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Hending D, Randrianarison H, Andriamavosoloarisoa NNM, Ranohatra-Hending C, Cotton S, Holderied M, McCabe G. Effects of forest fragmentation on the dietary ecology and activity of a nocturnal lemur community in North West Madagascar. Am J Primatol 2024; 86:e23569. [PMID: 37899689 DOI: 10.1002/ajp.23569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 08/16/2023] [Accepted: 10/16/2023] [Indexed: 10/31/2023]
Abstract
Deforestation and habitat fragmentation is the primary threat to primate populations. The primates that live within degraded and anthropogenically disturbed habitats typical of fragmented landscapes have to cope with lower availability of resources in comparison to primates in continuous, undisturbed forests. While some species are sensitive to forest fragmentation, some evidence exists to suggest that primates can alter their behavior and adapt to such changes, which enables their survival in suboptimal habitat. In this study, we assessed how forest fragmentation and its associated edge-effects impact the feeding ecology and activity levels of a nocturnal primate community in the Sahamalaza-Iles Radama National Park, North West Madagascar. From March 06, 2019 to May 17, 2022, we collected data on tree and invertebrate phenology at our study site, and feeding ecology and activity for 159 lemur individuals from four species. Fruit and flower availability varied significantly between continuous and fragmented forest, and between forest core and edge areas, with continuous forest exhibiting higher continuous fruit and flower availability. Lemur feeding ecology varied significantly too, as the feeding niches of all four species were significantly different between continuous and fragmented forest and between core and edge areas. However, lemur activity levels were mostly consistent among all forest areas. The results of this study suggest that nocturnal lemurs are able to adapt their dietary ecology in response to the available food sources within their habitat. Due to this flexible ecology and dietary plasticity, the lemurs do not need to significantly alter their behavior in different environments to fulfill their dietary needs. While nocturnal lemurs demonstrate adaptability and flexibility to degraded habitat, it is unclear how far this plasticity will stretch considering that Madagascar's forests are still being cleared at an alarming rate. Urgent conservation action is therefore needed to ensure the future of lemur habitat.
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Affiliation(s)
- Daniel Hending
- Department of Biology, University of Oxford, Oxford, UK
- School of Biological Sciences, University of Bristol, Bristol, UK
- Institute of Conservation Science & Learning, Bristol Zoological Society Ltd, Bristol, UK
| | | | | | - Christina Ranohatra-Hending
- School of Biological Sciences, University of Bristol, Bristol, UK
- Institute of Conservation Science & Learning, Bristol Zoological Society Ltd, Bristol, UK
| | - Sam Cotton
- Institute of Conservation Science & Learning, Bristol Zoological Society Ltd, Bristol, UK
| | - Marc Holderied
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Grainne McCabe
- Institute of Conservation Science & Learning, Bristol Zoological Society Ltd, Bristol, UK
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Schüßler D, Rabemananjara NR, Radriarimanga T, Rafamantanantsoa SM, Randimbiharinirina RD, Radespiel U, Hending D. Habitat and ecological niche characteristics of the elusive Hairy-eared Dwarf Lemur (Allocebus trichotis) with updated occurrence and geographic range data. Am J Primatol 2023; 85:e23473. [PMID: 36739112 DOI: 10.1002/ajp.23473] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/18/2023] [Accepted: 01/21/2023] [Indexed: 02/06/2023]
Abstract
Ecological niche modeling (ENM) is particularly useful in the study of cryptic and elusive species that are only rarely seen, difficult to study in the wild, and simultaneously threatened by a multitude of anthropogenic factors. We collected presence records one such example, the understudied Hairy-eared Dwarf Lemur (Allocebus trichotis), from the literature and supplemented these with observations from surveys in previously unstudied areas to model its fundamental and realized niche throughout Madagascar. We further evaluated habitat characteristics at each sighting location to judge its conservation status and its adaptability toward habitat degradation. We found 31 presence localities in the literature and directly observed A. trichotis a further 23 times. According to the ENMs, precipitation of the driest quarter and maximum temperature of the warmest month mostly influenced its distribution, restricting it to the higher altitudes of the northeastern humid forests of Madagascar. Its fundamental niche, extent of occurrence, and area of occupancy were estimated as 65,819, 53,054, and 16,967 km² respectively. The latter, however, declined by 29.2% since 1990. On a habitat level, it was most often observed in primary forest habitats of different degradation stages (85.7%, n = 21). The fundamental niche of A. trichotis is most likely restricted by climatic factors. Although it can be found in moderately degraded forests, it is known to depend on the availability of tree holes and therefore old-growth forest structures. Ongoing deforestation and habitat fragmentation are likely to be the major threats to the survival of this species. Our ENMs provide evidence on where to intensify survey efforts on the elusive Hairy-eared Dwarf Lemurs of Madagascar.
