Portrait of Dr David Roberts

Dr David Roberts

Reader in Biodiversity Conservation
Academic Head Conservation Biology
Programme Convenor for MSc Conservation and International Wildlife Trade


  • 2013 MA in Higher Education (Kent)
  • 2001 PhD ‘Reproductive biology and conservation of the orchids of Mauritius’ (Aberdeen)
  • 1997 MPhil ‘Analysis of genetic structure in oak woodlands of west Wales’ (Aberystwyth)
  • 1996 BSc (Hons) Botany 2.1 (Aberystwyth)

Prior to moving to the University of Kent, Dr David Roberts was a senior scientist in the orchid section of the Royal Botanic Gardens, Kew, for over eight years. During this time, he conducted extensive fieldwork in Africa, Madagascar and the Western Indian Ocean islands. Much of his initial work focused on taxonomy and the uses of museum specimens in relation to conservation, including modelling extinction, phenological responses to climate change and conservation status. Since moving to the University of Kent, David has expanded within these areas of research, as well as moving into areas such as wildlife trade and technology developments in support of conservation. Currently, his main areas of research are : 

  • new, extinct and rediscovered species
  • plant conservation (especially orchids)
  • wildlife trade (especially illegal online trade).

Dr David Roberts is a member of the Durrell Institute of Conservation and Ecology

Research interests

New, extinct and rediscovered species

Knowing if a species exists is important for conservation, whether it is a species at the edge of extinction or an invasive species. Much of Dr Roberts’s work has been on developing methods for determining if a species is present, particularly species only known from a handful of sightings. In other words, if a species has not been seen for 20 years, is it extinct? This work has led on to the biases associated with the process of species discovery: for example, why is one species discovered before another? And what is the uncertainty surrounding the identify of individual sightings?

Active researchDeveloping methods to measure sighting uncertainty; identifying how this uncertainty arises and how it impacts models; model accuracy in relation to type of data available; investigating movement behaviour in humans when surveying biodiversity.

Plant conservation (especially orchids)

Much of Dr Roberts' early work was on orchids, and he still maintains an interest. Dave has conducted fieldwork in Africa, Madagascar and the Western Indian Ocean islands. More recently, he has become interested in modelling orchid seed dispersal. Having worked in a herbarium, Dr Roberts has an interest in the application of museum specimens to conservation questions, including phonological shifts associated with climate change and estimating a species' conservation status, as this is often the only data we have. 

Active researchDetermining if data-deficient species are more likely to be critically endangered; developing technologies to detect poaching of cycads from the wild.

Wildlife trade

From Dr Roberts' work on orchids, he has become interested in the wildlife trade, in particular: (a) identifying attributes that relate to demand and thus develop a tradeability index; (b) research surrounding illegal trade particularly over the internet; (c) developing technologies to tackle the illegal wildlife trade; and (d) how the wildlife trade relates to livelihoods along the supply chain. While Dave's initial research was on orchids, he now works on a variety of species and their products including timber, ivory, reptiles, amphibians and other plant species. 

Active research: Application of stable isotopes to identify origin of timber, orchids and crocodile skins; identifying, estimating the preference of and developing software to detect illegal online trade; characterising the structure, actors and attribute demand in the wildlife supply chain for orchids, reptiles and ornamental fish.



  • DI311: The Green Planet (module convenor)
  • DI508 Skills for Conservation Biologists (module convenor)
  • Supervision of final-year projects


  • DI871: International Wildlife Trade - Achieving Sustainability (module convenor)
  • DI881: Advanced Topics in Conservation Ecology and Management
  • DI883: Special Topics in Conservation (supervisor)


Current students

  • Hermenegildo Matimele: Testing the effectiveness of different site-based biodiversity and conservation prioritisation approaches in Mozambique
  • Trang Nguyen: The impact of traditional Chinese medicine on African wildlife: the role of East Asian immigrants
  • Helen Pheasey: Methods of, and motives for, laundering a wildlife commodity beyond captive farms
  • Jack Slattery: Feasibility of reintroducing the red-billed chough (Pyrrhocorax pyrrhocorax) to Kent

PhD (completed)

  • Tristan Pett: The benefits of biodiversity: understanding human-wildlife interactions in urban environments
  • Gail Austen-Price: Eyeing-up biodiversity: how we identify species
  • Janine Robinson: Captive-farming in the exotic pet trade
  • Amy Hinsley: Characterising the formation and structure of international wildlife trade networks in the age of online communication
  • Hiro Shimai: Taxonomy, evolution & ecology of the genus Pinguicula
  • Sarah Stow: Bryophytes as environmental indicators of habitat quality: a new toolset for conservation assessment
  • Lydia Yeo: Application of mark-recapture models in assessing wildlife trade



  • Association pour l’Étude Taxonomique de la Flore d’Afrique Tropicale
  • Partnership for Action Against Wildlife Crime (PAW)
  • Cyber Security Centre, University of Kent


Showing 50 of 123 total publications in the Kent Academic Repository. View all publications.


