Colony Structure in Seabirds as an Indicator of Population Health

• Main Author: Cole, Leanne
• Other Authors: Hart, Tom, Lynch, Heather, Manthorpe, Sarah
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Oxford Brookes University 2023
• Subjects: Antarctic; Antarctic Peninsula; The Antarctic; Antarc*
• Online Access: https://radar.brookes.ac.uk/radar/items/a6419540-471b-4212-a574-629dbcb14931/1/; https://radar.brookes.ac.uk/radar/file/a6419540-471b-4212-a574-629dbcb14931/1/MASTER_FINAL.pdf

Colonial breeding is one of the most striking examples of group living in nature, with 98% of marine birds exhibiting this behaviour. The benefits of breeding in colonies are manifold, including access to limited nesting sites and food sources, as well as predator avoidance and access to multiple mates. However, individuals may pay personal fitness costs for the privilege of breeding in a colony, such as increased exposure to disease and increased competition for resources. The relationship between the population size of a colony and its density is thus far unknown but is expected to show a positive connection. Here we show that there is no statistically significant relationship found between population size and density, however this is speculated to be the result of the effect size not being visible on such a small study group. We found that the high number of environmental and anthropogenic variables impacting Pygoscelis colonies across the Antarctic Peninsula makes it increasingly difficult to extrapolate individual influences on colony structure. This is also compounded by a lack of historical data and the significant species-specific responses to unique regional threats. Our results demonstrate the need for continued large-scale monitoring alongside individual colony assessments in order to understand future trends in real time. Additionally, our results demonstrate the capability of UAVs and other remote technologies to be effective tools for monitoring animals in challenging environments, highlighting the additional capacity they provide to conservation projects gather the large quantities of data needed.