Effects of tropical rainforest fragmentation on bird species: a case study from the Bemanevika Protected Area, northwestern Madagascar

Benjara, Armand; Roland, Lily-Arison Réné de; Rakotondratsima, Marius; Thorstrom, Russell

doi:10.2989/00306525.2021.2005704

Cited by 6 publications

(19 citation statements)

References 31 publications

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“…Perhaps the flat to negative association with LAI was related to our low occurrence sample and further compounded by the inclusion of the evergreen forest landcover layer. Importantly, our penalized SDM was able to identify a strong positive association with >95 % evergreen forest cover, following previous ground-based associations(Thorstrom & Rene de Roland 2000;Benjara et al 2021).Estimating population size is key for IUCN Red List assessments, because it is used in the criteria for designating the specific Red List threat category for a given taxon (IUCN 2019). Our estimate of 533 mature individuals based on predicted AOH is within the population size range currently given by the IUCN (250-999; BirdLife International 2016).…”

supporting

confidence: 60%

“…2001). We masked out the remaining ecoregions in the far north, east, and south of Madagascar, because the Madagascar Serpent-eagle is a habitat specialist of moist tropical forest (Thorstrom & Rene de Roland 2000; Benjara et al . 2021) and has not been recorded outside of these ecoregions.…”

Section: Methodsmentioning

confidence: 99%

“…1; Olson et al 2001). We masked out the remaining ecoregions in the far north, east, and south of Madagascar, because the Madagascar Serpent-eagle is a habitat specialist of moist tropical forest (Thorstrom & Rene de Roland 2000;Benjara et al 2021) and has not been recorded outside of these ecoregions. We compiled a database of 33 Madagascar Serpent-eagle point localities from the Global Raptor Impact Network (GRIN), a global population monitoring information system for all raptors (McClure et al 2021).…”

Section: Study Extent and Species Locationsmentioning

confidence: 99%

“…We considered eight potential habitat covariates a prioiri related empirically to known Madagascar Serpent-eagle habitat associations (Thorstrom & Rene de Roland 2000;Benjara et al 2021). These were derived from satellite remote sensing products representing climate, landcover, topography, and vegetation at a spatial resolution of 30 arc-seconds (~1 km resolution; Table 1).…”

Section: Habitat Covariate Modelsmentioning

confidence: 99%

“…Despite being termed a serpent eagle, snakes comprise only a small proportion of Madagascar Serpent-eagle prey, with chameleons and geckos accounting for > 80 % of diet (Thorstrom & de Roland 2000). Recent research suggests the Madagascar Serpent-eagle may be vulnerable to both climate change (Andriamasimanana & Cameron 2013) and increasing forest fragmentation (Benjara et al . 2021).…”

Section: Introductionmentioning

confidence: 99%

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Extensive protected area coverage and an updated global population estimate for the Endangered Madagascar Serpent-eagle identified from species-habitat associations using remote sensing data

Sutton

Benjara²,

Roland³

et al. 2022

Preprint

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Knowledge gaps regarding distribution, habitat associations, and population size for rare and threatened range-restricted taxa leads to uncertainty in directing conservation action. Quantifying range metrics and species-habitat associations using Species Distribution Models (SDMs) with remote sensing habitat data can overcome these setbacks by establishing baseline estimates for biological parameters critical for conservation assessments. Area of habitat (AOH) is a new range metric developed by the International Union for the Conservation of Nature (IUCN) Red List. AOH seeks to quantify inferred habitat within a species’ range to inform extinction risk assessments. Here, we use SDMs correlating occurrences with remote-sensing covariates, to calculate a first estimate of AOH for the Endangered Madagascar Serpent-eagle (Eutriorchis astur), and then update additional IUCN range metrics and the current global population estimate. From these baselines we then conduct a gap analysis assessing protected area coverage. Our continuous SDM had robust predictive performance (Continuous Boyce Index = 0.835) and when reclassified to a binary model estimated an AOH = 30,121 km2, 13 % less than the current IUCN range map. We estimate a global population of 533 mature individuals derived from the Madagascar Serpent-eagle AOH metric, which was within the current IUCN population estimates. The current protected area network covered 95 % of AOH, with the binary model identifying three key habitat areas as new protected area designations to fully protect Madagascar Serpent-eagle habitat. Our results demonstrate that correlating presence-only occurrences with remote sensing habitat covariates can fill knowledge gaps useful for informing conservation action. Applying this spatial information to conservation planning would ensure almost full protected area coverage for this endangered raptor. For tropical forest habitat specialists, we recommend that potential predictors derived from remote sensing, such as vegetation indices and biophysical measures are considered as covariates, along with other variables including climate and topography.

