What Migrating Birds appreciate the Savanna Wildflowers and Grasses of Somme Prairie Grove?

Mourning Warbler

September 24, 2024. 

I was out in Somme Prairie Grove gathering seeds for restoration. The rare plants here surprised me with three great birds, on the same day, when I wasn't looking for them, and without binoculars: mourning warbler, black-billed cuckoo, and merlin.

The mourning warbler came first - with its gray head, black bib, and yellow breast. It jumped up, briefly, blurrily, on a stem to check me out - and then was gone. I was happy to see it. 

This bird was in an area of scattered six-foot oaks, down feeding in the dropseed grass, asters, savanna blazing star, and cream gentians. The mourning warbler nests in Wisconsin and Canada, winters in Central and South America, and need insect food to power its migration in between. It's uncommon to see them, partly because they tend to stay low, under vegetation. 

The second bird was the bigger surprise. Occasionally nesting at Somme, though not this year, the black-billed cuckoo is on the Threatened list as a breeding bird in Illinois. I would have expected to see it, if anywhere, in the same mixed-shrubs-and-herbs vegetation as the mourning warbler. 

Black-billed Cuckoo

But it flew up from an open grassland, at least fifty feet away from shrubs and trees. Little bluestem, heath aster, and rattlesnake master. I saw clearly the brown wings that distinguish it from its rusty-winged cousin, the yellow-billed cuckoo. It flew to the top of the nearest Hill's oak, and sat there for a bit. Then it flew a bit higher and dove like a peregrine into the open grassland on the other side of that tree. I waited a while, but it stayed down. Must have seen a delicious insect and chose to eat it among the flowers. 

My third bird, that late September day, was a merlin. This powerful little falcon was just migrating through, on the way from open woodlands and "parklike grasslands with scattered trees" in Canada to similar open habitats as far south as Ecuador. The Somme wildflowers and grasses provide food for it too, indirectly. Those plants provide most of the food for the large insects and small birds that the merlin eats. 

When we started restoration, Somme's open areas were poor habitat - typical former overgrazed pasture - soils worn out. Low scrawny plants like poverty oats and daisy predominated. Not attractive to many birds. 

In July, the area where the mourning warbler popped up today looked like this. 

It's been inspiring to see birds return as the soils and vegetation recovered. Now during the breeding season we share the viewscape and soundscape with orchard orioles, kingbirds, flickers, bluebirds, field and song sparrows, hummingbirds, indigo buntings, and yellow-throats - all of which depend largely on the herb vegetation. Also returning are larger predators including the Cooper's hawk and kestrel. Cooper's came back first, and then after three decades of restoration, we now have had one or two nesting pairs of kestrels every year. This recovering ecosystem has the resources that many rare or uncommon birds need. 

We of the Somme team happily work to be good neighbors to the birds, butterflies, and all biota who share this precious preserve with us.

For a companion Somme Woods bird post, click here.