  • Alfino, S. and Roberts, D. (2019). Estimating identification uncertainties in CITES ‘look-alike’ species. Global Ecology and Conservation [Online]:1-24. Available at: https://doi.org/10.1016/j.gecco.2019.e00648.
    Achieving sustainability in international wildlife trade encompasses a series of challenges, such as identification uncertainty for taxonomically complex groups. Although CITES has developed a ‘look-alike’ policy to collectively manage trade in morphologically similar species and thus facilitate enforcement, its effective application with regards to the export quota system is questionable. We used a multidisciplinary approach to provide an understating of the trade in a taxonomically complex genus of Malagasy chameleons. An online systematic survey of trade was undertaken to identify which species of Calumma have been the subject of trade. A matching task was employed to calculate identification error rates among species in the genus. Results suggest that the online market for Calumma is thriving, including species with long-standing zero quotas. Identification error rates varied widely, reaching high levels of error for some species pairs here identified as ‘look-alike’ species. Findings suggest manual identification technique has varying reliability, potentially resulting in misidentification by stakeholders within the trade. Such errors have negative consequences for both chameleon conservation and the long-term socio-economic development of Madagascar. An understanding of the patterns of identification error can help tailor future management and policy plans.
  • Moshier, A., Steadman, J. and Roberts, D. (2019). Network analysis of a stakeholder community combatting illegal wildlife trade. Conservation Biology [Online]:1-28. Available at: https://doi.org/10.1111/cobi.13336.
    The illegal wildlife trade has emerged as a growing and urgent environmental issue. Stakeholders involved in the efforts to curb wildlife trafficking include non- governmental organizations (NGOs), academia, and state government/enforcement bodies. The extent to which these stakeholders work and communicate amongst each other is fundamental to effectively combatting illicit trade. Using the United Kingdom as a case study, we conducted a mixed methods study using a social network analysis and stakeholder interviews to assess communication relationships in the counter wildlife trafficking community. NGOs consistently occupied 4 of the 5 most central positions in the generated networks, while academic institutions were routinely the converse, filling 4 of the 5 most peripheral positions. However, NGOs were also shown to be the least diverse in their communication practices, compared to the other stakeholder groups. Through semi- structured interviews, personal relationships were identified as the biggest key to functioning communication. Participant insights also showed that stakeholder-specific variables (e.g. ethical/confidentiality concerns), and competition and fundraising, can have a confounding effect on inter-communication. Evaluating communication networks and intra- stakeholder communication trends is essential to facilitate a more cohesive, productive, and efficient response to the challenges of combatting illegal wildlife trade.
  • Jari?, I., Correia, R., Roberts, D., Gessner, J., Meinard, Y. and Courchamp, F. (2019). On the overlap between scientific and societal taxonomic attentions — Insights for conservation. Science of the Total Environment [Online] 648:772-778. Available at: https://www.sciencedirect.com/science/article/pii/S0048969718331541.
    Attention directed at different species by society and science is particularly relevant within the field of conservation, as societal preferences will strongly impact support for conservation initiatives and their success. Here, we assess the association between societal and research interests in four charismatic and threatened species groups, derived from a range of different online sources and social media platforms as well as scientific publications. We found a high level of concordance between scientific and societal taxonomic attention, which was consistent among assessed species groups and media sources. Results indicate that research is apparently not as disconnected from the interests of society as it is often reproached, and that societal support for current research objectives should be adequate. While the high degree of similarity between scientific and societal interest is both striking and satisfying, the dissimilarities are also interesting, as new scientific findings may constitute a constant source of novel interest for the society. In that respect, additional efforts will be necessary to draw scientific and societal focus towards less charismatic species that are in urgent need of research and conservation attention.
  • Robinson, J., Fraser, I., St John, F., Randrianantoandro, J., Andriantsimanarilafy, R., Razafimanahaka, J., Griffiths, R. and Roberts, D. (2018). Wildlife supply chains in Madagascar from local collection to global export. Biological Conservation [Online] 226:144-152. Available at: https://doi.org/10.1016/j.biocon.2018.07.027.
    International trade in wildlife is a complex multi-billion dollar industry. To supply it, many animals are extracted from the wild, sourced from biodiversity-rich, developing countries. Whilst the trade has far-reaching implications for wildlife protection, there is limited information regarding the socio-economic implications in supply countries. Consequently, a better understanding of the costs and benefits of wildlife supply chains, for both livelihoods and conservation, is required to enhance wildlife trade management and inform its regulation. Using Madagascar as a case study, we used value chain analysis to explore the operation of legal wildlife trade on a national scale; we estimate the number of actors involved, the scale, value and profit distribution along the chain, and explore management options. We find that the supply of wildlife provided economic benefits to a number of actors, from local collectors, to intermediaries, exporters and national authorities. CITES-listed reptiles and amphibians comprised a substantial proportion of the quantity and value of live animal exports with a total minimum export value of 230,795USD per year. Sales prices of reptiles and amphibians increased over 100-fold between local collectors and exporters, with exporters capturing ~92% of final export price (or 57% when their costs are deducted). However, exporters shouldered the largest costs and financial risks. Local collectors obtained ~1.4% of the final sales price, and opportunities for poverty alleviation and incentives for sustainable management from the trade appear to be limited. Promoting collective management of species harvests at the local level may enhance conservation and livelihood benefits. However, this approach requires consideration of property rights and land-tenure systems. The complex and informal nature of some wildlife supply chains make the design and implementation of policy instruments aimed at enhancing conservation and livelihoods challenging. Nevertheless, value chain analysis provides a mechanism by which management actions can be more precisely targeted.
  • Alfino, S. and Roberts, D. (2018). Code word usage in the online ivory trade across four European Union member States. Oryx [Online]. Available at: https://doi.org/10.1017/S0030605318000406.
    Illegal wildlife trade is a rapidly evolving environmental crime that is expanding through e-commerce. Because of the nature of the internet, detection of online illegal wildlife and enforcement has proven to be difficult and time-consuming, often based on manual searches through the use of keywords. As a result of scrutiny, traders in elephant ivory now use code words to disguise the trade, thus adding an additional level of complexity. Here we look at the use of 19 code words and phrases associated with the online trade in elephant ivory items on eBay across four European Union (EU) member States. Results show that, in spite of eBay’s ban on ivory, elephant ivory is still being offered for sale across all four sites we searched (183 ivory items offered by 113 sellers during 18 January–5 February 2017). Beyond the violation of eBay’s Terms and Conditions, other potential illegalities included offers for sale across international borders without mention of CITES permit requirements, and the offer of ivory that may be considered 'unworked', which violates EU regulations. Code word usage was found to be consistent across all four EU countries. Although the rise of online wildlife trade is of concern, the growth of global markets may homogenize conventions within trading communities, such as in this case the code words used. Homogenization of conventions may therefore offer opportunities for tackling the illegal online trade in wildlife.
  • Hutchings, M., Robbirt, K., Roberts, D. and Davy, A. (2018). Vulnerability of a specialized pollination mechanism to climate change revealed by a 356-year analysis. Botanical Journal of the Linnean Society [Online] 186:498-509. Available at: https://doi.org/10.1093/botlinnean/box086.
    Pollination of Ophrys sphegodes by sexual deception of male Andrena nigroaenea bees depends on male bees emerging before female bees and before flowering, and on the orchid flowering before female bee emergence, so that competition for the services of naïve male bees is avoided. Using previously established relationships between the timing of these phenological events and spring temperature, we model flowering and bee emergence dates from 1659 to 2014, using central England temperature records. All phenological events were predicted to advance significantly over this period, accompanying a trend towards warmer springs. The interval between male and female flight decreased over time, whereas that between male flight and flowering increased. In addition, female flight preceded orchid flowering after warm springs and it preceded flowering and male bee flight following the warmest springs. Such reversals in phenology have increased in frequency over the last 356 years. In most years, the Ophrys/Andrena pollination system achieves limited pollination success. The results presented here suggest that climate warming has changed the timing of the phenological events that are critical to reproductive success in O. sphegodes and that continuing warming will increase the frequency of years in which this rare orchid suffers complete reproductive failure.
