691 research outputs found

    Adaptive female choice for middle-aged mates in a lekking sandfly

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    Most theoretical models of age-related mate choice predict that females should prefer older males because they have proven survival ability. An alternative view is that older males represent inferior mates because of negative genetic correlations between early and late fitness components, or because older males have traded off longevity against other fitness components, have accumulated deleterious germ-line mutations, or are less well adapted to current conditions than more recently born individuals. While numerous studies have reported female choice for older males, few have explicitly examined the fitness consequences of such a preference. We present evidence from a lekking sandfly, Lutzomyia longipalpis , showing that choosy females discriminate against older males and gain a fitness benefit from their choice. When permitted free choice from an aggregation consisting of males aged zero to two days (young), four to six days (middle-aged) and eight to ten days (old), females preferentially mated with middle-aged males, but all measures of female reproductive success were independent of male age. In contrast, when a second set of females was randomly assigned single virgin males of known age, the eggs of those paired to old mates exhibited lower hatching success than the eggs of females mated to young or middle-aged males. These results suggest that females avoid mating with older males because they represent poorer quality mates. Age-related differences in male quality may have a genetic basis, but could equally well arise through a phenotypic decline in sperm quality or sperm transfer ability with male age. The lack of evidence of female discrimination against older males from other studies may be because these did not explore the reproductive success of the full age range of males

    COVID-19: Analogues and lessons for tackling the extinction and climate crises

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    As environmental scientists working in countries whose COVID-linked deaths already exceed their military casualties from all campaigns since 1945, we believe there are significant messages from the handling of this horrific disease for efforts addressing the enormous challenges posed by the ongoing extinction and climate emergencies

    The ecomics of ecosystems and biodiversity: scoping the scale

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    The G8 decided in March 2007 to initiate a “Review on the economics of biodiversity loss”, in the so called Potsdam Initiative: 'In a global study we will initiate the process of analysing the global economic benefit of biological diversity, the costs of the loss of biodiversity and the failure to take protective measures versus the costs of effective conservation. The study is being supported by the European Commission (together with the European Environmental Agency and in cooperation with the German Government. “The objective of the current study is to provide a coherent overview of existing scientific knowledge upon which to base the economics of the Review, and to propose a coherent global programme of scientific work, both for Phase 2 (consolidation) and to enable more robust future iterations of the Review beyond 2010.

    Changes in wild meat hunting and use by rural communities during the COVID‐19 socio‐economic shock

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    There is limited quantitative evidence of the effects of socio‐economic shocks on biological resource use. Focusing on wild meat hunting, a substantial livelihood and food source in tropical regions, we evaluated the impacts of the shock from Nigeria's coronavirus disease (COVID‐19) lockdown on species exploitation around a global biodiversity hotspot. Using a 3‐year quantitative dataset collected during and after the lockdown (covering 1008 hunter‐months) and matching by time of year, we found that successful hunting trip rates were more frequent during the lockdown, with a corresponding increase in the monthly number, mass, and value of animals caught. Moreover, hunters consumed a larger proportion of wild meat and sold less during lockdown, compared to non‐lockdown periods. These results suggest that local communities relied on wild meat to supplement reduced food and income during the lockdown, buffering the COVID‐19's socio‐economic shock. Our findings also indicate that wild species may be especially vulnerable to increased hunting pressure during socio‐economic shocks

    Conserving nature out of fear or knowledge? Using threatening versus connecting messages to generate support for environmental causes

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    Threatening and connecting messages are two types of appeals commonly used to encourage conservation behaviors, yet little research has examined their psychological impacts and behavioral outcomes. This paper describes two studies contrasting these approaches with a neutral comparison and testing their effects on state levels of negative affect, caring, and openness, psychological states which we expected in turn would encourage conservation behavior. Participants viewed visually identical nature videos with no text, connecting text or negative text. They then reported on their state experiences, and were asked to engage in conservation behaviors, including supporting conservation organizations. Findings showed that connecting messages increased caring and openness, and decreased negative affect, and by doing so elicited more conservation behaviors. On the other hand, threatening messages showed no beneficial effects above a neutral comparison without an appeal. Our findings, which we contextualize in motivational theory, can be used to inform the use of messages to promote conservation.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.jnc.2015.04.00

    The worldwide costs of marine protected areas

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    Declines in marine harvests, wildlife, and habitats have prompted calls at both the 2002 World Summit on Sustainable Development and the 2003 World Parks Congress for the establishment of a global system of marine protected areas (MPAs). MPAs that restrict fishing and other human activities conserve habitats and populations and, by exporting biomass, may sustain or increase yields of nearby fisheries. Here we provide an estimate of the costs of a global MPA network, based on a survey of the running costs of 83 MPAs worldwide. Annual running costs per unit area spanned six orders of magnitude, and were higher in MPAs that were smaller, closer to coasts, and in high-cost, developed countries. Models extrapolating these findings suggest that a global MPA network meeting the World Parks Congress target of conserving 20–30% of the world’s seas might cost between 5billionand5 billion and 19 billion annually to run and would probably create around one million jobs. Although substantial, gross network costs are less than current government expenditures on harmful subsidies to industrial fisheries. They also ignore potential private gains from improved fisheries and tourism and are dwarfed by likely social gains from increasing the sustainability of fisheries and securing vital ecosystem services
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