Field & Street | Field & Street | Chicago Reader

Field & Street 

Sign up for our newsletters Subscribe

Last week's mail brought my copy of the Cook County results from this year's State-Wide Spring Bird Count. We birders put together a pretty good year, with 191 total species and 48,353 individuals recorded on count day.

The count is sponsored by the state Department of Conservation (DOC). It takes place every year on the Saturday that falls between the fourth and tenth of May. This year the date was the eighth.

Each county has a compiler whose job it is to organize the local birders into a force of census takers who will blanket the landscape on count day. In some rural counties where birders are scarcer than Volvos, the DOC recruits mercenaries to at least sample the local bird life.

Most years Cook County turns out a larger number of birders and discovers a larger number of birds than any other county in the state. Our only serious competition is Lake County, which still holds the all-time record for species seen: 206, which they got in 1983. That same year Cook County reached a total of 204.

The big news on this year's count was the ibis seen at Lake Calumet by Walter Marcisz and his party. The bird was in flight when they saw it, and they couldn't tell if it was a glossy or a white-faced ibis, but whichever it was it was the first member of the genus Plegadis ever seen on a Cook County spring count and only about the 12th ibis ever seen in the Chicago area.

As usual, the ring-billed gull won the prize for most abundant bird, with 16,274 individuals counted. This species regularly tops the list, and its numbers keep growing. The 1990 count recorded just under 4,000 ring-bills. These gulls are so common in Chicago that even nonbirders notice them. They gather in parking lots all over town, and it is hard to look up at the sky without seeing at least one. However, their seeming abundance may be partly the result of their conspicuousness. Birds that habitually lurk in the weeds may be undercounted, while big birds that hang around shopping centers may be recorded in larger numbers than are actually present.

The abundance of this species teaches us a small conservation lesson. The birds we see locally in spring and early summer are--except for the occasional wanderer--all from the nesting colony at Lake Calumet. The next nearest nesting colony for this species is at the northern end of Lake Michigan. If the Calumet colony were to be destroyed--if, for example, an airport were to be built over it--we would see a continuing decline in gull numbers during the spring and summer nesting season. Within a couple of decades--gulls do live that long--the last of our local birds would be dead, and gull sightings would be rare.

Our species total of 191 is pretty good. Most years our totals are in the 180s. What put us over the 190 mark this year were sightings of some songbirds we often miss on the count. The clay-colored sparrow is of rare-but-regular occurrence around here as a migrant but is only occasionally discovered on the spring count. LeConte's sparrow also passes through each spring but is usually gone from here by the first week in May and is therefore rarely seen on count day.

Some years we miss the pine warbler, which is also an April bird. This year we found 20 of them, a record high for the species. In all, a dozen wood warblers were recorded in greater numbers this year than on any previous count. The spring count began in 1972, but for the first decade the number of participants was fairly small. Since the early 80s we have regularly turned out 40 to 50 parties of birders, so the numbers of birds seen can be at least roughly compared from year to year.

Record highs for wood warblers are always good news. This whole family of birds, Neotropical migrants all, is suffering a continuing decline. Their numbers have been going down unrelentingly for decades. A slight uptick in the numbers reported from one county's spring count is the most modest of improvements, but we will take anything we can get at this point.

The plight of our Neotropical migrant forest birds has been drawing considerable attention, but a press release I just received from the U.S. Fish and Wildlife Service opens up yet another grim vista. The lead sentence reads "Native birds in North America's grasslands have suffered steeper, more consistent, and more widespread declines over the past 25 years than any other U.S. bird group."

The focus of the release is mainly on birds of the Great Plains, particularly the mountain plover, lark bunting, Franklin's gull, and Cassin's sparrow, all of which have suffered "statistically significant" declines. The mountain plover is a candidate for listing as an endangered or threatened species.

The release also notes declines in 16 species considered "secondarily evolved" to grasslands. Among those showing statistically significant declines are four species typical of the tall-grass prairies of Illinois: eastern meadowlark, dickcissel, grasshopper sparrow, and Henslow's sparrow. The Henslow's is already on the Illinois endangered list.

We did find fewer eastern meadowlarks this year than in past years--only 64 birds, compared to nearly twice that many on earlier counts--but one count can't really tell us much. Results of nesting surveys would be more meaningful. We rarely see either dickcissel or Henslow's sparrows on the count--we had one Henslow's this year--and grasshopper sparrows are reported in such low numbers that we can't draw conclusions from the count data.

We do know that all the prairie birds are in trouble in Illinois because of habitat loss. And birders know that here in Cook County prairie birds are usually found in only a few forest preserves, some at the southern end of the county and some in the panhandle around Barrington and Palatine. Birds confined to small areas are always vulnerable.

There is some good news in the count results. Double-crested cormorants continued their increase. In the early years of the count this species was seldom reported. As recently as 1985 only 5 birds were counted. In 1987 just 13 were found. By 1990 83 cormorants showed up on count day. This year an amazing 362 were counted. We have ample additional evidence that this species is making a major comeback, and we should be cheerful about any good news we can find.

Nancy Standley of Chicago served again this year as compiler of the Cook County count, and she deserves our gratitude. I know from experience--I did it for five years--that this is an endless job, a task that requires making lots of nagging phone calls and fussing with lots of niggling details.

What made it worthwhile for me was the opportunity to see the county as a whole. And what I saw seemed to suggest patterns that I would like to investigate more closely. Spring migration is not a steady march to the north. It happens in waves. The birds wait for favorable winds and then ride them as far as they can. If count day happens to fall on a day when your county is in the trough of a wave you will see fewer birds. If you catch a wave at the crest you will see lots of birds. That much is obvious.

What is intriguing is the distribution of birds in the county. Lake Calumet and Palos are always the birdiest places in Cook County. They show slight fluctuations from year to year, but no other area can challenge their preeminence. Some areas show very large fluctuations. The lakefront is especially subject to these oscillations. A wave of birds can roll in on a southerly wind in the morning, but if the wind shifts to the northeast during the day the lakefront parks are practically devoid of birds by evening. Where do they go?

There are even more complexities in this picture. On some counts Jackson Park is full of birds and the Northwestern landfill in Evanston is lifeless. On other days that pattern is reversed. On some counts the forest preserves along the Des Plaines River have birds fighting each other for perching space on tree limbs, while the North Branch of the Chicago and the North Shore Channel are dead. Other days that pattern is reversed.

I think we ought to use some of the peace dividend (you remember the peace dividend--there were a number of reported sightings a few years back) to hire about 50 good birders to conduct a twice-a-week county census during the months of April and May. Do that every year for ten years or so. Correlate your results with weather patterns, and who knows? You might learn something about bird migration before all the migrant birds go extinct.

Comments

Subscribe to this thread:

Add a comment

More by Jerry Sullivan

  • Vote Kestrel!

    Neither waxwing, nor kingbird, the best candidate for official bird of Chicago is right under our noses.
    • Oct 7, 1999
  • Field & Street

    • Feb 4, 1999
  • Field & Street

    • Jan 7, 1999
  • More »

Tabbed Event Search

Popular Stories