BARN SWALLOW DEPARTURE DATES AT VANCOUVER, BC

Wayne C. Weber contopus at shaw.ca
Thu Jan 24 08:32:13 PST 2002


Birders,

In previous messages, I have referred to the extremely late fall
departure dates for BARN SWALLOWS in the Vancouver, B.C. area. Here
are some details, going back to 1968. The dates for most of the last
decade have not been compiled yet, but have not changed much.

Barn Swallow departure dates:

1968 Dec 7
1969 Jan 2 (1970)
1970 Nov 22
1971 Dec 6
1972 Dec 3
1973 Dec 20
1974 Dec 21
1975 to 1978 Not available
1979 Oct 31
1980 Nov 23
1981 Nov 26
1982 Nov 8
1983 Nov 19
1984 Dec 3
1985 Nov 20
1986 Nov 8
1987 Dec 13
1988 Dec 15
1989 Dec 15
1990 Dec 2
1991 Not available
1992 Dec 2

Mean departure date: Dec 2 (20 years)
Median departure date: Dec 3
Earliest departure date: Oct 31
Latest departure date: Jan 2

In all but 3 or 4 of these years, the last departure dates were at the
Reifel Bird Sanctuary in Delta, BC. This locality (for those not
familiar with it) is at the mouth of the Fraser River and has several
tree-bordered sloughs which offer shelter from the wind, and nearly
always have some flying insects (midges, etc.) on days when the
temperature is above freezing.

My belief is that these late Barn Swallows were actually attempting to
overwinter (migration is pretty much over by the end of October), but
eventually succumbed to cold and lack of food. The pattern of late
BARN SWALLOWS at this locality has not changed over the last 30+
years. This is in sharp contrast to the pattern of BARN SWALLOWS
appearing at scattered localities in January and February, which has
become apparent only in the last 5 years or so.

Is there anywhere else in the Pacific Northwest where Barn Swallows
consistently remain so late? If so, I'm not aware of it. On two
occasions (1969 and 1974), Barn Swallows were tallied on the Ladner
Christmas Bird Count, which includes the Reifel Sanctuary. In 1969,
the 4 Barn Swallows on the Ladner CBC were a North American high
count, even beating out Coot Bay, FL, which usually has a few!

Wayne C. Weber
Kamloops and Delta, BC
contopus at shaw.ca






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