Biology subjects

Delord, K. C.

Publications and source records attributed to Delord, K. C..

4 recordsLinked to original sources

bioRxiv2026

Large-scale exposure of southern seabirds to avian cholera Pasteurella multocida: scavengers as sentinels at different spatial scales

Seabird communities represent spatially structured social networks within which potential sentinels could inform us where multi-host pathogens could be present. Pasteurella multocida, the agent of avian cholera, is responsible for recurrent massive seabird mortality events on remote Amsterdam Island, Southern Indian Ocean, but little is known about its broad spatial occurrence. To explore its distribution and whether avian scavengers and predators could be used as sentinels, we screened 18 southern seabird species from 11 islands for antibodies against P. multocida (2634 plasma samples). We detected widespread but heterogeneous exposure among host populations. High seroprevalences were found in widely roaming predators and scavengers (giant petrels (Macronectes spp), and brown skua (Stercorarius antarcticus)), which could represent efficient sentinels at broad scales. Antibodies were also detected over a series of years in a non-migratory scavenger, the lesser sheathbill (Chionis minor) and an abundant penguin species, the king penguin (Aptenodytes patagonicus), suggesting that the bacterium was circulating locally at some sites. This broad scale serological screening of whole seabird host communities provides critical information to assess disease emergence risks in the context of global change.

ecology↗

bioRxiv2026

Wind pattern oscillations explain seabird movements at-sea: a nested multiscale approach

Wind has a strong influence on the flight characteristics, movements, energetics, demography, life-history traits and biogeography of flying animals. With climate change affecting atmospheric circulation patterns at different time scales, understanding the links between wind and animal movements is crucial for predicting its impact on flying biodiversity. Most studies on the relationship between wind and seabird movements have, however, focused on local scales, exploring birds perceptive sensitivity to local wind. In this study, we examine low-level wind pattern oscillations in the Southern Indian Ocean at multiple time scales to explain the local- to large-scale movements of the Amsterdam albatross. Adult individuals exhibited smooth trajectories, strongly correlated with seasonal, intra-seasonal or interannual wind oscillations. Conversely, younger individuals displayed more erratic and exploratory movements, often being swept away by eastward moving low-pressure systems at a synoptic time scale. Our results suggest that Amsterdam albatrosses can learn and adapt to the annual and monthly low-level wind climatology and interannual variability of the Southern Indian Ocean. This also highlights the importance of investigating seabird movements in relation to broader-scale wind patterns to support their conservation in a changing climate due to human activities. A robust assessment of regional circulation response to climate change for upcoming decades could help project the impact of climate change on seabird movements and mitigate its effects.

ecology↗

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

Subtropical anticyclone impacts life-history traits of a marine top predator

Subtropical anticyclones are semi-permanent atmospheric high-pressure systems located in all major ocean basins and are associated with large-scale wind and weather patterns. They shape the physical environments of many species, yet their demographic impacts on wild populations remain largely unexplored. We combined population and climate analyses to investigate the demographic effects of subtropical anticyclones. Using 39 years of monitoring data on wandering albatrosses (Diomedea exulans), the "wind rider", breeding in the southern Indian Ocean, we explored the mechanisms linking subtropical anticyclone with demographic rates. We found that an intensified and poleward-shifted Indian Ocean subtropical anticyclone enhances westerly winds, improving survival and reproduction across all life stages in wandering albatrosses. These findings uncover a direct link between subtropical anticyclones and population dynamics, highlighting subtropical anticyclones as potential drivers of wind-reliant taxa responses to climate variability and change.

ecology↗