Whidbey Island Guillemot Survey
Maps and Data

ABSTRACT

Some of the Fish Species Delivered to Young in Burrows
Pigeon Guillemots are an important indicator species for the waters of Puget Sound because they are one of the few seabirds that breed here and often stay the entire year. On Whidbey Island they nest in burrows in the bluffs. Volunteers from the Whidbey Audubon Society have monitored the breeding colonies on Whidbey Island for the last 5 years. Here we present data from the last 2 years. Volunteers visited each colony at least 7 times during each breeding season and observed the birds for one hour/visit. They counted the birds, identified active burrows and identified the fish being delivered to burrows. A burrow was deemed active if adults entered the burrow or if they brought food to the burrow. Prey items were identified visually using binoculars and spotting scopes. Selected photos of fish were sent to experts to verify identification.

Over 1000 birds gather at 26 colony sites around the island in the early spring. In 2008, 225 active burrows were identified and in 2009, 255 were identified. About 45% of the birds attempted to breed each year. In 2008 we observed 754 fish deliveries to 161 burrows and in 2009 we observed 1288 deliveries to 183 burrows. Fish deliveries began in late June and reached a peak in late July. The fish delivered to the burrows were primarily gunnels and sculpins. Later in the nesting period larger fish such as pricklebacks and perch were occasionally delivered.

TABLE 1:  Summary of volunteer observations in 2009
Site Name# Burrows*# PD Burrows**Ave # Birds Max. # Birds
Cliffside 13 11 30 48
Crescent Harbor 3 3 10 18
Double Bluff North 37 16 90 118
Double Bluff South 4 3 18 20
Fort Casey 8 8 36 55
Hancock North 10 8 60 73
Harrington Lagoon N 7 7 18 24
Harrington Lagoon S 9 9 18 22
Hastie Lake 9 2 29 39
Keystone 5 5 29 39
Lagoon North, Sites 1A & 1B 13 11 44 64
Lagoon North, Site 2 3 3 12 18
Lagoon North, Site 3 5 5 20 26
Lagoon South 10 6 46 56
Ledgewood 12 9 31 39
Limpet Lane 3 3 16 32
Malmo Bluff 12 12 22 30
Maylor's Point 5 5 16 24
Monroe Landing 5 3 10 26
Mutiny Sands 9 9 34 45
Possession Point 6 5 20 26
Pratt's Bluff 8 6 19 30
Rolling Hills -- Section 1 14 6 28 39
Rolling Hills -- Section 2 12 9 38 50
Shore Meadow 27 14 57 82
Swantown 6 5 23 26
Totals 255 183 774 1069
*Number of burrows deemed active by adult entering or adult delivering prey
**Number of burrows that had prey delivered
Figure 1. Weekly prey deliveries in 2009. The designation other includes unidentified prey and prey other than gunnels or sculpins.

View full-size map

Figure 2. Map of the colonies in 2008-2009. Data from some colonies very near one another were combined for mapping purposes.
TABLE 2:  Estimation of the number of birds attempting to breed and the number of burrows with chicks
Year20082009
Year 2008 2009
Max # Birds 1082 1069
Ave. # Birds 740 774
# Burrows 225 255
# Burrows with Chicks 161 183
% Attempting to Breed* 41.6 47.7
% Hatching Chicks** 71.6 71.7
*((# Burrows x 2)/Max # Birds) x 100
** (#Burrows with Chicks/# Burrows) x 100

Contact:
Frances Wood, 360-341-2326 Online Letter
Phyllis Kind, Ph.D. 360-331-6337 Online Letter

CONCLUSIONS

1.  Pigeon Guillemot colonies are found in virtually every erosional bluff on Whidbey Island.

2.  The number of Pigeon Guillemots in the colonies and the percent of adults attempting to breed appeared stable over the short period we have been monitoring the colonies.

3.  Pigeon Guillemot eggs begin to hatch in late June. The rate of fish delivery increased as eggs were hatching in June and early July, reached a peak in the middle of July and continued into August.

4.  Fish delivered to the chicks were primarily blennies and sculpins.  Near the end of the nesting period larger fish such as perch and pricklebacks were delivered.

5.  The presence of our 35 volunteers on the beaches helps us educate the public about these birds and the stresses human activity may cause them.

6.  Pigeon Guillemots are important to study because large numbers breed here and many spend their entire lives in the Salish Sea. Their vitality is a good indicator of our ecosystem.

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