Tuesday, January 16, 2018

2017 Brattleboro CBC Results

2017 Brattleboro Christmas Bird Count
Summary and Analysis
By Cory Ross 

The 118th Audubon Christmas Bird Count was conducted all over the United States and Canada between December 15th and January 5th. This annual census of birds is one of the most valuable tools ornithologists have to track the changing distribution and abundance of avian populations. The count is also a great example of citizen science.

Members of our Southeastern Vermont Audubon Society surveyed the Brattleboro count area on Saturday, December 16th. This marked the 57th year the local bird count took place, with the first count dating back to 1903. Counts have been held nearly annually from 1966 to the present following similar routes for the past 50 years. Birders divided into seven teams, searching out birds wherever they could be found. 33 people logged 176.5 person-hours, walking 11 miles and driving 262.3 miles over the course of 8 hours. Participants traversed snow depths of 3 to 10 inches with temperatures as low as 9 degrees. Limited open water on the West and Connecticut Rivers may have contributed to lower numbers of waterfowl species being observed, with the exception of mallard and Canada goose.

An additional 16 people conducted home feeder counts. In total, 4,742 individual birds of 50 different species were counted and a number of unusual sightings were made. This year marked the first Baltimore oriole in the Brattleboro count’s history. Next, was a lone gray catbird along the railroad tracks in downtown Brattleboro, the first one to be found on count day in a decade. In addition, a red-winged blackbird visiting a feeder in Hinsdale was the first sighting in 8 years. Red-winged blackbirds were once a common count day bird in the 1980’s. A small amount of open water around the Vernon Dam accounted for the bulk of the 754 Canada geese observed, the largest number since 2008. The 156 mallards observed represented the highest number since 2001. A rough-legged hawk flying over Chesterfield late in the day was only the 6th sighting of the species in the count’s history. The 3 great blue herons sighted matched a previous high from 1992, a particular surprise on such a cold day with very little open water. The 25 red-bellied woodpeckers seen provided the second highest total in count history. These birds have expanded their range into Southern Vermont over the past 15 years. The two red-breasted nuthatches were the lowest number found since the count of 1949. Brown creeper was absent for the second year in a row after being observed in 18 consecutive counts prior to last year. A hermit thrush found in Dummerston was only the 6th occurrence in the count’s history. Only 6 American robins were found, the lowest total in a decade. The 632 dark-eyed juncos found was the highest total since 2000.

Overall, the total number of birds counted was about 17% higher than the past ten-year average, and a full 23% higher than the thirty-year average. However, the number of species represented an 8% decline from the ten-year average. The limited amount of open water may have played a role in fewer species being seen.

Species
2017
Previous 10-year mean
Previous 20-year mean
Previous 30 year mean
Canada Goose
754
356.7777778
313.4705882
287.0526316
American Black Duck
3
21.7
16.9
12.8
Mallard
156
59.3
59.35
40.36666667
Hooded Merganser
4
35.5
23.1
15.73333333
Common Merganser
23
16.4
16.85
12.5
Ruffed Grouse
0
1.555555556
1.647058824
2.333333333
Wild Turkey
21
44.9
53.77777778
44.07407407
Great Blue Heron
3
0.375
0.388888889
0.444444444
Sharp-shinned Hawk
2
1.1
1.277777778
1.37037037
Cooper's Hawk
3
2.111111111
1.421052632
1.068965517
Bald Eagle
3
2.8
1.75
1.333333333
Red-tailed Hawk
15
12.2
11
8.966666667
Rough-legged Hawk
1
0.2
0.15
0.103448276
Ring-billed Gull
5
81.1
60.4
42.86666667
Herring Gull
0
19.22222222
19.68421053
104.7241379
Rock Pigeon
122
219.9
264.35
307.7333333
Mourning Dove
106
154.8
175.4
193.8666667
Barred Owl
2
2.5
1.857142857
1.347826087
Belted Kingfisher
0
1.875
1.533333333
1.16
Red-bellied Woodpecker
25
13.5
7.7
5.166666667
Yellow-bellied Sapsucker
1
1
0.526315789
0.344827586
Downy Woodpecker
31
43.9
41.9
36.66666667
Hairy Woodpecker
14
24.1
19.35
18.16666667
Northern Flicker (Yellow-shafted)
1
1
0.85
0.633333333
Pileated Woodpecker
7
4.8
3.894736842
3.24137931
Blue Jay
227
233.1
220.05
223.0333333
American Crow
468
277.8
245.2
244.3666667
Common Raven
9
7.2
5.5
4.7
Horned Lark
0
74.44444444
41.58823529
14.5
Black-capped Chickadee
294
433.2
423.15
421.3
Tufted Titmouse
69
60.7
56.2
47.7
Red-breasted Nuthatch
2
10.2
15.75
16.63333333
White-breasted Nuthatch
50
63.9
59.2
54.73333333
Brown Creeper
0
2.1
2.5
2.733333333
Carolina Wren
1
4.9
3.55
2.551724138
Golden-crowned Kinglet
8
5.2
17.1
14.36666667
Ruby-crowned Kinglet
cw
0.9
0.55
0.5
Eastern Bluebird
45
42.2
26.3
17.86666667
Hermit Thrush
1
0.333333333
0.157894737
0.137931034
American Robin
6
63.6
41.9
28.56666667
Gray Catbird
1
0
0.105263158
0.068965517
Northern Mockingbird
5
5.5
6.95
7.3
European Starling
745
400.6
374.35
468.1
Cedar Waxwing
86
235.7
204.75
155.8666667
Snow Bunting
0
6.8
7.5
8.633333333
American Tree Sparrow
25
66
57.45
72.86666667
Dark-eyed Junco (Slate-colored)
632
222.1
248.9
221.1
White-throated Sparrow
10
11.4
12.75
10.5
Song Sparrow
5
7.6
7.55
9.2
Northern Cardinal
64
56.6
44.3
39.8
Red-winged Blackbird
1
0.4
0.45
1.533333333
Brown-headed Cowbird
0
0
0.388888889
3.357142857
Baltimore Oriole
1
0
0
0
Pine Grosbeak
0
9.7
5.6
4.655172414
House Finch
66
55.9
60.7
100.4333333
Purple Finch
2
5.2
6.684210526
6
Red Crossbill
0
0.1
0.052631579
0.035714286
Common Redpoll
0
48.125
37.66666667
26.28571429
Pine Siskin
0
44.7
40.10526316
49.37931034
American Goldfinch
275
262.5
250.85
202.4
Evening Grosbeak
0
14.7
17.63157895
50
House Sparrow
342
245.7
237.05
242.5
Total Birds
4742
4065
3961.888889
3857
# of Species
50
54.5
53.88888889
50.33333333