Biology subjects

Le Breton, C.

Publications and source records attributed to Le Breton, C..

3 recordsLinked to original sources

bioRxiv2025

COMPARING THE EFFICACY OF CONVENTIONAL SURVEY METHODS TO EDNA IN A RAPID MULTI-TAXA SURVEY OF A TROPICAL RAINFOREST ECOSYSTEM

Madagascar is globally recognized for its exceptional biodiversity and endemism yet remains severely under-sampled for many taxa. We evaluate the effectiveness of environmental DNA (eDNA) metabarcoding as a rapid, non-invasive method for surveying vertebrate biodiversity in the Makira Forest Protected Area (MFPA), comparing its performance to conventional surveys across a range of vertebrate taxa. eDNA sampling detected 158 OTUs across 17 sites, outperforming conventional surveys in birds (p = 0.000107), mammals (p = 0.000718) amphibians (p = 0.000725), reptiles (p = 0.000877) and ray-finned fish (p = 0.00788). We further examined the result for ray-finned fish by modelling species-accumulation curve asymptotes which supported this result. However, significant primer bias and amplification inconsistencies were observed, particularly in amphibian detections, and a high proportion of OTUs could not be resolved to species level due to a combination of taxonomic gaps in reference databases, DNA degradation affecting sequence quality or length, and marker-specific limitations. We demonstrate, using species accumulation curves of our eDNA data and inventoried taxa lists of the MFPA, that the widespread practice of considering only resolved OTUs, rather than all unresolved OTUs, significantly underestimates biodiversity. This study underscores both the promise and current limitations of eDNA as a tool for tropical biodiversity assessment, specifically when compared to conventional sampling techniques. Combining eDNA and conventional survey methods increased species detection rates by 66.4% in comparison to the use of visual surveys alone, highlighting their complementary strengths and reinforcing the value of integrated monitoring strategies for biodiversity-rich, data-deficient regions.

ecology↗

bioRxiv2024

Lost to science for 126 years: Indigenous Knowledge and Camera Trapping Document the Critically Endangered Black-Naped Pheasant-Pigeon Otidiphaps insularis

We combined questionnaires collecting local ecological knowledge with passive and directed camera trapping and bird surveys to scientifically document the Black-Naped Pheasant-Pigeon Otidiphaps insularis for the first time since 1896. This species is endemic to Fergusson Island, in eastern Papua New Guinea, and is New Guineas most endangered terrestrial bird species. Indigenous subsistence-based hunters who participated in this research as informants had high levels of local bird knowledge and helped direct camera trapping for one of two successful camera trap captures. Local participants also shared traditional ecological knowledge about the Black-Naped Pheasant-Pigeon, including legends, chants, and a local name for this taxon, Auwo. The scarcity of observations over the course of a month-long expedition, its obscurity to the majority of local respondents interviewed, and prevalent threats from habitat destruction and introduced alien species further support its current Red List status (CR). Our results provide a case study for leveraging local ecological knowledge in combination with standardized survey techniques and may be an especially effective strategy for determining the status of other undocumented or data-deficient species in the southwest Pacific.

ecology↗

bioRxiv2024

An ornithological survey of Fergusson Island, D'Entrecasteaux Archipelago, Papua New Guinea, reveals new island records and noteworthy natural history observations

Fergusson Island lies off the southeastern end of New Guinea and is the largest landmass in the DEntrecasteaux and Trobriand Island Endemic Bird Area. We conducted audiovisual and camera trapping surveys in eastern Fergusson in September 2022 and recorded 97 bird species, documenting breeding and vocalizations for several of the EBAs endemic taxa. Notably, we provide the first confirmed documentation of the "lost" insularis subspecies of Pheasant Pigeon Otidiphaps nobilis (often recognized as a distinct species, Black-naped Pheasant-pigeon), in 126 years, observations of eight bird species not previously recorded from Fergusson, and nesting of Goldies Bird-of-Paradise Paradisea decora and the endemic crookshanki taxon of Capped White-eye Zosterops fuscicapilla (or Oya Tabu White-eye). Our new distributional records were mostly either migratory species or species found in open habitats, highlighting the value of surveying across seasons and habitats. We summarise our results and provide comments on distributional records, breeding behaviour, and vocalizations.

ecology↗