Time filter

Source Type

Fa J.E.,Durrell Wildlife Conservation Trust | Fa J.E.,Imperial College London | Stewart J.R.,Bournemouth University | Lloveras L.,University of Barcelona | And 2 more authors.
Journal of Human Evolution | Year: 2013

High dependence on the hunting and consumption of large mammals by some hominins may have limited their survival once their preferred quarry became scarce or disappeared. Adaptation to smaller residual prey would have been essential after the many large-bodied species decreased in numbers. We focus on the use of a superabundant species, the rabbit, to demonstrate the importance of this taxon in Iberia as fundamental to predators. We show that the use of the rabbit over time has increased, and that there could have been differential consumption by Neanderthals and Anatomically Modern Humans (AMH). Analysis of bone remains from excavations throughout Iberia show that this lagomorph was a crucial part of the diet of AMH but was relatively unutilised during the Mousterian, when Neanderthals were present. We first present changes in mammalian biomass and mean body mass of mammals over 50,000 years, to illustrate the dramatic loss of large mammalian fauna and to show how the rabbit may have contributed a consistently high proportion of the available game biomass throughout that period. Unlike the Italian Peninsula and other parts of Europe, in Iberia the rabbit has provided a food resource of great importance for predators including hominins. We suggest that hunters that could shift focus to rabbits and other smaller residual fauna, once larger-bodied species decreased in numbers, would have been able to persist. From the evidence presented here, we postulate that Neanderthals may have been less capable of prey-shifting and hence use the high-biomass prey resource provided by the rabbit, to the extent AMH did. © 2013 Elsevier Ltd.


Funk S.M.,Durrell Wildlife Conservation Trust | Fa J.E.,Durrell Wildlife Conservation Trust
PLoS ONE | Year: 2010

In the face of accelerating species extinctions, map-based prioritization systems are increasingly useful to decide where to pursue conservation action most effectively. However, a number of seemingly inconsistent schemes have emerged, mostly focussing on endemism. Here we use global vertebrate distributions in terrestrial ecoregions to evaluate how continuous and categorical ranking schemes target and accumulate endangered taxa within the IUCN Red List, Alliance for Zero Extinction (AZE), and EDGE of Existence programme. We employed total, endemic and threatened species richness and an estimator for richness-adjusted endemism as metrics in continuous prioritization, and WWF's Global200 and Conservation International's (CI) Hotspots in categorical prioritization. Our results demonstrate that all metrics target endangerment more efficiently than by chance, but each selects unique sets of top-ranking ecoregions, which overlap only partially, and include different sets of threatened species. Using the top 100 ecoregions as defined by continuous prioritization metrics, we develop an inclusive map for global vertebrate conservation that incorporates important areas for endemism, richness, and threat. Finally, we assess human footprint and protection levels within these areas to reveal that endemism sites are more impacted but have more protection, in contrast to high richness and threat ones. Given such contrasts, major efforts to protect global biodiversity must involve complementary conservation approaches in areas of unique species as well as those with highest diversity and threat. © 2010 Funk, Fa.


Van Vuuren B.J.,Stellenbosch University | Woolaver L.,Durrell Wildlife Conservation Trust | Goodman S.M.,Field Museum of Natural History
Animal Conservation | Year: 2012

