39 research outputs found

    Measurements of H2O in the terrestrial mesosphere and implications for extra-terrestrial sources

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    Recent measurements of mesospheric water vapor and their implications for the existence of extraterrestrial sources of water are discussed. This study was prompted by the work of L. Frank and others who, based on their interpretation of transient dark spots visible in ultraviolet images of the Earth's dayglow emission, have proposed that a large flux of small comets enters the Earth's upper atmosphere each day. To date, however, analysis does not conclusively refute or support the idea of an external source

    The legal international wildlife trade favours invasive species establishment: the Monk and Ring-necked parakeets in Spain

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    The international wildlife trade is a lucrative business. Although a huge variety of animal groups are trafficked, the Psittaciformes (parrots) are amongst the most traded avian groups. Deliberate or accidental releases of imported parrots have led to the establishment of feral populations in many countries. Far from their native habitats, parrots may cause economic and ecological damage, and may even favour the transmission of zoonotic diseases. Despite this, the links between numbers of imported individuals and the establishment of non-native populations is not well known. In this study, we analysed data on imports of two well-known invasive parrots, the Monk Parakeet Myiopsita monachus and the Ring-necked Parakeet Psittacula krameri, in Spain. We contrasted this information with the growth of known naturalised populations of these species from 1975 to 2015 and compared the success of these two species with other Psittaciformes imported in similar numbers into the country. We show that more than 190,000 Monk Parakeets were imported from Uruguay and Argentina, and almost 63,000 Ring-necked Parakeets were legally brought into the country from Pakistan and Senegal. For both species, wild populations grew exponentially following peak importation periods in 2015 (18,980–21,455 Monk Parakeets and 3,005–3,115 Ring-necked Parakeets). Even though imports of the two species were banned in Spain in 2005, wild populations are now self-sustaining. We argue that these parrot populations started from accidental and deliberate bird escapes, especially from birds originally captured in the wild. Although lack of more precise data makes it difficult for us to propose clear statistical associations between imports and established bird populations, we nonetheless suggest that the international trade is with some certainty the main cause for the origin of naturalised populations of invasive species in Spain. Our conclusions are useful to help manage similar animal groups that are numerous in the wildlife trade, especially for wild-caught social species.—Lucrecia Souviron-Priego, Antonio Román Muñoz, Jesús Olivero, J. Mario Vargas & John E. Fa. (2018). The legal international wildlife trade favours invasive species establishment: the Monk and Ring-neked Parakeets in Spain

    A large-scale assessment of European rabbit damage to agriculture in Spain

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    BACKGROUND: Numerous small and medium-sized mammal pests cause widespread and economically significant damage to crops all over the globe. However, most research on pest species has focused on accounts of the level of damage. There are fewer studies concentrating on the description of crop damage caused by pests at large geographical scales, or on analysing the ecological and anthropogenic factors correlated with these observed patterns. We investigated the relationship between agricultural damage by the European rabbit (Oryctolagus cuniculus) and environmental and anthropogenic variables throughout Spain. RESULTS: Rabbit damage was mainly concentrated within the central-southern regions of Spain. We found that rabbit damage has increased significantly between the early 2000s and 2013. Greater losses were typical of those areas where farming dominated and natural vegetation was scarce, where main railways and highways were present, and where environmental conditions were generally favourable for rabbit populations to proliferate. CONCLUSIONS: From our analysis we suggest that roads and railway lines act as potential corridors along which rabbits can spread. The recent increase in Spain of such infrastructure may explain the rise in rabbit damage reported in this study. Our approach is valuable as a method for assessing drivers of wildlife pest damage at large spatial scales, and can be used to propose methods to reduce human-wildlife conflict

    Mammalian biogeography and the Ebola virus in Africa

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    ABSTRACT 1. Ebola virus is responsible for the fatal Ebola virus disease (EVD). 2. Identifying the distribution area of the Ebola virus is crucial for understanding risk factors conditioning the emergence of new EVD cases. Existing distribution models have underrepresented the potential contribution that reservoir species and vulnerable species make in sustaining the presence of the virus. 3. In this paper, we map favourable areas for Ebola virus in Africa according to environmental and zoogeographic descriptors, independent of human-to-human transmissions. We combine two different biogeographic approaches: analysis of mammalian distribution types (chorotypes), and distribution modelling of the Ebola virus. 4. We first obtain a model defining the distribution of environmentally favourabl

    Social Perceptions of Forest Ecosystem Services in the Democratic Republic of Congo

