Abstract Title
NORTHERN GANNET RESILIANCE FOLLOWING AN OUTBREAK OF HPAI OF AT THEIR SOUTHERNMOST COLONY
Abstract
Northern Gannet (Morus bassanus) colonies in North America are experiencing stagnant or declining population trends. Infectious disease and ocean warming are contributing to these demographics. Highly pathogenic avian influenza virus (HPAI) subtype H5N1 clade 2.3.4.4b had devastating effects on Northern Gannet populations throughout their breeding range in 2022. At Cape St. Mary’s, Newfoundland and Labrador, Canada, HPAI caused at least 5.0% colony mortality. Cape St. Mary's is the Northern Gannet's southernmost colony and one of the most severely impacted by HPAI. Yet in 2023, reproductive success at Cape St. Mary's was higher than average, despite the effects of a moderate marine heatwave and population losses of the previous year. We used GPS-tracking and time-depth recorders to assess if surviving gannets worked harder (i.e. were higher quality individuals) and invested more energy in foraging effort, thus facilitating the high reproductive success. We compared foraging behaviour (trip distance, trip duration, maximum trip distance from the colony) and diving effort of adult breeding Northern Gannets before (2019-2021), during (2022), and after (2023-2024) the HPAI event. Preliminary results show that gannets had higher total trip distances in 2023 compared to pre-HPAI, and in 2024 total trip distance returned to normal. HPAI outbreaks could reoccur and understanding the post-HPAI influences on surviving individuals will aid in understanding the selective pressures of the avian pandemic. This could allow us to anticipate population changes and create conservation strategies to minimize potential declines throughout their range.
Co-Author(s)
Sydney Collins1, Kyle d’Entremont1, Noah Careen1, William A. Montevecchi1
1Department of Psychology, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in wild birds