Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.64898/2026.10.30.763177

Identifying the source population of naturally recolonised rhinoceros (Rhinoceros unicornis) in Laokhowa-Burhachapori Wildlife Sanctuary, Assam, through multidisciplinary methods

Kumar, S.·Soun, J.·Biswas, D.·Mehta, M.·Deka, J.·Ghosh, S.·Sharma, A.·Mondol, S.
View original source ↗Export metadata ↓

Abstract

Megaherbivore population recovery largely depends on restoring connectivity between fragmented protected areas to facilitate natural dispersal, gene flow, and range expansion. The Indian rhinoceros (Rhinoceros unicornis) has recovered from severe population decline in the past, but several populations remain spatially restricted. Recent conservation efforts and the expansion of protected areas in Assam have coincided with natural rhino recolonization in Laokhowa-Burhachapori Wildlife Sanctuary (WLS). This has occurred from nearby regions of Orang NP and Kaziranga NP after the species was locally extinct in the 1980s. Identifying the source population of these recolonised rhinos is crucial for managing this emerging metapopulation. We used non-invasive genetic sampling, genetic assignment and a landscape connectivity model to investigate the origin and potential movement routes of the recolonising rhinos. We identified eight unique individuals from Laokhowa-Burhachapori WLS and assigned them to the potential source population using Bayesian and frequency-based approaches against a reference dataset of 365 individual rhinos across the rhino-bearing areas of Assam. Habitat suitability was modelled using 161 spatially thinned presence points and eight environmental variables. We applied least-cost path (LCP) analysis to assess landscape resistance between protected area nodes. All eight recolonising rhinos were assigned to Orang NP with high Bayesian assignment probabilities (q = 0.97-0.99). The connectivity model identified two least-cost pathways, with the Orang NP-Laokhowa-Burhachapori WLS linkage showing lower landscape friction than the Kaziranga NP linkage. These findings provide genetic evidence that the recolonisation occurred through natural dispersal, most likely from Orang NP, and indicate that recent landscape restoration has re-established the structural connectivity across this floodplain. Maintaining these linkages will be essential to promote natural range expansion and the long-term persistence of Indian rhinoceros in Assam.

Explore related subjects

ecologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kumar, S., Soun, J., Biswas, D., Mehta, M., Deka, J., Ghosh, S., Sharma, A., Mondol, S.. 2026-11-02. Identifying the source population of naturally recolonised rhinoceros (Rhinoceros unicornis) in Laokhowa-Burhachapori Wildlife Sanctuary, Assam, through multidisciplinary methods. https://doi.org/10.64898/2026.10.30.763177

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

MillionTrees: A global benchmark for tree detection across geography, sensor, and annotation geometry

Airborne tree monitoring using remotely sensed data, combined with the growth of computer vision models for object detection and segmentation, can facilitate broad scale assessment of tree health, ecology and ecosystem function. However, datasets for airborne tree detection have been largely limited to a single geography, resolution, or annotation approach, making it difficult to develop general models and benchmark their utility for broad applications. We compile existing and newly published annotation datasets to create a comprehensive dataset for training and evaluating airborne tree detection in RGB imagery. The MillionTrees dataset has over a million individual trees from a broad range of forest types, tree species, and geographic locations. In addition, it has six million weakly supervised annotations from a range of sources including airborne LiDAR and photogrammetry, arborist surveys, and simulated landscapes. An evaluation standard is provided to facilitate rapid model development. We benchmark several existing tree detection algorithms and demonstrate that while current open-source models do not generalize across the diverse datasets in the benchmark, training on MillionTrees improves both within-domain and out-of-domain performance. Held-out validation datasets using ground truth derived from terrestrial LiDAR paired with overhead RGB show that overfitting to test data is common and hyperparameter tuning is an underappreciated challenge towards a global zero shot tree detection method. We discuss the limitations of the currently available data for airborne RGB tree detection, how to create more robust evaluation data and the need for better understanding of the uncertainty and utility of tree detection from airborne remote sensing.

ecology↗
bioRxiv2026

Individual-specific recovery of the healthy human gut microbiota after antibiotics

Following disruption by broad-spectrum antibiotics, the human gut microbiome undergoes a prolonged recovery where coarse ecological features, such as species richness and diversity, are largely restored. However, as these features are shared by most healthy individuals, it remains unclear whether, even after strong perturbation, individuals preferentially return toward their own pre-treatment composition ('individual-specific recovery') or instead switch to alternative equally healthy states. Resolving this question is fundamental for evaluating the long-term impacts of antibiotics, because an individual's health is affected by their unique microbiome composition, affecting immune regulation and metabolic processing, so a state switch, even to a broadly healthy configuration, could carry unintended consequences. Here we compare each subject's post-antibiotic endpoint with their own baseline and with the baselines of every other subject, across four cohorts (n = 121) whose regimens ranged from a five-day fluoroquinolone course to a four-day three-drug combination given to deplete the gut community. The recovered community was significantly closer to the subject's own baseline than to the alternative healthy baselines in more than 90% of individuals under the mildest regimen and in two thirds of those under regimens that broadly target the gut anaerobes, remaining above chance in every cohort and the majority outcome even where most baseline taxa fell below detection during treatment. This specificity is not merely the persistence and fast regrowth of survivors: it persists among baseline taxa that remain undetected for weeks to months, and the same taxon re-establishes more readily in a host where it was previously detected than in one where it was not. Newly established taxa are consistently more functionally similar to the pre-treatment community than transient arrivals, and their identity correlates with the surviving community's composition in a substantial fraction of subjects. State switching, in contrast, was uncommon and occurred almost exclusively among subjects with the largest reduction in detected taxa during the treatment. Together, these observations reveal the individual-specific nature of the microbiome resilience to broad-spectrum antibiotics, whereas the compositional changes are not random but rather functionally and ecologically associated with the subject's baseline.

ecology↗
bioRxiv2026

Tropical Peatlands as Hotspots of Hidden Arcellinida Diversity: Insights from Maludam National Park, Borneo (Sarawak, Malaysia)

Recent investigations on tropical peatlands have shown their extremely high efficiency as carbon sinks, far beyond better studied boreal bogs. The microbial diversity found in those ecosystems, as well as their corresponding ecological and metabolic processes, are just starting to be revealed, and differ considerably from high latitudes systems. However, these efforts have been concentrated almost exclusively towards prokaryotes and fungi, leaving protist communities virtually unknown. Arcellinida (testate amoebae) are well acknowledged to play an important role in boreal and temperate peatland ecology by driving microbial community composition as top predators, but also as nutrient recyclers and carbon fixers. Yet, to our knowledge, no community-level study has addressed their diversity and its drivers in tropical peatlands. In this study, we surveyed Arcellinida communities' diversity across five functionally distinct vegetation-hydrological zones situated along a hydrological transect in a coastal tropical peatland in the Maludam National Park, Malaysia. Taxonomic composition of Arcellinida communities, characterized by a high diversity of Trigonopyxis-related taxa, indicated fundamental differences in diversity and community composition from extratropical ecosystems. Species richness was significantly higher in the zones with developed understory vegetation. Furthermore, the composition of diversity varied significantly among vegetation-hydrological zones. Altogether, this study shows unique Arcellinida communities in a Southeastern Asian peatland and suggests the importance of vegetation-hydrological characteristics for protist diversity.

ecology↗