By Bill Cook
According to the U.S. Fish and Wildlife Service, wildlife watching in Michigan is estimated to be a two-plus billion-dollar activity. Birding, alone, attracts about two million people. In the high altitude economic picture, these aren’t huge numbers but they’re significant in the natural resources world.
Roughly half of all birds that occur in Michigan use at least one kind of forest. Habitat quality is not a straight-forward thing. Different habitats serve different functions, and at different times.
Take the Ruffed Grouse, for example. It likes thick “brushy” conditions to nest and raise young. In winter, mature aspen and the male flowers are preferred food. Young sapling stands offer critical escape cover from predators. The males like to have large logs from which they “drum” to attract mates and establish territory. So, in a landscape of a few acres, a diversity of forest characteristics is needed for optimum habitat.
What makes “good” bird habitat? It depends.
Let’s start with a large parking lot. Not good habitat? Well, it’s great habitat if you’re a Ring-billed Gull looking for discarded and spilled food. It’s also a pretty safe haven to congregate during migration as potential predators can be spotted long before they can reach the gulls.
Now, if Ring-billed Gulls and their allies were the only thing that mattered, then biologists might advocate for more paved parking lots.
There are about 150 bird species that use Lake States forests, not to mention the other vertebrate taxa and the mind-boggling numbers of invertebrates. Every species has a unique set of habitat requirements. It can be quite complex and, therefore, a bit challenging to answer the “best habitat” question.
The better question is; “Which birds do you wish to manage for?” A forest owner makes choices, either intentionally or by default.
Forest conditions tend to run along gradients such as age, size, density, and composition. Proximity to different habitats is important. There’s also upland/lowland and deciduous/conifer. To make assessments more interesting, all these things change with time. Then, many bird species change their preferences with the season.
What can forest owners do?
1. Learn what sort of forests you have from a “bird’s-eye” view. Assess conditions from a larger landscape perspective. Consider managing for something different from the prevailing set of forest conditions.
2. Encourage understory growth of shrubs and tree saplings. Think of a “green wall” in the summer time. This can be nearly impossible in areas where deer numbers are high.
3. Maintain or create large dead trees. Biologists call these assets “snags”.
4. Underplant conifer species in stands dominated by hardwoods (deciduous trees). You’ll likely need to cage them from deer and rabbits.
5. Plant woody species that produce berries, nuts, and similar fruits. This food source is called “mast”.
6. Large logs on the ground are valuable habitat components.
7. Protecting those spring season puddles (vernal pools) is important.
8. Build and/or maintain corridors between different habitats. These are ribbons of vegetation types where birds (and other animals) like to travel from one place to another.
9. Create young forests, which are declining across the Lake States along with many of the bird species that use them regularly. Be warned, this involves clearcutting.
10. If you have several acres of “scrubland”, a mix of grasses and shrubs, then you’re really fortunate! Consider prescribed fire to maintain these conditions.
While each bird species has different requirements, suites of species can be aggregated into groups. One suite of birds will prefer young forests. Another suite is more readily found in the forests of old trees. Other suites will occupy lowland forests, upland forests, and so on.
The names for most of these birds are unknown to most forest owners. Incidentally, common names have been standardized and should be capitalized. Regardless, identifying bird species and learning their habitat preferences can be an addictive past-time and a great way to teach forest and wildlife appreciation to kids. Ultimately, actively managing forests with birds in mind is highly rewarding.