Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
Emerg Microbes Infect ; 13(1): 2343911, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38618930

RESUMO

Malaria remains one of the most important infectious diseases globally due to its high incidence and mortality rates. The influx of infected cases from endemic to non-endemic malaria regions like Europe has resulted in a public health concern over sporadic local outbreaks. This is facilitated by the continued presence of competent Anopheles vectors in non-endemic countries.We modelled the potential distribution of the main malaria vector across Spain using the ensemble of eight modelling techniques based on environmental parameters and the Anopheles maculipennis s.l. presence/absence data collected from 2000 to 2020. We then combined this map with the number of imported malaria cases in each municipality to detect the geographic hot spots with a higher risk of local malaria transmission.The malaria vector occurred preferentially in irrigated lands characterized by warm climate conditions and moderate annual precipitation. Some areas surrounding irrigated lands in northern Spain (e.g. Zaragoza, Logroño), mainland areas (e.g. Madrid, Toledo) and in the South (e.g. Huelva), presented a significant likelihood of A. maculipennis s.l. occurrence, with a large overlap with the presence of imported cases of malaria.While the risk of malaria re-emergence in Spain is low, it is not evenly distributed throughout the country. The four recorded local cases of mosquito-borne transmission occurred in areas with a high overlap of imported cases and mosquito presence. Integrating mosquito distribution with human incidence cases provides an effective tool for the quantification of large-scale geographic variation in transmission risk and pinpointing priority areas for targeted surveillance and prevention.


Assuntos
Anopheles , Malária , Mosquitos Vetores , Anopheles/parasitologia , Animais , Malária/epidemiologia , Malária/transmissão , Espanha/epidemiologia , Humanos , Mosquitos Vetores/parasitologia , Doenças Transmissíveis Importadas/epidemiologia , Doenças Transmissíveis Importadas/transmissão , Incidência
2.
Behav Ecol ; 35(2): arae005, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38287939

RESUMO

Intraspecific phenotypic variability is key to respond to environmental changes and anomalies. However, documenting the emergence of behavioral diversification in natural populations has remained elusive due to the difficulty of observing such a phenomenon at the right time and place. Here, we investigated how the emergence of a new trophic strategy in a population subjected to high fluctuations in the availability of its main trophic resource (migrating songbirds) affected the breeding performance, population structure, and population fitness of a specialized color polymorphic predator, the Eleonora's falcon from the Canary Islands. Using long-term data (2007-2022), we found that the exploitation of an alternative prey (a local petrel species) was associated with the growth of a previously residual falcon colony. Pairs in this colony laid earlier and raised more fledglings than in the other established colonies. The specialization on petrels increased over time, independently of annual fluctuations in prey availability. Importantly, however, the positive effect of petrel consumption on productivity was stronger in years with lower food availability. This trophic diversification was further associated with the genetically determined color morph, with dark individuals preying more frequently on petrels than pale ones, which might promote the long-term maintenance of genotypic and phenotypic diversity. We empirically demonstrate how the emergence of an alternative trophic strategy can buffer populations against harsh environmental fluctuations by stabilizing their productivity.

