Amphibian Conservation: Global evidence for the effects of interventions

This comprehensive British synopsis was prepared with funding by Synchronicity Earth and Aria. It is the fourth volume in the Synopses of Conservation Evidence series and is linked to the online www.conservation evidence.com where the full text is available without charge as an alternative to paying for it in print. Its dense text summarizes and discusses selected world studies concerned with the results, positive and negative, of tampering with natural populations. These have been usually well-meaning attempts to compensate for the damage done by expanding human populations. Impacts may have been either direct by past eradication of individuals or indirect through destruction or alteration of habitats critical to the survival of one or more amphibian species. The introduction stresses that this survey is intended to influence those in a position to make decisions that could save biodiversity one case at a time. Al though recommendations are not provided, basic ecology is included. Interventions that are discussed are not ranked by importance or extent of their effects or evaluated by their quality. The multitudes of references to publications of many countries are grouped with the headings where they are appropriate. The text is broken into 14 sections each with key messages and various subheadings. Ten concentrate on threats: residential and commercial development (interventions specific to development); agriculture (engage farmers and other volunteers, terrestrial and aquatic habitat management); energy production and mining (mist habitat); transportation and service corridors (install culverts or tunnels, barrier fencing, modify drains and kerbs, signs and road closures, assistance during migration); human intrusions and disturbance (signs and access restriction); natural system modifications (prescribed fire, herbicides, mechanical removal of vegetation, regulate water levels); invasive alien and other problematic species (reduce predation, competition and habitat alteration by other species, reduce parasitism and disease by chytridiomycosis and ranaviruses); pollution (agricultural and industrial); climate change and severe weather (irrigation, ephemeral ponds, shelter habitat, gradients). These are followed by habitat protection (connectivity, buffer zones); habitat restoration and creation (terrestrial, aquatic); species management (translocate, captive breeding, rearing, release); education and awareness raising (campaigns, programs, citizen science). A 17-page index concludes the book but is a disappointment. Canadian studies are not cited by country or province forcing the reader to search through the text for references to them. However, there are entries for other countries and many entries by species. This is part of an ambitious series that aims toward accumulating a comprehensive summary of evidence on the effects of conservation interventions on saving the diversity of life over the entire planet. Among other titles completed is Bee, Bird, Farmland and more are being prepared to cover different groups and habitats. -- Francis R. Cook * The Canadian Field Naturalist * Nature management for amphibians based on scientific research is rare in practice. Field workers read little, especially literature which is not in their mother-tongue, and readily assume they know what to do based on their experience. This book collects all relevant literature regarding amphibian management and shows what interventions have a real effect and to what extent, but also includes those about which knowledge is still lacking. The book is organised in a practical fashion and gives a detailed overview of all possible interventions and their relevance. Topics are divided in an orderly fashion with separate entries for types of threat, for approaches from the habitat or species concept, and for educational purposes. This set-up makes the book exceptionally well-suited to the realities of nature management. It does not provide recipes for what exactly to do, but does offer the reader the option of choosing certain interventions based on proven efficacy. An example might clarify the book's contents. The construction of new pools is described in detail, and is supported by results from 28 studies. These have been divided into their effects on amphibians generally, into comparisons with natural pools with regards to numbers and species composition, into the success rates of colonisation and population stability, and into factors influencing reproductive success. After that the information is further divided into effects on species and species groups. Based on all this information readers can determine for themselves whether planned interventions can be expected to lead to the desired outcome. The book's contents are also accessible online via www.conservationevidence.com, where it can be downloaded or read online. Similar books have been published on, amongst others, bats, birds, and bees. This book clearly brings us a large step closer to making the right choices in practical nature management, and is indispensable for those involved in doing so. -- Tom Stumpel * RAVON * The book begins with six pages briefly describing the methods the authors used to identify and locate published studies, and to systematically quantify their results. The authors summarize evidence for nine threats (Residential and Commercial