The state of nature in Madagascar

Abstract

The new natural history of Madagascar (Vols. 1 and 2). Goodman, S.M. (Ed.). Princeton University Press, Princeton, NJ. 2246 pp. £146.00 (hardback). ISBN 9780691222622.

The sloth lemur's song. Richard, A. The University of Chicago Press, Chicago, IL. 352 pp. $16.00 (paperback). ISBN 9780226829494.

These books offer remarkable insights into the rich biodiversity of this extraordinary mini-continent, unravel the complexity of the evolutionary history of the island and region, and bring sharp focus to conservation challenges. Although conveying similar messages, the works could not be more contrasting. Goodman's The Natural History of Madagascar is a magnum opus that updates the state of knowledge of Madagascar's wildlife, and Richard's The Sloth Lemur's Song combines current understanding with a personal account of her time on the island.

Richard draws on a lifetime's research and her engagement with the country's culture through time spent with Malagasy people and provides a full perspective on past and current conservation problems. The story weaves together the science and the socioeconomic context that will need to be part of any future conservation efforts. The result is a superb mix of scientific analysis and a narrative about the Malagasy people that yields an accessible read for all, from students seeking an introduction to the topics to curious visitors to Madagascar.

Richard sets the scene for the present-day conservation problems by exploring the multilayered past of the island, from major geological events to the relatively recent arrival of humans, rightly persuading the reader to avoid drawing simple conclusions. This is most evident in her examination of the age of Madagascar's grasslands. The idea that the island's grasslands were anthropogenic in origin (hence just a few thousand years old) (e.g., Humbert, 1927; Perrier de la Bathie, 1921) has been negated through research indicating an evolutionary history of millions of years (Bond et al., 2008; Vorontsova et al., 2016). Climate shifts, natural fires, and an ancient grazing community most likely shaped the grasslands, and Richard highlights the intriguing role that now extinct giant tortoises and flightless birds may have played in forming Madagascar's vegetation communities. Richard uses evidence from wild giant tortoises on Aldabra that shows how the mix of trees, scrub, and grasses can be maintained by the grazing of these animals.

Complex interactions between climate and humans underpin Richard's story of the recent history of Madagascar, where, previously, megafaunal extinctions were attributed solely to the arrival of humans approximately 10,000 years ago, followed by more widespread colonization 2500 years BP. The idea, largely formulated in colonial times, that the current vegetation landscape and animal community of the island are a result of untrammeled human activity is laid to rest, although a complete understanding of the loss of megafauna is still lacking.

Richard emphasizes that poverty drives rural farmers to continue to clear land (tavy [slash and burn or swidden agriculture]) for subsistence but illustrates the greater impact of postcolonial initiatives and policies that have exacerbated habitat loss. Well-meaning conservation efforts, national and international, have produced mixed results, often through shortcomings in strengthening community-led management and profound differences between stakeholders in the meaning and values attributed to land.

Rays of hope are evident. Over 100 protected areas now exist, and burgeoning numbers of Malagasy biologists contribute research and conservation efforts, especially through the action of in-country nongovernmental organizations and community-based work. If, as Richard asserts, this can be supported by stable competent government, environmentally sensitive economic development, and strengthened land rights, the future of conservation in Madagascar can be positive. Goodman's book provides important context for conservation planning through documentation of the current situation of the science.

The New Natural History of Madagascar is an exceptional contribution to the literature. The sheer scale of the work and its breadth and depth of information make this a valuable addition for academics and would-be researchers, as well as for anyone with an interest in evolution, natural history, or Madagascar. Both volumes are superbly illustrated throughout with excellent photographs. A minor criticism is that some of the maps and figures appear cluttered, which makes deciphering the information challenging.

Building on the earlier Natural History of Madagascar (Goodman & Benstead, 2003), a notable aspect of this book is the impressive number of discoveries of new species on the island across virtually all taxa in such a relatively short time. First-time readers of this work will notice gaps in certain plant and animal groups. These are explained, following contact with the original authors, by a lack of advances in knowledge of these groups since the 2003 version. Because such a broad range of organisms occur on Madagascar, decisions on what to include in these new volumes will have been difficult. Goodman acknowledges some well-known groups are omitted. Notably, species-rich invertebrate taxa, such as centipedes (Chilopoda), carabid beetles (Coleoptera), and bees and wasps (Hymenoptera), are, among others, absent.

An introductory section details the biogeophysical aspects of the evolutionary history of the island that give context to the succeeding taxonomic inventory of the current state of knowledge of the flora and fauna. Improved understanding since the original book casts new light on the past as more biogeographical and phylogenetic research has accrued. The facets of the geological history and long isolation of Madagascar in producing spectacular levels of endemism are complemented here by further nuance. The theme of microendemism is more evident in this new work. Narrow temporal and spatial aspects of environmental change, especially climate, illustrate more complexity in the evolution of floral and faunal communities on this continental island than previously appreciated. A new section is presented on zoonotic disease, supplementing the updated chapters on human ecology.