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    The forests of the Albertine Rift are known for their high biodiversity and the important ecosystem services they provide to millions of inhabitants. However, their conservation and the maintenance of ecosystem service delivery is a challenge, particularly in the Democratic Republic of the Congo. Our research investigates how livelihood strategy and ethnicity affects local perceptions of forest ecosystem services. We collected data through 25 focus-group discussions in villages from distinct ethnic groups, including farmers (Tembo, Shi, and Nyindu) and hunter-gatherers (Twa). Twa identify more food-provisioning services and rank bush meat and honey as the most important. They also show stronger place attachment to the forest than the farmers, who value other ecosystem services, but all rank microclimate regulation as the most important. Our findings help assess ecosystem services trade-offs, highlight the important impacts of restricted access to forests resources for Twa, and point to the need for developing alternative livelihood strategies for these communities

    The impact of the Cretaceous–Paleogene (K–Pg) mass extinction event on the global sulfur cycle: Evidence from Seymour Island, Antarctica

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    The Cretaceous–Paleogene (K–Pg) mass extinction event 66 million years ago led to large changes to the global carbon cycle, primarily via a decrease in primary or export productivity of the oceans. However, the effects of this event and longer-term environmental changes during the Late Cretaceous on the global sulfur cycle are not well understood. We report new carbonate associated sulfate (CAS) sulfur isotope data derived from marine macrofossil shell material from a highly expanded high latitude Maastrichtian to Danian (69–65.5 Ma) succession located on Seymour Island, Antarctica. These data represent the highest resolution seawater sulfate record ever generated for this time interval, and are broadly in agreement with previous low-resolution estimates for the latest Cretaceous and Paleocene. A vigorous assessment of CAS preservation using sulfate oxygen, carbonate carbon and oxygen isotopes and trace element data, suggests factors affecting preservation of primary seawater CAS isotopes in ancient biogenic samples are complex, and not necessarily linked to the preservation of original carbonate mineralogy or chemistry. Primary data indicate a generally stable sulfur cycle in the early-mid Maastrichtian (69 Ma), with some fluctuations that could be related to increased pyrite burial during the ‘mid-Maastrichtian Event’. This is followed by an enigmatic +4‰ increase in δ³⁴SCAS during the late Maastrichtian (68–66 Ma), culminating in a peak in values in the immediate aftermath of the K–Pg extinction which may be related to temporary development of oceanic anoxia in the aftermath of the Chicxulub bolide impact. There is no evidence of the direct influence of Deccan volcanism on the seawater sulfate isotopic record during the late Maastrichtian, nor of a direct influence by the Chicxulub impact itself. During the early Paleocene (magnetochron C29R) a prominent negative excursion in seawater δ³⁴S of 3–4‰ suggests that a global decline in organic carbon burial related to collapse in export productivity, also impacted the sulfur cycle via a significant drop in pyrite burial. Box modelling suggests that to achieve an excursion of this magnitude, pyrite burial must be reduced by >15%, with a possible role for a short term increase in global weathering rates. Recovery of the sulfur cycle to pre-extinction values occurs at the same time (∼320 kyrs) as initial carbon cycle recovery globally. These recoveries are also contemporaneous with an initial increase in local alpha diversity of marine macrofossil faunas, suggesting biosphere-geosphere links during recovery from the mass extinction. Modelling further indicates that concentrations of sulfate in the oceans must have been 2 mM, lower than previous estimates for the Late Cretaceous and Paleocene and an order of magnitude lower than today

    A large-scale assessment of European rabbit damage to agricultura in Spain

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    Negative impacts of wildlife on humans or their resources have occurred throughout prehistory and recorded history. Consequences of human− wildlife conflict can be both direct, including disease, injury and death from encounters with dangerous animals, and indirect, such as loss of crops and livestock and damaged infrastructure. Measures for preventing or reducing human− wildlife conflict are increasingly being developed.1 Successful conflict resolution plans are often the result of the assimilation of proven methods of control or deterrence and their clear adaptation to the nature of the problem at hand.2 The latter requires an accurate assessment of the human− wildlife conflict situation investigated, and a clear understanding of the efficacy, cost-effectiveness and social acceptability of the methods to be applied. Although human−animal conflict involving large mammals is often highlighted in the media, human livelihoods are arguably much more impacted by small and medium-sized mammals. These species often cause substantial damage to pastures as well as ground and tree crops through grazing or browsing. For example, outbreaks of rodents in apple-growing areas in Germany can cause up to €25 million per year of damage.4 Close by large numbers of the European rabbit (Oryctolagus cuniculus) can weaken or kill even persistent leafy crops, and scratching and burrowing can degrade pasture still further by encouraging the establishment of weed
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