Foraging #ecology drives viral community structure in #NZ's aquatic #birds

 

Abstract

Wild migratory birds play a major role in the global spread of viruses, yet the diversity, host range and transmission patterns of viruses harboured by migratory species in Aotearoa/New Zealand remain largely unknown. This knowledge gap is critical given New Zealand's position along major migratory flyways spanning Oceania, Antarctica and east Asia, where understanding viral diversity is key to assessing the risk of viral introductions such as highly pathogenic avian influenza virus and viral dispersal across these regions. To address this, we conducted the first large-scale metatranscriptomic survey of wild birds from New Zealand and its subantarctic islands, collecting 1,348 samples from 31 host species spanning four avian orders. We identified 118 avian viruses from 17 families, including 107 novel species, greatly expanding our knowledge of avian viral diversity. Viral communities differed significantly by host order and foraging behaviour, with scavenger birds harbouring more diverse viromes than non-scavengers. Although no HPAI subtypes were detected, we recovered a low-pathogenic avian influenza A/H1N9 virus from red knots (Calidris canutus) and a divergent tobanivirus from Auckland Island teal (Anas aucklandica), the first putative avian member of the Tobaniviridae. Notably, we detected 12 mammalian-associated viruses, primarily in scavenger birds, including Hedgehog hepatovirus, Rabbit haemorrhagic disease virus 2, and sea lion astroviruses, with mammalian host reads confirming their dietary origin. This study establishes the first virome baseline for New Zealand's migratory birds, highlighting the ecological role of foraging in shaping viral communities and improving regional preparedness for HPAI and other emerging avian pathogens.

Competing Interest Statement

The authors have declared no competing interest.

Funder Information Declared

Te Niwha, New Zealand's Infectious Disease Research Platform, TN/SWC/24/UoOJG

Source: 

Link: https://www.biorxiv.org/content/10.64898/2025.12.09.693119v1

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#Genetic characterization of the #marmot gut #virome in high-altitude #Qinghai Province and identification of novel #viruses with zoonotic potential

ABSTRACT

The high-altitude ecosystems of Qinghai Province, China, harbor unique viral communities shaped by extreme environmental conditions and host adaptations. This study presents a comprehensive genetic characterization of the marmot gut virome, revealing novel viral strains with zoonotic potential. Using viral metagenomics, we analyzed intestinal contents from 70 marmots collected from Chengduo and Maqin counties. Sequencing on the Illumina NovaSeq 6000 platform identified 19 viral genomes belonging to four major families: Adenoviridae, Astroviridae, Parvoviridae, and Picornaviridae, along with four novel circular Rep-encoding single-stranded DNA (CRESS DNA) viruses. Phylogenetic analyses demonstrated close relationships between marmot-derived strains and viruses from humans, bats, and other mammals, highlighting potential cross-species transmission risks. Notably, bat-associated adenoviruses showed closer phylogenetic proximity to human strains, while novel parvoviruses formed a distinct clade within the Dependoparvovirus genus. The discovery of a novel astrovirus with low sequence similarity to known genera underscores the need for taxonomic reclassification. Additionally, a novel picornavirus related to Sapelovirus and four divergent CRESS DNA viruses were identified, expanding our understanding of viral diversity in high-altitude rodents. These findings emphasize the role of marmots as viral reservoirs and highlight the importance of high-altitude ecosystems as hotspots for zoonotic pathogen emergence. This study provides critical insights into viral evolution, host adaptation, and zoonotic risks, advocating for integrated surveillance strategies to mitigate future spillover events.

IMPORTANCE

Viruses are the most abundant and diverse biological entities on Earth, yet their presence in wildlife from extreme environments remains poorly understood. High-altitude ecosystems, shaped by harsh conditions like intense UV radiation and low oxygen levels, create unique settings for virus evolution. This study is the first to comprehensively profile the gut virome of marmots in Qinghai Province, uncovering novel viral strains and highlighting how extreme environments drive viral diversity. Marmots, as key species in these regions, can act as bridges for virus transmission among wildlife, livestock, and humans, posing zoonotic risks. Understanding these viral communities is essential for predicting and preventing future outbreaks. Our findings emphasize the urgent need for integrated, One Health-based surveillance strategies to safeguard both public health and biodiversity in fragile high-altitude ecosystems.

Source: mSphere, https://journals.asm.org/doi/full/10.1128/msphere.00297-25?af=R

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