  • Robinson, J., Griffiths, R., Fraser, I., Raharimalala, J., Roberts, D. and St. John, F. (2018). Supplying the wildlife trade as a livelihood strategy in a biodiversity hotspot. Ecology and Society [Online] 23:13. Available at: https://doi.org/10.5751/ES-09821-230113.
    Much of the global wildlife trade is sourced from biodiversity-rich developing countries. These often have high levels of poverty and habitat loss, particularly in rural areas where many depend on natural resources. However, wildlife collection may incentivize local people to conserve habitats that support their livelihoods. Here we examined the contribution of the commercial collection of live animals to rural livelihoods in Madagascar, one of the world’s most important biodiversity hotspots. Using questionnaires, we investigated the prevalence, profitability relative to other livelihood activities, and local importance of the trade, and its capacity to provide incentives for conservation. Thirteen percent of households were engaged in live animal collection in the study area (~5% trapped reptiles and amphibians and the remainder trapped invertebrates). This formed part of a diverse livelihood strategy, and was more profitable than other activities (in terms of returns per unit of effort), with median earnings of ~US$100 per season (~25% of Gross National Income per year). However, trapping was part-time, usually undertaken by poorer members of the community, and often perceived as opportunistic, risky, and financially unreliable. Further, trappers and nontrappers held similar perceptions regarding conservation, suggesting wildlife trade currently does not incentivize enhanced stewardship of traded species and their habitats. Our study brings together a range of methodologies to present the most comprehensive insights into livelihoods and conservation in poor rural communities involved in the commercial collection of live animals to supply international trade. This improved understanding of the wider socioeconomic dimensions of wildlife trade can inform policy and management interventions for both the threats and opportunities associated with global trade in biodiversity both in Madagascar and more generally.
  • Traxmandlova, I., Ackerman, J., Tremblay, R., Roberts, D., Stipkova, Z. and Kindlmann, P. (2017). Determinants of orchid species diversity in world islands. New Phytologist [Online]. Available at: http://dx.doi.org/10.1111/nph.14862.
  • Roberts, D., Jari?, I. and Solow, A. (2017). On the functional extinction of the Passenger Pigeon. Conservation Biology [Online] 31:1192-1195. Available at: http://dx.doi.org/10.1111/cobi.12914.
    The Passenger Pigeon (Ectopistes migratorius) was a social breeder and it has been suggested that the species experienced functional extinction, defined as a total reproductive failure, prior to its actual extinction in the early years of the 20th century. Here, we apply a novel statistical method to a record of egg specimens and so-called skin specimens to test for functional extinction. The results indicate that the species did not become functionally extinct, suggesting that proposals to reverse its rapid decline in the late 19th century could have been successful.
  • Yeo, L., McCrea, R. and Roberts, D. (2017). A novel application of mark-recapture to examine behaviour associated with the online trade in elephant ivory. PeerJ [Online] 5:e3048. Available at: https://doi.org/10.7717/peerj.3048.
    The illegal trade in elephant ivory is driving the unlawful killing of elephants such that populations are now suffering unsustainable reductions. The internet is increasingly being used as a platform to conduct illegal wildlife trade, including elephant ivory. As a globally accessible medium the internet is as highly attractive to those involved in the illegal trade as it is challenging to regulate. Characterising the online illegal wildlife (ivory) trade is complex, yet key to informing enforcement activities. We applied mark-recapture to investigate behaviour associated with the online trade in elephant ivory on eBay UK as a generalist online marketplace. Our results indicate that trade takes place via eBay UK, despite its policy prohibiting this, and that two distinct trading populations exist, characterised by the pattern of their ivory sales. We suggest these may represent a large number of occasional (or non-commercial) sellers and a smaller number of dedicated (or commercial) sellers. Directing resource towards reducing the volume of occasional sales, such as through education, would enable greater focus to be placed upon characterising the extent and value of the illegal, “commercial” online ivory trade. MRC has the potential to characterise the illegal trade in ivory and diverse wildlife commodities traded using various online platforms.
  • Roberts, D. and Hernandez-Castro, J. (2017). Bycatch and illegal wildlife trade on the dark web. Oryx [Online] 51:393-394. Available at: https://doi.org/10.1017/S0030605317000679.
  • Lee, T., Bowman, C. and Roberts, D. (2017). Are extinction opinions extinct?. PeerJ [Online] 5:e366. Available at: http://dx.doi.org/10.7717/peerj.3663.
    Extinction models vary in the information they require, the simplest considering the rate of certain sightings only. More complicated methods include uncertain sightings and allow for variation in the reliability of uncertain sightings. Generally extinction models require expert opinion, either as a prior belief that a species is extinct, or to establish the quality of a sighting record, or both. Is this subjectivity necessary? We present two models to explore whether the individual quality of sightings, judged by experts, is strongly informative of the probability of extinction: the 'quality breakpoint method' and the `quality as variance method'. For the first method we use the Barbary lion as an exemplar. For the second method we use the Barbary lion, Alaotra grebe, Jamaican petrel and Pohnpei starling as exemplars. The 'quality breakpoint method' uses certain and uncertain sighting records, and the quality of uncertain records, to establish whether a change point in the rate of sightings can be established using a simultaneous Bayesian optimisation with a non-informative prior. For the Barbary lion, there is a change in subjective quality of sightings around 1930. Unexpectedly sighting quality increases after this date. This suggests that including quality scores from experts can lead to irregular effects and may not offer reliable results. As an alternative, we use quality as a measure of variance around the sightings, not a change in quality. This leads to predictions with larger standard deviations, however the results remain consistent across any prior belief of extinction. Nonetheless, replacing actual quality scores with random quality scores showed little difference, inferring that the quality scores from experts are superfluous. Therefore, we deem the expensive process of obtaining pooled expert estimates as unnecessary, and even when used we recommend that sighting data should have minimal input from experts in terms of assessing the sighting quality at a fine scale. Rather, sightings should be classed as certain or uncertain, using a framework that is as independent of human bias as possible.
  • Hinsley, A. and Roberts, D. (2017). Assessing the extent of access and benefit sharing in the wildlife trade : lessons from horticultural orchids in Southeast Asia. Environmental Conservation [Online] 45:261-268. Available at: https://doi.org/10.1017/S0376892917000467.
    The equitable sharing of benefits from natural resources is a key target of the Convention on Biological Diversity. Trade in its native species is one way in which a country can potentially benefit from its natural resources, and even small-scale traders can now access global markets online. However, little is known about the extent of benefit sharing for many products, and to what extent the appropriate processes and permits are being used. We surveyed online trade in a lucrative and widely-sold product in Southeast Asia (horticultural orchids), to assess the extent of access and benefit sharing. In total, 20.8% (n=1120) of orchid species from the region were being sold. Although 7/10 countries were trading, five had very little or no trade in their native species, and the majority of recently described endemic species being traded from non-range states had no reported CITES exports from their country of origin. We suggest that addressing access and benefit sharing gaps requires wider recognition of the problem, coupled with capacity building in the countries currently benefitting least: Laos, Myanmar and Cambodia. The priority should be to increase botanical capacity and enable these countries to better control the commercialization and trade of their native species.
  • Faulkner, S., Verity, R., Roberts, D., Roy, S., Robertson, P., Stevenson, M. and Le Comber, S. (2017). Using geographic profiling to compare the value of sightings vs trap data in a biological invasion. Diversity and Distributions [Online] 23:104-112. Available at: http://dx.doi.org/10.1111/ddi.12498.
    Aim: The development of conservation plans, including those dealing with invasive species, is underpinned by the need to obtain reliable and accurate data. However, in many cases responding rapidly is equally critical.

