Abstract Title

Session S-04D: Marine Birds and Mammals of the Salish Sea: Identifying Patterns and Causes of Change - I

Presenter/Author Information

Frances WoodFollow

Keywords

Species and Food Webs

Start Date

1-5-2014 5:00 PM

End Date

1-5-2014 6:30 PM

Description

Pigeon Guillemots are a good indicator species for the health of the Salish Sea because they nest throughout the area, they are found here all year and they are near the top of the food chain. Since 2008, members of Whidbey Audubon Society have monitored the 25 colonies of guillemots nesting on Whidbey Island. During the breeding season, 40-50 trained volunteers spent one hour per week at each colony observing the birds. They began no later than 9 a.m. and counted the number of adults in the colony, the number of occupied burrows (defined as burrows an adult has entered), the number of burrows with chicks (defined as burrows to which an adult has delivered prey) and the type of prey delivered. In addition, paid interns monitored selected colonies for 5 hours per day each week following the same protocol. Since they were at the site for a prolonged period, they also estimated the number of burrows that fledged chicks, defined as burrows that have received prey for at least 3 consecutive weeks. Over this six-year period the population appeared to be stable. The mean number of adults was 1038 ± 33, of occupied burrows was 233 ± 16 and of burrows with chicks 168 ± 14. The fledging success was more variable, from a high of 81% of burrows with chicks to a low of 55% with a mean of 68% ± 11%. Prey were identified as gunnels, sculpins or other (including unidentified prey and other prey such as perch or cod). Over the 6 year observation period, 3543 gunnels, 1720 sculpin and 1031 other prey were delivered. Gunnels were the predominant prey delivered each year. Prey deliveries began in the middle of June, reached a peak in the middle of July and ended by the last week of August. This on-going study is jointly supported by the Northwest Straits Initiative, the Island County Marine Resources Committee, National Audubon Society and Whidbey Audubon Society. We educate community members about this indicator species and its place in the nearshore ecosystem.

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May 1st, 5:00 PM May 1st, 6:30 PM

Breeding Pigeon Guillemots on Whidbey Island: A Six Year Study

Room 6C

Pigeon Guillemots are a good indicator species for the health of the Salish Sea because they nest throughout the area, they are found here all year and they are near the top of the food chain. Since 2008, members of Whidbey Audubon Society have monitored the 25 colonies of guillemots nesting on Whidbey Island. During the breeding season, 40-50 trained volunteers spent one hour per week at each colony observing the birds. They began no later than 9 a.m. and counted the number of adults in the colony, the number of occupied burrows (defined as burrows an adult has entered), the number of burrows with chicks (defined as burrows to which an adult has delivered prey) and the type of prey delivered. In addition, paid interns monitored selected colonies for 5 hours per day each week following the same protocol. Since they were at the site for a prolonged period, they also estimated the number of burrows that fledged chicks, defined as burrows that have received prey for at least 3 consecutive weeks. Over this six-year period the population appeared to be stable. The mean number of adults was 1038 ± 33, of occupied burrows was 233 ± 16 and of burrows with chicks 168 ± 14. The fledging success was more variable, from a high of 81% of burrows with chicks to a low of 55% with a mean of 68% ± 11%. Prey were identified as gunnels, sculpins or other (including unidentified prey and other prey such as perch or cod). Over the 6 year observation period, 3543 gunnels, 1720 sculpin and 1031 other prey were delivered. Gunnels were the predominant prey delivered each year. Prey deliveries began in the middle of June, reached a peak in the middle of July and ended by the last week of August. This on-going study is jointly supported by the Northwest Straits Initiative, the Island County Marine Resources Committee, National Audubon Society and Whidbey Audubon Society. We educate community members about this indicator species and its place in the nearshore ecosystem.