[Show abstract][Hide abstract] ABSTRACT: The trade in wildlife and keeping of exotic pets is subject to varying levels of national and international regulation and is a topic often attracting controversy. Reptiles are popular exotic pets and comprise a substantial component of the live animal trade. High mortality of traded animals raises welfare concerns, and also has implications for conservation if collection from the wild is required to meet demand. Mortality of reptiles can occur at any stage of the trade chain from collector to consumer. However, there is limited information on mortality rates of reptiles across trade chains, particularly amongst final consumers in the home. We investigated mortality rates of reptiles amongst consumers using a specialised technique for asking sensitive questions, additive Randomised Response Technique (aRRT), as well as direct questioning (DQ). Overall, 3.6% of snakes, chelonians and lizards died within one year of acquisition. Boas and pythons had the lowest reported mortality rates of 1.9% and chameleons had the highest at 28.2%. More than 97% of snakes, 87% of lizards and 69% of chelonians acquired by respondents over five years were reported to be captive bred and results suggest that mortality rates may be lowest for captive bred individuals. Estimates of mortality from aRRT and DQ did not differ significantly which is in line with our findings that respondents did not find questions about reptile mortality to be sensitive. This research suggests that captive reptile mortality in the home is rather low, and identifies those taxa where further effort could be made to reduce mortality rates.
PLoS ONE 11/2015; 10(11):e0141460. DOI:10.1371/journal.pone.0141460 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Captive breeding and reintroduction remain high-profile but controversial conservation interventions. It is important to understand how such programs develop and respond to strategic conservation initiatives. Here we analyse the contribution to conservation made by amphibian captive breeding and reintroduction since the launch of the IUCN Amphibian Conservation Action Plan (ACAP) in 2007. Compared to earlier data spanning four decades, the number of species involved in captive breeding and reintroduction projects has increased by 57% in the seven years since the ACAP. However, there have been relatively few new reintroductions over this period with most programs focussing on securing captive assurance populations and conservation-related research. There has been a shift to a broader representation of frogs, salamanders and caecilians within programs and an increasing emphasis on threatened species. Equally, there has been a relative increase of species in programs from Central and South America and the Caribbean, where amphibian biodiversity is high. About half of the programs involve zoos and aquaria with a similar proportion represented in specialist facilities run by governmental or non-governmental agencies. Despite successful reintroduction often being regarded as the ultimate milestone for such programs, the irreversibility of many current threats to amphibians may make this an impractical goal. Instead, research on captive assurance populations may be needed to develop imaginative solutions to enable amphibians to survive alongside current, emerging and future threats. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Grass snakes (Natrix natrix) were monitored for nine years on a site in eastern England restored for an amphibian reintroduction. Counts of snakes increased between 2004 and 2012 from 1.25 to 3.83 snakes per survey visit. Grass snake counts were positively correlated with the number of common frog spawn clumps each year and peak counts of pool frogs. During surveys and incidental encounters 137 adult males, 161 adult females, 131 juveniles and 44 hatchlings were captured and individually photographically identified. Captures of hatchlings were erratic and recapture rates were low, so they were excluded from the analysis. Annualised capture data were analysed in the capture-recapture programme MARK, using the Cormack-Jolly-Seber model. The top ranked model gave an apparent annual survival rate of 0.66 (95% CI=0.543–0.755) and an individual detection rate of 0.17 (0.118–0.245). Population estimates based on this model ranged from 53 (95% CI=37–76) to 576 (95% CI=400–831) over the nine years of study. Grass snake population estimates were equivalent to densities of 4.8 to 52.4 individuals ha-1. Nevertheless, it is unlikely that these snakes were permanently resident within the study area, and annual survival may therefore be underestimated. A more plausible explanation for the large population estimates is that the snakes were temporarily resident within a patch of high quality habitat and moved through home ranges that included the study site.
[Show abstract][Hide abstract] ABSTRACT: Bridging the gap between conservation science and conservation practice is a widely acknowledged issue in applied ecology (Hulme 2011). Nowhere is the gap greater than in the area of data collection, analysis and interpretation. Population assessments for conservation are frequently based on traditional practices that use rules of thumb and quasi-quantitative methods. This means that important decisions that have far-reaching conservation, commercial and financial implications are often based on sketchy population assessments.This article is protected by copyright. All rights reserved.