    Location: The data were obtained from the Hebridean Mink Project, which was set up with the objective of removing mink from North Uist, Benbecula and South Uist.

    Methods: Here, we introduce an extension of the Dirichlet process mixture (DPM) model of geographic profiling that can be used to estimate source locations of invasions directly from spatial point pattern data without the need to specify dispersal parameters. We use this model to analyse a biological invasion of American mink (Neovison vison) in the Hebrides.

    Results: Our results suggest that sightings data – which are relatively easy and quick to acquire – can be used to capture much of the information about sources of invasive species that is obtained from the harder to acquire and more intensive trap data.

    Main conclusion: These results have important implications for the development of conservation plans and, in this case, in the early stages of biological invasions, when interventions are most likely to be successful.
  • Jari?, I., Roberts, D., Gessner, J., Solow, A. and Courchamp, F. (2017). Science responses to IUCN Red Listing. PeerJ [Online] 5:e4025. Available at: https://doi.org/10.7717/peerj.4025.
    The IUCN Red List of Threatened Species is often advocated as a tool to assist decision-making in conservation investment and research focus. It is frequently suggested that research efforts should prioritize species in higher threat categories and those that are Data Deficient (DD). We assessed the linkage between IUCN listing and research effort in DD and Critically Endangered (CR) species, two groups generally advocated as research priorities. The analysis of the change in the research output following species classification indicated a listing effect in DD species, while such effect was observed in only a minority of CR species groups. DD species, while chronically understudied, seem to be recognized as research priorities, while research effort for endangered species appears to be driven by various factors other than the IUCN listing. Optimized conservation research focus would require international science planning efforts, harmonized through international mechanisms and promoted by financial and other incentives.
  • Hinsley, A. and Roberts, D. (2017). The wild origin dilemma. Biological Conservation [Online] 217:203-206. Available at: https://doi.org/10.1016/j.biocon.2017.11.011.
    The sustainable production and trade of plants, animals, and their products, including through artificial propagation and captive breeding, is an important strategy to supply the global wildlife market, particularly when the trade in wild specimens is restricted by CITES or other wildlife trade legislation. However, these production methods can become a potential mechanism for the laundering of material illegally collected from the wild, leading to recent calls for the development of traceability methods to determine the origin of traded products. Currently, identifying wild origin can be complex and may require expert knowledge and/or resource intensive molecular techniques. Here we show, using CITES Appendix I slipper orchids as a model system, that production times can be used as a threshold to identify plants in trade that have a high likelihood of being of wild origin. We suggest that this framework could be used by enforcement officers, online vendors, and others to flag material of potential concern for orchids and other high value plants in trade. Specifically, this knowledge combined with nomenclature and the list of CITES Trade Database could be used to construct a species watch list and automate online searches. The results suggest that had this been applied, questions would have been raised regarding online sales of three recently described species.
  • Hinsley, A., de Boer, H., Fay, M., Gale, S., Gardiner, L., Gunasekara, R., Kumar, P., Masters, S., Metusala, D., Roberts, D., Veldman, S., Wong, S. and Phelps, J. (2017). A review of the trade in orchids and its implications for conservation. Botanical Journal of the Linnean Society [Online]. Available at: https://doi.org/10.1093/botlinnean/box083.
    Orchids are one of the largest plant families and are commercially traded for a variety of purposes, including as ornamental plants, medicinal products and food. These markets involve thousands of species, which may be traded legally or illegally, sustainably or unsustainably, and take place at local, national or international scales. In this review, we provide the first overview of commercial orchid trade globally and highlight the main types that involve wild-collected plants. Much of this trade is the result of illegal harvest meaning that it is little documented and is absent from official statistics, at the same time as being of growing conservation concern. We discuss the associated legal–regulatory context, identify key conservation challenges and highlight four key priorities for addressing these challenges. These are to (1) research trade dynamics and the impacts of harvest; (2) strengthen the legal trade of orchids; (3) adopt measures to reduce illegal trade; and (4) raise the profile of orchid trade among policy makers, conservationists and the public.
  • Austen, G., Bindemann, M., Griffiths, R. and Roberts, D. (2017). Species identification by conservation practitioners using online images: accuracy and agreement between experts. PeerJ [Online]. Available at: https://doi.org/10.7717/peerj.4157.
    Emerging technologies have led to an increase in species observations being recorded via digital images. Such visual records are easily shared, and are often uploaded to online communities when help is required to identify or validate species. Although this is common practice, little is known about the accuracy of species identification from such images. Using online images of newts that are native and non-native to the UK, this study asked holders of great crested newt (Triturus cristatus) licences (issued by UK authorities to permit surveying for this species) to sort these images into groups, and to assign species names to those groups. All of these experts identified the native species, but agreement among these participants was low, with some being cautious in committing to definitive identifications. Individuals’ accuracy was also independent of both their experience and self-assessed ability. Furthermore, mean accuracy was not uniform across species (69–96%). These findings demonstrate the difficulty of accurate identification of newts from a single image, and that expert judgements are variable, even within the same knowledgeable community. We suggest that identification decisions should be made on multiple images and verified by more than one expert, which could improve the reliability of species data.
  • Roberts, D. and Jari?, I. (2016). Inferring extinction in North American and Hawaiian birds in the presence of sighting uncertainty. PeerJ [Online] 4:1-9. Available at: https://doi.org/10.7717/peerj.2426.
    For most species the timing of extinction events is uncertain, occurring sometime after the last sighting. However, the sightings themselves may also be uncertain. Recently a number of methods have been developed that incorporate sighting uncertainty in the inference of extinction based on a series of sightings. Here we estimate the timing of extinction for 41 of 52 North American and Hawaiian bird taxa and populations, the results of which suggest all became extinct before 2009. By acknowledging sighting uncertainty it results in two opposite effects, one pushing the timing of extinction away from the last sighting and the other drawing the timing of extinction nearer to it. However, for 14 assessed taxa and populations the upper 95% bounds lie beyond the end of the observation period and therefore suggest the possibility of continued persistence. This has important implications for conservation decision-makers and potentially reduces the likelihood of Romeo’s Error.
  • Roberts, D., Taylor, L. and Joppa, L. (2016). Threatened or Data Deficient: assessing the conservation status of poorly known species. Diversity and Distributions [Online] 22:558-565. Available at: http://dx.doi.org/10.1111/ddi.12418.
    Aim: To determine whether extinction risk assessments based on biological collections and using Criterion B of the IUCN Red List Criteria reflect in part an accurate measure of species rarity and thus extinction risk.

    Location: Madagascar.

    Methods: We calculate the extent of occurrence (EOO) and area of occupancy (AOO) for orchids using herbarium specimen data. Correlations were made against range, occupancy, extinction risk, number of specimens and the date of description. We calculated the average increase in range per species specimen, correlated this against the date of description and determined significance of the observed EOO accumulation using randomization tests.

    Results: Significant negative correlations were found between date of description and all measures of range, occupancy and associated Red List Categories and number of specimens, as well as between the average range accumulation per specimen and date of description. Seventy-five percentage of species’ observed EOO accumulations significantly differed from random. Maximum deviations between observed EOO accumulations and those derived from random sampling were always significantly positive. For most species, this occurred more frequently during the first half of the accumulation sequence.

