BACKGROUND The Republic of Madagascar is home to a unique assemblage of taxa and a diverse set of ecosystems. These high levels of diversity have arisen over millions of years through complex processes of speciation and extinction. Understanding this extraordinary diversity is crucial for highlighting its global importance and guiding urgent conservation efforts. However, despite the detailed knowledge that exists on some taxonomic groups, there are large knowledge gaps that remain to be filled. ADVANCES Our comprehensive analysis of major taxonomic groups in Madagascar summarizes information on the origin and evolution of terrestrial and freshwater biota, current species richness and endemism, and the utilization of this biodiversity by humans. The depth and breadth of Madagascar’s biodiversity—the product of millions of years of evolution in relative isolation —is still being uncovered. We report a recent acceleration in the scientific description of species but many remain relatively unknown, particularly fungi and most invertebrates. DIGITIZATION Digitization efforts are already increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge in Madagascar. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. Among the new data presented, our update on plant numbers estimates 11,516 described vascular plant species native to Madagascar, of which 82% are endemic, in addition to 1215 bryophyte species, of which 28% are endemic. Humid forests are highlighted as centers of diversity because of their role as refugia and centers of recent and rapid radiations, but the distinct endemism of other areas such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest is also important despite lower species richness. Endemism in Malagasy fungi remains poorly known given the lack of data on the total diversity and global distribution of species. However, our analysis has shown that ~75% of the fungal species detected by environmental sequencing have not been reported as occurring outside of Madagascar. Among the 1314 species of native terrestrial and freshwater vertebrates, levels of endemism are extremely high (90% overall)—all native nonflying terrestrial mammals and native amphibians are found nowhere else on Earth; further, 56% of the island’s birds, 81% of freshwater fishes, 95% of mammals, and 98% of reptile species are endemic. Little is known about endemism in insects, but data from the few well-studied groups on the island suggest that it is similarly high. The uses of Malagasy species are many, with much potential for the uncovering of useful traits for food, medicine, and climate mitigation. OUTLOOK Considerable work remains to be done to fully characterize Madagascar’s biodiversity and evolutionary history. The multitudes of known and potential uses of Malagasy species reported here, in conjunction with the inherent value of this unique and biodiverse region, reinforce the importance of conserving this unique biota in the face of major threats such as habitat loss and overexploitation. The gathering and analysis of data on Madagascar’s remarkable biota must continue and accelerate if we are to safeguard this unique and highly threatened subset of Earth’s biodiversity. Emergence and composition of Madagascar’s extraordinary biodiversity. Madagascar’s biota is the result of over 160 million years of evolution, mostly in geographic isolation, combined with sporadic long distance immigration events and local extinctions. (Left) We show the age of the oldest endemic Malagasy clade for major groups (from bottom to top): arthropods, bony fishes, reptiles, flatworms, birds, amphibians, flowering plants, mammals, non-flowering vascular plants, and mollusks). Humans arrived recently, some 10,000 to 2000 years (top right) and have directly or indirectly caused multiple extinctions (including hippopotamus, elephant birds, giant tortoises, and giant lemurs) and introduced many new species (such as dogs, zebu, rats, African bushpigs, goats, sheep, rice). Endemism is extremely high and unevenly distributed across the island (the heat map depicts Malagasy palm diversity, a group characteristic of the diverse humid forest). Human use of biodiversity is widespread, including 1916 plant species with reported uses. The scientific description of Malagasy biodiversity has accelerated greatly in recent years (bottom right), yet the diversity and evolution of many groups remain practically unknown, and many discoveries await.
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Amphibian and reptile diversity along a ridge-to-reef elevational gradient on a small isolated oceanic island of the central Philippines
Despite multiple recent field studies, herpetological species diversity of the Romblon Island Group in the central Philippines—particularly Sibuyan Island—has remained underestimated. Recently, we investigated the diversity of the herpetofauna of Mount Guiting-Guiting Natural Park, based on an elevational transect (10–1557 m a.s.l.). Our surveys resulted in a total of 47 species of amphibians and reptiles, including 14 new island records and one atypical occurrence of a snake species recorded for the first time from a high elevation (939 m a.s.l). These new records constitute a notable increase (21%) in Sibuyan’s herpetological species diversity as compared to surveys from a decade ago. We also provide updates of the taxonomy and identification of species endemic to this island (e.g., members of the genera Platymantis Günther, 1858, Brachymeles Duméril & Gibron, 1839, and Pseudogekko Taylor, 1922), and discuss the importance of continued surveys and field-derived data to inform conservation status assessments of Sibuyan’s unique assemblage of amphibians and reptiles.
