Wild birds have experienced unprecedented, near‐global mass mortalities since 2021, driven by outbreaks of high‐pathogenicity avian influenza virus (HPAIV) H5N1 lineage 2.3.4.4b. Managing this panzootic requires identification of transmission pathways. We investigated potential HPAIV transmission via kleptoparasitism (food theft) by examining the distribution, behaviors, and movements of two globally widespread and commonly kleptoparasitic seabird families: Fregatidae (frigatebirds) and Stercorariidae (skuas). These kleptoparasites force other seabirds (targets) to regurgitate food, which the kleptoparasite then ingests, potentially facilitating direct transfer of viral particles from target to kleptoparasite. Scavenging and predation probably contribute further to viral spread. Although frigatebirds use kleptoparasitism on a year‐round basis, skuas more commonly do so outside of the breeding season. Both frequently forage, disperse, or migrate across oceans and hemispheres. Dense aggregations of kleptoparasitic and target seabirds at breeding and/or roosting sites may facilitate the spread of HPAIV. In addition, the migration of these species could also facilitate broadscale geographic spread of HPAIV. Surveillance of kleptoparasites for HPAIVs could aid in early detection and may be important for seabird conservation.

中文翻译：

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海鸟的盗贼寄生——全球禽流感病毒传播的潜在途径


自 2021 年以来，由于高致病性禽流感病毒 (HPAIV) H5N1 谱系 2.3.4.4b 的爆发，野生鸟类经历了前所未有的、近乎全球性的大规模死亡。管理这种泛动物疫情需要确定传播途径。我们通过检查两个全球广泛分布且常见的盗窃寄生海鸟家族：Fregatidae（军舰鸟）和 Stercorariidae（贼鸥）的分布、行为和活动，调查了 HPAIV 通过盗窃寄生（食物盗窃）传播的可能性。这些盗贼寄生虫迫使其他海鸟（目标）反刍食物，然后盗贼寄生虫将食物摄入，从而可能促进病毒颗粒从目标直接转移到盗贼寄生虫。食腐和捕食可能进一步促进病毒传播。尽管军舰鸟全年都会进行盗贼寄生，但贼鸥在繁殖季节之外更常见。两者都经常跨越海洋和半球觅食、分散或迁徙。盗窃寄生虫和目标海鸟在繁殖和/或栖息地的密集聚集可能会促进 HPAIV 的传播。此外，这些物种的迁徙也可能促进高致病性禽流感病毒的大范围地理传播。对 HPAIV 盗贼寄生虫进行监测有助于及早发现，并且对于海鸟保护可能很重要。