3.
Ecol Evol ; 13(8): e10371, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37529590

RESUMO

Variation in offspring sex ratio, particularly in birds, has been frequently studied over the last century, although seldom using long-term monitoring data. In raptors, the cost of raising males and females is not equal, and several variables have been found to have significant effects on sex ratio, including food availability, parental age, and hatching order. Sex ratio differences between island populations and their mainland counterparts have been poorly documented, despite broad scientific literature on the island syndrome reporting substantial differences in population demography and ecology. Here, we assessed individual and environmental factors potentially affecting the secondary sex ratio of the long-lived Egyptian vulture Neophron percnopterus. We used data collected from Spanish mainland and island populations over a ca. 30-year period (1995-2021) to assess the effects of insularity, parental age, breeding phenology, brood size, hatching order, type of breeding unit (pairs vs. trios), and spatial and temporal variability on offspring sex ratio. No sex bias was found at the population level, but two opposite trends were observed between mainland and island populations consistent with the island syndrome. Offspring sex ratio was nonsignificantly female-biased in mainland Spain (0.47, n = 1112) but significantly male-biased in the Canary Islands (0.55, n = 499), where a male-biased mortality among immatures could be compensating for offspring biases and maintaining a paired adult sex ratio. Temporal and spatial variation in food availability might also have some influence on sex ratio, although the difficulties in quantifying them preclude us from determining the magnitude of such influence. This study shows that insularity influences the offspring sex ratio of the Egyptian vulture through several processes that can affect island and mainland populations differentially. Our research contributes to improving our understanding of sex allocation theory by investigating whether sex ratio deviations from parity are possible as a response to changing environments comprised by multiple and complexly interrelated factors.

4.
One Health ; 16: 100478, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37363246

RESUMO

Introduction/objective: West Nile virus (WNV) is one of the most widely distributed flaviviruses worldwide. It is considered an endemic and emerging pathogen in different areas of the Europe and Mediterranean countries (MR). Mosquitoes of the genus Culex spp. are the main vectors, and birds its main vertebrate hosts. It can occasionally infect mammals, including humans. Different environmental factors can influence its distribution and transmission through its effects on vector or host populations. Our objective was to determine environmental factors associated with changes in vector distribution and WNV transmission in Europe and MR. Material & methods: Systematic peer review of articles published between 2000 and 2020. We selected studies on WNV, and its vectors carried out in Europe and MR. The search included terms referring to climatic and environmental factors. Results: We included 65 studies, of which 21 (32%) were conducted in Italy. Culex spp. was studied in 26 papers (40%), humans in 19 papers (29%) and host animals (mainly horses) in 16 papers (25%), whereas bird reservoirs were addressed in 5 studies (8%). A significant positive relationship was observed between changes in temperature and precipitation patterns and the epidemiology of WNV, although contrasting results were found among studies. Other factors positively related to WNV dynamics were the normalized difference vegetation index (NDVI] and expansion of anthropized habitats. Conclusion: The epidemiology of WNV seems to be related to climatic factors that are changing globally due to ongoing climate change. Unfortunately, the complete zoonotic cycle was not analyzed in most papers, making it difficult to determine the independent impact of environment on the different components of the transmission cycle. Given the current expansion and endemicity of WNV in the area, it is important to adopt holistic approaches to understand WNV epidemiology and to improve WNV surveillance and control.

5.
Proc Biol Sci ; 288(1958): 20211603, 2021 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-34493076

RESUMO

Flying over the open sea is energetically costly for terrestrial birds. Despite this, over-water journeys of many birds, sometimes hundreds of kilometres long, are uncovered by bio-logging technology. To understand how these birds afford their flights over the open sea, we investigated the role of atmospheric conditions, specifically wind and uplift, in subsidizing over-water flight at a global scale. We first established that ΔT, the temperature difference between sea surface and air, is a meaningful proxy for uplift over water. Using this proxy, we showed that the spatio-temporal patterns of sea-crossing in terrestrial migratory birds are associated with favourable uplift conditions. We then analysed route selection over the open sea for five facultative soaring species, representative of all major migratory flyways. The birds maximized wind support when selecting their sea-crossing routes and selected greater uplift when suitable wind support was available. They also preferred routes with low long-term uncertainty in wind conditions. Our findings suggest that, in addition to wind, uplift may play a key role in the energy seascape for bird migration that in turn determines strategies and associated costs for birds crossing ecological barriers such as the open sea.