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- Award ID(s):
- 1654388
- NSF-PAR ID:
- 10427879
- Date Published:
- Journal Name:
- Check List
- Volume:
- 18
- Issue:
- 5
- ISSN:
- 1809-127X
- Page Range / eLocation ID:
- 941 to 948
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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ABSTRACT Biodiversity monitoring is important for species and habitat management, although it can be costly in terms of personnel time and expertise. Citizen Science projects that engage community participants to collect species distribution data can provide high volumes of data at little cost, but data are often associated with unknown observer error. Projects that remove decision‐making (e.g., species identification) allow for higher participation because expertise requirements are eliminated. We piloted a project using Citizen Science principles to solve logistical challenges for a synoptic amphibian survey across an island array in the United States Virgin Islands by inviting the community to collect recordings of frogs using cell phones. We received >270 recordings and location data from community participants during a 2‐week survey window; these were processed manually, using bioacoustics analysis software for species identification and location. Species detections were comparable to previous methods of survey although new distribution records were substantially increased. Utilizing Citizen Scientists to conduct recorded surveys of amphibians using cell phones offers a low‐cost method for expanding survey effort for predictably‐vocalizing species. © 2020 The Wildlife Society.
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BACKGROUND Madagascar is one of the world’s foremost biodiversity hotspots. Its unique assemblage of plants, animals, and fungi—the majority of which evolved on the island and occur nowhere else—is both diverse and threatened. After human arrival, the island’s entire megafauna became extinct, and large portions of the current flora and fauna may be on track for a similar fate. Conditions for the long-term survival of many Malagasy species are not currently met because of multiple anthropogenic threats. ADVANCES We review the extinction risk and threats to biodiversity in Madagascar, using available international assessment data as well as a machine learning analysis to predict the extinction risks and threats to plant species lacking assessments. Our compilation of global International Union for Conservation of Nature (IUCN) Red List assessments shows that overexploitation alongside unsustainable agricultural practices affect 62.1 and 56.8% of vertebrate species, respectively, and each affects nearly 90% of all plant species. Other threats have a relatively minor effect today but are expected to increase in coming decades. Because only one-third (4652) of all Malagasy plant species have been formally assessed, we carried out a neural network analysis to predict the putative status and threats for 5887 unassessed species and to evaluate biases in current assessments. The percentage of plant species currently assessed as under threat is probably representative of actual numbers, except in the case of the ferns and lycophytes, where significantly more species are estimated to be threatened. We find that Madagascar is home to a disproportionately high number of Evolutionarily Distinct and Globally Endangered (EDGE) species. This further highlights the urgency for evidence-based and effective in situ and ex situ conservation. Despite these alarming statistics and trends, we find that 10.4% of Madagascar’s land area is protected and that the network of protected areas (PAs) covers at least part of the range of 97.1% of terrestrial and freshwater vertebrates with known distributions (amphibians, freshwater fishes, reptiles, birds, and mammal species combined) and 67.7% of plant species (for threatened species, the percentages are 97.7% for vertebrates and 79.6% for plants). Complementary to this, ex situ collections hold 18% of vertebrate species and 23% of plant species. Nonetheless, there are still many threatened species that do not occur within PAs and are absent from ex situ collections, including one amphibian, three mammals, and seven reptiles, as well as 559 plants and more yet to be assessed. Based on our updated vegetation map, we find that the current PA network provides good coverage of the major habitats, particularly mangroves, spiny forest, humid forest, and tapia, but subhumid forest and grassland-woodland mosaic have very low areas under protection (5.7 and 1.8% respectively). OUTLOOK Madagascar is among the world’s poorest countries, and its biodiversity is a key resource for the sustainable future and well-being of its citizens. Current threats to Madagascar’s biodiversity are deeply rooted in historical and present social contexts, including widespread inequalities. We therefore propose five opportunities for action to further conservation in a just and equitable way. First, investment