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Affiliation(s)
- Dominik Schüßler
- Institute of Biology and Chemistry, University of Hildesheim, Hildesheim, Germany
| | - Naina R Rabemananjara
- Mention Anthropobiologie et Développement Durable (MADD), University of Antananarivo, Antananarivo, Madagascar
- Groupe d'Edute et de Recherche sur les Primates de Madagascar (GERP), Antananarivo, Madagascar
| | - Tahiriniaina Radriarimanga
- Mention Anthropobiologie et Développement Durable (MADD), University of Antananarivo, Antananarivo, Madagascar
- Groupe d'Edute et de Recherche sur les Primates de Madagascar (GERP), Antananarivo, Madagascar
| | - Stephan M Rafamantanantsoa
- Mention Anthropobiologie et Développement Durable (MADD), University of Antananarivo, Antananarivo, Madagascar
| | | | - Ute Radespiel
- Institute of Zoology, University of Veterinary Medicine Hannover Foundation, Hannover, Germany
| | - Daniel Hending
- Department of Biology, University of Oxford, John Krebs Field Station, Oxford, Wytham, UK
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Hending D, Randrianarison H, Andriamavosoloarisoa NNM, Ranohatra-Hending C, Solofondranohatra JS, Tongasoa HR, Ranarison HT, Gehrke V, Andrianirina N, Holderied M, McCabe G, Cotton S. Seasonal Differences in the Encounter Rate of the Fat-Tailed Dwarf Lemur (Cheirogaleus medius) in the Transitional Forests of Northwest Madagascar: Implications for Reliable Population Density Assessment. INT J PRIMATOL 2023. [DOI: 10.1007/s10764-023-00353-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Abstract
Primate encounter rates often vary throughout the year due to seasonal differences in activity, ecology, and behaviour. One notably extreme behaviour is continuous hibernation. Although a rare adaptation in primates, the dwarf lemurs of Madagascar (genus Cheirogaleus) enter obligate hibernation each year during the dry season, after spending the wet season consuming high-energy foods. Whilst seasonal changes in activity in some Cheirogaleus populations are well-known, many species remain little-studied, and there is no specific information on their encounter rates, nor when they enter and emerge from hibernation. This uncertainty critically affects reliable calculation of population density estimates for these highly threatened lemurs. In this study, we assessed how encounter rates of the fat-tailed dwarf lemur (C. medius) vary seasonally in the transitional forests of the Sahamalaza-Iles Radama National Park, northwest Madagascar, during a 4-year period. We established a system of line transects (N = 60) throughout our study area, on which we conducted distance sampling of C. medius. We then used our distance sampling data to calculate encounter rate and population density data. We found encounter rates of C. medius to be significantly higher during the wet season compared with the dry season. Furthermore, encounter rates of C. medius were particularly low from May–August. These results provide some evidence to suggest the time period that C. medius hibernate in Sahamalaza-Iles Radama National Park. These findings underpin the importance of careful study design when surveying threatened species with seasonal differences in activity, such as those that hibernate. This study also demonstrates the importance of species-specific behavioural data for accurate population density assessment, which is required to inform conservation action.