Journal of Applied Ecology 05/2015; DOI:10.1111/1365-2664.12463 · 4.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Biodiversity-rich countries provide wildlife for the exotic pet trade, but the implications of this for conservation, sustainable use and livelihoods remain poorly understood. CITES Appendix II import data from 1996 to 2012 were used to analyse spatial and temporal trends in live reptiles, a group comprising a substantial component of the commercial wildlife trade. Between 2001 and 2012 the trade declined by a third. The decrease was greatest in wild-caught reptiles (70%), but imports in captive-bred reptiles also decreased (40%), due to reduced trade in green iguanas. Imports originating from captive sources comprised about half of the total trade over the period. In contrast, there was a nearly 50-fold increase in imports of ranched reptiles, dominated by royal pythons from sub-Saharan Africa, but including a recent upsurge of ranched turtles from South America and Asia. Additionally, the proportion of reptiles sourced from ‘range countries’ (where species naturally occur in the wild) declined. Numbers of reptiles captive bred within consumer countries to supply domestic markets are difficult to obtain, but may be impacting international trade. Captive breeding may ease collection pressure on wild populations, but might also divert benefit flows, impacting local livelihoods. Ranching may benefit livelihoods and have low impacts on natural populations, but along with captive breeding, could be detrimental if loopholes allow wild animals to be exported as ranched. Given the shift from wild to ranched reptiles, more information is required on the benefits and impacts of commercial ranching operations for traded reptile species.
[Show abstract][Hide abstract] ABSTRACT: Despite rapid growth in the field of reintroduction biology, results from scientific research are often not applied to translocations initiated when human land-use change conflicts with the continued persistence of a species’ population at a particular site. Such mitigation-driven translocations outnumber and receive more funding than science-based conservation translocations, yet the conservation benefit of the former is unclear. Because mitigation releases are economically motivated, outcomes may be less successful than those of releases designed to serve the biological needs of species. Translocation as a regulatory tool may be ill-suited for biologically mitigating environmental damage caused by development. Evidence suggests that many mitigation-driven translocations fail, although the application of scientific principles and best practices would probably improve the success rate. Lack of transparency and failure to document outcomes also hinder efforts to understand the scope of the problem. If mitigation-driven translocations are to continue as
part of the growing billion-dollar ecological consulting industry, it is imperative that the scale and effects of these releases be reported and evaluated.
Frontiers in Ecology and the Environment 01/2015; 13(2). DOI:10.1890/140137 · 7.44 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The use of environmental DNA (eDNA) is rapidly emerging as a potentially valuable survey technique for rare or hard to survey freshwater organisms. For the great crested newt (Triturus cristatus) in the UK, the substantial cost and manpower requirements of traditional survey methods have hampered attempts to assess the status of the species. We tested whether eDNA could provide the basis for a national citizen science-based monitoring programme for great crested newts by (i) comparing the effectiveness of eDNA monitoring with torch counts, bottle trapping and egg searches and (ii) assessing the ability of volunteers to collect eDNA samples throughout the newt’s UK range. In 35 ponds visited four times through the breeding season, eDNA detected newts on 139 out of 140 visits, a 99.3% detection rate. Bottle traps, torch counts and egg searches were significantly less effective, detecting newts 76%, 75% and 44% of the time. eDNA was less successful at predicting newt abundance being positively, but weakly, correlated with counts of the number of newts. Volunteers successfully collected eDNA samples across the UK with 219 of 239 sites (91.3%) correctly identified as supporting newts. 8.7% of sites generated false negatives, either because of very small newt populations or practical difficulties in sample collection. There were no false positives. Overall, we conclude that eDNA is a highly effective survey method and could be used as the basis for a national great crested newt monitoring programme.
