RESUMEN
In seasonal environments, the timing of reproduction has important fitness consequences. Our current understanding of the determinants of reproductive phenology in natural systems is limited because studies often ignore the spatial scale on which animals interact with their environment. When animals use a restricted amount of space and the phenology of resources is spatially variable, selection may favor sensitivity to small-scale environmental variation. Population-level studies of how songbirds track the changing phenology of their food source have been influential in explaining how populations adjust to changing climates but have largely ignored the spatial scale at which phenology varies. We explored whether individual great tits (Parus major) synchronize their breeding with phenological events in their local environment and investigated the spatial scale at which this occurs. We demonstrate marked variation in the timing of food availability, at a spatial scale relevant to individual birds, and that such local variation predicts the breeding phenology of individuals. Using a 45-year data set, we show that measures of vegetation phenology at very local scales are the most important predictors of timing of breeding within years, suggesting that birds can fine-tune their phenology to that of other trophic levels. Knowledge of the determinants of variation in reproductive behavior at different spatial scales is likely to be critical in understanding how selection operates on breeding phenology in natural populations.
Asunto(s)
Passeriformes/fisiología , Adaptación Fisiológica , Animales , Ecosistema , Inglaterra , Femenino , Cadena Alimentaria , Larva , Masculino , Mariposas Nocturnas , Quercus , Reproducción , Estaciones del Año , Factores de TiempoRESUMEN
Conservation resources are limited, necessitating prioritization of species and locations for action. Most prioritization approaches are based solely on biologically relevant characteristics of taxa or areas and ignore geopolitical realities. Doing so risks a poor return on conservation investment due to nonbiological factors, such as economic or political instability. We considered felids, a taxon which attracts intense conservation attention, to demonstrate a new approach that incorporates both intrinsic species traits and geopolitical characteristics of countries. We developed conservation priority scores for wild felids based on their International Union for Conservation of Nature status, body mass, habitat, range within protected area, evolutionary distinctiveness, and conservation umbrella potential. We used published data on governance, economics and welfare, human population pressures, and conservation policy to assign conservation-likelihood scores to 142 felid-hosting countries. We identified 71 countries as high priorities (above median) for felid conservation. These countries collectively encompassed all 36 felid species and supported an average of 96% of each species' range. Of these countries, 60.6% had below-average conservation-likelihood scores, which indicated these countries are relatively risky conservation investments. Governance was the most common factor limiting conservation likelihood. It was the major contributor to below-median likelihood scores for 62.5% of the 32 felid species occurring in lower-likelihood countries. Governance was followed by economics for which scores were below median for 25% of these species. An average of 58% of species' ranges occurred in 43 higher-priority lower-likelihood countries. Human population pressure was second to governance as a limiting factor when accounting for percentage of species' ranges in each country. As conservation likelihood decreases, it will be increasingly important to identify relevant geopolitical limitations and tailor conservation strategies accordingly. Our analysis provides an objective framework for biodiversity conservation action planning. Our results highlight not only which species most urgently require conservation action and which countries should be prioritized for such action, but also the diverse constraints which must be overcome to maximize long-term success.
Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Felidae/fisiología , Animales , Conservación de los Recursos Naturales/economía , Conservación de los Recursos Naturales/legislación & jurisprudencia , Política Ambiental/legislación & jurisprudencia , Política , Dinámica PoblacionalRESUMEN
Major histocompatibility complex (Mhc) genes are believed to play a key role in the genetic basis of disease control. Although numerous studies have sought links between Mhc and disease prevalence, many have ignored the ecological and epidemiological aspects of the host-parasite interaction. Consequently, interpreting associations between prevalence and Mhc has been difficult, whereas discriminating alleles for qualitative resistance, quantitative resistance and susceptibility remains challenging. Moreover, most studies to date have quantified associations between genotypes and disease status, overlooking the complex relationship between genotype and the properties of the Mhc molecule that interacts with parasites. Here, we address these problems and demonstrate avian malaria (Plasmodium) parasite species-specific associations with functional properties of Mhc molecules (Mhc supertypes) in a wild great tit (Parus major) population. We further show that correctly interpreting these associations depends crucially on understanding the spatial variation in risk of infection and the fitness effects of infection. We report that a single Mhc supertype confers qualitative resistance to Plasmodium relictum, whereas a different Mhc supertype confers quantitative resistance to Plasmodium circumflexum infections. Furthermore, we demonstrate common functional properties of Plasmodium-resistance alleles in passerine birds, suggesting this is a model system for parasite-Mhc associations in the wild.