Assuntos
Voo Animal , Vento , Migração Animal , Animais , Aves , Água
6.
Mov Ecol ; 9(1): 37, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34253264

RESUMO

BACKGROUND: Route choice and travel performance of fly-forage migrants are partly driven by large-scale habitat availability, but it remains unclear to what extent wind support through large-scale wind regimes moulds their migratory behaviour. We aimed to determine to what extent a trans-equatorial fly-forage migrant engages in adaptive drift through distinct wind regimes and biomes across Africa. The Inter-tropical Front (ITF) marks a strong and seasonally shifting climatic boundary at the thermal equator, and we assessed whether migratory detours were associated with this climatic feature. Furthermore, we sought to disentangle the influence of wind and biome on daily, regional and seasonal travel performance. METHODS: We GPS-tracked 19 adult Eleonora's falcons Falco eleonorae from the westernmost population on the Canary Islands across 39 autumn and 36 spring migrations to and from Madagascar. Tracks were annotated with wind data to assess the falcons' orientation behaviour and the wind support they achieved in each season and distinct biomes. We further tested whether falcon routes across the Sahel were correlated with the ITF position, and how realized wind support and biome affect daily travel times, distances and speeds. RESULTS: Changes in orientation behaviour across Africa's biomes were associated with changes in prevailing wind fields. Falcons realized higher wind support along their detours than was available along the shortest possible route by drifting through adverse autumn wind fields, but compromised wind support while detouring through supportive spring wind fields. Movements across the Sahel-Sudan zone were strongly associated to the ITF position in autumn, but were more individually variable in spring. Realized wind support was an important driver of daily travel speeds and distances, in conjunction with regional wind-independent variation in daily travel time budgets. CONCLUSIONS: Although daily travel time budgets of falcons vary independently from wind, their daily travel performance is strongly affected by orientation-dependent wind support. Falcons thereby tend to drift to minimize or avoid headwinds through opposing wind fields and over ecological barriers, while compensating through weak or supportive wind fields and over hospitable biomes. The ITF may offer a climatic leading line to fly-forage migrants in terms of both flight and foraging conditions.

7.
Sci Total Environ ; 793: 148534, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34182458

RESUMO

Accidents on power lines are the leading cause of mortality for many raptor species. In order to prioritise corrective measures, much effort has been focused on identifying the factors associated with collision and electrocution risk. However, most studies lack of precise data about the use of pylons and its underlying driving factors, often relying on biased information based on recorded fatalities. Here, we used multiple years of high-resolution data from 49-GPS tagged Canarian Egyptian Vultures (Neophron percnopterus majorensis) to overcome these typical biases. Birds of our target population use electric pylons extensively for perching (diurnal) and roosting (nocturnal), so accidents with these infrastructures are nowadays the main cause of mortality. Predictive models of pylon intensity of use were fitted for diurnal and nocturnal behaviour, accounting for power line, environmental, and individual vulture's features. Using these measures as a proxy for mortality risk, our model predictions were validated with out-of-sample data of actual mortality recorded during 17 years. Vultures used more pylons during daytime, but those chosen at night were used more intensively. In both time periods, the intensity of use of pylons was determined by similar drivers: vultures avoided pylons close to roads and territories of conspecifics, preferentially used pylons located in areas with higher abundance of food resources, and spread their use during the breeding season. Individuals used pylons unevenly according to their sex, age, and territorial status, indicating that site-specific mitigation measures may affect different fractions of the population. Our modelling procedures predicted actual mortality reasonably well, showing that prioritising mitigation measures on relatively few pylons (6%) could drastically reduce accidents (50%). Our findings demonstrate that combining knowledge on fine-scale individual behaviour and pylon type and distribution is key to target cost-effective conservation actions aimed at effectively reducing avian mortality on power lines.