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Hending D, Andrianiaina A, Rose M, Rowlands A, Storm S, Holderied MW, Cotton S. Vanilla Bats: Insectivorous Bat Diversity in the Vanilla Agroecosystems of Northeastern Madagascar. ACTA CHIROPTEROLOGICA 2023. [DOI: 10.3161/15081109acc2022.24.2.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Daniel Hending
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol BS8 3HA, United Kingdom
| | - Angelo Andrianiaina
- Mention: Zoologie et Biodiversité Animale, Université d'Antananarivo, BP 906 Antananarivo 101, Madagascar
| | - Miranda Rose
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol BS8 3HA, United Kingdom
| | - Adèle Rowlands
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol BS8 3HA, United Kingdom
| | - Savannah Storm
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol BS8 3HA, United Kingdom
| | - Marc W. Holderied
- School of Biological Sciences, University of Bristol, Bristol BS8 1TQ, United Kingdom
| | - Sam Cotton
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol BS8 3HA, United Kingdom
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Conservation value of vanilla agroecosystems for vertebrate diversity in north-east Madagascar. ORYX 2022. [DOI: 10.1017/s0030605321001265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Abstract
As a result of increasing global demand for food, large areas of natural habitat are being converted to agroecosystems to accommodate crop cultivation. This agricultural expansion is most prominent in the tropics, where many rural communities are dependent solely on farming income for their livelihoods. Such agricultural land conversion can have severe implications for local fauna. In this study, we compared vertebrate species diversity between natural forest habitat and three types of vanilla plantations maintained under varying management regimes in north-east Madagascar. We used diurnal and nocturnal transects to survey vertebrate diversity. Natural forest habitat contained the greatest vertebrate species diversity, and had proportionally more threatened and endemic species than all vanilla plantation types. However, we observed a greater number of species and a higher inverse Simpson index in minimally managed vanilla plantations located within or near natural forest compared to intensively managed vanilla plantations. These findings are important and encouraging for animal conservation and sustainable crop cultivation in Madagascar, and suggest that newly created vanilla plantations, and already existing plantations, should endeavour to follow the more traditional, minimalistic management approach to improve sustainability and promote higher faunal diversity.
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Hending D. Environmental drivers of Cheirogaleidae population density: Remarkable resilience of Madagascar's smallest lemurs to habitat degradation. Ecol Evol 2021; 11:5874-5891. [PMID: 34141190 PMCID: PMC8207435 DOI: 10.1002/ece3.7449] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/15/2021] [Accepted: 02/20/2021] [Indexed: 11/09/2022] Open
Abstract
AIM Global animal populations are in decline due to destruction and degradation of their natural habitat. Understanding the factors that determine the distribution and density of threatened animal populations is therefore now a crucial component of their study and conservation. The Cheirogaleidae are a diverse family of small-bodied, nocturnal lemurs that are widespread throughout the forests of Madagascar. However, many cheirogaleid lemurs are now highly threatened with extinction and the environmental factors that determine their distribution and population density are still little known. Here, I investigated the environmental drivers of Cheirogaleidae population density at genus level. LOCATION Various forest sites across Madagascar. METHODS I investigated how six environmental variables affect Cheirogaleidae population density at the genus level via random-effect meta-analyses. I then used a generalized linear mixed-effects model to identify the primary predictors of Cheirogaleidae population density. Finally, I investigated how the population density of this family of lemurs varies between protected and unprotected areas of Madagascar via a GLM analysis. RESULTS My results indicate that the relationships between the tested environmental factors and population density are genus-specific among the Cheirogaleidae. Rather remarkably, the density of Microcebus appears to have a profoundly positive relationship with anthropogenic disturbance and a negative relationship with forest cover, a finding that is also reflected by larger population densities within unprotected areas in comparison with localities within Madagascar's protected area network. MAIN CONCLUSIONS The results of this study are highly encouraging for the conservation of the Cheirogaleidae and highlight the remarkable resilience of these lemurs to habitat degradation and anthropogenic activity. However, this study also outlines the dearth of knowledge that we have for many species, and why these data are urgently needed to understand the biogeography and ecology of threatened animal populations and implement successful conservation.
