WINFIELD — Max Thompson has been hosting some special visitors for breakfast this winter.
A lot of visitors.
“One day I counted more than 300 in the tree,” Thompson said early Thursday morning, pointing to a 25-foot locust that rose above bird feeders in his backyard. “Hard to believe, but some years we never had a siskin all winter.”
He was referring to pine siskins, thumb-sized birds that mostly spend their spring and summers well to the north, like the conifer forests of mid-Canada. Where they spend their falls and winters can vary greatly.
“I suspect a lot of it has to do with food,” said Thompson, a retired biology professor at Southwestern College. “When the snow is deep, there’s no food.”
Birders refer to unusually high migrations as “invasions.” Thompson said this year’s siskin invasion seems to be centered on south-central Kansas, with Winfield as its bull’s-eye.
The recent annual Christmas Bird Count for the Winfield and Udall area turned up 659 pine siskins. That was by far the most of the 58 counts in Kansas.
Thompson said one reason the Winfield count was so high was that he played the recorded sounds of a screech owl, an enemy of most songbirds, near Winfield City Lake.
“I played the owl tape and almost immediately had about 300 siskins all around me,” he said.
Though American goldfinches weigh about twice as much as pine siskins, Thompson said the smaller birds are aggressive enough to usually rule the feeders.
Both species appear to be taking invasions farther south than southern Kansas.
“I have a friend in Texas who said they’d just arrived down there, and last year he didn’t have any siskins or goldfinches, or at least very few,” Thompson said. “But two years ago he banded 4,000 in his backyard. That’s why it’s so much fun birding, you never know what you’re going to see.”
Thompson, who has birded or done avian research on all seven continents, said winter invasions into central Kansas can come from large birds, as well as small.
Last winter the state had one of its best snowy owl invasions in memory. About 131 of the Arctic-born owls, the largest owls in North America, were reported across the state.
“We usually have one or two,” Thompson said.
This year Thompson referred to a day when a birder counted 81 rough-legged hawks, another Arctic bird of prey, around the Cheyenne Bottoms wetland area.
“Apparently they cleaned up the rodents in that area because they moved on through,” Thompson said. “Most of our invasions come from the north or the west, and it’s usually because they’re looking for food.”
Though retired, Thompson likes to stay active in ornithological research, especially when there are things like hundreds of pine siskins in his backyard.
For the past few days he has hung a baited wire trap from the locust tree.
Thursday morning, Thompson emptied the trap twice and placed tiny research leg bands on several dozen pine siskins.
All flew from his hands when released. The majority will never be officially documented again. Those that are could be far away.
Checking an edition of “Birds of Kansas,” a comprehensive book that he co-authored, Thompson said that through 2010 about 47,000 pine siskins had been banded in Kansas. Of those, only about 181 had been re-encountered, 110 in Kansas. The other 71 were recovered far and wide across the U.S. and Canada.
He expects the current invasion of pine siskins to last into early March, when they will take off for nesting grounds.
In the meantime, Thompson will continue to keep his feeders filled with enough seed to feed a few hundred dainty visitors a day.
“At least my lawn is getting well fertilized,” he said with a smile.