Assuntos
Falconiformes , Aves Predatórias , Animais , Aves , Conservação dos Recursos Naturais , Humanos , Territorialidade
8.
Biol Rev Camb Philos Soc ; 96(4): 1367-1385, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33686781

RESUMO

Mosquito host utilization is a key factor in the transmission of vector-borne pathogens given that it greatly influences host-vector contact rates. Blood-feeding patterns of mosquitoes are not random, as some mosquitoes feed on particular species and/or individuals more than expected by chance. Mosquitoes use a number of cues including visual, olfactory, acoustic, and thermal stimuli emitted by vertebrate hosts to locate and identify their blood meal sources. Thus, differences in the quality/intensity of the released cues may drive host selection by mosquitoes at both inter- and intra-specific levels. Such patterns of host selection by mosquitoes in space and time can be structured by factors related to mosquitoes (e.g. innate host preference, behavioural plasticity), to hosts (e.g. emission of host-seeking cues, host availability) or to both (e.g. pathogen infection). In this study, we review current evidence, from phenomena to mechanisms, of how these factors influence host utilization by mosquitoes. We also review the methodologies commonly used in this research field and identify the major challenges for future studies. To bridge the knowledge gaps, we propose improvements to strengthen traditional approaches and the use of a functional trait-based approach to infer mosquito host utilization in natural communities.


Assuntos
Culicidae , Animais , Comportamento Alimentar , Humanos , Mosquitos Vetores
9.
Animals (Basel) ; 10(11)2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33207713

RESUMO

Recent changes in European legislation have legalized the abandonment of carcasses around livestock farms, but our understanding of how vultures exploit these semi-predictable food sources is still very limited. For filling this gap, we determine the individual and ecological drivers influencing vulture visits to farms. We assessed the effects of individual characteristics of both birds and farms on the frequency of vultures' visits to livestock facilities using data collected from 45 GPS-tagged Egyptian Vultures (Neophron percnopterus) and 318 farms (>94% of livestock) on Fuerteventura Island, Spain. Farms were more visited during the vultures' breeding season. Farms located closer to highly predictable feeding places (i.e., vulture restaurants and garbage dumps) or with more available feeding resources were visited by more vultures, whereas those located close to roads and vultures' breeding territories received fewer visits. Younger territorial birds visited a farm more frequently than older territorial ones, whereas older non-territorial individuals concentrated those visits on farms closer to their activity core areas compared with younger ones. Our findings indicate that visits to farms were determined by their spatial distribution in relation to the age-specific birds' activity centers, the availability of carcasses, seasonality, and individual characteristics of vultures. These interacting factors should be considered in vulture conservation, avoiding very general solutions that ignore population structure.

10.
Int J Parasitol ; 50(8): 569-575, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32505648

RESUMO

Parasites can manipulate their hosts to increase their transmission success. Avian malaria parasites (Plasmodium) are thought to alter the cues such as host odour, used by host-seeking mosquitoes. Bird odour is affected by secretions from the uropygial gland and may play a role in modulating vector-host interactions. We tested the hypothesis that mosquitoes are more attracted to the uropygial secretions and/or whole-body odour (headspace) of Plasmodium-infected house sparrows (Passer domesticus) than to those of uninfected birds. We tested the attraction of nulliparous (e.g. uninfected mosquitoes without previous access to blood) Culex pipiens females towards these stimuli in a dual-choice olfactometer. We used Gas Chromatography-Mass Spectrometry (GC-MS) analyses to assess whether Plasmodium infection is associated with differences in the chemical composition of uropygial secretions. Mosquitoes were more attracted to the odours of infected than uninfected birds, regardless of sex. However, the significant interaction between infection status and the stimuli (uropygial secretion or headspace) showed that mosquitoes were more attracted to the headspace of infected birds; no differences were found in the case of uropygial secretions. The compounds in the volatile lipophilic fraction of the uropygial secretion did not differ between infected and uninfected birds. These results support the host manipulation hypothesis since avian Plasmodium parasites may be capable of altering their host's body odour, thereby making infected individuals more attractive to mosquitoes.