[Show abstract][Hide abstract] ABSTRACT: Globally, amphibians face many potential threats, including international trade. However, there is a lack of
knowledge regarding the types, levels and dynamics of the amphibian trade at the global scale. This study reviewed the trade in CITES-listed species between 1976 and2007. Four main trade groups (eggs, skins, meat and individuals) were identified. Trade in amphibian leather focused on Hoplobatrachus tigerinus 5,572individuals), whereas trade in eggs focused on Ambystoma mexicanum(6,027eggs). However, for the entire study period (1976–2007), trade in skins and eggs was small compared with trade in meat and live animals. The meat trade was estimated to be worth .USD111 million, whereas the trade in live animals was
estimated to be worth.USD11.5million in only three of the genera involved. Trade dynamics have changed as a
result of changes in legislation, such as a ban on H. tigerinus exports from Bangladesh for meat. Within the live trade 22species categorized as either Critically Endangered or Endangered were traded during the study period, and these require greater attention. International trade and potential conservation benefits are affected by countries supplying captive-bred individuals to their domestic markets as this trade goes unrecorded. However, this study only investigated trade in species listed by CITES, and other species may comprise a significant additional component of international trade. The trade in amphibians is dynamic, and changes in both the types of trade and the species concerned were identified over the study period. Conservation concerns have multiplied from issues concerning population depletions to include indirect impacts associated with disease, predation and competition, which requires a reappraisal of data capture and reporting.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: An understanding of the conservation status of Madagascar's endemic reptile species is needed to underpin conservation planning and priority setting in this global biodiversity hotspot, and to complement existing information on the island's mammals, birds and amphibians. We report here on the first systematic assessment of the extinction risk of endemic and native non-marine Malagasy snakes, lizards, turtles and tortoises.
METHODOLOGY/PRINCIPAL FINDINGS: Species range maps from The IUCN Red List of Threatened Species were analysed to determine patterns in the distribution of threatened reptile species. These data, in addition to information on threats, were used to identify priority areas and actions for conservation. Thirty-nine percent of the data-sufficient Malagasy reptiles in our analyses are threatened with extinction. Areas in the north, west and south-east were identified as having more threatened species than expected and are therefore conservation priorities. Habitat degradation caused by wood harvesting and non-timber crops was the most pervasive threat. The direct removal of reptiles for international trade and human consumption threatened relatively few species, but were the primary threats for tortoises. Nine threatened reptile species are endemic to recently created protected areas.
CONCLUSIONS/SIGNIFICANCE: With a few alarming exceptions, the threatened endemic reptiles of Madagascar occur within the national network of protected areas, including some taxa that are only found in new protected areas. Threats to these species, however, operate inside and outside protected area boundaries. This analysis has identified priority sites for reptile conservation and completes the conservation assessment of terrestrial vertebrates in Madagascar which will facilitate conservation planning, monitoring and wise-decision making. In sharp contrast with the amphibians, there is significant reptile diversity and regional endemism in the southern and western regions of Madagascar and this study highlights the importance of these arid regions to conserving the island's biodiversity.
PLoS ONE 08/2014; 9(8-8):e100173. DOI:10.1371/journal.pone.0100173 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Effective conservation requires a step change in the way practitioners can contribute to science and can have access to research outputs. The journal Conservation Evidence was established in 2004 to help practitioners surmount several obstacles they face when attempting to document the effects of their conservation actions scientifically. It is easily and freely accessible online. It is free to publish in and it enables global communication of the effects of practical trials and experiments, which are virtually impossible to get published in most scientific journals. The driving force behind Conservation Evidence is the need to generate and share scientific information about the effects of interventions.
[Show abstract][Hide abstract] ABSTRACT: Since the 1990s the number of papers published by four mainstream conservation journals (Conservation Biology, Biological Conservation, Biodiversity and Conservation and Oryx) has increased by 133%. The main subject areas of research have not changed over time, with population biology, habitat change, community ecology and species conservation remaining the most popular topics. Equally, mammals, birds, invertebrates and plants have remained the most popular taxa, and – surprisingly – the number of papers dealing with general or global issues or using molecular approaches has remained low. Although collaboration increased over time, most conservation biology is still conducted by researchers working in developed countries. Most research published from developing countries in the 1990s did not have a local researcher as co-author. This trend has now been reversed, although there is only marginal evidence of an increase in collaboration between authors from developed and developing countries. Although conservation science has undergone dramatic technological changes as we have moved into the new millennium, published research remains rooted within the cultural traditions of developed countries, with a continuing emphasis on charismatic taxa.
