A small brown bird that sounds like it doesn’t even want to be singing; what could possibly be interesting enough about this to justify a blog post? As is often the case in nature, there’s a lot more than meets the eye (and ear). In my ten years of birdwatching I had only seen this species once before, six years ago. Central Nebraska is on the far western edge of its range, so I was thrilled to document it attempting to breed in one of our prairies. It turns out, this brown speck is an elusive and declining species that epitomizes why we need to manage our prairie so that the full range of habitat structure is present.
Often described as “mouselike,” Henslow’s Sparrows spend most of their time on the ground and prefer to run rather than fly when threatened. The only time they emerge from the grass is to whisper their two-note song, described by Roger Troy Peterson as “one of the poorest vocal efforts of any bird.” While this makes them an exciting challenge to find, it has also made them a difficult species to conserve. Due to their secretive lifestyle, scientists have had a very hard time studying basic facts about their lives, including how many of them there are and what habitat they actually prefer. While most sources say that Henslow’s require large grasslands free of trees and shrubs, there are some shrubby prairies that actually have high Henslow’s populations, such as in Missouri. What is certain is that many of the pastures and hayfields that Henslow’s once nested in have been converted to row crops over the last forty years. Lack of fire and grazing in the remaining grasslands have let trees and shrubs establish, which seem to deter nesting in most cases. As a result, Henslow’s are thought to have declined even more than other grassland birds, although it’s difficult to tell for sure.
Fortunately, land managers and owners can provide suitable habitat for this species by conducting prescribed burns; removing fencelines, hedgerows, and trees; and allowing the grass in some areas to grow tall and rank. The management strategy that The Nature Conservancy practices here on the Platte River Prairies, called patch burn grazing, helps create this habitat. Additionally, Henslow’s have shown signs of adapting to grasslands created by the Conservation Reserve Program. But convincing people to care about species like Henslow’s might be more difficult. How do we raise appreciation for tiny species that require binoculars, excellent hearing, and lots of patience to see well? It’s tough, but I think an important part of enjoying a Henslow’s is understanding how lucky you are to find one. If you do, it probably means that you’re in a scarce type of grassland, a great observer, and a bit lucky. Drab as they may be, Henslow’s are a special species to find. In many ways, Henslow’s Sparrows epitomize the challenges facing all grassland species. For them to survive, we must preserve large tracts of grassland, manage them for specific conditions, and learn to appreciate prairies slowly and thoughtfully.
Sadly, after two weeks of singing, our Henslow’s Sparrow vanished for the rest of the year. Perhaps the prairie wasn’t big enough, or the grass thick enough, but I wish him luck, and I hope it’s not six more years until I find another.
For more information about Henslow’s Sparrows: