Aerial Photographic Surveys of Seabird Breeding Colonies

• Main Authors: Daniel Barton, Phil Capitolo
• Format: Dataset
• Language: unknown
• Published: Knowledge Network for Biocomplexity
• Subjects: North Coast:Baseline Characterization of Seabirds:Aerial Photographic Surveys of Seabird Breeding Colonies:2000 to 2014; Ecological data; Photos; Non-Consumptive Uses; Seabird; Common Murre
• Online Access: https://doi.org/10.5063/F1X34VJW

Seabirds are an important component of healthy marine ecosystems given their status as apex predators, and are readily accessible indicators of change in marine ecosystems. The North Coast Study Region baseline monitoring program provides a means of evaluating the region-wide effect of a network MPAs. The reported data and seabird population trends represent a region-wide baseline for seabird populations in 2014 and change in population size over the 26-year time period from 1989-2014. We report a region-wide survey of seabird colonies in the NCSR in 2014 from aerial photography, and analysis of colony population growth using aerial surveys from 1989-2014. We report region-wide counts of colony attendance or nests of 3 readily-observed piscivorous seabird species, Common Murre (N = 350,923 attending individuals), Brandt’s Cormorant (N = 4,583 nests), and Double-crested Cormorant (N = 1,840 nests) from a complete aerial survey of the region’s colonies in 2014. These individuals were spread across 32 colonies, including 6 now in special closures and 9 located in or adjacent to marine reserves or marine conservation areas. We also report a region-wide trend analysis of seabird colonies in the NCSR from 1989-2014. Aerial survey photographs were previously collected by numerous collaborators, and some photographs not previously counted from 1989-2013 were counted as part of this project. Additionally, data were provided by numerous collaborators for use in this trend analysis and were combined with data collected as part of the NCSR baseline monitoring program. We used 173 observations of Common Murre colony attendance at 14 colonies or sub-colonies over the 26-year study period to estimate a mean overall growth rate of 4.0% (range: -7.3% to 14.1%; Summary Figure 1). We report colony-specific annual growth rates that varied in space and time, but overall, show a pattern of increase in Common Murre colony attendance in the region.