Spring Arrival Dates
for the Cayuga Lake Basin:
1999-2004


This list presents median and mean spring arrival dates from 1999 to 2004 for 129 species of migratory birds found in the Cayuga Lake Basin. The vast majority of these species was observed each spring. A species marked with an asterisk (*) was seen in at least one January between 1999 and 2004. For these species, every effort was made to use records of migrant (rather than overwintering) individuals to calculate spring arrival dates. In the case of certain species, such as Peregrine Falcon, the line between overwintering and migrant birds has become so blurred that it is impossible to provide a spring arrival date.

This list was compiled by Matthew Medler based on sightings reported to the Cayugabirds listserve. He sincerely thanks all who have contributed their sightings to Cayugabirds, and he also thanks Bill Ostrander for providing access to his database of Kingbird Region 3 bird sightings.

Species
Median Arrival Date
Mean Arrival Date
Std. Dev.
American Woodcock
March 2
March 3
6.9
Wood Duck*
March 7
March 9
5.4
Fox Sparrow
March 7
March 8
11.3
Northern Shoveler*
March 8
March 9
6.4
Golden Eagle
March 8
March 4
10.1
American Pipit*
March 9
March 8
7.7
Eastern Phoebe
March 13
March 6
19.0
Blue-winged Teal
March 14
March 16
6.5
Eastern Meadowlark
March 14
March 14
4.7
Wilson's Snipe
March 18
March 14
19.7
Tree Swallow
March 18
March 17
6.8
Rusty Blackbird*
March 18
March 16
8.1
Bonaparte's Gull*
March 25
March 23
8.1
Osprey
March 26
March 25
2.9
Sandhill Crane
March 30
April 5
10.6
Savannah Sparrow*
March 31
March 23
13.6
Barn Swallow
April 1
April 3
5.1
Field Sparrow*
April 1
April 2
4.1
Greater Yellowlegs
April 3
April 3
4.3
Yellow-bellied Sapsucker*
April 3
April 3
2.7
Chipping Sparrow*
April 3
April 3
1.4
Winter Wren*
April 4
April 4
3.1
Pectoral Sandpiper
April 7
April 6
13.6
Vesper Sparrow
April 7
April 7
4.6
Purple Martin
April 8
April 9
7.6
Pine Warbler
April 8
April 7
6.6
Caspian Tern
April 9
April 11
6.3
Northern Rough-winged Swallow
April 9
April 10
2.7
Hermit Thrush*
April 9
April 10
5.3
Lesser Yellowlegs*
April 10
April 8
5.0
Ruby-crowned Kinglet*
April 10
April 10
4.7
Eastern Towhee*
April 10
April 10
4.3
Dunlin*
April 12
April 13
9.0
American Bittern*
April 13
April 11
9.8
Great Egret
April 13
April 14
17.7
Virginia Rail
April 13
April 14
8.0
Louisiana Waterthrush
April 13
April 12
6.1
Yellow-rumped Warbler*
April 14
April 13
5.6
Cattle Egret
April 15
April 16
15.8
Broad-winged Hawk
April 15
April 15
1.6
Spotted Sandpiper
April 16
April 17
2.6
Blue-headed Vireo
April 16
April 16
3.3
Brown Thrasher
April 16
April 17
3.5
Palm Warbler
April 17
April 17
6.5
Common Moorhen
April 18
April 18
8.6
Green Heron
April 19
April 19
5.1
House Wren
April 19
April 20
3.4
Blue-gray Gnatcatcher
April 20
April 19
5.0
Common Tern
April 21
April 21
7.8
Forster's Tern
April 21
April 21
8.6
Yellow Warbler
April 22
April 22
2.4
Black-crowned Night-Heron
April 23
April 22
7.5
Upland Sandpiper
April 23
April 23
9.5
Chimney Swift
April 23
April 22
2.9
Cliff Swallow
April 23
April 22
7.3
Northern Waterthrush
April 23
April 23
4.0
Bank Swallow
April 24
April 22
4.5
Black-throated Green Warbler
April 24
April 24
3.3
Black-and-white Warbler
April 24
April 24
2.5
Eastern Kingbird
April 25
April 27
4.2
Great Crested Flycatcher
April 26
April 26
5.2
White-crowned Sparrow*
April 27
April 27
4.7
Solitary Sandpiper
April 28
April 27
2.8
Northern Parula
April 28
April 28
3.7
Nashville Warbler
April 29
April 27
4.6
Common Yellowthroat*