Assuntos
Culex , Odorantes , Plasmodium , Pardais/parasitologia , Animais , Culex/fisiologia , Feminino , Mosquitos Vetores
11.
Ecol Appl ; 30(6): e02125, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32167643

RESUMO

Individual traits such as body mass can serve as early warning signals of changes in the fitness prospects of animal populations facing environmental impacts. Here, taking advantage of a 19-yr monitoring, we assessed how individual, population, and environmental factors modulate long-term changes in the body mass of Canarian Egyptian vultures. Individual vulture body mass increased when primary productivity was highly variable, but decreased in years with a high abundance of livestock. We hypothesized that carcasses of wild animals, a natural food resource that can be essential for avian scavengers, could be more abundant in periods of weather instability but depleted when high livestock numbers lead to overgrazing. In addition, increasing vulture population numbers also negatively affect body mass suggesting density-dependent competition for food. Interestingly, the relative strength of individual, population and resource availability factors on body mass changed with age and territorial status, a pattern presumably shaped by differences in competitive abilities and/or age-dependent environmental knowledge and foraging skills. Our study supports that individual plastic traits may be extremely reliable tools to better understand the response of secondary consumers to current and future natural and human-induced environmental changes.


Assuntos
Falconiformes , Gado , Animais , Animais Selvagens , Aves , Peixes , Humanos
12.
Parasitology ; 147(4): 441-447, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31965951

RESUMO

Factors such as the particular combination of parasite-mosquito species, their co-evolutionary history and the host's parasite load greatly affect parasite transmission. However, the importance of these factors in the epidemiology of mosquito-borne parasites, such as avian malaria parasites, is largely unknown. Here, we assessed the competence of two mosquito species [Culex pipiens and Aedes (Ochlerotatus) caspius], for the transmission of four avian Plasmodium lineages (Plasmodium relictum SGS1 and GRW11 and Plasmodium cathemerium-related lineages COLL1 and PADOM01) naturally infecting wild house sparrows. We assessed the effects of parasite identity and parasite load on Plasmodium transmission risk through its effects on the transmission rate and mosquito survival. We found that Cx. pipiens was able to transmit the four Plasmodium lineages, while Ae. caspius was unable to transmit any of them. However, Cx. pipiens mosquitoes fed on birds infected by P. relictum showed a lower survival and transmission rate than those fed on birds infected by parasites related to P. cathemerium. Non-significant associations were found with the host-parasite load. Our results confirm the existence of inter- and intra-specific differences in the ability of Plasmodium lineages to develop in mosquito species and their effects on the survival of mosquitoes that result in important differences in the transmission risk of the different avian malaria parasite lineages studied.


Assuntos
Culex/parasitologia , Malária Aviária/transmissão , Mosquitos Vetores/parasitologia , Ochlerotatus/parasitologia , Plasmodium/fisiologia , Pardais , Aedes/parasitologia , Animais , Feminino , Masculino , Plasmodium/classificação , Plasmodium/genética , Espanha , Especificidade da Espécie
13.
J Anim Ecol ; 89(11): 2631-2643, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33439490

RESUMO

Large-scale environmental forces can influence biodiversity at different levels of biological organization. Climate, in particular, is often associated with species distributions and diversity gradients. However, its mechanistic link to population dynamics is still poorly understood. Here, we unravelled the full mechanistic path by which a climatic driver, the Atlantic trade winds, determines the viability of a bird population. We monitored the breeding population of Eleonora's falcons in the Canary Islands for over a decade (2007-2017) and integrated different methods and data to reconstruct how the availability of their prey (migratory birds) is regulated by trade winds. We tracked foraging movements of breeding adults using GPS, monitored departure of migratory birds using weather radar and simulated their migration trajectories using an individual-based, spatially explicit model. We demonstrate that regional easterly winds regulate the flux of migratory birds that is available to hunting falcons, determining food availability for their chicks and consequent breeding success. By reconstructing how migratory birds are pushed towards the Canary Islands by trade winds, we explain most of the variation (up to 86%) in annual productivity for over a decade. This study unequivocally illustrates how a climatic driver can influence local-scale demographic processes while providing novel evidence of wind as a major determinant of population fitness in a top predator.


