Pine Siskin/Redpoll invasion 1977-78 at Norristown, PA

Raymond J. Middleton

Until this winter we had previously banded 108 Pine Siskins (Spinus pinus), 60 of these in early 1972. An AHY bird banded 10 March 1970 returned 18 January 1972; another AHY bird banded 23 January 1972 was trapped and released 23 April 1972 by John Buckalew. An AHY bird banded here 8 April was found dead 18 May 1973 at Winnipeg, Canada.

The siskins came in flocks toward the end of 1977. By January's end we had banded 381. They remained in smaller numbers until 29 April at our station but some were noted nearby for the next two weeks. We had banded 471 and had 368 repeats during this invasion. One foreign retrap was taken--1470-86471.

We had 2 bags and 1 cylinder feeder hanging from a tree limb near our back door; these were kept filled with thistle seed. Directly under the feeders we had a Modesto trap and a Middleton thrush trap into which the seeds fell. A few feet away were two four-celled Potter and one drop trap, all on posts five feet from the ground. Sunflower seed, millet, and finely cracked corn were used for bait. Some millet was placed in the ground traps. Three-quarters of the birds were taken in the two ground traps.

On 1 February the Common Redpolls (Acanthus flammea) came in flocks. As the redpolls increased, the Pine Siskins decreased. The first redpoll appeared on 23 January. During February 481 were banded. A Hoary Redpoll (Acanthus hornemanni), with a much whiter plumage and a large white rump patch, was taken on 11 February.

From early January until mid-March we had a deep snow cover and all traps around the perimeter of our yard were of no use. All redpolls, Pine Siskins, goldfinches, and Purple Finches were caught 5-15 feet from our back door.

From 7 January to 3 March we had problems with hawks coming into the yard. With the fields covered with deep snow, the rodents were hard to come by. One Cooper's Hawk (Accipiter cooperii) and one Sharp-shinned Hawk (Accipiter striatus) were seen in the trees. Nine times American Kestrels (Falco sparverius) entered one section of the Potter traps as they tried to get at a bird in the other sections of the trap. Seven kestrels were banded and removed five miles or more from here; two returned a second time and were again removed some distance away.

Whenever the hawks appeared, the small birds scattered widely but, as I walked out, the hawks flew off and the small birds soon returned to feed. Early on 3 March the flocks of birds were here but a kestrel flew in and all scattered never to return in any large numbers, although some 15-20 were noted for the remainder of the season.

Redpolls were last seen on 2 April (this was also the last date for 1960; 1960 was the only other year in which we banded redpolls--60). During January and February we had 2220 captures, 1153 new birds, 1054 repeats, and 13 returns.

By May we had taken:

The seven House Finch (Carpodacus mexicanus) returns were from five birds banded in 1977 and two banded in 1976. Five of the American Goldfinch (Spinus tristus) returns were banded in 1977--an AHY bird banded in 1974 and an AHY M banded in 1973.

The two Purple Finch (Carpodacus purpureus) returns were: an AHY M banded 31 January 1973, at least seven years old; and an AHY, brown-plumage at banding on 22 March 1973, was in full male coloring--probably six years old. A Purple Finch banded 23 March 1975 (#850-71754) was found dead 24 February in the southern part of Arkansas near the Louisiana border, in the town of Crosserr.

Common Redpoll #1480-38531, banded 12 February 1978, was trapped and released--as an AHY F--at Schenectady, NY on 9 April 1978 by Robert P. Yunick.

131 North Whitehall Rd., Norristown, PA 19401.