Tufted Puffin (Fratercula cirrhata) populations have apparently declined significantly in Washington State waters, including the Salish Sea region (Puget Sound, Strait of Juan de Fuca, Strait of Georgia), during the 1980s and 1990s. However, quantitative assessments of the extent of the decline and of factors influencing puffin population trends are lacking. To begin to evaluate population trends and potential explanatory factors, we used boat-based surveys to assess occupancy of historic breeding sites. To examine reproductive trends, we monitored the puffin population on Tatoosh Island, Washington since 2005, and are compared breeding performance to that of sympatric seabird species like the rhinoceros auklet.
This work was funded by the SeaDoc Society, the Puget Sound Action Team, and Washington Department of Fish and Wildlife.
- Boat-based surveys, conducted during the 2007 and 2008 breeding seasons, indicated that only 12 of 25 (48% in 2007) and 17 of 32 (53% in 2008) historically occupied breeding sites in Washington were active. Additionally, these surveys also found a lack of colony attendance in August 2007, consistent with concurrent low on-water and on-colony counts on Tatoosh Island. This apparent premature abandonment suggests a possible widespread breeding failure in the Washington population during 2007. Declines in occupancy of historic breeding sites have occurred not solely in the Salish Sea and along the outer coast of Washington, but also throughout the California Current System, with reductions in numbers of active breeding sites in both Oregon and California.
- We monitored the puffin population on Tatoosh Island, Washington since 2005, using counts of birds on the water, in flight and on the colony surface as abundance metrics and following fates of marked breeding burrows. Attendance patterns varied intra-seasonally and inter-annually. The percentage of active burrows on Tatoosh was consistently high, ranging from 72-90%. Hatching success was more variable (range: 56-82%), with 2007 being significantly lower than the other three years. Fledging success was generally low, with only 2006 and 2008 exceeding 40%. Overall poor puffin reproductive success contrasts strongly with contemporaneous studies of Rhinoceros Auklets (Cerorhinca monocerata), which had high levels of hatching (range: 76-90%) and fledging success (range: 65-81%) during the same four-year period. These results imply that Tufted Puffins may be particularly sensitive to factors such as bottom-up changes, top-down changes, and/or on-colony disturbance.
- Preliminary results were presented at the Pacific Seabird Group meeting in 2008.
- Peter Hodum, Scott Pearson and Julia Parrish are writing a manuscript summarizing our findings for submittal to a journal in spring 2010.