The Audubon Society is in the midst of its 114th Christmas Bird Count season. It all began back in 1900 when Frank Chapman, an early officer of the young Audubon Society, proposed an alternative to the then popular tradition of a holiday season competitive hunt. Hunters would choose sides and the team with the biggest pile of game taken won the contest. The first bird count had 27 participants scattered around North America’s population centers. They tallied around 90 species that day.
The Christmas Count has grown steadily since that time, and helped give birth to the idea of valuable “citizen science.” There are now over 2300 registered count circles, each with a diameter of 15 miles. Tens of thousands of people participate. The count season runs from mid December into early January, and includes counts from Mexico and the Caribbean Islands, to Canada and Arctic Alaska, and even some of the Pacific Islands. The data gathered has become a major source of information on the relative abundance of bird life in the Western Hemisphere and where those birds occur. It has shown the ongoing loss of total numbers and range of grassland species like meadow larks, and continuing declines of some tropical migrants like scarlet tanagers. These declines are due in large part to losses of grassland and large forest breeding habitats. Some species, like Canada and snow geese, have shown dramatic increases. Other species have shown steady northward winter range expansion due, it is assumed, to climate change.
The Ames area count on Saturday, Dec. 14, tallied 74 species. That was well more than the usual 60 to 65 species, thanks to a group of more than 20 dedicated and sharp-eyed counters. Some less common (at least for winter) species seen during the Ames count included a red-headed woodpecker south of Nevada, a common grackle in Nevada, a red-shouldered hawk southeast of Ames and a lone ring-billed gull in Ames. It’s become usual to see a few bald eagles and many thousands of Canada geese. Last year was an “invasion year” for several northern species like pine siskins, red polls, red-breasted nuthatches and snowy owls. Those species were absent or rare this year, so the higher count number was all the more surprising.
Bird feeder sites play a big role in concentrating winter song birds where they can be seen and counted. We noted an ongoing trend in our Nevada count area of fewer and fewer active feeder sites. Empty feeders still hung at some of our old favorite sites, and the area around them was birdless. Even my well-tended feeders offered few birds when we checked them in late morning. That could have been due to the beautiful adult Cooper’s hawk that we spotted nearby. My wife reported that a young Cooper’s hawk perched in our yard for awhile, too. No wonder the birds were staying under cover. A couple of rural feeder sites south of Nevada along Indian Creek helped us build our total count numbers, though.
Habitat loss is still the biggest concern for birds of all kinds. Another factor is becoming a greater concern, according to the Iowa DNR’s Nongame Wildlife Program, and that’s feral house cats. It has been estimated that there were 30 million house cats in North America in 1970. That number doubled to 60 million in 1990 and is estimated at 114 million today. Many, if not most of these animals, are not pets in the classic sense of the word. They may hang out at a particular farm or near a particular home, but they live pretty much as wild animals. Research has shown that a single cat is capable of killing as many as 1000 birds and small animals every year. One researcher estimated that cats killed 2-7 percent of all birds in southern Canada each year. The U. S. Fish and Wildlife Service estimates that 1.4 to 3.7 billion birds, and as many as 20 billion animals, are killed by house cats each year. Cats are an alien, human-introduced predator. Both wild and tame, they are now thought to be the second leading cause of human-influenced bird mortality, right behind habitat loss. You can do your part to reduce this loss by having your cat neutered and keeping it indoors.
(Steve Lekwa is the former director of Story County Conservation.)