The boky-boky, Mungotictis decemlineata, is an endemic and presumed forest-dependent carnivoran species restricted to lowland central western Madagascar. It inhabits dry deciduous forests, which have been severely reduced in surface area with ∼60% destroyed or degraded by humans during the past 60 years. M. decemlineata is limited to the remnant forests of the central and southern Menabe, and using samples collected from sites across this zone, a phylogeographic study was conducted based on two mitochondrial (1140 base pairs [bp] of cytochrome b and 563bp of the control region) and one nuclear fragment (591bp of the seventh intron of the fibrinogen gene). Forty-seven individuals were included from the central Menabe from four principal localities and two animals from the southern Menabe from a single locality. Low sequence divergence (1.65% for the combined fragment, 4.26% for the control region and 0.78% for cytochrome b) characterized specimens across a zone of 130km delimited by the Tsiribihina River to the north and the Mangoky River to the south; this area includes most of the geographical range of M. decemlineata. Phylogenetic trees, haplotype networks and exact test of population differentiation did not reveal any meaningful geographic partitioning of genetic variation. However, shallow yet significant genetic structure was revealed by Φ ST calculations for the combined as well as separate DNA fragments, which we ascribe to isolation-by-distance. We proposed two different scenarios to explain the lack of meaningful phylogeographical structure in Mungotictis: (1) for this forest-dependent species, dispersal during periods of more continuous forest cover gave rise to a genetic meta-population or (2) that it is able to cross non-forested zones and broadly disperses, leading to high levels of genetic homogeneity. Current inferences favour the first hypothesis. The short- and medium-term future of this taxon is in jeopardy associated with habitat destruction across its geographical range. © 2011 The Authors. Animal Conservation © 2011 The Zoological Society of London.


Burgess M.D.,University of Reading | Nicoll M.A.C.,University of Reading | Jones C.G.,Durrell Wildlife Conservation Trust | Norris K.,University of Reading
Journal of Animal Ecology | Year: 2011

1.Spatial variation in habitat quality and its demographic consequences have important implications for the regulation of animal populations. Theoretically, habitat quality is typically viewed as a single gradient from 'poor' to 'good', but in wild populations it is possible that there are multiple environmental gradients that determine spatial variation in demography. 2.Understanding environmental gradients is important to gain mechanistic insights into important population processes, but also to understand how populations might respond to environmental change. Here, we explore habitat and elevation gradients and their implications for population persistence using detailed long-term data on 600 individuals of the Mauritius kestrel. These data allow us to statistically separate spatial variation in demography from variation arising out of individual or environmental quality and explore its relationships with habitat and topography. 3.Birds that breed earlier in the season have higher reproductive success, and we found that the timing of breeding varies significantly between territories. This variation is primarily driven by elevation, with birds breeding progressively later as elevation increases. 4.Pre-fledging survival from the egg to fledgling stage (independently of timing), and recruitment, also varied significantly between territories. This variation is driven by the habitat surrounding breeding sites with increasing agricultural encroachment causing survival and recruitment to decline. 5.Taken together, our results suggest that there are likely to be multiple environmental gradients affecting spatial variation in productivity in wild populations, and hence multiple and different routes through which environmental change might have consequences for population dynamics by modifying spatial processes. © 2011 The Authors. Journal of Animal Ecology © 2011 British Ecological Society.


Senapathi D.,University of Reading | Nicoll M.A.C.,University of Reading | Teplitsky C.,French Natural History Museum | Jones C.G.,Durrell Wildlife Conservation Trust | And 2 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2011

There is growing evidence of changes in the timing of important ecological events, such as flowering in plants and reproduction in animals, in response to climate change, with implications for population decline and biodiversity loss. Recent work has shown that the timing of breeding in wild birds is changing in response to climate change partly because individuals are remarkably flexible in their timing of breeding. Despite this work, our understanding of these processes in wild populations remains very limited and biased towards species from temperate regions. Here, we report the response to changing climate in a tropical wild bird population using a long-term dataset on a formerly critically endangered island endemic, the Mauritius kestrel. We show that the frequency of spring rainfall affects the timing of breeding, with birds breeding later in wetter springs. Delays in breeding have consequences in terms of reduced reproductive success as birds get exposed to risks associated with adverse climatic conditions later on in the breeding season, which reduce nesting success. These results, combined with the fact that frequency of spring rainfall has increased by about 60 per cent in our study area since 1962, imply that climate change is exposing birds to the stochastic risks of late reproduction by causing them to start breeding relatively late in the season. © 2011 The Royal Society.