in conservation and restoration must be based on evidence and effectiveness and be tailored to meet future challenges through inclusive solutions. Second, expanded biodiversity monitoring, including increased dataset production and availability, is key. Third, improving the effectiveness of existing PAs—for example through community engagement, training, and income opportunities—is more important than creating new ones. Fourth, conservation and restoration should not focus solely on the PA network but should also include the surrounding landscapes and communities. And finally, conservation actions must address the root causes of biodiversity loss, including poverty and food insecurity. In the eyes of much of the world, Madagascar’s biodiversity is a unique global asset that needs saving; in the daily lives of many of the Malagasy people, it is a rapidly diminishing source of the most basic needs for subsistence. Protecting Madagascar’s biodiversity while promoting social development for its people is a matter of the utmost urgency Visual representation of five key opportunities for conserving and restoring Madagascar’s rapidly declining biodiversity identified in this Review. The dashed lines point to representative vegetation types where these recommendations could have tangible effects, but the opportunities are applicable across Madagascar. ILLUSTRATION: INESSA VOETmore » « less
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Studies of the Caribbean herpetofauna (amphibians and reptiles) have made significant contributions to our knowledge of evolutionary patterns and processes. A prerequisite for these studies are accurate taxonomies and robust phylogenetic hypotheses. One notable Caribbean radiation lacking such data are dwarf geckos of the genus Sphaerodactylus. Systematics of the Puerto Rican Sphaerodactylus have been turbulent since the initial species descriptions and no molecular phylogenies exist that include complete or near-complete taxon sampling. Here, we combine a multi-locus molecular phylogeny with extensive morphological information to investigate the current diversity of Sphaerodactylus geckos from the Puerto Rican Bank, with a large number of species from Hispaniola as an outgroup. In particular, we focus our efforts on resolving the taxonomy of the Sphaerodactylus macrolepis Günther species complex. We find S. macrolepis sensu lato (currently two nominal species with nine subspecies) is made up of at least four diagnosable species within two clades: (1) the sister species Sphaerodactylus macrolepis sensu stricto from the Virgin Islands (including St. Croix) and Culebra, and S. parvus King from islands in the northern Lesser Antilles; and (2) all other Sphaerodactylus macrolepis subspecies from Puerto Rico, Vieques, and Culebra. We resurrect Sphaerodactylus grandisquamis Stejneger from synonymy to refer to all subspecies from Puerto Rico and elevate the subspecies Sphaerodactylus inigoi Thomas & Schwartz for geckos from Vieques and western Culebra. The resulting phylogeny and revised taxonomy will be a useful tool for subsequent research into Sphaerodactylus conservation and evolution.more » « less
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One of the possible consequences of biological invasions is the decrease of native species abundances or their replacement by non-native species. In Andean Patagonia, southern Argentina and Chile, many non-native animals have been introduced and are currently spreading. On Isla Victoria, Nahuel Huapi National Park, many non-native vertebrates were introduced ca. 1937. Records indicate that several native vertebrates were present before these species were introduced. We hypothesize that seven decades after the introduction of non-native species and without appropriate management to maintain native diversity, non-native vertebrates have displaced native species (given the known invasiveness and impacts of some of the introduced species). We conducted direct censuses in linear transects 500 m long (
n = 10) in parallel with camera-trapping (1,253 camera-days) surveys in two regions of the island with different levels of disturbance: high (n = 4) and low (n = 6) to study the community of terrestrial mammals and birds and the relative abundances of native and non-native species. Results show that currently non-native species are dominant across all environments; 60.4% of census records and 99.7% of camera trapping records are of non-native animals. We detected no native large mammals; the assemblage of large vertebrates consisted of five non-native mammals and one non-native bird. Native species detected were one small mammal and one small bird. Species with the highest trapping rate were red and fallow deer, wild boar, silver pheasant (all four species are non-native) and chucao (a native bird). These results suggest that native species are being displaced by non-natives and are currently in very low numbers.
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.15560/18.5.941