    Main conclusions: Species described more recently have smaller ranges and occupancies, fewer specimens and greater perceived extinction risk status. Levels of geographic uniqueness of collections are higher in species described more recently. Awareness of a species range increased faster than random, particularly in the first half of the sampling process, suggesting that newly discovered or yet to be discovered species are rare and likely have a higher risk of extinction. For many species, biological collections represent the sum of our knowledge. While data may be limited, such species should be listed in an appropriate Red List Category in accordance with the IUCN Red List Guidelines rather than as Data Deficient.
  • Lee, T. and Roberts, D. (2016). Devaluing rhino horns as a theoretical game. Ecological Modelling [Online] 337:73-78. Available at: http://dx.doi.org/10.1016/j.ecolmodel.2016.06.009.
    The poaching of rhinos has increased dramatically in recent years, creating an ongoing problem and cost to rhino managers. A manager may decrease the reward to the poacher by devaluing the horn such as dehorning so that only a stub is left, or inserting a poison, dye or GPS tracker. However, as it is impossible to remove all value of the horn (a stub remains, poison fades, or GPS trackers can be removed) a poacher may still kill the rhino for the partial gain from the horn, and to avoid tracking this particular rhino in the future. We consider the problem as a theoretical game, where the players are poachers and a rhino manager. By considering the payoff to both manger and poachers we highlight the manager's struggle to discourage poachers to not kill a devalued rhino, despite the loss of time, and increase of risk, to the poacher. Generally, the manager can only influence the situation if virtually all rhino horns are devalued, or the risk involved to the poacher is increased, such as through greater enforcement. However, the cost to devalue the last few rhinos may be very costly due to the sparsity of rhinos, and the rhino manager can easily make a loss by trying to devalue the last, few rhinos. But, whilst a few rhinos remain with their intact horn, a poacher is unlikely to avoid a particular ranch.
  • Jari?, I., Courchamp, F., Gessner, J. and Roberts, D. (2016). Potentially threatened: a Data Deficient flag for conservation management. Biodiversity and Conservation [Online] 25:1995-2000. Available at: http://doi.org/10.1007/s10531-016-1164-0.
    Data Deficient species (DD) comprise a significant portion of the total number of species listed within the IUCN Red List. Although they are not classified within one of the threat categories, they may still face high extinction risks. However, due to limited data available to infer their extinction risk reliably, it is unlikely that the assessment of the true status of Data Deficient species would be possible before many species decline to extinction. An appropriate measure to resolve these problems would be to introduce a flag of potentially threatened species within the Data Deficient category [i.e., DD(PT)]. Such a flag would represent a temporary Red List status for listed Data Deficient species that are, based on the available direct evidence and/or indirect indices, likely to be assigned to one of the threat categories, but where current data remains insufficient for a complete classification. The use of such a flag could increase the focus of the scientific community and conservation decision-makers on such species, thus avoiding the risk that necessary conservation measures are implemented too late. As such, establishment of the DD(PT) category as a kind of alarm for priority species could be beneficial.
  • Jari?, I., Courchamp, F., Gessner, J. and Roberts, D. (2016). Data mining in conservation research using Latin and vernacular species names. PeerJ [Online] 4:1-9. Available at: https://doi.org/10.7717/peerj.2202.
    In conservation science, assessments of trends and priorities for actions often focus on species as the management unit. Studies on species coverage in online media are commonly conducted by using species vernacular names. However, the use of species vernacular names for web-based data search is problematic due to the high risk of mismatches in results. While the use of Latin names may produce more consistent results, it is uncertain whether a search using Latin names will produce unbiased results as compared to vernacular names. We assessed the potential of Latin names to be used as an alternative to vernacular names for the data mining within the field of conservation science. By using Latin and vernacular names, we searched for species from four species groups: diurnal birds of prey, Carnivora, Primates and marine mammals. We assessed the relationship of the results obtained within different online sources, such as Internet pages, newspapers and social media networks. Results indicated that the search results based on Latin and vernacular names were highly correlated, and confirmed that one may be used as an alternative for the other. We also demonstrated the potential of the number of images posted on the Internet to be used as an indication of the public attention towards different species.
  • Hinsley, A., Lee, T., Harrison, J. and Roberts, D. (2016). Estimating the extent and structure of trade in horticultural orchids via social media. Conservation Biology [Online] 30:1038-1047. Available at: http://dx.doi.org/10.1111/cobi.12721.
    The wildlife trade is a lucrative industry involving thousands of animal and plant species. The
    increasing use of the internet for both legal and illegal wildlife trade is well documented, but there is evidence
    that trade may be emerging on new online technologies such as social media. Using the orchid trade as a
    case study, we conducted the first systematic survey of wildlife trade on an international social-media website.
    We focused on themed forums (groups), where people with similar interests can interact by uploading images
    or text (posts) that are visible to other group members. We used social-network analysis to examine the ties
    between 150 of these orchid-themed groups to determine the structure of the network. We found 4 communities
    of closely linked groups based around shared language. Most trade occurred in a community that consisted of
    English-speaking and Southeast Asian groups. In addition to the network analysis, we randomly sampled 30
    groups from the whole network to assess the prevalence of trade in cultivated and wild plants. Of 55,805 posts
    recorded over 12 weeks, 8.9% contained plants for sale, and 22–46% of these posts pertained to wild-collected
    orchids. Although total numbers of posts about trade were relatively small, the large proportion of posts
    advertising wild orchids for sale supports calls for better monitoring of social media for trade in wild-collected
  • Hinsley, A., Nuno, A., Ridout, M., St. John, F. and Roberts, D. (2016). Estimating the extent of CITES noncompliance among traders and end-consumers; Lessons from the global orchid trade. Conservation Letters [Online] 10:602-609. Available at: http://doi.org/10.1111/conl.12316.
    The Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES) regulates trade in over 35,000 species, over 70% of which are orchids. To investigate rule-breaking behavior among traders and buyers in a specific international wildlife trading community, we used direct questions (DQs) and the unmatched count technique (UCT) to survey the orchid growing community about CITES compliance and their knowledge and opinions of the rules. In DQ, 9.9% had smuggled, 4.8% had laundered, and 10.8% had been sent orchids from online purchases without paperwork; UCT estimates did not differ significantly. Growers with greater knowledge of CITES rules were more likely to break them, and there were widespread negative views of CITES among respondents. We recommend targeted enforcement focusing on both online trade and at the point of import, coupled with efforts to encourage traders and end-consumers to engage with discussions on CITES rule implementation.
  • Harrison, J., Roberts, D. and Hernandez-Castro, J. (2016). Assessing the extent and nature of wildlife trade on the dark web. Conservation Biology [Online] 30:900-904. Available at: http://dx.doi.org/10.1111/cobi.12707.
    Use of the internet as a trade platform has resulted in a shift in the illegal wildlife trade. Increased
    scrutiny of illegal wildlife trade has led to concerns that online trade of wildlife will move onto the dark web.
    To provide a baseline of illegal wildlife trade on the dark web, we downloaded and archived 9852 items
    (individual posts) from the dark web, then searched these based on a list of 121 keywords associated with
    illegal online wildlife trade, including 30 keywords associated with illegally traded elephant ivory on the
    surface web. Results were compared with items known to be illegally traded on the dark web, specifically
    cannabis, cocaine, and heroin, to compare the extent of the trade. Of these 121 keywords, 4 resulted in hits,
    of which only one was potentially linked to illegal wildlife trade. This sole case was the sale and discussion of
    Echinopsis pachanoi (San Pedro cactus), which has hallucinogenic properties. This negligible level of activity
    related to the illegal trade of wildlife on the dark web relative to the open and increasing trade on the surface
    web may indicate a lack of successful enforcement against illegal wildlife trade on the surface web.
  • Motes, M., Gardiner, L. and Roberts, D. (2016). The identity of spotted Vanda denisoniana. Orchid Review [Online] 124:228-233. Available at: https://www.rhs.org.uk/about-the-rhs/publications/magazines/the-orchid-review.
  • Austen, G., Bindemann, M., Griffiths, R. and Roberts, D. (2016). Species identification by experts and non-experts: comparing images from field guides. Scientific Reports [Online] 6. Available at: http://dx.doi.org/10.1038/srep33634.
    Accurate species identification is fundamental when recording ecological data. However, the ability to correctly identify organisms visually is rarely questioned. We investigated how experts and non-experts compared in the identification of bumblebees, a group of insects of considerable conservation concern. Experts and non-experts were asked whether two concurrent bumblebee images depicted the same or two different species. Overall accuracy was below 60% and comparable for experts and non-experts. However, experts were more consistent in their answers when the same images were repeated, and more cautious in committing to a definitive answer. Our findings demonstrate the difficulty of correctly identifying bumblebees using images from field guides. Such error rates need to be accounted for when interpreting species data, whether or not they have been collected by experts. We suggest that investigation of how experts and non-experts make observations should be incorporated into study design, and could be used to improve training in species identification.