Development, Agriculture, Energy Production and Mining, Transportation and Service Corridors, Human Disturbances, Habitat Modification, Invasive Species, Pollution, and Climate Change) and four solutions (Habitat Protection, Habitat Restoration, Species Management, and Education and Outreach). All topics are focused on practical hands-on actions; the book does not reference any modeling studies, does not address policy efforts, and does not discuss ethical considerations. The book would have benefitted from a summary chapter that gave an overview of success for each topic and taxonomic group. Skimming through the extensive examples, I concluded that we have had inconsistent results in our interventions to conserve amphibians, despite varied approaches in numerous systems. It was sobering to realize that even habitat protection efforts—considered as close to a sure thing as we get in conservation—are often not assessed, and are only partially successful. To demonstrate how the book is organized, I summarize the chytridiomycosis abatement strategies, listed under the Invasive Species section. This section included eleven actions that attempted to reduce chytridiomycosis: two reducing geographic spread, three reducing amount of Bd in the environment, and six reducing infection load on amphibians. The authors provided (a) a short overview, (b) a statement of reported successes, (c) a brief background summary, (d) a few pages of text describing each article’s findings, and (e) references. It would have been nice if the authors included some sort of gap analysis identifying actions that have not been tested. I thought readers would have benefited if the authors provided details on the original causes of declines, what kind of effort went into finding unreported and unpublished failures, and whether interventions were designed to address those original threats or were only able to assess net changes. It would also be helpful if the authors discussed whether effective interventions would likely work for other species or in other areas. As in most cases in conservation biology, the devil is in the details, and because many of the details are not included, it’s hard to assess the assessment. A good example of the importance of details is the section on Species Management. In this section, two approaches are described: translocations and ex-situ conservation (e.g., captive breeding, rearing, and releases). Translocations are organized by taxonomic group (i.e., frogs, toads, salamanders), which shows the incredibly small number of such studies and the bias towards three species: Wood Frogs (Lithobates sylvaticus), Natterjack Toads (Epidalea calamita), and Great Crested Newts (Triturus cristatus). Success was qualified by the type of persistence, the length of persistence, and the percent of attempts that persisted for some amount of time; only one study mentioned that a population was self-sustaining. The authors use the original study to define success rather than adopting a universal definition. Consequently, projects that they identify as successful may not actually result in self-sustaining populations. Sections on captive breeding and release are also organized into sections on frogs, toads, and salamanders with most studies conducted on three other species: midwife toads (Alytes spp.), harlequin frogs (Atelopus spp.), and Green and Golden Bell Frogs (Litoria aurea). Here’s where I’d want to know what the original threats were that led to captive breeding and also what has been done, but not published. For example, in the case of the harlequin frogs, we know they are in captivity because of chytridiomycosis, but the book does not mention this. Do they breed in captivity? Yes! Is it a success? Well, maybe. We don’t really know how many Atelopus species were brought in to create captive assurance colonies but failed and were never reported in the literature, or even the degree to which the facility tried to establish large captive populations. We also don’t know why they failed; there are many practical reasons why organizations do not even attempt to breed their frogs (limited space, time, funding, interest). Negative results, details on causes of failure (lack of knowledge, resources, patience, policies), and what the stated objectives of holding captive assurance colonies were are what we need to determine effectiveness. The details of how we define success are critical to assessing the efficacy of our conservation efforts, and those details are glossed over here. In terms of mechanics, the writing is simple, straightforward, and factual, but not especially engaging, as it avoids any personal ideas or synthesis statements, focusing instead on reproducing the original information. I found few errors in the sections I read and the presentation was balanced and uncontroversial. The layout is not especially attractive as the book completely lacks images, graphics, tables, figures, and color. The book also uses small fonts, and many styles and formats of headings and subheadings, but without figures or tables to break up the text, I found it easy to get lost. A more serious complaint is the lack of a combined literature cited for the whole book. This book and online journal will be excellent resources for those looking to get up to speed on what actions have been attempted to conserve amphibians and the outcomes of those efforts. It will be a valuable guide for graduate students interested