COS 192-1 - Spatial analysis of trends in tufted puffin breeding habitat on the Oregon Coast

Abstract: Tufted puffins (Fratercula cirrhata) are an iconic species in the Pacific Northwest that provide a wide range of ecological, economic, and historically important services such as ecotourism for local communities- and bringing marine derived nutrients to terrestrial habitats. Further, tufted puffins are sensitive to changes in prey availability and as such, are good indicators of overfishing and ecosystem disturbance. Tufted puffin populations on the Oregon Coast have declined dramatically over the past 30 years from over 5,000 birds in 1989 to only 550 birds in 2021. In 2018, the tufted puffin Species Status Assessment (SSA) determined that factors related to breeding site conditions are one of the most probable causes of puffin decline; however, little is known about the specific characteristics of nesting habitat along the Oregon Coast, or how it relates to their population demographics. To address this knowledge gap, we conducted a spatial analysis to examine the distribution of suitable breeding habitat for tufted puffins on the Oregon Islands National Wildlife Refuge, OR, USA. Specifically, we compared the percent cover of vegetation at tufted puffin breeding sites from 1979 to 2021 using a combination of ground truth data, aerial photos of the islands, data from the National Agriculture Imagery Program (NAIP), and other remote sensing data sets. Preliminary results suggest a decrease in the percent cover of live vegetation at critical breeding habitat. After measuring the magnitude of habitat change, we related vegetation loss to site-specific, climatic, and environmental variables to determine potential key drivers of habitat change. Assessing how suitable puffin breeding habitat characteristics have changed over time will provide necessary information to guide refuge managers in habitat restoration and support adaptive management decisions.