2013 Edmonds Christmas Bird Count


December 21, 2013

Eighty field observers covered approximately 75 miles on foot, 562 miles by car and 29 miles by boat counting 46,230 birds in 120 species.  An additional 53 home observers spent 68 hours counting 1,455 birds and added one species (Peregrine Falcon) not seen by the field teams. The 133 participants recorded new or tied previous high counts for 31 of the 121 species seen, and a historic low count (9) for the Western Grebe.  On further evaluation of the field and home counts, the numbers for 57 species were greater than one standard deviation above the 29-year mean (an up signal).  A listing of these 31 and the 57 bird species is here.  Only one species, the Northern Harrier, was less than one standard deviation below the mean (a down signal).  Edmonds Count by Area lists all bird species observed within the CBC area.

A second way to evaluate the data is by normalization using factors that effect the count, like weather and the overall effort by the participants.  Normalization should provide a clearer look at trends in the data on a level playing field.  In normalizing by total count observation hours, only five species (Harlequin Duck, Anna’s Hummingbird, Hairy Woodpecker, Spotted Towhee and Fox Sparrow) have record high counts and none with low counts.  Further, the numbers for only 20 and 6 species were greater or less than one standard deviation from the mean, respectively.  This normalization may not be an entirely accurate look at the data as it assumes that every observer has an equal chance of seeing each bird species.  Clearly observers in land locked areas have less of a chance of seeing some waterfowl species.  Also, the effects of weather on historic counts were not factored into this analysis.  Nonetheless, it does provide a look at bird populations that perhaps is not as optimistic as the raw data analyses.

Species of Interest
Perhaps the most unusual sighting was a group of three Trumpeter Swans flying near shore in Puget Sound.  They were initially seen by two shore observers at Picnic Point in Area 3.  As these birds flew south, the boat team saw these birds off Ocean Avenue in Edmonds at about noon as they were flying out of Area 2 toward the Edmonds waterfront.

Uncommon birds seen were Ancient Murrelet (1 at Possession Point), American Pipet (1 in Edmonds) and Cedar Waxwing (2 in Area 9S).  The rarest bird that may have been in the count area was a Northern Mockingbird, never seen before during the CBC.  It was observed by a non-participant north of Perrinville in Area 2, but was not reported until Jan 10, 2014.

There were no notable misses this year.  However, two species usually seen, the American Kestrel and the Western Gull (seen in 20 and 18 of 29 years, respectively) were not seen.  The former, however, was seen just north of the count circle in Area 5N.

American Crow
Counting American Crows during the CBC has always been a challenge.  After roosting overnight at various locations in south county, presently mainly at or near the UW Bothell campus, they disperse at dawn.  Crows moving from roosting areas in the morning and returning in the evening can be concentrated.  Approximately 3,000 crows were seen at dawn on Dec 21, 2013 at Lake Forest Park apparently headed for the greater Seattle area.   The returning movement to roosting areas from the north, however, is more impressive and can be described as a “river of crows” that occasionally parallels the Bothell-Everett Highway north of I-405.  At times, this river has been observed to be approximately 7 miles in length, and it contained nearly 10,000 crows during the late afternoon of the CBC.  Where do these crows come from?  During the CBC roughly 2,700 crows were counted by 32 field teams on their neighborhood routes.  Many of these crows, particularly those found in the southern two-thirds of the CBC area, likely do not join the “river of crows.”  About 1,500 crows were counted on Dec 14, 2013 during the Everett CBC.  Where the remaining 1,000’s (6-8K?) of crows in the “river” are located during the day is unknown at this point.  According to the Washington Department of Fish & Wildlife, crows can travel as far as 40 miles each day between roosting and feeding areas, and from late summer to winter they gather from many miles to form communal night roosts.

Cavity Nesting Birds
In 2011, seven species of cavity nesting birds (five woodpecker species: Red-breasted, Downy, Hairy, Northern Flicker and Pileated; and two chickadees species: Black-capped and Chestnut Backed) were seen at or near record levels.  This trend continued in 2012, and in 2013 record or high levels for cavity nesting birds were seen even when the raw data were normalized by total observer hours.  This seems counter intuitive given the continued clearing of old growth timber, removal of snags, and development that is continuing in south Snohomish County.   It appears, however, that adequate habitat is presently being preserved or not developed to support these bird populations.

Field vs. Home Counts

During the CBC, birds were counted either by field teams or at home (i.e., at feeders, in yards and, in one case, also in an adjacent lake).  Field teams counted birds on more-or-less establish routes covering (1) several miles and involving some means of transportation (car, boat, bike, etc.) and walking when on land, or (2) a much shorter distance, usually less than 2 miles, and only by walking.  This latter group will hereafter be referred to as a mini field team, usually just one person.

Of the field and home counts, four field and one home can be categorized as neighborhood mini field counts.  The results of the three types of counts during this CBC are summarized below.
 
 
Total
Birds
Total Species
New Species
Total distance covered (miles)
Total observation
time (hrs:mins)
Field1
46,935
119
118
641.25
157
Mini field
750
43
22
5
   10:15
Home
1272
45
1
0
 66:45
Notes:
1   Overall totals minus the mini field counts, distances and times.
 Plus the only Yellow-shafted Flicker observed.

When measured against the field effort, the number of birds seen by the mini field and home observers was very low—about 2% and 3%, respectively.  However, the number of species seen by these observers was much higher—about 36% and 38%, respectively.  Further, the mini field teams and home observers added three additional bird species, Peregrine Falcon, Mourning Dove and Evening Grosbeak, to the CBC list.

The time differentials for making species identifications were noteworthy.  Mini field teams saw 36% of the species in about 7% of the time that it took the field teams.  Similarly, home birders saw 37% of the species in 40% of the time that it took the field teams.  Further,  the home birders saw 57% of the California Quail, 89% of the Band-tailed Pigeons, 50% of the Barn Owls, 33% of the Anna’s Hummingbirds,  50% of the Bush Tits, 37% of the Red-breasted Nuthatches, 45% of the Townsend’s Warblers, 40% of the White-throated Sparrows, and 50% of the Purple Finches in the CBC.

There are obvious shortcomings with this analysis, such as a low sample size, but it shows that an effort should be placed on shorter routes covered by birders more familiar with that area, and an expansion of home birder participation.  As south Snohomish County continues to develop, it may be difficult to gain access and have knowledge about the pockets of remaining habitat, other than parks.  Using smaller groups to cover smaller areas is one way to approach this potential problem.
 

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