in evaluating evidence for effective amphibian conservation, and is sure to generate new approaches, critical analyses, and discussions. The free online version makes this especially valuable for conservation practitioners and students from all countries, and should facilitate real-time updates as new studies are published. More than anything, this book reveals the surprisingly large number of species, regions, and threats that have yet to be tested, the need for critical assessment and discussion of “success,” and a realization of how much work we have to do. -- Karen R. Lips * Copeia * This book attempts to summarize all of the published evidence relating to conservation interventions aimed at amphibians and specifically, where interventions have been quantitatively monitored. This ranges from very small specific interventions such as the introduction of artificial hibernacula to wide ranging interventions such as the Million Ponds Project in the UK. No attempt is made to make recommendations, merely to lay out the evidence in an easy to read and easy to find format in a way that can help decision makers at a local, national or international scale make more informed judgements as to the most effective measures to implement. The first half of the book is arranged into chapters that each relate to a specific threat such as climate change, transport networks, agriculture and pollution whilst the second half examines the impact of habitat management, species management (captive breeding and translocations) and education and awareness raising. One of the big plus points of this book is that it is very easy to establish if there is evidence available about a particular subject and where to find the source material. In this respect it serves its purpose well. However, it is intriguing to examine whether the book can actually be applied by land managers or those giving advice to land managers to fine tune the management of sites for their amphibian populations. The Kent Reptile and Amphibian Group regularly gives advice to a wide range of organisations and individuals about managing ponds and terrestrial habitat for amphibians and most of the advice is based around generally accepted best practice guidance. At least 90% of advice is covered by just a few basic principles. In other words, creating ponds is good, and almost always more cost effective than managing existing ponds, discouraging birds and fish is useful, maintaining structurally complex terrestrial habitat will help and not moving the widespread amphibians around except under exceptional circumstances is the best option. So, could this book confirm that this is sound advice based on well established, published literature or just the ramblings of well meaning amateurs that is at best ineffective or in a worst case scenario, counterproductive? Things started well, pond creation gets a resounding thumbs up though the success of specific species depends upon the kind of ponds created and some studies have expressed doubt that the creation of ponds specifically for translocated species leads to self-sustaining populations. In contrast, evidence suggests that pond restoration can have mixed effects on existing amphibian populations. Fish control similarly has good evidence to back up its effectiveness though the use of piscicides can also kill off amphibian populations. The evidence to support other interventions is less conclusive as the example of excluding waterfowl shows. The book simply states that ‘We captured no evidence for the effects of preventing heavy usage or excluding wildfowl from aquatic habitat on amphibian populations.’ Herein lays the challenge of writing a book such as this. The complexities of amphibian habitat management and the impact of interventions on a range of species mean that there simply isn’t enough published information to fully inform a land manager. Other examples, particularly broad ranging interventions such as introducing a grazing regime or the management of terrestrial habitat have evidence of both success and failure. This simply illustrates that for most interventions it is the fine-tuning of management techniques and regimes that yield success rather than simply the type of intervention itself. In short, this book provides a useful starting point for justifying specific interventions (or not intervening) and can help direct the reader to further information. One of the conclusions it is impossible not to draw from reading this text is that there are still significant areas of amphibian conservation that are not covered by scientific literature. This is exemplified by the lack of evidence for either protecting brownfield sites or habitat connectivity having a positive impact on amphibian populations. It is a challenge to summarize so much information into one relatively small book and even more of a challenge to make sense of what all the data means. This book is a useful tool and perhaps an ideal first step for identifying or rejecting potential interventions for amphibian conservation but does not provide all of the answers to making the most of the limited resources available for amphibian conservation. That would just be too simple wouldn’t it? -- Mike Phillips * Herpetological Bulletin * The global amphibian decline crisis, first noted in 1989, has stimulated a huge amount of conservation activity across the world, much of it building on existing conservation efforts focused