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Abstract Madagascar's lemurs are threatened by forest loss, fragmentation, and degradation. Many species use flexible behaviors to survive in degraded habitat, but their ability to persist in very small areas may be limited. Insular lemurs, like those found on Nosy Be, an island off the northwestern coast of Madagascar, are at heightened risk of sudden population declines and extirpation. Nosy Be is home to two Critically Endangered species—the endemic Nosy Be sportive lemur (Lepilemur tymerlachsoni) and Claire's mouse lemur (Microcebus mamiratra)—as well as the Endangered black lemur (Eulemur macaco). Most of the remaining forest on Nosy Be is protected by the 862‐ha Lokobe National Park. To document how Nosy Be lemurs use their restricted habitat, we conducted vegetation and reconnaissance surveys on 53 transects in and around Lokobe. We collected data on tree size, canopy cover, understory visibility, and elevation for 248 lemur sightings. We used a spatially explicit, multi‐species occupancy model to investigate which forest‐structure variables are important to lemurs. Our results represent some of the first data on habitat use by insular lemurs. Black lemurs preferred significantly larger trees and areas with less dense understory. They also occurred significantly less outside of Lokobe National Park, even when accounting for sampling effort and geography. The distributions of the sportive and mouse lemurs were not related to the forest structure variables we documented, but they did negatively predict each other—perhaps because their habitat requirements differ. These results also underscore the importance of the national park to protecting the black lemur population on Nosy Be and raise questions about what factors do influence the distribution of Nosy Be's smaller lemurs. Close monitoring is needed to prevent these populations and the ecosystem services they provide from disappearing, as have other island lemurs.
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A surprising haven: The biodiversity of an old‐growth forest amidst a scorched landscape in Madagascar
Abstract For the endemic wildlife of Madagascar, the risk of extinction increases as the island's forest cover decreases. Many of the remaining forests are isolated fragments serving as important refugia for biodiversity. In this research note, we describe the biodiversity of the Ivohiboro Humid Forest (IHF), and its conservation importance in Madagascar. Located in a region dominated by wooded savannah, the IHF represents a very rare vegetation type. We conducted six biological surveys to explore the diversity of vertebrates and vascular plants in this isolated forest. Our results show that the IHF maintains a diverse ecosystem and harbors species of conservation significance. Thirty‐four of the identified species are categorized as Threatened by the IUCN, such as the ring‐tailed lemur (Lemur catta) and Isalo Madagascar frog (Gephyromantis corvus). Furthermore, we inventoried species distant from their known IUCN‐reported geographic ranges such as a species of blue‐nosed chameleon (Calummasp. aff. boettgeri,linotum) and the Lavasoa dwarf lemur (Cheirogaleus lavasoensis).
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- Award ID(s):
- 2314898
- PAR ID:
- 10431941
- Publisher / Repository:
- Wiley-Blackwell
- Date Published:
- Journal Name:
- Conservation Science and Practice
- Volume:
- 5
- Issue:
- 9
- ISSN:
- 2578-4854
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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