  • Hernandez-Castro, J. and Roberts, D. (2015). Automatic detection of potentially illegal online sales of elephant ivory via data mining. PeerJ Computer Science [Online] 1:e10:1-11. Available at: http://dx.doi.org/10.7717/peerj-cs.10.
    In this work, we developed an automated system to detect potentially illegal elephant ivory items for sale on eBay. Two law enforcement experts, with specific knowledge of elephant ivory identification, manually classified items on sale in the Antiques section of eBay UK over an 8 week period. This set the “Gold Standard” that we aim to emulate using data-mining. We achieved close to 93% accuracy with less data than the experts, as we relied entirely on metadata, but did not employ item descriptions or associated images, thus proving the potential and generality of our approach. The reported accuracy may be improved with the addition of text mining techniques for the analysis of the item description, and by applying image classification for the detection of Schreger lines, indicative of elephant ivory. However, any solution relying on images or text description could not be employed on other wildlife illegal markets where pictures can be missing or misleading and text absent (e.g., Instagram). In our setting, we gave human experts all available information while only using minimal information for our analysis. Despite this, we succeeded at achieving a very high accuracy. This work is an important first step in speeding up the laborious, tedious and expensive task of expert discovery of illegal trade over the internet. It will also allow for faster reporting to law enforcement and better accountability. We hope this will also contribute to reducing poaching, by making this illegal trade harder and riskier for those involved.
  • Robinson, J., St. John, F., Griffiths, R. and Roberts, D. (2015). Captive reptile mortality rates in the home and implications for the wildlife trade. PLoS ONE [Online] 10:e0141460. Available at: http://www.dx.doi.org/10.1371/journal.pone.0141460.
    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
  • Gibbon, G., Bindemann, M. and Roberts, D. (2015). Factors affecting the identification of individual mountain bongo antelope. PeerJ [Online] 3:1-12. Available at: http://dx.doi.org/10.7717/peerj.1303.
    The recognition of individuals forms the basis of many endangered species monitoring protocols. This process typically relies on manual recognition techniques. This study aimed to calculate a measure of the error rates inherent within the manual technique and also sought to identify visual traits that aid identification, using the critically endangered mountain bongo, Tragelaphus eurycerus isaaci, as a model system. Identification accuracy was assessed with a matching task that required same/different decisions to side-by-side pairings of individual bongos. Error rates were lowest when only the flanks of bongos were shown, suggesting that the inclusion of other visual traits confounded accuracy. Accuracy was also higher for photographs of captive animals than camera-trap images, and in observers experienced in working with mountain bongos, than those unfamiliar with the sub-species. These results suggest that the removal of non-essential morphological traits from photographs of bongos, the use of high-quality images, and relevant expertise all help increase identification accuracy. Finally, given the rise in automated identification and the use of citizen science, something our results would suggest is applicable within the context of the mountain bongo, this study provides a framework for assessing their accuracy in individual as well as species identification.
  • Lee, T., Black, S., Fellous, A., Yamaguchi, N., Angelici, F., Al Hikmani, H., Reed, J., Elphick, C. and Roberts, D. (2015). Assessing uncertainty in sighting records: an example of the Barbary lion. PeerJ [Online] 3. Available at: http://dx.doi.org/10.7717/peerj.1224.
    As species become rare and approach extinction, purported sightings can be controversial, especially when scarce management resources are at stake. We consider the probability that each individual sighting of a series is valid. Obtaining these probabilities requires a strict framework to ensure that they are as accurately representative as possible. We used a process, which has proven to provide accurate estimates from a group of experts, to obtain probabilities for the validation of 32 sightings of the Barbary lion. We consider the scenario where experts are simply asked whether a sighting was valid, as well as asking them to score the sighting based on distinguishablity, observer competence, and verifiability. We find that asking experts to provide scores for these three aspects resulted in each sighting being considered more individually, meaning that this new questioning method provides very different estimated probabilities that a sighting is valid, which greatly affects the outcome from an extinction model. We consider linear opinion pooling and logarithm opinion pooling to combine the three scores, and also to combine opinions on each sighting. We find the two methods produce similar outcomes, allowing the user to focus on chosen features of each method, such as satisfying the marginalisation property or being externally Bayesian.
  • Robinson, J., Griffiths, R., St. John, F. and Roberts, D. (2015). Dynamics of the global trade in live reptiles: Shifting trends in production and consequences for sustainability. Biological Conservation [Online] 184:42-50. Available at: http://dx.doi.org/10.1016/j.biocon.2014.12.019.
    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.
  • Hinsley, A., VeríssimoD. and Roberts, D. (2015). Heterogeneity in consumer preferences for orchids in international trade and the potential for the use of market research methods to study demand for wildlife. Biological Conservation [Online] 190:80-86. Available at: http://www.dx.doi.org/10.1016/j.biocon.2015.05.010.
    The demand for wildlife products drives an illegal trade estimated to be worth up to $10 billion per year, ranking it amongst the top transnational crimes in terms of value. Orchids are one of the best-selling plants in the legal horticultural trade but are also traded illegally and make up 70% of all species listed by the Convention on the International Trade in Endangered Species (CITES). To study consumer preferences for horticultural orchids we use choice experiments to survey 522 orchid buyers online and at large international orchid shows. Using latent class modelling we show that different groups of consumers in our sample have distinct preferences, and that these groups are based on gender, genera grown, online purchasing and type of grower. Over half of our sample, likely to be buyers of mass-produced orchids, prefer white, multi-flowered plants. Of greater conservation interest were a smaller group consisting of male hobbyist growers who buy their orchids online, and who were willing to pay significantly more for species that are rare in trade. This is the first in-depth study of consumer preferences in the international orchid trade and our findings confirm the importance of rarity as a driver of hobbyist trade. We show that market-research methods are a new tool for conservationists that could provide evidence for more effective conservation of species threatened by trade, especially via campaigns that focus on demand reduction or behaviour change.
  • Motes, M., Gardiner, L. and Roberts, D. (2015). Vanda section Dactylolobatae: a summary, two new species, and a key to identification. Orchid Digest:98-104.
  • Robbirt, K., Roberts, D., Hutchings, M. and Davy, A. (2014). Potential disruption of pollination in a sexually deceptive orchid by climatic change. Current Biology [Online] 24:2845-2849. Available at: http://dx.doi.org/10.1016/j.cub.2014.10.033.
    Warmer springs advance many phenological events, including flowering time in plants and the flight time of insects [ 1 ]. Pollination by insects, an ecosystem service of immense economic and conservation importance [ 2 ], depends on synchrony between insect activity and flowering time. If plants and their pollinators show different phenological responses to climate warming, pollination could fail. Information about the effects of warming on specific plant-insect mutualisms is difficult to obtain from complex pollination networks [ 3 ]. In contrast, the extraordinarily specific deceptions evolved by orchids [ 4 ] that attract a very narrow range of pollinators allow direct examination of the potential for climatic warming to disrupt synchrony. Here we show that a sexually deceptive orchid and the solitary bee on which it depends for pollination will diverge in phenology with increasing spring temperature. Male bees inadvertently pollinate the orchid flowers during pseudocopulation. Analysis of museum specimens (1893–2007) and recent field-based records (1975–2009) showed that flight date of the solitary bee Andrena nigroaenea is advanced more by higher temperatures than is flowering date in the deceptive orchid Ophrys sphegodes. Male bees emerged slightly earlier than females, which attract male copulatory attentions away from the deceptive flowers. Warming by as little as 2°C increased both the probability of male flight and the proportion of females flying in the bee population before orchid flowering; this would reduce the frequency of pseudocopulation and thus lower pollination success rate in the orchid. Our results demonstrate a significant potential for coevolved plant-pollinator relationships to be disrupted by climatic warming.
  • Roberts, D. and St. John, F. (2014). Estimating the prevalence of researcher misconduct: a study of UK academics within biological sciences. PeerJ [Online] 2:1-7. Available at: http://dx.doi.org/10.7717/peerj.562.
    Misconduct in academic research is undoubtedly increasing, but studies estimating the prevalence of such behaviour suffer from biases inherent in researching sensitive topics. We compared the unmatched-count technique (UCT) and the crosswise-model (CM), two methods specifically designed to increase honest reporting to sensitive questions, with direct questioning (DQ) for five types of misconduct in the biological sciences. UCT performed better than CM and either outperformed or produced similar estimates to DQ depending on the question. Estimates of academic misconduct increased with decreasing seriousness of the behaviour, from c. 0% for data fabrication to >68% for inappropriate co-authorship. Results show that research into even minor issues of misconduct, is sensitive, suggesting that future studies should consider using specialised questioning techniques as they are more likely to yield accurate figures.
  • Humle, T., Duffy, R., Roberts, D., Sandbrook, C., St. John, F. and Smith, R. (2014). Biology’s drones: undermined by fear. Science [Online] 344:1351-1351. Available at: http://dx.doi.org/10.1126/science.344.6190.1351-a.