on local concerns about amphibians. In Britain, for example, realisation that amphibian declines are a global problem gave fresh impetus to efforts to reverse the widespread destruction of amphibian breeding ponds that has occurred, as a result of changing agricultural practices, since World War II. A key question raised by all this activity is: does it work? This remarkable and very important book addresses this question. It is a product of the Conservation Evidence project, an initiative that pursues an evidence-based approach to determine the effectiveness of the many and various interventions that have been made across the world to conserve biodiversity. The Conservation Evidence project produces an open-access journal, Conservation Evidence, maintains an expanding database, and compiles detailed synopses on specific topics, of which this book is the fourth to be published. It is the product of an enormous effort of scholarship, covering 107 different interventions that have been made to conserve amphibians around the world, and analyzing the result of 416 studies. Only studies in which the outcome of interventions has been assessed are included. Sadly, a great deal of conservation effort has been conducted over the years, the success of which, for lack of motivation or funding, has not been evaluated. A majority of studies come from Europe and North America and thus deal with temperate species. The book is divided into 14 sections, representing major areas of conservation activity. These include: agricultural landscapes, the use of biological resources (including amphibians themselves and the habitats in which they live), countering the impact of invasive species (including chytridiomycosis), pollution, and habitat creation and restoration. A large section deals with all aspects of relocating amphibians, rearing them in captivity and releasing them into the wild. A final section discusses education and awareness raising. The book contains a mass of detailed information, concisely presented and with virtually no discussion. The reader is left to reach his or her own conclusions on the basis of the evidence presented. It is by no means ‘easy reading’ but it is an invaluable resource for anyone contemplating doing something useful to help amphibians. In keeping with an evidence-based approach, the tone of this book is measured and scrupulously objective, and free of both the optimistic rhetoric or the doom-laden foreboding that pervades much of the conservation literature. The overall message is that conservation efforts work in some instances, but not in others. What works for one species does not necessarily work for another. The book is thus an invaluable resource for anyone designing a new conservation project and it should lead to better-designed and better-informed conservation efforts in the future. It should also lead to a better use of limited resources, both financial and human, by enabling project designers to focus on procedures the effectiveness of which has been demonstrated. Some of the results of the analyses presented in this book are surprising and thought provoking. For many years I participated in a ‘help a toad across the road’ exercise, going out at night to rescue migrating toads from a busy road before they were squashed. There are many such exercises in the UK, resulting in the apparent rescue of thousands of toads each year. The evidence suggests, however, that the impact of such activity on toad population sizes is rather modest. However, toad rescues are a low-cost activity that achieves the invaluable objectives of involving local people and raising awareness of conservation issues. In contrast, the translocation of Great Crested Newts (Triturus cristatus) in Britain incurs huge costs for developers, but yields low returns in terms of the successful long-term establishment of new populations. Sadly, amphibians across the world are threatened by a variety of factors that cannot be addressed by dedicated groups of people working at the local level. Much of the habitat deterioration and destruction that is causing amphibian declines is global in origin, resulting from pollution and climate change. Reversing the results of these processes lies not with local groups but with the world’s political and industrial leaders, who show no sign of deviating from their pursuit of the continuing economic growth that threatens our planet’s biodiversity. This excellent book reports many successful attempts to conserve amphibians at a local scale but, globally, the sixth mass extinction continues to gather pace. -- Dr Tim Halliday, Oxford UK * Phyllomedusa 13(2), December 2014, ISSN 1519-1397 (print) / ISSN 2316-9079 (online) * To properly evaluate this book, I focused this review on four (out of many) subjects of personal interest. The first takes me back to my childhood in suburban Brookfield, Illinois. The one and only amphibian inhabiting the world of my youth was the American toad, Anaxyrus (a. k. a. Bufo) americanus. I encountered toads in the nearby forest preserve, in neighborhood yards and gardens, as well as in the street as they fed on insects under the light of street lamps in the evening. In addi- tion, I often observed --- with anguish --- toads at the bottom of storm drains that were built into the roadbed adjacent to the curb. Because each storm drain was covered with an immov- able steel grate, I was unable to extract the entrapped toads. Over time, the toads succumbed to starvation and/or desiccation. Did the authors of Amphibian Conservation consider this threat to amphibians and, if so, did they find a solution? Indeed, they had. In the “ Threat: Transportation and service corridors” chapter, I found a subsection entitled, “ Modify gully pots and kerbs. ” In the United Kingdom, the terms “gully pot” and “kerb” are synonymous with our “storm drain” and “curb” respectively. Research in Europe found that separating storm drains from the curb by 4 inches decreased the number of great crested newts (Triturus cristatus) that fell in by 80%. Intrigued, I searched the internet and found the original article. Separation of the storm drain from the adjacent curb is achieved by replac- ing the standard section of curb with a section that has a recessed wall. Small animals following the curb wall diverge slightly into the recessed portion, thus avoiding the storm drain. This modified curb provides a simple solution to my vexing childhood dilemma of what to do about toads falling into storm drains. Perhaps urban/suburban readers of the Bulletin can lobby their respective community leaders to implement this solution in their neighborhoods. Interested readers are encouraged to visit www. aco. co. uk to learn more about these commercially-produced modified curbs. As field herpetologists know, many of our more interesting amphibians cannot successfully reproduce in water bodies harboring large, predatory fishes. These fishes (sunfishes, in particular) look upon frog and salamander larvae as delectable treats. Paradoxically, I have captured larvae of fish-intolerant amphibian species co-existing with predatory fishes. How is this possible? Invariably, these larvae take refuge in aquatic vegetation. Because a large number of people enjoy fishing, water bodies are commonly stocked with game fish. As a result, many otherwise suitable water bodies are off limits to amphibians that are palatable to fish. Perhaps it’s possible, however, to encourage the presence of aquatic vegetation in fish ponds so they can also provide amphibian habitat. Did the authors of Amphibian Conservation consider this potential intervention? Yes, in Chapter 8, “ Threat: Invasive alien and other problematic species. ” Here, I found a subsection entitled, “ Encourage aquatic plant growth as refuge against fish predation. ” Unexpectedly, the authors did not find any studies demonstrating the efficacy of such an intervention. This result was surprising as I know relevant literature exists. Two studies come to mind, one conducted in the laboratory (Baber and Babbitt, 2004) and the other in the field (Shulse et al. , 2012). Although both provide valuable support for providing aquatic vegetation as a means to protect amphibian larvae from fish predation --- evidence that could inform real-world solutions --- neither appeared to meet the criteria for inclusion in the book. The exclusion of these studies illustrates the necessity of looking beyond the literature captured by the Conservation Evidence Project (as encouraged by the authors). Worldwide, wetland losses have been enormous (Zedler and Kercher, 2005). Wetland loss is one of the greatest threats to amphibians because so many species rely on them for reproduction. How is this addressed in Amphibian Conservation? Chapter 12, “ Habitat restoration and creation” provides numerous examples of interventions that have been implemented to miti- gate the loss of amphibian habitat, including the creation of ponds and wetlands. I was heartened to see the substantial collection of literature pertaining to this subject. Humans are very adept at tinkering with their surroundings, whether it be for human benefit (e. g. , draining a marsh to increase agricultural acreage) or the benefit of wildlife (e. g. , creating a wetland). The popularity and proven benefits of habitat restoration and creation is evidenced by the length of this chapter which, at 54 pages, is the longest in the book. The authors did an excellent job of providing readers with a treasure trove of information on the subject. More than any other chapter, this one gives the reader the greatest feeling of hope. The literature shows that when provided with a new home, amphibians will move in. Amphibian Conservation is a welcome antidote to the proliferation of depressing reports of amphibian declines. The book is packed with literature summaries and citations; a veritable information goldmine for graduate students and researchers. It also admirably provides decision makers with a well-researched resource of proven interventions that can be employed to stem/reverse the decline of amphibian populations. The free, downloadable pdf version and other relatively inexpensive formats that are available (eBook, for example) generously provide individuals who lack deep pockets access to this significant source of information. Interventions described in the book are available at the Conservation Evidence Project website (www. conservationevidence.com) where one can also peruse the open-access journal Conservation Evidence. My only caution for the reader is to take seriously the authors’ advice and perform supplementary reviews of the literature for their particular topic or species of interest. To do otherwise risks missing pertinent and important information not captured in Amphibian Conservation. -- John G. Palis * Bulletin of the Chicago Herpetological Society *