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supporting

confidence: 60%

Section: Methodsmentioning

confidence: 99%

Section: Study Extent and Species Locationsmentioning

confidence: 99%

Section: Habitat Covariate Modelsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Extensive protected area coverage and an updated global population estimate for the Endangered Madagascar Serpent-eagle identified from species-habitat associations using remote sensing data

Sutton

Benjara²,

Roland³

et al. 2022

Preprint

Self Cite

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The grassy ecosystems of Madagascar in context: Ecology, evolution, and conservation

Silander,

Bond,

Ratsirarson

2023

Plants People Planet

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Societal Impact StatementMadagascar is famous for its unique forests and their fauna. Most of the island is covered by flammable grassy ecosystems long considered to be of human origin and threatening the remaining forests. Yet new studies show that many plants and animals of the grassy systems are unique to Madagascar and restricted to these open habitats. Open grassy ecosystems have markedly different management requirements from forests and bring different contributions to society. We argue that the grassy ecosystems can benefit Madagascar if understood and managed wisely using expanded knowledge bases that also include collaboration with locals.SummaryUntil recently, nearly all research and interests in Madagascar focused on forested habitats. To help place Madagascar's grassy ecosystems in context, we provide a summary of the origin, development, and evolution of open tropical, C4 grassy ecosystems elsewhere, especially those from Africa; we summarize similarities and differences with the distribution of C3 and C4 grasses in the Malagasy landscape, their plant traits, and inferences on the evolutionary legacy of grasses. We also discuss the animal communities that use and have coevolved in these grassy systems; to help resolve controversies over the pre‐settlement extent of grassy ecosystems, we suggest a variety of complementary geochemical, palaeobotanical, and molecular genetic tools that have been effectively used elsewhere to untangle forest/grassy ecosystem mosaics and the ecological and evolutionary processes that influence them. Many of these tools can and should be employed in Madagascar to fully understand the spatio‐temporal dynamics of open, grassy, and closed forest systems across the island; as regards conservation, we discuss the ecosystem services provided by grassy systems, which are too often ignored in general, not only as a biome, vis‐à‐vis forests, but also for their global importance as a carbon sink and role they play in water management and providing goods to local villagers. We conclude by outlining the necessary research to better manage open ecosystems across Madagascar without threatening endangered forest ecosystems.

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Species traits and latitude mediate bird responses to forest edges globally

Vallejos,

Prevedello,

Vecchi

et al. 2024

Landsc Ecol

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Context Although local studies comparing species abundance between forest edges and interiors are common, general patterns in the response of different species to edges are still to be determined. There is little consensus on the impacts of forest edge effects on the abundance of individual bird species, probably because the species traits affecting edge responses have rarely been synthesized. Objective We aimed to identify how different species’ traits, as well as extrinsic (environmental) factors, mediate the responses of birds to forest edges globally. Methods We collected global information from bibliographic databases from 59 studies with 63 different datasets that compared bird abundance between forest edges and interiors. For each species, we compiled six traits (diet, habitat preference, territoriality, body mass, hand-wing index, and foraging stratum). Using Linear Mixed-effects Models, we evaluated how species traits, latitude, edge contrast, and sampling method affected bird responses to edges. Results Based on 2981 responses of 1414 bird species, we found that plant/seedeaters birds responded positively to edges. The strength of habitat preferences on edge responses was also mediated by latitude. Open-area species from tropics exhibited a positive response, diminishing as latitude increases. Conversely, forest species tend to exhibit a somewhat more negative response in tropical zones. Edge effects were more negative for soft (low-contrast) edges. Conclusions Species traits, in particular diet and habitat preferences interacting with latitude, mediate the impacts of edge effects on different bird species. These species traits and latitudinal gradients must be explicitly considered in models attempting to explain variability in edge responses among species, as well as in conservation actions in fragmented landscapes.

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Effects of tropical rainforest fragmentation on bird species: a case study from the Bemanevika Protected Area, northwestern Madagascar

Cited by 6 publications

References 31 publications

Extensive protected area coverage and an updated global population estimate for the Endangered Madagascar Serpent-eagle identified from species-habitat associations using remote sensing data

Extensive protected area coverage and an updated global population estimate for the Endangered Madagascar Serpent-eagle identified from species-habitat associations using remote sensing data

The grassy ecosystems of Madagascar in context: Ecology, evolution, and conservation

Species traits and latitude mediate bird responses to forest edges globally

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