Asunto(s)
Genes MHC Clase I , Malaria Aviar/epidemiología , Plasmodium/fisiología , Polimorfismo Genético , Pájaros Cantores/genética , Pájaros Cantores/parasitología , Alelos , Animales , Inglaterra , Femenino , Genotipo , Malaria Aviar/parasitología , Malaria Aviar/transmisión , Masculino , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
Sympatry between primates and felids is potentially relevant to both their behavioural ecology and their conservation. This paper briefly introduces felids and primates, for the purposes of assessing their interrelationships and the patterns in their spatial congruence using IUCN spatial data. First, we review evidence and opportunity for predator-prey interactions between the felids and primates. Second, we analyse the overlap between species of the two taxa to reveal the potential of particular felid species or guilds (unique combinations of 2 or more felids) to act as umbrellas for the conservation of co-occurring primates. Felid guilds vary in terms of their geographical ranges and numbers of members. Some felid species overlap the ranges of many primate species, and the most speciose felid guilds, while geographically limited in distribution, have the potential to act as protective umbrellas to large numbers of primate species. This prompts the hypothesis that threatened primates and felids are facing similar threats and might thus benefit from similar interventions, which is evaluated in a sister paper by Macdonald et al. in this special issue.
Asunto(s)
Distribución Animal , Conservación de los Recursos Naturales , Felidae/fisiología , Cadena Alimentaria , Primates/fisiología , Animales , Biota , Modelos Biológicos , Análisis EspacialRESUMEN
Threats faced by mammalian species can be grouped into one of a handful of categories, such as habitat loss, unsustainable hunting and persecution. Insofar as they face common threats, diverse species may benefit from the same conservation intervention, thereby offering efficiencies in conservation action. We explore this proposition for primates and felids by examining coarse scale overlaps in geographical distributions, using IUCN Red List assessments of the primary threats posed to each species. A global analysis of primates and felids that face common threats reveals the greatest overlap is in Central and South Asia, where up to 14 primates and felids co-occur. More than 80% of the land where at least 1 threatened species of either primate or felid occurs also contains at least one threatened species of the other taxon, yet over 60% of these grid cells containing both threatened primates and felids lie outside Conservation International's hot spots. A review of IUCN Action Plans of the threats to felids and primates strongly supports the hypothesis that they are often the same and occur in the same place. In principle, steps to conserve big cats have the potential to benefit several species of threatened primates, and vice versa.
Asunto(s)
Conservación de los Recursos Naturales , Felidae/fisiología , Primates/fisiología , Animales , Biodiversidad , Especies en Peligro de ExtinciónRESUMEN
Human activity affecting the welfare of wild vertebrates, widely accepted to be sentient, and therefore deserving of moral concern, is widespread. A variety of motives lead to the killing of individual wild animals. These include to provide food, to protect stock and other human interests, and also for sport. The acceptability of such killing is widely believed to vary with the motive and method. Individual vertebrates are also killed by conservationists. Whether securing conservation goals is an adequate reason for such killing has recently been challenged. Conventional conservation practice has tended to prioritise ecological collectives, such as populations and species, when their interests conflict with those of individuals. Supporters of the 'Compassionate Conservation' movement argue both that conservationists have neglected animal welfare when such conflicts arise and that no killing for conservation is justified. We counter that conservationists increasingly seek to adhere to high standards of welfare, and that the extreme position advocated by some supporters of 'Compassionate Conservation', rooted in virtue ethics, would, if widely accepted, lead to considerable negative effects for conservation. Conservation practice cannot afford to neglect consequences. Moreover, the do-no-harm maxim does not always lead to better outcomes for animal welfare.
RESUMEN
Cognition has been studied intensively for several decades, but the evolutionary processes that shape individual variation in cognitive traits remain elusive [1-3]. For instance, the strength of selection on a cognitive trait has never been estimated in a natural population, and the possibility that positive links with life history variation [1-5] are mitigated by costs [6] or confounded by ecological factors remains unexplored in the wild. We assessed novel problem-solving performance in 468 wild great tits Parus major temporarily taken into captivity and subsequently followed up their reproductive performance in the wild. Problem-solver females produced larger clutches than nonsolvers. This benefit did not arise because solvers timed their breeding better, occupied better habitats, or compromised offspring quality or their own survival. Instead, foraging range size and day length were relatively small and short, respectively, for solvers, suggesting that they were more efficient at exploiting their environment. In contrast to the positive effect on clutch size, problem solvers deserted their nests more often, leading to little or no overall selection on problem-solving performance. Our results are consistent with the idea that variation in cognitive ability is shaped by contrasting effects on different life history traits directly linked to fitness [1, 3].