[Show abstract][Hide abstract] ABSTRACT: Biodiversity monitoring programs need to be designed so that population changes can be detected reliably. This can be problematical for species that are cryptic and have imperfect detection. We used occupancy modeling and power analysis to optimize the survey design for reptile monitoring programs in the UK. Surveys were carried out six times a year in 2009-2010 at multiple sites. Four out of the six species--grass snake, adder, common lizard, slow-worm -were encountered during every survey from March-September. The exceptions were the two rarest species--sand lizard and smooth snake--which were not encountered in July 2009 and March 2010 respectively. The most frequently encountered and most easily detected species was the slow-worm. For the four widespread reptile species in the UK, three to four survey visits that used a combination of directed transect walks and artificial cover objects resulted in 95% certainty that a species would be detected if present. Using artificial cover objects was an effective detection method for most species, considerably increased the detection rate of some, and reduced misidentifications. To achieve an 85% power to detect a decline in any of the four widespread species when the true decline is 15%, three surveys at a total of 886 sampling sites, or four surveys at a total of 688 sites would be required. The sampling effort needed reduces to 212 sites surveyed three times, or 167 sites surveyed four times, if the target is to detect a true decline of 30% with the same power. The results obtained can be used to refine reptile survey protocols in the UK and elsewhere. On a wider scale, the occupancy study design approach can be used to optimize survey effort and help set targets for conservation outcomes for regional or national biodiversity assessments.
PLoS ONE 08/2012; 7(8):e43387. DOI:10.1371/journal.pone.0043387 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The Natterjack toad remains one of the best-studied amphibians
within Europe and much of the research conducted has had a direct
conservation focus. Long-term collaboration between researchers
and conservation practitioners in different countries has been a
hallmark of the programme, and the exchange of data and experiences
has been of mutual benefit.
[Show abstract][Hide abstract] ABSTRACT: 1. Altered global climates in the 21st century pose serious threats for biological systems and practical actions are needed to mount a response for species at risk.
2. We identify management actions from across the world and from diverse disciplines that are applicable to minimizing loss of amphibian biodiversity under climate change. Actions were grouped under three thematic areas of intervention: (i) installation of microclimate and microhabitat refuges; (ii) enhancement and restoration of breeding sites; and (iii) manipulation of hydroperiod or water levels at breeding sites.
3. Synthesis and applications. There are currently few meaningful management actions that will tangibly impact the pervasive threat of climate change on amphibians. A host of potentially useful but poorly tested actions could be incorporated into local or regional management plans, programmes and activities for amphibians. Examples include: installation of irrigation sprayers to manipulate water potentials at breeding sites; retention or supplementation of natural and artificial shelters (e.g. logs, cover boards) to reduce desiccation and thermal stress; manipulation of canopy cover over ponds to reduce water temperature; and, creation of hydrologoically diverse wetland habitats capable of supporting larval development under variable rainfall regimes. We encourage researchers and managers to design, test and scale up new initiatives to respond to this emerging crisis.
[Show abstract][Hide abstract] ABSTRACT: Mobilising volunteers to carry out biodiversity assessments can help to identify priorities for conservation across broad geographical scales. However, even when volunteers carry out simple presence–absence surveys, there can be significant issues over false absences and subsequent data interpretation. Simple but scientifically robust protocols are therefore required for these programmes. Here we evaluate amphibian survey protocols for the National Amphibian and Reptile Recording Scheme (NARRS) in Britain, which aims to assess the status of five widespread amphibian species. Surveys were undertaken by trained volunteers and researchers in two contrasting landscapes over 2 years, and occupancy modelling was used to determine covariates of detection, and to optimise the number of surveys and number of methods required. Although surveys need to take into account seasonal and annual changes in the detectability of different species, there were also landscape effects. Frogs and toads were generally harder to detect in ponds in Kent than in Wales, while the converse was true of newts. Adding bottle-trapping to the suite of methods increased the detection of smooth and palmate newts in both areas, and of great crested newts in Wales. Overall, reliable assessment of the presence or absence of all five species at a site required four separate surveys, each using four different methods (visual encounter surveys during both day and night, dip netting and bottle-trapping). Our approach may prove useful for finding the best compromises between rigor and simplicity when volunteers are used in large-scale surveys.
