The spring morning air is filled with the delicious sweet fragrance of American plum tree blossoms. I slowly inhale, savoring the pleasing aroma. The wild plum thicket is aglow in white, its dense flowers seemingly floating like clouds just above the ground. Suddenly, a rich, melodious song of doubled phrases explodes through the air. It’s a brown thrasher, the rock star of the bird world, jamming for all his worth in the plum thicket. I try to follow along with his song, accepting his repeated notes as his patient invite for me to join in, but it’s no use. His repertoire of songs is too vast, with no discernable beginning or end. This is why we must pay the shrub thicket tax.
Maintaining shrub thickets in a grassland setting offers unique habitat opportunities for at-risk species such as the brown thrasher, American woodcock, loggerhead shrike, Bell’s vireo, willow flycatcher and others. However, it comes with a tax – its management cost. The thickets need to be protected from fire and “swept and cleaned” of invasive species every year
Protection from fire is critical in order to maintain the woody structure that attracts these at-risk bird species. While occasional fire typically doesn’t kill most native shrub species, it can top-kill them, greatly reducing their stature and attractiveness for nesting birds.
Managing a grassland fire is difficult enough without the extra burden of protecting shrub thickets, so choose wisely in where to establish a “save feature” thicket. The easiest location to protect shrub thickets from fire is along a permanent burn or fire break. This keeps the fire crew out of the burn unit interior, and fire intensity along burn breaks is typically less, which eases fire suppression efforts.
Typically in the fall, I mow the prairie grass in a ring 20-feet wide around the shrub thickets, then burn these mowed areas in late fall or winter when conditions offer mild fire behavior. Once late winter/early spring rolls around, and we’re racing to get all our burns done, it’s a simple matter to protect these thickets because there’s no fuel immediately adjacent to them.
Unlike fire protection, invasive species control in shrub thickets is needed annually. A shrub thicket in an open grassland setting is a wildlife magnet. Animals of all types will frequent shrub thickets and leave behind unwanted seeds in their feces or tracked in from fur, hair, feathers, hooves or feet. Invasive species such as garlic mustard, Japanese hedge parsley, multiflora rose, European buckthorn, and honeysuckle will show up year after year with likely no end in sight as long as neighboring lands are unmanaged.
These thickets are, well, thick, and often require a good belly crawl to get at that last garlic mustard plant. To add insult to injury, sometimes the wildlife tenants are not receptive to our good intentions. Nesting birds, such as the brown thrasher, can be aggressive and may give you a good whack if you’re not careful. I took a blow to the head from a blue jay years ago. Another time, came face to face (thank goodness it was not the other end) with Pepé Le Pew.
The brown thrasher continues his concert, working his way through Greatest Hits Volume II. Soon, I hope, if the passage of life repeats itself, I’ll hear a willow flycatcher calling from this very same thicket. And come November, I’ll likely get to see shrikes in this thicket as they migrate through the area.
Like the seasonal fragrance of the plum blossoms and the melodious songs of the thrasher, so too marks my shrub thicket management efforts on nature’s calendar.
It is a tax I am happy to pay.