle , Quimioterapia Combinada/tendências , Serviço de Farmácia Hospitalar , Encaminhamento e Consulta/tendências , Adolescente , Adulto , Bases de Dados Factuais , Quimioterapia Combinada/efeitos adversos , Quimioterapia Combinada/estatística & dados numéricos , Feminino , Hospitalização/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Veteranos/estatística & dados numéricos , Adulto Jovem
6.
Evolution ; 70(12): 2909-2914, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27813056

RESUMO

The canalization hypothesis postulates that the rate at which trait variation generates variation in the average individual fitness in a population determines how buffered traits are against environmental and genetic factors. The ranking of a species on the slow-fast continuum - the covariation among life-history traits describing species-specific life cycles along a gradient going from a long life, slow maturity, and low annual reproductive output, to a short life, fast maturity, and high annual reproductive output - strongly correlates with the relative fitness impact of a given amount of variation in adult survival. Under the canalization hypothesis, long-lived species are thus expected to display less individual heterogeneity in survival at the onset of adulthood, when reproductive values peak, than short-lived species. We tested this life-history prediction by analysing long-term time series of individual-based data in nine species of birds and mammals using capture-recapture models. We found that individual heterogeneity in survival was higher in species with short-generation time (< 3 years) than in species with long generation time (> 4 years). Our findings provide the first piece of empirical evidence for the canalization hypothesis at the individual level from the wild.


Assuntos
Artiodáctilos/fisiologia , Aves/fisiologia , Longevidade , Animais , Dinâmica Populacional , Especificidade da Espécie
7.
Ecol Evol ; 4(4): 474-87, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24634731

RESUMO

Allocation decisions depend on an organism's condition which can change with age. Two opposite changes in life-history traits are predicted in the presence of senescence: either an increase in breeding performance in late age associated with terminal investment or a decrease due to either life-history trade-offs between current breeding and future survival or decreased efficiency at old age. Age variation in several life-history traits has been detected in a number of species, and demographic performances of individuals in a given year are influenced by their reproductive state the previous year. Few studies have, however, examined state-dependent variation in life-history traits with aging, and they focused mainly on a dichotomy of successful versus failed breeding and non-breeding birds. Using a 50-year dataset on the long-lived quasi-biennial breeding wandering albatross, we investigated variations in life-history traits with aging according to a gradient of states corresponding to potential costs of reproduction the previous year (in ascending order): non-breeding birds staying at sea or present at breeding grounds, breeding birds that failed early, late or were successful. We used multistate models to study survival and decompose reproduction into four components (probabilities of return, breeding, hatching, and fledging), while accounting for imperfect detection. Our results suggest the possible existence of two strategies in the population: strict biennial breeders that exhibited almost no reproductive senescence and quasi-biennial breeders that showed an increased breeding frequency with a strong and moderate senescence on hatching and fledging probabilities, respectively. The patterns observed on survival were contrary to our predictions, suggesting an influence of individual quality rather than trade-offs between reproduction and survival at late ages. This work represents a step further into understanding the evolutionary ecology of senescence and its relationship with costs of reproduction at the population level. It paves the way for individual-based studies that could show the importance of intra-population heterogeneity in those processes.

8.
Oecologia ; 173(4): 1283-94, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23797411

RESUMO

Sex differences in lifespan and aging are widespread among animals. Since investment in current reproduction can have consequences on other life-history traits, the sex with the highest cost of breeding is expected to suffer from an earlier and/or stronger senescence. This has been demonstrated in polygynous species that are highly dimorphic. However in monogamous species where parental investment is similar between sexes, sex-specific differences in aging patterns of life-history traits are expected to be attenuated. Here, we examined sex and age influences on demographic traits in a very long-lived and sexually dimorphic monogamous species, the wandering albatross (Diomedea exulans). We modelled within the same model framework sex-dependent variations in aging for an array of five life-history traits: adult survival, probability of returning to the breeding colony, probability of breeding and two measures of breeding success (hatching and fledging). We show that life-history traits presented contrasted aging patterns according to sex whereas traits were all similar at young ages. Both sexes exhibited actuarial and reproductive senescence, but, as the decrease in breeding success remained similar for males and females, the survival and breeding probabilities of males were significantly more affected than females. We discuss our results in the light of the costs associated to reproduction, age-related pairing and a biased operational sex-ratio in the population leading to a pool of non-breeders of potentially lower quality and therefore more subject to death or breeding abstention. For a monogamous species with similar parental roles, the patterns observed were surprising and when placed in a gradient of observed age/sex-related variations in life-history traits, wandering albatrosses were intermediate between highly dimorphic polygynous and most monogamous species.