Brown D.S.,University of Cardiff | Burger R.,University of Cardiff | Cole N.,Durrell Wildlife Conservation Trust | Cole N.,Mauritian Wildlife Foundation | And 4 more authors.
Molecular Ecology | Year: 2014

Re-introduction of rare species to parts of their historical range is becoming increasingly important as a conservation strategy. Telfair's Skinks (Leiolopisma telfairii), once widespread on Mauritius, were until recently found only on Round Island. There it is vulnerable to stochastic events, including the introduction of alien predators that may either prey upon it or compete for food resources. Consequently, skinks have been introduced to Ile aux Aigrettes, another small Mauritian island that has been cleared of rats. However, the island has been invaded by Asian Musk Shrews (Suncus murinus), a commensal species spread by man well beyond its natural Asian range. Our aim was to use next-generation sequencing to analyse the diets of the shrews and skinks to look for niche competition. DNA was extracted from skink faeces and from the stomach contents of shrews. Application of shrew- and skink-specific primers revealed no mutual predation. The DNA was then amplified using general invertebrate primers with tags to identify individual predators, and then sequenced by 454 pyrosequencing. 119 prey MOTUs (molecular taxonomic units) were isolated, although none could be identified to species. Seeding of cladograms with known sequences allowed higher taxonomic assignments in some cases. Although most MOTUs were not shared by shrews and skinks, Pianka's niche overlap test showed significant prey overlap, suggesting potentially strong competition where food resources are limited. These results suggest that removal of the shrews from the island should remain a priority. © 2013 John Wiley & Sons Ltd.


Nevoux M.,University of Reading | Nevoux M.,University of Pretoria | Arlt D.,University of Reading | Arlt D.,Swedish University of Agricultural Sciences | And 4 more authors.
Ecology Letters | Year: 2013

Dispersal is a key process in population and evolutionary ecology. Individual decisions are affected by fitness consequences of dispersal, but these are difficult to measure in wild populations. A long-term dataset on a geographically closed bird population, the Mauritius kestrel, offers a rare opportunity to explore fitness consequences. Females dispersed further when the availability of local breeding sites was limited, whereas male dispersal correlated with phenotypic traits. Female but not male fitness was lower when they dispersed longer distances compared to settling close to home. These results suggest a cost of dispersal in females. We found evidence of both short- and long-term fitness consequences of natal dispersal in females, including reduced fecundity in early life and more rapid aging in later life. Taken together, our results indicate that dispersal in early life might shape life history strategies in wild populations. © 2013 Blackwell Publishing Ltd/CNRS.


Kundu S.,University of Kent | Jones C.G.,Durrell Wildlife Conservation Trust | Jones C.G.,Mauritian Wildlife Foundation | Prys-Jones R.P.,Bird Group | Groombridge J.J.,University of Kent
Molecular Phylogenetics and Evolution | Year: 2012

Parrots are among the most recognisable and widely distributed of all bird groups occupying major parts of the tropics. The evolution of the genera that are found in and around the Indian Ocean region is particularly interesting as they show a high degree of heterogeneity in distribution and levels of speciation. Here we present a molecular phylogenetic analysis of Indian Ocean parrots, identifying the possible geological and geographical factors that influenced their evolution. We hypothesise that the Indian Ocean islands acted as stepping stones in the radiation of the Old-World parrots, and that sea-level changes may have been an important determinant of current distributions and differences in speciation. A multi-locus phylogeny showing the evolutionary relationships among genera highlights the interesting position of the monotypic Psittrichas, which shares a common ancestor with the geographically distant Coracopsis. An extensive species-level molecular phylogeny indicates a complex pattern of radiation including evidence for colonisation of Africa, Asia and the Indian Ocean islands from Australasia via multiple routes, and of island populations 'seeding' continents. Moreover, comparison of estimated divergence dates and sea-level changes points to the latter as a factor in parrot speciation. This is the first study to include the extinct parrot taxa, Mascarinus mascarinus and Psittacula wardi which, respectively, appear closely related to Coracopsis nigra and Psittacula eupatria. © 2011 Elsevier Inc.


