Many of our birds are obviously migratory. Much less obvious is how predictable the times of their arrivals and departures are. At San Juan Capistrano, the arrival date of Cliff Swallows is almost like clockwork, but how predictable are the arrivals for many of our birds in Oregon?

Once one delves into the world of migration dates, one quickly learns that dates can vary from site to site. For example, in Lincoln County, Tree and Violet-green Swallows typically arrive at marshes along the coast several weeks before they do at dry inland sites in the Coast Range. The downside of this variation is that migration dates for one area can not be blindly extrapolated to other areas. The upside is that each of us has the opportunity to DISCOVER the migration dates for our own area without knowing if other areas will have similar dates. Further, it is fun to compare migration dates for one's own area with other areas to see what differences exist.

Unfortunately, arrival and especially departure dates for Oregon birds are not widely available for many areas. Gabrielson and Jewett's (1940) work is still the most comprehensive work giving migration dates, but it is really only a thumbnail sketch of migration dates for the state. For the Malheur National Wildlife Refuge, Littlefield and McLaury (1973)] and Littlefield and Cornely (1984) give the average migration dates but more importantly also gives the range in migration dates. Other papers (e.g., Winter 1976, Bayer 1977, 1986a; McGie 1979, 1980; Ramsey and Hacker 1984) suffer from not being available to the average Oregon birder and also from only listing the average or typical migration dates. The problem with "average" migration dates is that they may markedly differ from the actual observed dates.

Below are listed the migration dates found by Grace French in the Carlton and Dayton portions of Yamhill County during 1913-1950. These migration dates are excerpted from the migration dates given yearly in Bayer (1986b). An abstract of this 40 page monograph is in Bayer (1986c).

A problem with French's migration dates as with most studies of migration dates is variability in observation effort. It is easy to miss the date that birds first arrive, and it is even more difficult to record the last date that they are present. Further, more time may be spent one year than another in trying to determine migration dates. Thus, observed "migration" dates are really the dates that birds are first or last REPORTED, not necessarily the dates that the birds actually first arrived and last departed.

In spite of these shortcomings, French's migration dates are still of interest because she has data for so many years, and they are for an area where migration dates have not been previously published.

---------------------------------------------------------------------------
                           First Reported________    Last Reported________
                           Yrs    Mean  Range        Yrs   Mean  Range
---------------------------------------------------------------------------
Turkey Vulture              32    3/23  3/10-4/29     19   9/24  8/27-10/4
Sandhill Crane              13    4/17  4/8-5/3        1   10/9  10/9
Red-necked Phalarope         8    5/3   4/14-5/22      0    -    -
Band-tailed Pigeon          28    4/27  4/8-5/26       8   9/17  8/12-10/18
Mourning Dove               24    5/2   2/27-6/2       7   9/8   8/14-10/13
Common Nighthawk            26    6/5   5/28-6/18      3   8/24  8/18-8/31
Vaux's Swift                15    5/11  4/22-6/17     13   9/12  8/18-9/30
Rufous Hummingbird          33    3/26  3/10-4/15     11   8/27  8/4-10/4
Western Wood-Pewee          31    5/14  4/30-5/28      7   8/18  8/5-9/18
Willow Flycatcher           25    5/23  5/2-6/1        4   9/9   8/21-9/28
Tree Swallow                31    3/5   2/12-3/30      1   9/23  9/23
Violet-green Swallow        34    3/7   2/15-3/25     22   10/1  9/12-10/12
No. Rough-winged Swallow    21    4/27  4/2-5/18       0    -    -
Cliff Swallow               31    4/10  3/22-5/12      4   9/21  9/11-9/28
Barn Swallow                13    5/23  4/21-6/7       4   9/9   8/31-9/19
House Wren                  30    4/26  4/9-5/25       3   9/12  9/11-9/13
Swainson's Thrush           30    5/12  4/27-5/24     10   9/11  8/29-9/28
American Robin*             29    2/1*  1/4-3/8*       0    -    -
Cedar Waxwing               30    5/19  5/5-5/31      13   9/24  8/29-10/27
Solitary Vireo              31    4/18  4/6-5/2       10   9/14  8/30-10/27
Warbling Vireo              27    5/5   4/24-6/3       1   8/10  8/10
Orange-crowned Warbler      32    4/11  3/31-4/26      2   9/2   8/21-9/13
Yellow Warbler              32    5/2   4/21-5/10      3   8/30  8/22-9/12
Yellow-rumped Warbler
     Audubon's              31    3/10  2/16-4/13      0    -    -
     Myrtle                 29    4/2   2/21-5/11      0    -    -
Black-throated Gray Warbler 28    4/20  4/2-5/12       7   9/18  8/25-10/3
Townsend's Warbler           8    5/9   4/25-5/22      0    -    -
Hermit Warbler               5    5/14  5/4-5/24       0    -    -
MacGillivray's Warbler      27    5/1   4/12-5/21      3   8/23  8/14-9/6
Common Yellowthroat         31    4/22  4/10-5/10      5   9/9   9/5-9/13
Wilson's Warbler            23    5/6   4/29-5/23      1   9/14  9/14
Yellow-breasted Chat        26    5/16  4/25-6/2       4   8/21  8/4-9/3
Western Tanager             29    5/10  5/1-5/20      17   9/3   8/8-9/23
Black-headed Grosbeak       29    5/15  5/6-6/4        5   8/17  8/8-8/25
Lazuli Bunting              29    5/9   4/27-5/25      3   8/22  8/13-8/31
Chipping Sparrow            32    4/10  3/23-4/27     12   9/16  8/30-10/1
Vesper Sparrow              30    4/3   3/11-4/23      0    -    -
Savannah Sparrow            21    4/17  3/22-5/12      0    -    -
Lincoln's Sparrow           16    4/25  4/12-5/5       1   8/27  8/27
Golden-crowned Sparrow@     30    4/5   3/7-4/23@     18   5/12  5/4-5/21@
Golden-crowned Sparrow      19    9/25  9/11-11/10     0    -    -
White-crowned Sparrow       32    3/27  2/21-4/14     13   9/18  8/19-10/8
Lesser Goldfinch%           27    4/18  3/7-5/24%      0    -    -
American Goldfinch#         32    4/17  3/28-5/2#      0    -    -
Pine Siskin                 29    4/11  3/1-5/1        0    -    -

*   This is when robins first arrived in flocks; scattered ones were 
     present earlier.
@  Some Golden-crowned Sparrows remained throughout the winters, but they 
     were mainly spring and fall migrants.
%  Lesser Goldfinches were sometimes present in winter.
#  These are the first arrival dates of male American Goldfinches.

Bayer, R. D. 1977. Birds of Lincoln County, Oregon. 19 p. Oregon State Univ. Sea Grant Marine Advisory Program. (Out of print.)

________. 1986a. 1884-1923 Oregon Coast Bird Notes in Biological Survey Files. Studies in Oregon Ornithol. No. 1. 68 p.

________. 1986b. A Guide to the Bird Notes of Grace McCormac French of Yamhill County, Oregon. Studies in Oregon Ornithol. No. 2. 40 p.

________. 1986c. Studies in Oregon Ornithology. Oregon Birds 12:251-252.

Gabrielson, I. N. and S. G. Jewett. 1940. Birds of Oregon. Oregon State Monogr. No. 2. Oregon State Univ., Corvallis. (Dover Publications republished this in 1970 as "Birds of the Pacific Northwest.")

Littlefield, C. D. and J. E. Cornely. 1984. Fall migration of birds at Malheur National Wildlife Refuge, Oregon. Western Birds 15:15-22.

________ and E. L. McLaury. 1973. Bird arrival dates on Malheur National Wildlife Refuge, Oregon. Western Birds 4:83-88.

McGie, A. 1979. Spring phenology for Coos Bay. Cape Arago Tattler 2(4):8-9.

________. 1980. Fall phenology for Coos Bay. Cape Arago Tattler 4(3):4-5.

Ramsey, F. L. and N. Hacker. 1984. Corvallis phenology. Chat (Aud. Soc. of Corvallis) 13:51.

Winter, A. 1976. Davis Lake migration dates. SWOC Talk 2:69-70.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.