Contents 3 Are we doing the right type of conservation science? 8 Training two captive Sumatran orang-utans for ultrasound scanning 11 As dead as a dodo – when do we declare a species Extinct? 13 Conservation and data management 17 Morbidity of Alaotran gentle lemurs at Durrell Wildlife Park 22 Effects of diet on the health of captive Geoffroy’s marmosets 25 Biodiversity loss in Gerald Durrell’s early works 27 Assessing muscle condition in captive Livingstone’s fruit bats 30 Conservation update on the ploughshare tortoise 33 Seed dispersal by ecological replacement Aldabra giant tortoises Welcome to Solitaire 27. This issue starts with a very thought-provoking essay by Professor Richard Griffiths that highlights some of the problems both field and zoo-based conservationists face not only in doing high quality research, but in communicating it to the rest of the conservation world. These are problems Durrell’s staff and students face regularly, and they are problems for which Solitaire is trying to provide some solutions. Although we are aiming at the highest standards, we are often working with small numbers of individuals, and in situa- tions that cannot be easily, if ever, repeated. Solitaire is an outlet for such studies, making our results available to a wider audience and, hopefully, stimulating more research and encouraging collaboration. This year’s Solitaire demonstrates perfectly what we are trying to do to improve evidence-based conserva- tion and the management of threatened species. Articles range from descriptions of techniques that have the potential to be of benefit to a wide variety of species – for example, habituating our female Sumatran orangutans to ultrasound equipment so that they can be monitored during pregnancy without stress – through updates on vitally important conservation initiatives in the field, to basic research on biology, behaviour and health, providing information that forms the essential underpinning of any conservation action. I hope you enjoy this issue and that it gives you an insight into the huge range of work that Durrell is doing around the world to achieve its mission of saving species from extinction. Very best wishes Eluned Price Wildlife Park Research Coordinator [email protected] Cover photo: Alaotran gentle lemur (James Morgan) Solitaire No. 27 2 Guest essay Are we doing the right type of conservation science? Richard Griffiths Durrell Institute of Conservation and Ecology, University of Kent Although he had no formal scientific training, Gerald how do we go about collecting, analysing and disseminating Durrell recognised the importance of a systematic, scientific the results? approach to animal husbandry and conservation very early on in his career. Few other zoos embraced this philosophy at Hard and fuzzy data the time, which meant that the Jersey Zoological Park was The terms ‘science’, ‘research’ and ‘evidence’ are often used founded using scientific principles that have continued to synonymously, but actually mean slightly different things. underpin the organisation through to the present day. Indeed, When we talk about ‘evidence’ we refer to factual informa- many zoos – and many of the broader conservation organi- tion to support conservation needs. This information may take sations – have been playing catch-up, as ‘evidence-based a variety of forms – published papers and reports, quantita- decision making’ has become increasingly recognised as an tive data, qualitative data, or even information residing in the essential component of good management practice. Howev- heads of experts that is extracted during a workshop. Howev- er, the ‘evidence’ that is needed to do effective conservation er, scientists are a sceptical lot that need a lot of convincing. is often complex, costly, and time-consuming to accumulate. The scientific method is rooted in rigorous hypothesis testing In addition, there are often competing pressures on research- using designs that incorporate observational, experimental ers that dictate the type of research that they do. So what or theoretical methods (or preferably a combination of all type of data do we need to inform sound conservation and three). This is fine if you are working in a physics lab where It has been difficult to publish field research on the impacts of predation on the Mallorcan midwife toad because of small sample sizes (Photo: Richard A. Griffiths). Solitaire No. 27 3 Guest essay extraneous variables can be neatly controlled, or even if you fuzzy data that might cause a journal editor to wince, but it still are working on fruitflies where multiple generations can be may be valuable. For some endangered species it is not unusual bred in a couple of months in a converted broom-cupboard. for there to be practically no data at all, and in such cases you For larger scale ecological and conservation questions, ap- have to rely on opinions from experts or from local people plying the scientific method is enormously challenging. who are familiar with the species or