Chris Izworski's daily Michigan birding report turns to Mecosta County this morning, where fall migration continues to deliver the goods despite a soggy forecast. The past two weeks have seen 112 species reported across the county, with the big story being the Bay-breasted Warblers working through at Macauley farm. Seven individuals were logged there on September 18, making this one of the strongest warbler concentrations eBird has tracked in the county recently. American Redstarts are also moving through at Northend Riverside Park with four sightings as of September 17, part of the broader wave of Setophaga species pushing south ahead of conditions.
What's Moving Now
The resident and short-distance migrants remain solid across Mecosta's productive areas. Macauley farm has become the hotspot du jour with Turkey Vultures, Cedar Waxwings, Black-capped Chickadees, Cardinals, and Chipping Sparrows all active as of September 18. The Turkey Vulture count of eight birds at the Fred Meijer White Pine Trail on September 18 suggests good thermal activity earlier this week before today's rain system moves in.
Brown-headed Cowbirds continue their September dominance with 30 individuals reported at Morton Two Cemetery on September 15. This is typical end-of-summer behavior as they congregate before dispersal, though their numbers are worth noting if you're tracking breeding season aftermath.
One item of note: Blue-winged Warblers were flagged at Northend Riverside Park on September 5, with three separate records on the same date. This is worth monitoring at that location as Northend has a solid all-time species list of 142 and sits right on riparian habitat. No follow-up sightings in the data since then, but the species is scarce enough in Mecosta that any subsequent report would be worth verifying.
Waterbirds and the Muskegon River
Common Mergansers remain present on the Muskegon River at the White Pine Trail with five birds logged on September 10. That river corridor continues to be the county's most reliable waterbird zone. Canada Geese are still about in small flocks, and with the northeast wind expected tomorrow, there's a chance for downstream movement of dabbling ducks over the next few days if conditions hold.
The Weather Factor
Today brings showers and thunderstorms likely with a 75 percent rain chance and temperatures only reaching 61 degrees. This will suppress activity during peak hours. The wind is light at 9 mph from the east-southeast, which won't push birds dramatically, but the rain itself will keep things quiet. Tonight's patchy fog and tomorrow's clearing with northeast winds at 8 to 12 mph makes Sunday the better field day. Cooler air and northeast flow often push warblers and shorebirds closer to the lakeshore areas and can concentrate migrants in smaller patches.
If you're out this morning before the rain intensifies, the dawn window runs from 6:53 to 8:53 AM with sunrise at 7:23. The chickadees and nuthatches should be vocal in the Macauley farm area and around Northend Riverside Park regardless of the weather early on.
Where to Point the Scope
Martiny Lakes remains the county's flagship hotspot with 190 species on the all-time list and should be your first choice if you have a dry spell today or early tomorrow. The Haymarsh SGA at Haymarsh Campground with 165 all-time species is your second best bet for coverage and habitat diversity. Both locations have enough acreage and varied terrain to absorb today's weather better than smaller sites. The rain may actually concentrate warblers in the dense cover around both of these areas.
The data is current through September 18 and represents solid mid-September activity for Mecosta County. Migration is in full swing, and with tomorrow's clearing, Sunday could be productive for shorebirds and additional warbler activity along the county's river and wetland systems.
For the live map and complete county data, check https://birding.chrisizworski.com.