Assuntos
Envelhecimento , Aves/fisiologia , Reprodução , Caracteres Sexuais , Animais , Cruzamento , Meio Ambiente , Feminino , Masculino , Modelos Biológicos
9.
Ecology ; 94(1): 208-20, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23600255

RESUMO

Theoretical and empirical studies have highlighted the effects of age on several life-history traits in wild populations. There is also increasing evidence for environmental effects on their demographic traits. However, quantifying how individuals differentially respond to environmental variations according to their age remains a challenge in ecology. In a population of Black-browed Albatrosses monitored during 43 years, we analyzed how life-history traits varied according to age, and whether individuals of different ages responded in different ways to environmental conditions. To do so, we: (1) examined how age affected seven life-history traits, (2) investigated differences in temporal variance of demographic traits between age classes, and (3) tested for age-dependent effects of climate and fisheries covariates on demographic traits. Overall, there was a tendency for traits to improve during the first years of life (5-10 years), to peak and remain stable at middle age (10-30 years), and decline at old ages. At young ages, survival and reproductive parameters increased, except offspring body condition at fledging, suggesting that younger parents had already acquired good foraging capacities. However, they suffered from inexperience in breeding as suggested by their higher breeding failures during incubation. There was evidence for reproductive and actuarial senescence. In particular, breeding success and offspring body condition declined abruptly, suggesting altered foraging capacities of old individuals. Middle-aged individuals had the lowest temporal variance of demographic traits. Although this is predicted by the theory of environmental canalization, it could also results from a higher susceptibility of young and old birds due to their respective inexperience and senescence. The highest temporal variances were found in old individuals. Survival was significantly influenced by sea surface temperatures in the foraging zone of this albatross population during breeding. During warm events survival of young and old individuals improved, whereas a decrease was observed for middle-aged individuals. Presumably, during cold years with poor environmental conditions, young and old breeding birds may suffer more from intraspecific competition for resources than middle-aged individuals. This study showed that age, known as a major factor structuring demography in long-lived species, can also potentially influence the response of populations to global change.


Assuntos
Envelhecimento/fisiologia , Charadriiformes/fisiologia , Animais , Ecossistema , Dinâmica Populacional , Reprodução
10.
PLoS One ; 8(3): e60389, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23555965

RESUMO

In long-lived species only a fraction of a population breeds at a given time. Non-breeders can represent more than half of adult individuals, calling in doubt the relevance of estimating demographic parameters from the sole breeders. Here we demonstrate the importance of considering observable non-breeders to estimate reliable demographic traits: survival, return, breeding, hatching and fledging probabilities. We study the long-lived quasi-biennial breeding wandering albatross (Diomedea exulans). In this species, the breeding cycle lasts almost a year and birds that succeed a given year tend to skip the next breeding occasion while birds that fail tend to breed again the following year. Most non-breeders remain unobservable at sea, but still a substantial number of observable non-breeders (ONB) was identified on breeding sites. Using multi-state capture-mark-recapture analyses, we used several measures to compare the performance of demographic estimates between models incorporating or ignoring ONB: bias (difference in mean), precision (difference is standard deviation) and accuracy (both differences in mean and standard deviation). Our results highlight that ignoring ONB leads to bias and loss of accuracy on breeding probability and survival estimates. These effects are even stronger when studied in an age-dependent framework. Biases on breeding probabilities and survival increased with age leading to overestimation of survival at old age and thus actuarial senescence and underestimation of reproductive senescence. We believe our study sheds new light on the difficulties of estimating demographic parameters in species/taxa where a significant part of the population does not breed every year. Taking into account ONB appeared important to improve demographic parameter estimates, models of population dynamics and evolutionary conclusions regarding senescence within and across taxa.


Assuntos
Aves/fisiologia , Fatores Etários , Animais , Comportamento Consumatório , Meio Ambiente , Longevidade , Masculino , Modelos Biológicos , Dinâmica Populacional , Reprodução
11.
J Neurosci ; 31(25): 9315-22, 2011 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-21697381

RESUMO

Most theories of attention propose that we maintain attentional templates in visual working memory to control what information is selected. In the present study, we directly tested this proposal by measuring the contralateral-delay activity (CDA) of human event-related potentials during visual search tasks in which the target is cued on each trial. Here we show that the CDA can be used to measure the maintenance of attentional templates in visual working memory while processing complex visual scenes. In addition, this method allowed us to directly observe the shift from working memory to long-term memory representations controlling attention as learning occurred and experience accrued searching for the same target object. Our findings provide definitive support for several critical proposals made in theories of attention, learning, and automaticity.


Assuntos
Atenção/fisiologia , Potenciais Evocados Visuais/fisiologia , Memória de Curto Prazo/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Córtex Visual/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto Jovem
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