Los factores ambientales a gran escala afectan a la biodiversidad a distintos niveles de organización. El clima en particular, a menudo se asocia a la distribución de especies y gradientes de diversidad. Sin embargo, los mecanismos que lo vinculan con la dinámica de poblaciones siguen siendo poco conocidos. En este estudio revelamos el mecanismo a través del cual un factor climático, los vientos Alisios atlánticos, determinan la viabilidad de una población de una especie de ave rapaz. Monitorizamos la población canaria de Halcón de Eleonor durante una década (2007­2017) e integramos distintos datos y métodos para reconstruir cómo la disponibilidad de alimento (pequeñas aves migratorias) es regulada por los vientos Alisios. Además, monitorizamos los movimientos de caza de adultos reproductores mediante GPS y el inicio de la migración de sus presas mediante un radar meteorológico, y simulamos la trayectoria de migración de estas presas utilizando un modelo espacialmente explícito basado en el individuo. Demostramos que los patrones de vientos del este regulan el flujo de aves migratorias que determina la disponibilidad de alimento para los halcones y sus pollos y, por tanto, su éxito reproductor. Al reconstruir cómo las aves migratorias son desviadas hasta las Islas Canarias por los vientos Alisios conseguimos explicar la mayor parte de la variación (hasta el 86%) en la productividad anual de los halcones durante una década. Este estudio ilustra cómo un fenómeno climático a gran escala puede afectar a los procesos demográficos a escala local y aporta nueva evidencia de que el viento puede ser un importante factor determinante de la eficacia biológica de un predador.


Assuntos
Aves , Falconiformes , Migração Animal , Animais , Estações do Ano , Espanha , Tempo (Meteorologia) , Vento
14.
Behav Ecol ; 30(3): 763-769, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31210721

RESUMO

Morph-specific mate choice has been proposed as one of the evolutionary mechanisms that contribute to the maintenance of variation in color polymorphic systems. Coloration usually covaries with other phenotypic traits affecting life history and thus is often used as a criterion for mate choice. Here, we assess whether mating patterns, natal dispersal, and breeding output are phenotype-dependent in the color polymorphic Eleonora's falcon. We used a long-term dataset of 946 individually ringed adult falcons that included 109 individuals monitored from birth up to recruitment into the breeding population. Overall, patterns of mate choice with regard to coloration were neither assortative nor disassortative. Natal dispersal distance was greater in females but was not associated with coloration. Breeding success was both morph-dependent and context-dependent. Although clutch size was similar in differently colored pairs, differences arose in the number of chicks that fledge. In some years, dark males raised more offspring, regardless of female color morph. Differences in the breeding tactics between male morphs could be associated with intraspecific predation and may thus contribute to the observed differences in breeding output, especially when food availability is low. This suggests that mating patterns may interact with other factors and give rise to the observed higher breeding output of dark males only under certain environmental conditions.

15.
Sci Rep ; 9(1): 8782, 2019 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-31217438

RESUMO

Plasmodium transmission success depends upon the trade-off between the use of host resources to favour parasite reproduction and the negative effects on host health, which can be mediated by infection intensity. Despite its potential influence on parasite dynamics, the effects of infection intensity on both, birds and vectors, and on Plasmodium transmission success are still poorly understood. Here, we experimentally reduced the Plasmodium load in naturally infected wild house sparrows with the antimalarial primaquine to assess the effects of intensity of infection in the vertebrate hosts on Plasmodium transmission to and by mosquitoes. We monitored the survival of Culex pipiens mosquitoes throughout the development of the parasite and the infection status of the mosquitoes by analysing the head-thorax and saliva at 13 days post-exposure to birds. The proportion of mosquitoes infected by Plasmodium and the presence of Plasmodium in saliva were not associated with the medication treatment of birds. However, the experimental treatment affected vector survival with mosquitoes fed on medicated birds showing a higher survival rate than those fed on control individuals. These results provide strong experimental evidence of the impact of parasite load of vertebrate hosts on the survival probability of malaria vectors.