Cartwright S.J.,University of Reading | Nicoll M.A.C.,University of Reading | Jones C.G.,Durrell Wildlife Conservation Trust | Jones C.G.,Mauritian Wildlife Foundation | And 2 more authors.
Current Biology | Year: 2014

Summary Recent work suggests that the environment experienced in early life can alter life histories in wild populations [1-5], but our understanding of the processes involved remains limited [6, 7]. Since anthropogenic environmental change is currently having a major impact on wild populations [8], this raises the possibility that life histories may be influenced by human activities that alter environmental conditions in early life. Whether this is the case and the processes involved remain unexplored in wild populations. Using 23 years of longitudinal data on the Mauritius kestrel (Falco punctatus), a tropical forest specialist, we found that females born in territories affected by anthropogenic habitat change shifted investment in reproduction to earlier in life at the expense of late life performance. They also had lower survival rates as young adults. This shift in life history strategy appears to be adaptive, because fitness was comparable to that of other females experiencing less anthropogenic modification in their natal environment. Our results suggest that human activities can leave a legacy on wild birds through natal environmental effects. Whether these legacies have a detrimental effect on populations will depend on life history responses and the extent to which these reduce individual fitness. © 2014 The Authors.


News Article | September 27, 2016
Site: www.scientificamerican.com

The ploughshare tortoise (Astrochelys yniphora) could be extinct in the wild in as little as two years if the government of Madagascar does not immediately step up and take action to protect them. That stark warning, from a quintet of conservation organizations, came this week as government representatives gathered in Johannesburg for the triennial meeting of the parties of the Convention on International Trade in Endangered Species (CITES). Protecting the ploughshare tortoise is just one of many items on the agenda for the 12-day event. Also known as the Angonoka tortoise, the ploughshare is one of the rarest turtle species on the planet, which makes it even more valuable to collectors, who keep the animals as luxury “pets.” As a result, poaching of these turtles has come close to wiping the species out at its only wild habitat, Madagascar’s Baly Bay National Park. Back in 2013, the wild population was estimated at 400 to 600 tortoises. Now the conservation organizations warn that the population has fallen to fewer than 100 mature animals and that poaching levels have reached their highest levels to date. All of this has gone on right under the noses of the Malagasy authorities. As a result, the five conservation groups—the Wildlife Conservation Society, Durrell Wildlife Conservation Trust, Turtle Survival Alliance, Turtle Conservancy and Global Wildlife Conservation—are calling on the government of Madagascar to finally start enforcing its existing anti-poaching and anti-trafficking laws. “At this point the fate of the tortoise is up to the government of Madagascar,” Peter Paul van Dijk, the Turtle Conservancy’s field conservation programs director, said in a prepared statement. “Conservationists can’t go in and be the police force or the customs official or the border inspections officer at the airport.” Why is this international meeting the opportunity to bring this up? The species is already listed on CITES Appendix 1, which means that all international trade in the tortoises is currently banned among the treaty’s signatories. Still, the groups say this is an opportunity to draw attention to the crisis, get the world’s attention, and hopefully inspire collaboration between Madagascar and the countries to which the tortoises are being smuggled. Most importantly, however, they want to get Madagascar’s attention. “At the end of the day, it is up to Madagascar to seize these opportunities and take control of this trade,” said Richard Lewis, director of Durrell Wildlife Conservation Trust’s Madagascar program. It’s no surprise that Madagascar hasn’t had much luck protecting these tortoises. Madagascar one of the ten poorest countries in the world and the site of tumultuous political upheaval over the past few years, none of which ever seems to get much notice by the international community. Will this international attention be enough to help turn the tide, if not for the whole country but for at least one of its rarest endemic species? I guess we’ll know the answer to that in about two years.

Loading Durrell Wildlife Conservation Trust collaborators
Loading Durrell Wildlife Conservation Trust collaborators