Conference or workshop item

  • Sujanani, S., Ziai, M., Batchelor, J. and Roberts, D. (2016). Conservation of Endangered Plant Species Using RFID Tags. In: Loughborough Antennas and Propagation Conference LAPC16. pp. 1-3.
    Radio Frequency Identification (RFID) tags in tamper-proof casings are proposed and tested as part of remote security systems for endangered plant species. The tag is shown to be sufficiently broadband and insensitive to the tamperproof box and underlying plant material and achieves a read range of more than 10m with a standard UHF reader system. Tests are undertaken to demonstrate the tag is readable from different elevations and azimuthal angles.
  • Austen, G., Roberts, D., Bindemann, M. and Griffiths, R. (2016). Reliability of experts in species identification: are images enough?. In: British Ecological Society / Cambridge Conservation Initiative.
  • Austen, G., Roberts, D., Bindemann, M. and Griffiths, R. (2015). Earning your stripes: Does expertise improve the ability to match bumblebee images in identification guides?. In: 27th International Congress for Conservation Biology and 4th European Congress for Conservation Biology.

Datasets / databases

  • Austen, G., Bindemann, M., Griffiths, R. and Roberts, D. (2018). Species identification by conservation practitioners using online images: accuracy and agreement between experts. [MS Excel file]. Available at: http://dx.doi.org/10.7717/peerj.4157.
    Emerging technologies have led to an increase in species observations being recorded via digital images. Such visual records are easily shared, and are often uploaded to online communities when help is required to identify or validate species. Although this is common practice, little is known about the accuracy of species identification from such images. Using online images of newts that are native and non-native to the UK, this study asked holders of great crested newt (Triturus cristatus) licences (issued by UK authorities to permit surveying for this species) to sort these images into groups, and to assign species names to those groups. All of these experts identified the native species, but agreement among these participants was low, with some being cautious in committing to definitive identifications. Individuals’ accuracy was also independent of both their experience and self-assessed ability. Furthermore, mean accuracy was not uniform across species (69–96%). These findings demonstrate the difficulty of accurate identification of newts from a single image, and that expert judgements are variable, even within the same knowledgeable community. We suggest that identification decisions should be made on multiple images and verified by more than one expert, which could improve the reliability of species data.
  • Austen, G., Bindemann, M., Griffiths, R. and Roberts, D. (2016). Species identification by experts and non-experts: comparing images from field guides. [Electronic deposit (Excel)].
    Accurate species identification is fundamental when recording ecological data. However, the ability to correctly identify organisms visually is rarely questioned. We investigated how experts and non-experts compared in the identification of bumblebees, a group of insects of considerable conservation concern. Experts and non-experts were asked whether two concurrent bumblebee images depicted the same or two different species. Overall accuracy was below 60% and comparable for experts and non-experts. However, experts were more consistent in their answers when the same images were repeated, and more cautious in committing to a definitive answer. Our findings demonstrate the difficulty of correctly identifying bumblebees using images from field guides. Such error rates need to be accounted for when interpreting species data, whether or not they have been collected by experts. We suggest that investigation of how experts and non-experts make observations should be incorporated into study design, and could be used to improve training in species identification.
  • Robinson, J., St. John, F., Griffiths, R. and Roberts, D. (2015). Captive reptile mortality rates in the home and implications for the wildlife trade. [Data file].


  • Robinson, J. (2017). Supplying the Exotic Pet Trade: Conservation and Livelihood Implications.
    The wildlife trade represents a significant threat to biodiversity, but may also provide opportunities for societal and economic benefits. To supply the trade, wildlife is often sourced from biodiverse developing countries where poverty rates are high. Ensuring a legal and sustainable trade is therefore critical not only for conservation and implementation of the Convention on International Trade in Endangered Species (CITES), but can contribute to UN Sustainable Development Goals to reduce poverty in developing regions. This thesis investigates trade in live animals, with emphasis on socio-economic implications of wildlife trade chains, and how these interact with conservation and sustainable use in supply countries. An interdisciplinary approach utilises global analysis of wildlife trade data; social research methods to examine the trade in Madagascar; and a specialised questioning technique to explore sustainability of the trade at the end-user level. The findings demonstrate an increasing component of the reptile pet trade comprises animals from ranching operations, or captive-bred in consumer countries. Although this may take pressure off wild populations, it may have implications for biodiversity and benefit sharing in supply countries. In Madagascar, a small proportion of the export value of reptiles and amphibians reaches local collectors. Whilst being potentially profitable and providing additional cash income to some households, wildlife trapping is also unreliable, part-time and financially risky. Consequently, it appears to bring limited opportunities for poverty alleviation or incentives for conservation at the local scale. Value chain analysis reveals the informal and complex nature of the supply chain, making design and implementation of interventions to enhance the trade challenging. Findings suggest that initiatives may be most effective working at the local level to improve organisation and cooperative management of the trade. At the consumer end, mortality of pet reptiles varies between taxa but appears to be relatively low. This directly informs debate concerning exotic pet keeping in consumer countries, for which there are limited data concerning sustainability of wildlife supply chains. Together, these studies enhance knowledge regarding implications of the wildlife trade for livelihoods and conservation, and inform dialogue concerning wildlife trade policy and practice more generally.
  • Nash, D. (2017). An Assessment of Mitigation Translocations for Reptiles at Development Sites.
    All native reptile species are protected against harm through their inclusion on UK legislation. With the exception of two species, this protection does not extend to reptile habitat. As a result, reptiles are frequently subject to mitigation translocations to facilitate the development of land. However, there are few published studies of the effects of mitigation translocation on reptile populations and whether such translocations are effective conservation interventions. The effectiveness of translocation was tested through a combination of: 1) field surveys of sites subject to mitigation across England and Wales; 2) the radio tracking of translocated adders; 3) the monitoring of a population of slow-worms at site where they were released 20 years ago; and 4) a penning experiment to test whether viviparous lizards attempt to disperse from the release site.

