Hundreds of greater white-fronted geese flew over Lake Renwick Preserve in Plainfield on Monday. (Photo by Glenn P. Knoblock)
If you've recently noticed a large number of geese flying overhead that look a little different than the incredibly loud Canada geese you're accustomed to seeing and hearing, you're not alone. That's because greater white-fronted geese are passing through the area, heading north from their wintering grounds as far south as Mexico.
It can be an impressive scene, as we saw on Monday while at Lake Renwick Preserve in Plainfield, when hundreds of these stocky brown birds dropped in. A number of other large flocks have been reported in Will County this week, including Monday at McKinley Woods in Channahon.
"If you know where and when to look, greater white-fronted geese can be found in select Will County preserves yearly," said Chris Gutmann, a facility supervisor at Four Rivers Environmental Education Center, located in McKinley Woods in Channahon. "Ranges of many species are shifting due to climate change, habitat alteration, etc."
He spotted these birds on Monday while outside near the Four Rivers building, reporting his sighting of approximately 560 geese on eBird.
So how does one go about counting that many birds at once? Gutmann uses a technique called "blocking," in which you count the birds in one section, or block, then extrapolate that number to the remainder of the flock.
"It's not exact, but if you do it well, it produces a very good estimate," Gutmann said.
Their migration has just begun, with the greatest chances of seeing them locally coming in late winter and in the fall. But unlike the American white pelicans that make a long stopover on Will County's waterways during their migration, these geese prefer a quick visit on their way to their breeding grounds in the arctic tundra. It won't be until later this spring that they reach this destination.
"They usually don't stay long," Gutmann said. "Because greater white-fronted geese use our area strictly as for migratory stopover site, the window to see these birds is relatively small. Even when greater white-fronted geese are in this area, they are not widespread. Although, when you find them, they can be in large numbers."
In addition to the large flocks reported at McKinley Woods and Lake Renwick, Gutmann also reported seeing a flock of 350 at Rock Run Rookery Preserve in Joliet.
They tend to pick stopover sites with open water and proximity to agricultural fields. The water provides them a place to rest, while the agricultural fields provide food.
When out and about in the preserves, don't assume those geese off in the distance are Canada geese, although some may be mixed in with the greater white-fronted geese. Gutmann said when greater white-fronted geese are flying overhead, you'll hear them before you see them, and their call is higher pitched than that of a Canada goose.
"For birders hoping to find this species, I suggest not overlooking the flocks of geese flying over their homes," he said. "I’ve seen large flocks flying over my yard almost as much as I’ve seen them in the water."
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