[Show abstract][Hide abstract] ABSTRACT: Conservation actions that have maintained populations in the past may not necessarily do so in the future. Population viability analysis provides one tool for exploring the impact of management actions on large temporal scales. However, there are relatively few long-term data sets that provide the demographic and environmental data demanded by such models. Using a 37-yr data set, we used RAMAS Metapop to model the persistence of natterjack toads Epidalea (Bufo) calamita on a heathland in southern Britain. A retrospective analysis showed that the best fit between the predicted population trajectories and the real population was when the management carried out was modelled as an increase in K of 150 toads yr−1. However, even if ongoing management continues to improve K by a further 40–60 toads yr−1 over the next 50 yr, the population still has an extinction risk of at least 60% if other factors remain unchanged. Sensitivity analyses and simulated management scenarios indicated that the population was most sensitive to changes in the survival of juvenile (i.e. 1–2 yr old) toads. In addition, if the frequency and severity of pond desiccation increases, the risk of extinction was predicted to increase as a result of reduced recruitment. Low levels of extinction risk occurred irrespective of K when juvenile survival was enhanced in combination with low frequency and severity of pond desiccation. The models suggest that populations that are responding to management against a background of natural fluctuations may remain vulnerable to extinction for several decades. These extinction risks may increase if habitat management fails to offset reductions in recruitment and juvenile survival caused by environmental change.
[Show abstract][Hide abstract] ABSTRACT: Climate can interact with population dynamics in complex ways. In this study we describe how climatic factors influenced the dynamics of an amphibian metapopulation over 12 years through interactions with survival, recruitment and dispersal. Low annual survival of great crested newts (Triturus cristatus) was related to mild winters and heavy rainfall, which impacted the metapopulation at the regional level. Consequently, survival varied between years but not between subpopulations. Despite this regional effect, the four subpopulations were largely asynchronous in their dynamics. Three out of the four subpopulations suffered reproductive failure in most years, and recruitment to the metapopulation relied on one source. Variation in recruitment and juvenile dispersal was therefore probably driving asynchrony in population dynamics. At least one subpopulation went extinct over the 12 year period. These trends are consistent with simulations of the system, which predicted that two subpopulations had an extinction risk of >50% if adult survival fell below 30% in combination with low juvenile survival. Intermittent recruitment may therefore only result in population persistence if compensated for by relatively high adult survival. Mild winters may consequently reduce the viability of amphibian metapopulations. In the face of climate change, conservation actions may be needed at the local scale to compensate for reduced adult survival. These would need to include management to enhance recruitment, connectivity and dispersal.
[Show abstract][Hide abstract] ABSTRACT: Although amphibians have been widely promoted as indicators of biodiversity and environmental change, rigorous tests are lacking. Here key indicator criteria are distilled from published papers, and a species that has been promoted as a bioindicator, the great crested newt, is tested against them. Although a link was established between the presence of great crested newts and aquatic plant diversity, this was not repeated with the diversity of macroinvertebrates. Equally, amphibians do not meet many of the published criteria of bioindicators. Our research suggests that a suite of indicators, rather than a single species, will usually be required.
[Show abstract][Hide abstract] ABSTRACT: The distribution of smooth newts, Triturus vulgaris, and palmate newts, Triturus helveticus, in north-west Europe is related to geology and water quality. This study compared the development of the eggs and larvae of the two species under sublethal acidic and neutral conditions. Newt embryos raised under low pH hatched at an earlier stage of development, at a smaller size, and before those raised under neutral conditions. T. vulgaris hatched at a smaller size than T. helveticus, but pH did not affect the species differentially. Larvae of both species grew to a larger size under neutral than under acid conditions. Larvae raised in heterospecific pairs grew at least as well as those raised in conspecific pairs. Feeding was depressed under acid conditions, and reduced growth may therefore be associated with changes in the behaviour of newt larvae and their prey.
[Show abstract][Hide abstract] ABSTRACT: The feeding responses of three species of newt larvae were compared under circumneutral and sublethal acid conditions. Under acid conditions (pH 4.5) feeding behaviour was suppressed in palmate newts, Triturus helveticus, and smooth newts. T. vulgaris, but not in crested newts, T. cristatus. At low pH, approach and orientation towards food occurred in T. helveticus and T. vulgaris, but snapping was inhibited; T. cristatus snapped and consumed food immediately it was offered under the same conditions. These differences are not consistent with the apparent greater tolerance of T helveticus for acidified ponds. The observations suggest that the chemosensory system of T. helveticus and T. vulgaris may be impaired at low pH.