(Chelsea Update would like to thank Tom Hodgson and the Waterloo Natural History Association for the information and photos in this story.)
It is staging season for the greater sandhill crane in the Chelsea Area once again.
Before they leave for their Florida wintering grounds in late November, the number of these fascinating birds resting and feeding in area fields is expected to grow to nearly 10,000.
Cranes are omnivorous, feeding on both plant and animal material. Until the first killing frost, the cranes will spend much of their time in area alfalfa fields feeding on grasshoppers and crickets. As farmers begin cutting their corn, they will move into these fields to feed on waste grain left behind by the harvesting process. They will also visit soy bean fields after the harvest, but seem to prefer corn.
During this staging period, the cranes can also be seen dancing in the fields. They jump high into the air often with wings extended. During the dancing they may call loudly and toss pieces of vegetation.
No one knows why they dance, but some wildlife biologists think it may be done to help strengthen pair bonding. That may only be partial explanation, as young birds of the year and even newly hatched nestlings have been observed dancing. Dancing seems to increase when large numbers of cranes are together. Perhaps it is a way of releasing stress caused by the presence of so many other birds.
Regardless of the reason, the dancing can be very entertaining for crane watchers. The areas early settlers called the cranes “preacher birds” because their antics and loud calling reminded them of an animated preacher trying to inspire his congregation.
Cranes do most of their feeding before 10 a.m. and after 2 p.m. Many spend the middle of the day in area marshes resting and digesting their morning meal before returning to the fields to feed again in the afternoon. As sunset nears, they seek out open wetlands with shallow water where they are relatively safe from predators that might attack during the night.
The primary predators for adult birds are coyotes and bobcats. Coyotes have become quite common in our area. While bobcats are occasionally seen, they are few and far between in southern lower Michigan. They are much more common in Florida where they contribute significantly to crane mortality on the wintering grounds.
During the fall crane season, the Jackson Audubon and the Waterloo Natural History Association produce crane-viewing maps that are updated weekly. Copies are available at the Haehnle Sanctuary, and at the Discovery Center in the Waterloo Recreation Area, or they can be downloaded from the Haehnle Sanctuary web site.
Each map also includes a suggested, self-guided fall color tour route so travelers are able to combine both crane watching and leaf-peeping.