Two themes emerge in the individual chapters that follow on plant and animal taxa, prefaced with contributions on selected research, conservation, and ecological topics. First, in 2 decades since Goodman and Benstead (2003), despite discovery of multiple new species (with many yet to be named), gaps in knowledge persist and are highlighted in each chapter. Second, conservation threats have not receded. Many chapters conclude with details on the taxa under consideration, including International Union for Conservation of Nature Red List status, with a separate chapter that explores a red list for ecosystems. Significantly, many species are categorized as data deficient, known examples of extinctions (mainly local) have occurred, and some species are known only from original collection or description. The extent of the coverage of the discrete taxa differs considerably; nevertheless, all the contributions represent the latest research from practicing scientists in their areas of knowledge.

Concluding sections for most taxa detail the threats to biodiversity that are already well documented globally, with some very specific to certain plants and animals, or localities, in Madagascar. A recurring reference to recent work on loss of forest cover (Vieilledent et al., 2018) shows an acceleration of deforestation. Nearly half of all forest in Madagascar is <100 m from an edge or clearing, and loss of forest habitat negatively affects most taxa. Unsurprisingly, habitat degradation, overexploitation (hunting and for the pet trade), and the impact of invasive species also figure in most of these chapter summaries. Freshwater fish have suffered disproportionately from introduced fish; 60% of all native fish are considered threatened. Some elements of Malagasy herpetofauna (e.g., chameleons, tortoises, frogs) are more affected by collection for the pet trade; mammals and birds are hunted for food; and certain hardwoods are prized by illegal loggers.

The final section on conservation combines the arrangement of protected areas, new technologies contributing to conservation and law enforcement, and the looming possibility of ecosystem collapse, together with an assessment of forest conservation. The latter contribution emphasizes the key components for successful conservation in Madagascar; critically, a one-size-fits-all approach does not exist. Rather, a blend of maintaining necessary funding, input from populations living adjacent to protected areas and forests, and backing from all tiers of the Malagasy community will be necessary to achieve positive conservation outcomes. Actions to address loss of biodiversity while ameliorating the effects of development on the Malagasy people are already understood but not yet implemented (Jones et al., 2019).

One of the most welcome aspects of The New Natural History of Madagascar is the upsurge of input from Malagasy biologists. Over 500 contributors are included, representing nearly 30% of all authors and considerably above the comparative figures from Goodman and Benstead (2003) (60 Malagasy contributors [21%]). The earlier predominance of research and publication by international scientists is now changing. It was not until 1972 that a Malagasy entomologist published a scientific paper, and 2 years later, this was followed by the first taxonomic study by a Malagasy.

Capacity building in Madagascar has undoubtedly played an important role in producing the increasingly influential cohort of Malagasy scientists, coupled with a rise in home-grown PhD students. Since the 1980s, international collaboration and support have been important in engaging Malagasy scientists and students through training programs, research, and cooperative projects. Recent initiatives, such as the Bibikely Biodiversity Centre for parataxonomic training in invertebrates, highlight a promising conservation development.

Despite encouraging signs, a sense of gloom can be detected in these works. The books make clear the imminent threat to the hyperdiverse biodiversity of Madagascar and highlight issues of poverty, land, and law that may point to a last chance for nature (Jones et al., 2019). For a biologist traveling across the island, aside from the sense of wonderment at the scenery and wildlife, it is easy to feel sad about the landscape, where can one see an abundance of non-native, sometimes invasive, plants; the effects of tavy in the central highlands; and ongoing large-scale deforestation of the dry deciduous ecosystem north of Morondava. This feeling overlooks people's needs, which is distilled in a single sentence by Elie Rajaonarison, a late coworker of Richard: “…if the choice is between providing food for your family today and saving the forest for the future, there really is no choice.” Improved understanding of people and place is inextricably linked to solving socioeconomic and conservation problems of this remarkable land, and success is far from guaranteed.

Around the time Alison Richard began her research career, environmentalists rallied behind the Joni Mitchell song “Big Yellow Taxi” that included the refrain “…you don't know what you've got ‘til it's gone.” The big yellow books that are The New Natural History of Madagascar and The Sloth Lemur's Song provide evidence that biodiversity continues to be lost almost as quickly as new discoveries are made. These books offer stark reminders that, respectively, there is still much to learn about the incredible biodiversity in Madagascar and that the interaction of the Malagasy people with their environment must be at the forefront of conservation if what remains can be successfully protected.