Biology subjects

Connan, M.

Publications and source records attributed to Connan, M..

4 recordsLinked to original sources

bioRxiv2026

Dispersal, adaptation and persistence of H5N1 in the sub-Antarctic and Antarctica

High pathogenicity avian influenza virus (HPAIV) H5N1 reached the sub-Antarctic and Antarctica in 2023, subsequently spreading to remote locations within this region where it had devastating impacts on seal, penguin and albatross populations. The threat to marine wildlife over this broad area exemplifies the need to understand H5N1 long-distance dispersal and evolution. We obtained 104 novel viral genomic sequences from samples that we collected at South Georgia, Kerguelen, Crozet, Prince Edward, Falklands/Malvinas Islands and the Antarctic Peninsula in a region spanning 8,000 kilometers. Using recent phylogeographic modeling advances we show that H5N1 spread encompassed numerous transmission events between distant locations, accumulating mammalian-adaptive mutations in the process. Seals are the most affected species, but we reveal that the long-distance eastward virus dispersal better aligns with the long-distance movements of large petrels and albatrosses. The risk of H5N1 endemisation, dispersal to other locations and ongoing evolution are highly concerning.

microbiology↗

bioRxiv2025

Shedding dynamics of the Ross seal (Ommatophoca rossii) whiskers investigated through carbon and nitrogen bulk stable isotope composition

Understanding the trophic ecology of pinnipeds is essential to define their role in ecosystems and anticipate their responses as top predators to environmental changes. Incremental analyses of carbon ({delta}13C) and nitrogen ({delta}15N) stable isotopes along their whiskers provide valuable records of their foraging habitat and trophic level over time. The effectiveness of this approach relies on knowledge of species-specific whisker shedding dynamics and growth rates. We investigated the shedding dynamics of Ross seal (Ommatophoca rossii) whiskers and attempted to evaluate the time captured in these tissues by combining whiskers bulk{delta} 13C and{delta} 15N incremental measurements with satellite tracking data, collected after whisker growth. Our tracking data are consistent with previous studies, in that Ross seals migrate post-moult between the marginal ice zone and the Antarctic Polar Front. Stable isotope profiles of whiskers did not show the typical decrease in{delta} {superscript 1}3C and increase in{delta} {superscript 1}N values at the whiskers tip that would be expected if shedding coincided with the annual fur moult, when fasting typically occurs. The occurrence of similar isotope variations, which were offset between the left and right whiskers of the same individual in relation to distance from the muzzle, further suggest asynchronous, non-seasonal whisker shedding. Our inability to identify known cyclic phenological events (i.e., fasting periods or seasonal migrations) prevented the determination of the average growth rate of whiskers. The additional data on whisker shedding dynamics of Ross seals is a valuable first step in support of future ecological studies based on the whiskers of this species.

ecology↗

bioRxiv2023

No evidence for highly pathogenic avian influenza virus H5N1 (clade 2.3.4.4b) in the Antarctic region during the austral summer 2022/23

The current highly pathogenic avian influenza H5N1 panzootic has substantial impacts on wild birds and marine mammals. Although major outbreaks occurred in South America, incursion to Antarctica emerged late in the breeding season of 2023/2024 and was confined the wider region of the Antarctic Peninsula. To infer potential underlying processes, we compiled H5N1 surveillance from Antarctica and Sub-Antarctic Islands prior to the first confirmed cases.

microbiology↗

bioRxiv2021

Sexual and individual signatures are encoded in the temporal rate of Cape gannet display calls

1.Abstract/SummaryVocalisations play a vital role in animal communication, as they are involved in many biological functions. Seabirds often breed in large and dense colonies, making successful recognition between mates or between parents -and offspring crucial for reproductive success. Most seabird species, including Cape gannets (Morus capensis), are monomorphic and likely rely on acoustic signals for mate selection and mate recognition. This study aimed to better understand the use of vocalisations for sex and individual recognition in Cape gannets by describing the acoustic structure of their display calls at the nest. Vocalisations of nesting Cape gannets were recorded and acoustic measurements were extracted in both temporal and frequency domains. Values of the fundamental frequency and the average of Inter-Onset-Interval appeared to be the most important acoustic variables for sex determination. Both temporal and frequency parameters showed a potential for individual identity coding, with the average units Inter-Onset-Interval being the most important variable for individual identification for both sexes. This study provides the first evidence of sex-specific and individual vocal signatures in adult breeding Cape gannets. From an applied perspective, identified sex specific differences could potentially be used as a non-invasive method for field-based sex-determination in research and monitoring projects on Cape gannets.

zoology↗