Assuntos
Culex/parasitologia , Interações Hospedeiro-Parasita , Malária/parasitologia , Carga Parasitária , Animais , Interações Hospedeiro-Parasita/efeitos dos fármacos , Primaquina/farmacologia , Pardais/parasitologia , Análise de Sobrevida
16.
Parasit Vectors ; 12(1): 87, 2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30867014

RESUMO

BACKGROUND: The transmission of mosquito-borne pathogens is strongly influenced by the contact rates between mosquitoes and susceptible hosts. The biting rates of mosquitoes depend on different factors including the mosquito species and host-related traits (i.e. odour, heat and behaviour). However, host characteristics potentially affecting intraspecific differences in the biting rate of mosquitoes are poorly known. Here, we assessed the impact of three host-related traits on the biting rate of two mosquito species with different feeding preferences: the ornithophilic Culex pipiens and the mammophilic Ochlerotatus (Aedes) caspius. Seventy-two jackdaws Corvus monedula and 101 house sparrows Passer domesticus were individually exposed to mosquito bites to test the effect of host sex, body mass and infection status by the avian malaria parasite Plasmodium on biting rates. RESULTS: Ochlerotatus caspius showed significantly higher biting rates than Cx. pipiens on jackdaws, but non-significant differences were found on house sparrows. In addition, more Oc. caspius fed on female than on male jackdaws, while no differences were found for Cx. pipiens. The biting rate of mosquitoes on house sparrows increased through the year. The bird infection status and body mass of both avian hosts were not related to the biting rate of both mosquito species. CONCLUSIONS: Host sex was the only host-related trait potentially affecting the biting rate of mosquitoes, although its effect may differ between mosquito and host species.


Assuntos
Doenças das Aves/transmissão , Culex/parasitologia , Malária/veterinária , Mosquitos Vetores/parasitologia , Ochlerotatus/parasitologia , Plasmodium/fisiologia , Animais , Comportamento Animal , Doenças das Aves/parasitologia , Corvos , Comportamento Alimentar , Feminino , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita , Mordeduras e Picadas de Insetos/veterinária , Malária/parasitologia , Malária/transmissão , Masculino , Fenótipo , Fatores Sexuais , Pardais
17.
Mol Ecol ; 28(7): 1812-1825, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30710395

RESUMO

Host shifts are widespread among avian haemosporidians, although the success of transmission depends upon parasite-host and parasite-vector compatibility. Insular avifaunas are typically characterized by a low prevalence and diversity of haemosporidians, although the underlying ecological and evolutionary processes remain unclear. We investigated the parasite transmission network in an insular system formed by Eleonora's falcons (the avian host), louse flies that parasitize the falcons (the potential vector), and haemosporidians (the parasites). We found a great diversity of parasites in louse flies (16 Haemoproteus and 6 Plasmodium lineages) that did not match with lineages previously found infecting adult falcons (only one shared lineage). Because Eleonora's falcon feeds on migratory passerines hunted over the ocean, we sampled falcon kills in search of the origin of parasites found in louse flies. Surprisingly, louse flies shared 10 of the 18 different parasite lineages infecting falcon kills. Phylogenetic analyses revealed that all lineages found in louse flies (including five new lineages) corresponded to Haemoproteus and Plasmodium parasites infecting Passeriformes. We found molecular evidence of louse flies feeding on passerines hunted by falcons. The lack of infection in nestlings and the mismatch between the lineages isolated in adult falcons and louse flies suggest that despite louse flies' contact with a diverse array of parasites, no successful transmission to Eleonora's falcon occurs. This could be due to the falcons' resistance to infection, the inability of parasites to develop in these phylogenetically distant species, or the inability of haemosporidian lineages to complete their development in louse flies.


