A Nature Ramble in Michigan

Any family trip is an opportunity to explore the natural history of a new area and rejuvenate your powers of observation dulled by residence in one area where you tend to see the same things over and over. Thus when we embarked on a visit to a grandson in Interlochen, Michigan, in the third week of May, I was enthusiastic about the possibilities of experiencing early spring in a northern latitude, in this case just south of the 45th parallel.

The lower peninsula of Michigan is a land of many lakes not to mention Lake Michigan to the west and Lake Huron to the east. Michigan brags about having the longest freshwater shoreline of any state. I was able to sample aquatic life from the shore and on a sunny but cool day noticed an interesting basking map turtle that is characteristic of large lakes and rivers. This female is much larger than the males which are lovers and not fighters, unlike the large and pugnacious male snapping turtles. This allows the adult female to feed on different prey than the males and to produce more eggs than a smaller female could. Two aquatic birds present on freshwater lakes were the trumpeter swan and the common merganser. The swan uses its long neck and sturdy bill to dredge up food items from the shallow bottom whereas the merganser dives to catch fish. Trumpeter males and females are identical in color and likely choose mates via behavioral means. In contrast merganser males are quite colorful in comparison with the cryptic females. Such a “gaudy male” syndrome seems to be associated with a breeding system in which females could choose the most fit males as mates by comparing their colors.

In late May the forest trees are starting to leaf out and bloom, and a marvelous movement of neotropical migrant birds is underway. We visited one of the most famous locations to observe this migratory phenomenon, Tawas Point on Saginaw Bay in Lake Huron. We were not disappointed by the remarkable display of birds to be easily observed in relatively low vegetation. One of the most spectacular birds, the male scarlet tanager, is the ultimate gaudy male whereas the female is a dull yellowish color. Near Grayling we found a pair of yellow bellied sapsuckers building a nest in a rotten tree and noticed how a basically dull male has patches of bright scarlet on the forehead and neck, presumably to attract the female. The evening grosbeak is a bird of the northern forests and although the male is more gaudy than the gray female, its colors are far more muted than most tanagers and orioles.

The ultimate neotropical migrants are the tiny and flamboyant wood warblers which migrate from the tropics to the temperate zone to breed. We encountered the golden winged warbler that requires rarely occurring early/middle successional old fields to breed. Near Grayling we visited the extremely specialized young jack pine habitat which has to be managed to prevent the Kirtland’s warbler from going extinct. Both of these species are threatened by their inability to utilize more generalized habitat types. In comparison the beautiful redstart is typical of a wide variety of wooded habitats and is so common in some areas that it borders on being a “trash bird.”

So when you embark on summer family trips, seize the opportunity to broaden your ecological horizons and learn some new animal and plant communities. It is fun and gives you a new perspective on the beauties of nature.

Bill Dunson

About Bill Dunson

Bill Dunson, born in rural Georgia, skipped 12th grade and went directly to Yale. Bill subsequent-ly received a PhD in Zoology from the University of Michigan, studying softshell turtles. Bill is Professor Emeritus of Pennsylvania State University thanks to a career spent entirely at that institution, teaching and doing research on the physio-logical ecology and ecotoxiciology of reptiles, amphibians and fish. Always curious about nature, Bill has dedicated his life to learning and sharing his knowledge with others. He has served on many advisory boards here in Southwest Florida to preserve the water that gives life to our region.

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