2001 Fermilab Bird Report

Le Conte's Sparrow (Photo by Jed Hertz)

The 2000 Christmas Bird Count was in some ways rather disappointing in that the species and individual counts for the lab were rather modest even though the species count for the entire count area equaled the second highest. There were however, a couple of surprises from the site. A Le Conte's Sparrow seen inside the Main Ring was the first ever winter record not only the site but also for the entire count circle. (Note that the previous fall was remarkable for the number of these birds seen on site.) The second surprise was a Red-shouldered Hawk which was the first count record for the site. Apart from several Lapland Longspur records, a Merlin, a Bald Eagle, and a Brown Thrasher the remainder of the winter was fairly uneventful. Of note however was the absence of both Long-eared Owls and Short-eared Owls. The former may have been driven off site due to excessive disturbance by Birdwatchers.

Early spring was very exciting this year. In February a Lesser Black-backed Gull on A.E.Sea brought the site list up to 269 and in March it became 270 when an Iceland Gull was seen on Lake Logo. March also produced a string of remarkable sightings including large numbers of Tundra Swans, the second site record of Thayer's Gull, more sightings of the Lesser Black-backed Gull, and another Bald Eagle.

The remarkably consistent weather throughout April and May produced a very poor paserine migration. Warbler numbers were well below average and few rarities were found. Finding migrants in late spring is easiest when a warm southerly winds are interrupted overnight by a cold front, the birds fly north with the southerlies and stop to rest when they encounter north winds. It is during these rest periods that the birds are most readily found.

Least Bittern (Photo by Tom Bentley)

Summer brought the 3rd addition this year to the site list when a Least Bittern was seen in the center of the Main Ring in early June. This confirmed a report from the same area last year. Remarkably, another one was reported from Lake Law in August. The usual significant breeding birds (Upland Sandpipers in ELM16 and Bell's Vireos in ELM14) were present again this year, reaffirming the success of the management stratagems for these areas. More importantly, however, was the presence of a number of breeding pairs of Henslow's Sparrows in ELM 15. This species reappeared on site last year after an absence of over 20 years. However last year their reappearance coincided with a large influx of the species throughout northern Illinois. There apparently was no influx this year making our site records all the more significant.

The fall migration also started off well with the second sight record of Red-necked Phalarope on Lake Law and a Yellow-troated Warbler in ELM14. However, despite a Northern Mockingbird in early October, late fall was again disappointing and again the reason is likely to be the unusually mild weather.