Assuntos
Evolução Biológica , Doenças das Aves/parasitologia , Dípteros/parasitologia , Falconiformes/parasitologia , Haemosporida/genética , Plasmodium/genética , Animais , Doenças das Aves/transmissão , Vetores de Doenças , Ectoparasitoses/veterinária , Filogenia
18.
Emerg Infect Dis ; 25(2): 346-348, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30666939

RESUMO

We assessed the vector competence of Aedes caspius and Aedes albopictus mosquitoes in Spain for the transmission of Zika virus. Whereas Ae. albopictus mosquitoes were a competent vector, Ae. caspius mosquitoes were unable to transmit Zika virus. We also identified high levels of vertical transmission of Zika virus in Ae. albopictus mosquitoes.


Assuntos
Aedes/virologia , Mosquitos Vetores/virologia , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/transmissão , Zika virus , Animais , Chlorocebus aethiops , Feminino , Humanos , Espanha/epidemiologia , Células Vero , Carga Viral , Zika virus/classificação , Zika virus/genética , Infecção por Zika virus/virologia
19.
Ambio ; 48(8): 900-912, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30244355

RESUMO

Society's perception of ecosystem services is a key issue in conservation, particularly for endangered species providing services linked to human activities. Misperceptions may lead to wildlife-human conflicts with the risk of disappearance of the species involved. We contrasted farmers' perceptions with highly accurate quantitative data of an endangered vulture species, which provide ecosystem services. We combined surveys of 59 farmers with data from 48 GPS-tagged Canarian Egyptian vultures (Neophron percnopterus majorensis endemic to the Spanish Canary Islands) to disentangle factors influencing consistency between farmers' awareness of vulture occurrence on their properties and vulture behavior. Egyptian vultures were perceived as the main providers of scavenging services and the most beneficial avian scavenger. Consistency between farmers' perceptions (surveys) and vulture use of their farms (GPS data) was higher in the morning, in older males, and at farms with lower livestock numbers, located near vulture communal roosts, and visited more frequently by vultures. Our results underline the potential influence of modern livestock husbandry in disconnecting people from ecosystems, and how appreciation could be even lower for scarce or threatened ecosystem service providers.


Assuntos
Ecossistema , Falconiformes , Idoso , Animais , Conservação dos Recursos Naturais , Fazendeiros , Humanos , Masculino , Espanha
20.
Sci Rep ; 8(1): 15155, 2018 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-30310140

RESUMO

Despite increasing work detailing the presence of foraging specializations across a range of taxa, limited attention so far has been given to the role of spatiotemporal variation in food predictability in shaping individual resource selection. Here, we studied the exploitation of human-provided carrion resources differing in predictability by Canarian Egyptian vultures (Neophron percnopterus majorensis). We focussed specifically on the role of individual characteristics and spatial constraints in shaping patterns of resource use. Using high-resolution GPS data obtained from 45 vultures tracked for 1 year, we show that individual vultures were repeatable in both their monthly use of predictable and semi-predicable resources (feeding station vs. farms) and monthly levels of mobility (home range size and flight activity). However, individual foraging activities were simultaneously characterized by a high degree of (temporal) plasticity in the use of the feeding station in specific months. Individual rank within dominance hierarchy revealed sex-dependent effects of social status on resource preference in breeding adults, illustrating the potential complex social mechanisms underpinning status-dependent resource use patterns. Our results show that predictable food at feeding stations may lead to broad-scale patterns of resource partitioning and affect both the foraging and social dynamics within local vulture populations.


Assuntos
Aves/fisiologia , Comportamento Alimentar , Comportamento Social , Distribuição Animal , Animais , Ecossistema , Movimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...