Blackbrook Audubon invites birders of all skill levels to a field trip to Old Woman Creek State Nature Preserve on Oct. 20. The group will meet there at 2514 Cleveland Road E. in Huron, at 9 a.m., or at Lakeland Community College’s Route 306 parking lot at 7:30 a.m. to carpool to the preserve, according to a news release. Designated a state nature preserve in 1979 and encompassing 574 acres, Old Woman Creek is also a National Estuarine Research Reserve, the release stated. An estuary is the area where the land’s fresh waters meet and mix with the saltwater of the sea. Although salinity is not a factor here, the waters of the lake and Old Woman Creek combine in the estuary to form a third type of water, chemically different from that of either the creek or lake. Old Woman Creek is the only national estuarine reserve in the Great Lakes and the only one in the reserve system not connected to an ocean. Over 220 bird species have been reported on eBird in this preserve’s mix of habitats, according to the release. In addition to waterfowl, key species this time of year include Field Sparrow, Great-Crested Flycatcher and Yellow-Rumped Warbler. Blackbrook Audubon asks those interested in attending the walk to RSVP to [email protected]. The field trip leader will have a couple pairs of binoculars to lend. Updates will be posted on Blackbrook Audubon Society’s Facebook page.