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Affiliation(s)
- Daniel Hending
- School of Biological SciencesThe University of BristolBristolUK
- Bristol Zoological SocietyClifton, BristolUK
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Hending D, Sgarlata GM, Le Pors B, Rasolondraibe E, Jan F, Rakotonanahary AN, Ralantoharijaona TN, Debulois S, Andrianiaina A, Cotton S, Rasoloharijaona S, Zaonarivelo JR, Andriaholinirina NV, Chikhi L, Salmona J. Distribution and conservation status of the endangered Montagne d’Ambre fork-marked lemur (Phaner electromontis). J Mammal 2020. [DOI: 10.1093/jmammal/gyaa065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Abstract
The geographic distribution of a species can provide insights into its population size, ecology, evolution, and how it responded to past (and may respond to future) environmental change. Improving our knowledge of the distribution of threatened species thus is a high priority in assessing their conservation status. However, there are few data available for many recently described yet understudied and potentially threatened primate taxa, making their conservation difficult. Here, we investigated the distribution of the Montagne d’Ambre fork-marked lemur, Phaner electromontis, a threatened nocturnal primate endemic to northern Madagascar and classified as Endangered by the IUCN. Because fork-marked lemurs are highly vocal, we used acoustic surveys to assess the species’ presence-absence and relative population density within 66 distinct forest survey sites in northern Madagascar. Further, we compared data among five forest types within the study area and investigated the relationship between relative population density and climate variables. We report the presence of P. electromontis in 22 study sites; several of these populations were unknown previously. Although we found P. electromontis most frequently in dry-transitional forests, our results suggest that geography (spatial autocorrelation) rather than environmental variables explains the species’ distribution. We hypothesize that environmental unpredictability and gummivory, combined with the presence of several distinct Phaner species in the studied area, could explain the observed distribution.
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Affiliation(s)
- Daniel Hending
- School of Biological Sciences, University of Bristol, Bristol, United Kingdom
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol, United Kingdom
| | | | | | | | - Fabien Jan
- Instituto Gulbenkian de Ciênca, Oeiras, Portugal
| | | | | | - Stéphane Debulois
- CNRS, Université Paul Sabatier, IRD; UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), Toulouse, France
| | - Angelo Andrianiaina
- Mention: Zoologie et Biodiversité Animale, Université d’Antananarivo, Antananarivo 101, Madagascar
| | - Sam Cotton
- Department of Field Conservation and Science, Bristol Zoological Society, Bristol, United Kingdom
| | | | - John R Zaonarivelo
- Département des Sciences de la Nature et de l’Environnement, Université d’Antsiranana, Antsiranana, Madagascar
| | | | - Lounès Chikhi
- CNRS, Université Paul Sabatier, IRD; UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), Toulouse, France
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Hending D, Andrianiaina A, Maxfield P, Rakotomalala Z, Cotton S. Floral species richness, structural diversity and conservation value of vanilla agroecosystems in Madagascar. Afr J Ecol 2019. [DOI: 10.1111/aje.12682] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Hending
- Department of Field Conservation & Science Bristol Zoological Society Bristol UK
- School of Biological Sciences University of Bristol Bristol UK
| | - Angelo Andrianiaina
- Mention: Zoologie et Biodiversité Animale Université d'Antananarivo Antananarivo Madagascar
| | - Pete Maxfield
- Department of Applied Sciences University of the West of England Bristol UK
| | | | - Sam Cotton
- Department of Field Conservation & Science Bristol Zoological Society Bristol UK
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Hending D, Andrianiaina A, Rakotomalala Z, Cotton S. The Use of Vanilla Plantations by Lemurs: Encouraging Findings for both Lemur Conservation and Sustainable Agroforestry in the Sava Region, Northeast Madagascar. INT J PRIMATOL 2018. [DOI: 10.1007/s10764-018-0022-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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