    Very few translocated reptiles were encountered during the monitoring of release sites. This paucity of recaptures is either due to post-release mortality, imperfect detection or dispersal. Translocated male adders dispersed farther and had larger home range sizes than resident conspecifics. Some male adders undertook large unidirectional migrations back to the donor site crossing areas of unsuitable habitat as they did so. A population of slow-worms persisted at an isolated site two decades after translocation, albeit in relatively small numbers. Body condition improved over 20 years and the population resumed breeding and recruitment. The temporary penning of viviparous lizards was effective in preventing post-release dispersal and resulted in an increase in recapture rates of greater than 16 times when compared to unpenned viviparous lizard populations. The fact that no lizards were recaptured in the unpenned areas provides strong evidence for the effect of post-release dispersal. Although, mitigation translocations may prevent the immediate death of animals that would otherwise be destroyed with their habitat, there is little evidence that they are compensating for the loss of populations on a broad scale.
  • Hinsley, A. (2016). Characterising the Structure and Function of International Wildlife Trade Networks in the Age of Online Communication.
    The international wildlife trade supports livelihoods but can seriously threaten species if not controlled. The Convention on the International Trade in Endangered Species (CITES) monitors and controls trade in over 35,000 at risk species, over 70% of which are orchids. Mitigating the negative effects of illegal wildlife trade is difficult as traders are motivated by the large potential profits (an estimated $7-10 billion per year in total) to frequently adopt new methods to avoid detection, such as the increasing use of the internet as a marketplace. In this thesis I use the international orchid horticultural trade as a case study in which to explore issues relating to the structure and function of online wildlife trade networks.
    I start by investigating consumer behaviour, one of the major gaps in knowledge relating to the function of wildlife trade networks. First I test the use of choice experiments to reveal information about consumer preferences, with a focus on identifying particular orchid attributes that may drive demand. I also identify specific groups of consumers who may be buying from the illegal market, with a particular focus on those buying online. I then extend this focus on behaviour to explore non-compliance with CITES rules amongst an international group of orchid growers. I test the use of a specialized questioning method known as the Unmatched Count Technique alongside direct questions to identify which types of growers are breaking the rules and why.
    I then move on to focus on the structure of trade networks currently operating online, beginning with a gap analysis of access and benefit sharing from the online orchid trade in Southeast Asia, to identify countries that are not selling their own species. The region is a centre of orchid diversity and export but the lower income countries are not currently benefitting from the widespread online trade in their own species. Following the study of formal online trade I switch to the informal trade operating within orchid themed groups on an international social media website. I use social network analysis to identify closely linked communities within the wider network and make recommendations for how best to communicate with these networks. I also assess the prevalence of both legal and illegal trade taking place via posts within these groups.
    The findings of this thesis have the potential for application to the conservation of species threatened by wildlife trade and the methods used provide new potential approaches to studying the structure and function of online trade networks in particular. My findings address key gaps in conservation knowledge relating to consumer behaviour, online trade networks and the efficacy of current regulations. For policy makers and practitioners it emphasises the importance of a coordinated and adaptive approach to tackling illegal online wildlife trade and strengthening the legal trade. It also highlights the current status of the orchid trade and emphasises the current lack of conservation attention being given to the trade in plants.
  • Worswick, G. (2016). A Population Genetic Study of Pasqueflower: In Situ and Ex Situ Conservation Genetics of a Vulnerable UK Plant Species.
    The population genetic structure of the vulnerable UK plant species Anemone pulsatilla L. reflects geographic patterns of historical range fragmentation and the influence of population decline and restoration intervention. Positive spatial auto-correlation of natural in situ populations of A. pulsatilla lends support to a scenario for genetic drift (i.e. random drift of allelic frequencies) driving the emergence of population genetic structure as a consequence of fragmentation. Multivariate and STRUCTURE analysis estimates the partitioning of genetic variation among four natural population genetic clusters (broadly defined by geographical regions of the species’ range) and a fifth, highly differentiated, genetic cluster defined by introduced genotypes of unverifiable genetic origin to the casually augmented AN population. It is recommended that restoration intervention (i.e. to augment declining populations or introduce populations to enhance gene flow) source propagules for introduction from within the local population genetic cluster in order to maximise the potential for introduction/exchange of locally adaptive genetic variation.
    The existing ex situ gene conservation strategy for A. pulsatilla can be predicted to under-represent the species’ natural genetic variability due to limited sampling effort. At a minimum, a representative ex situ gene conservation strategy for the safeguard of A. pulsatilla UK variability should aim to capture representative accessions from the most diverse population/s of each of the four natural population genetic clusters. It is also recommended that the six native AN genotypes are sampled for ex situ conservation due to a disproportionately high level of unique genetic variation. A pilot study of regenerated ex situ accessions supports a prediction that the following factors act on genetic diversity: (a) survivorship; (b) number of generation removed from the wild; (c) effective population size.
  • Wan, A. (2014). Drivers in the Demand for the Ornamental Trade of Discus (Genus Symphysodon) Between International Markets.
    The ornamental fish trade is a thriving industry that is especially important in conservation and poverty alleviation. To ensure and maintain a sustainable trade, research in consumer preferences and market demand is needed to obtain end-user information and derive the market-potential for trade-suitable species. Looking at the ornamental aquarist trade for genus Symphysodon as a case study, stated preference methods were used to investigate the importance and economic valuation of attributes in consumer choice for discus, and additionally examine the extent of consumer interest and market potential for sustainable wild-caught options. Unlabelled Choice Experiments (CE) and Card Sorting (CS) methods, in the form of picture sorts and preference ranking, were designed and conducted at international markets, with a focus in the United Kingdom and Singapore. CE Results of the international market expressed colour as the most influential attribute, followed by origin/type. Price was of minimal concern to consumers worldwide. The CS observed preferential differences in colour and particularly shape, with an overall attraction towards Blue Snakeskin and the greatest heterogeneity for Blue Diamond, Red Turquoise and Yellow Ghost varieties across groups. Heterogeneous preferences were observed between European and Far Eastern Asian markets, with both UK and Singapore expressing wild and cultivated discus interests, followed by additional markets in Hong Kong and Malaysia with strong cultivated discus interests. Hong Kong also expressed slight potential for wild discus types. Further heterogeneity between traders and different consumer groups expressed a strong preferential overlap between professionals and hobbyists within the discus industry, while significant differences were observed between the general consumers of the wider public and people with environmental employment, with further variations based on gender, age group, fishkeeping knowledge and survey type. These findings suggest that clear differences were observed between market regions, and heterogeneous consumer preferences are strong within the international market. Further research on changes in market demand over time and studies in source markets and emerging markets will be needed to review the international market potential of wild and cultivated discus varieties.
  • Smith, L. (2014). Mortality in the Ornamental Fish Retail Sector: an Analysis of Stock Losses and Stakeholder Opinions.
    The ornamental fish trade is a growing trade sector that has a number of stakeholders that form the supply chain. Stock loss has been highlighted as a concern in relation to the sustainable growth of the industry and welfare concerns. To investigate the issues surrounding stock loss and its extent within the ornamental fish trade, a mixed method approach was used. Specifically, the factors that affect stock loss were identified and the relation to care taken by retail staff (n=40) and consumers (n=110) were investigated. Direct occurrence of stock loss was also assessed – that was collated from 13 stores for the marine sample and 19 stores for the tropical sample – and stock loss within the tropical freshwater fish sample (n=32,204) was 5% compared with the marine sample (n=1004) that had 9% loss of stock. However, stock loss did vary in relation to species-specific stock loss, store-specific stock loss and care-category specific stock loss. The origin of stock, wild-caught v captive-bred, influenced the degree of losses. For marine fish, 10% of wild stock was lost compared with 8% for captive-bred stock. In contrast, tropical freshwater fish suffered 6% stock loss for captive-bred stock compared with only 3% for wild-caught stock. Binary logistic regression analysis found that all 11 variables influenced stock loss, although this varied based on species, store, care category and whether the sample was of marine or tropical freshwater ornamental fish. In terms of care, a number of classification systems were identified in the consumer and retail questionnaires, along with a survey of 15 web sites. Twenty-one terms were found in use, however 62% of retail staff did not use a care-level classification system when making recommendations. However, the majority of retail staff stated that in-house training was provided and rated their own as understanding and that of their colleagues as good or very good. The consumer questionnaire highlighted that care classification did influence consumers’ decision to purchase, with high-care classifications having a negative correlation. The majority of consumer respondents stated that visiting ornamental fish retails was the most common method of purchasing ornamental fish. Stock loss within the sample was found to have the ability to range from 0% loss to 100% occurrence. It is recommended that the industry works to standardise staff training within stores, and that greater consideration should be given to the individual needs of ornamental fish and how this can influence stock loss.
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