April 29
April 28
4.5
Rose-breasted Grosbeak
April 29
April 29
2.6
Baltimore Oriole*
April 29
April 29
1.8
Ruby-throated Hummingbird
April 30
April 29
6.1
Least Flycatcher
April 30
April 29
1.5
Warbling Vireo
April 30
April 28
3.1
Marsh Wren*
April 30
April 27
13.7
Blue-winged Warbler
April 30
April 30
2.4
Chestnut-sided Warbler
April 30
April 30
1.6
Ovenbird
April 30
April 29
2.5
Bobolink
April 30
April 30
2.8
Glossy Ibis
May 1
May 9
13.9
Black-bellied Plover
May 1
May 3
10.0
Least Sandpiper
May 1
May 1
2.6
Black Tern
May 1
April 29
2.7
Gray Catbird*
May 1
April 25
10.8
American Redstart
May 1
May 1
0.5
Whip-poor-will
May 2
May 5
7.4
Veery
May 2
April 30
4.7
Wood Thrush
May 2
April 30
3.7
Black-throated Blue Warbler
May 2
May 1
1.9
Blackburnian Warbler
May 2
May 2
1.9
Indigo Bunting
May 2
May 2
2.8
Sora
May 3
May 1
6.0
Yellow-throated Vireo
May 3
May 3
1.8
Red-eyed Vireo
May 3
May 3
2.0
Magnolia Warbler
May 3
May 3
2.9
Cape May Warbler
May 3
May 5
2.3
Prairie Warbler
May 3
May 3
1.0
Scarlet Tanager
May 3
May 3
2.1
Cerulean Warbler
May 4
May 4
2.2
Grasshopper Sparrow
May 5
May 6
5.8
Lincoln's Sparrow
May 6
May 5
3.3
Eastern Wood-Pewee
May 7
May 6
7.1
Philadelphia Vireo
May 7
May 8
2.7
Bay-breasted Warbler
May 7
May 8
3.3
Canada Warbler
May 7
May 6
1.8
Tennessee Warbler
May 8
May 7
2.3
Orange-crowned Warbler
May 8
May 9
1.8
Hooded Warbler
May 8
May 8
2.2
Wilson's Warbler
May 8
May 9
2.4
Orchard Oriole
May 8
May 8
1.7
Golden-winged Warbler
May 9
May 8
2.0
Black-billed Cuckoo
May 10
May 11
4.0
Swainson's Thrush
May 11
May 11
3.9
Henslow's Sparrow
May 11
May 8
8.1
Semipalmated Sandpiper
May 12
May 11
7.2
Blackpoll Warbler
May 12
May 11
2.0
Mourning Warbler
May 12
May 12
3.4
Semipalmated Plover
May 13
May 12
6.0
Worm-eating Warbler
May 13
May 13
3.4
Yellow-billed Cuckoo
May 15
May 13
5.2
Alder Flycatcher
May 15
May 15
5.2
Common Nighthawk
May 16
May 15
7.9
Willow Flycatcher
May 16
May 17
3.8
Short-billled Dowitcher
May 18
May 20
5.8
White-rumped Sandpiper
May 19
May 18
9.4
Wilson's Phalarope
May 20
May 17
9.4
Olive-sided Flycatcher
May 20
May 20
6.2
Yellow-bellied Flycatcher
May 20
May 20
3.4
Ruddy Turnstone
May 22
May 19
6.0
Gray-cheeked Thrush
May 22
May 22
3.4
Brant
May 26
May 21
14.0
Sanderling
May 30
May 30
4.8


An Explanation of Statistical Terms

Median and mean are both measures of the center of a data set. The median arrival date for a species was calculated by arranging the six arrival dates (expressed as day of year) from earliest to latest, and then averaging the middle two values. The mean arrival date was calculated by adding the six arrival dates (again expressed as day of year) and then dividing by six. Care was taken to properly treat reported arrival dates from leap years (in 2000 and 2004). The median and mean arrival dates provided in the above list are stated as dates for a non-leap year.

Standard Deviation (Std. Dev.) is a measure of the variation in a data set. American Redstart, with an extremely small standard deviation of 0.5, showed very little variation in its first arrival date in the years between 1999 and 2004. These dates were: May 1, 1999; April 30, 2000 (equivalent to May 1 in a non-leap year); May 1, 2001; May 2, 2002; May 2, 2003; and April 30, 2004 (again equivalent to May 1 in a non-leap year). The first arrival dates for Wilson's Snipe, by comparison, showed a huge amount of variation, ranging from February 6, 2002 to April 3, 2001. This wide range of arrival dates resulted in a very large standard deviation of 19.7 for this species.