habitats. Fortunately, a In addition to the problem of scale, you may find you are range of methods are available to obtain such data, and these working on a rare and cryptic species that confounds the re- are being increasingly embraced within conservation. The quirements of sample size and research design. We recently Population and Habitat Viability Analysis workshop process investigated how much survey effort would be has been invaluable in extracting information needed to reliably detect a population change from experts and using it to build population in a threatened amphibian species. Our “Within conservation, models of a whole range of threatened statistical models revealed that using tra- species (e.g. Conservation Breeding ditional methods we would actually need scientific rigour needs to Specialist Group 2016). As individual to monitor more sites than were actually experts are not always right (Austen at in existence to reliably detect a decline! be laced with a healthy al. 2016), there are also various tools On another occasion, we were doing field- available for consensus building among work in a remote mountain range on a very dose of pragmatism” experts and consolidating information in rare endemic frog – the Mallorcan midwife a systematic and balanced way (e.g. Pullin toad – that was threatened by introduced preda- et al. 2004; MacMillan & Marshall 2006; tors. We stumbled upon a small pond where it was uniquely Sutherland et al. 2011). In China, carrying out standard possible to do a predator removal experiment. We took some surveys of the giant salamander in streams and rivers has counts and measurements, and then duly removed the preda- proved to be logistically challenging. However, a survey of tors and monitored the impacts on the ecology, behaviour local communities has revealed extremely useful information and morphology of our rare frog over the coming weeks – a about past and present status and distribution (Pan et al. 2015). simple ‘before’ and ‘after’ field experiment using a single Scientists are starting to appreciate that within conservation, site. The results were quite compelling and showed signifi- scientific rigour needs to be laced with a healthy dose of cant predator impact, but we have never been able to publish pragmatism, and that the timescales needed for conservation the results. This is because referees of the paper deemed it action are usually substantially shorter than those needed to do insufficiently replicated. To do it properly we would have the relevant conservation research. Indeed, analytical methods needed to find at least another 10 sites with predators and an- are now emerging that combine available quantitative data other 10 without predators to act as controls. Unfortunately, with expert opinions (Kuhnert et al. 2010), and these have such sites were just not available. considerable potential for informing conservation practice. So what do we do when we just cannot get hard data? The simple answer is you have to work with what you have got When do we stop doing research and start doing and make an informed decision. This may include unpublished conservation? So when do we decide that we have accumulated enough evidence to make an informed decision about a conservation intervention? This problem was neatly summarised by Mc- Coy (1994) when considering what we do about amphibian declines: ‘…do ecologists wear their conservationist hats and muster their expertise in defense of life, or do they wear their scientist hats and muster their expertise in defense of “truth”?’. At one end of the spectrum, if conservationists have insufficient evidence to support a management inter- vention there is a risk they make an expensive mistake. At the other end of the spectrum, if they are too cautious and de- lay action until all necessary evidence has been assembled, the species may be extinct. Amphibian conservation provides examples of both extremes. In the early days of natterjack toad conservation in the UK, there was concern that ponds were drying up too early and killing all the tadpoles. The solution at the time seemed quite simple – deepen the ponds to make them more permanent. Unfortunately, this made the ponds much more attractive to predators and competitors that were unable to survive in temporary ponds, with the result that the natterjacks were actually worse off. Longer term research revealed that breeding in temporary ponds and occasional loss of natterjack Conservation management of the natterjack toad has tadpoles to desiccation is actually quite normal and part of been altered in light of long-term data on its requirements a wider metapopulation process. These are long-lived toads (Photo: Bernard Dupont, Creative Commons Attribution- and only need one or two seasons of reproduction in their Share Alike 2.0 license). lifetime to keep the population ticking over. As a result of Solitaire No. 27 4 Doing conservation science editorial aspirations of enlightened scientific journals, and the assessment criteria of grant panels.