Abstract

Amphibian Conservation is the fourth in the series of Synopses of Conservation Evidence, linked to the online resource www.ConservationEvidence.com.

This synopsis is part of the Conservation Evidence project and provides a useful resource for conservationists. It forms part of a series designed to promote a more evidence-based approach to biodiversity conservation. Others in the series include bee, bird, farmland and bat conservation and many others are in preparation.

Approximately 32% of the 7,164+ amphibian species are currently threatened with extinction and at least 43% of species are declining. Despite this, until recently amphibians and their conservation had received little attention. Although work is now being carried out to conserve many species, often it is not adequately documented.

This book brings together and summarises the available scientific evidence and experience relevant to the practical conservation of amphibians.

The authors consulted an international group of amphibian experts and conservationists to produce a thorough summary of what is known, or not known, about the effectiveness of amphibian conservation actions across the world.

"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." -John G Palis, Bulletin of the Chicago Herpetological Society

Dr Rebecca K. Smith is a Research Associate at the University of Cambridge.  She holds degrees in the ecology & conservation of European hares (PhD, University of Bristol), Applied Ecology & Conservation (MSc, University of East Anglia) and Biology (BSc with Honours, University of Bristol). Dr Smith is part of the Conservation Evidence group at the University of Cambridge, which focuses on summarising and disseminating scientific evidence about the effects of conservation interventions for habitats and species. She is an author of the Farmland Conservation synopsis and has undertaken systematic reviews on the effectiveness of conservation management for birds. Prior to this work Dr Smith undertook projects developing monitoring and management strategies for high conservation priority mammal species. Her current scientific duties include facilitating the development of further synopses including bat, reptile and forest conservation and invasive species management. She is also the Editorial Administrator of the Conservation Evidence Journal.

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.