Hubbard Fellowship Blog – The Vanishing Sparrow

This post was written by Evan Barrientos, one of our Hubbard Fellows.  Evan is a talented writer and photographer and I encourage you to check out his personal blog.

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.

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A Henslow’s Sparrow, not normally found in the Platte River Prairies, made an appearance last June.

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 Tory 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.

The prairie where I found the Henslow's Sparrow, photographed later in the year.

This is the prairie where I found the Henslow’s Sparrow, photographed a month later. To breed, Henslow’s Sparrows seem to prefer large, treeless prairies with tall, dense vegetation. This habitat is becoming scarce in many areas.

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:

The Great Drought (Again)

A warm and dry winter, followed by a hot dry spring and summer…  Temperatures over 100 degrees Fahrenheit for weeks at a time…  Wildflowers blooming two to three weeks earlier than normal, and often for much shorter periods than typical…  Other plants withering and/or going dormant before they get a chance to bloom.

Sound familiar?  It’s a good description of the conditions across much of the central United States in 2012.  However, it’s also a description of eastern Nebraska back in 1934. The famous prairie biologist, J.E. Weaver and two colleagues published a 1935 paper detailing the response of prairie plants to the “great drought of 1934”, in which they describe the weather conditions and plant community responses in prairies near Lincoln.  The similarities between the drought of 1934 and 2012 are pretty strong.  The main difference  is that much of Nebraska actually had fairly wet conditions during the spring and summer of 2011, whereas in 1934 the extreme drought came on the heels of dry seasons in both 1931 and 1933.  Apart from that, a warm dry winter, very low rainfall, and extraordinarily long stretches of very hot temperatures characterized both 1934 and 2012. 

Most prairies look pretty dry this year.  In this burned and grazed prairie, only the most drought tolerant plants, including plains sunflower, western ragweed, and prairie sandreed, are still green.

The paper by Weaver, Stoddart, and Noll is interesting for a couple reasons.  First, it’s nice to see evidence that prairies have been through the kind of conditions we’re experiencing this year, and to know that those prairies rebounded.  We all know prairie communities are resilient, but with a high likelihood of more frequent and intense droughts in our future, it’s comforting to see some historical evidence that prairies have the capability to handle extreme weather (in fact, the drought of 1934 was followed by drought conditions for most of the rest of that decade).  Second, the authors describe the way individual plant species responded to the drought conditions of 1934, and it’s both fascinating and reassuring to see the same plant species responding in similar ways now.  Weaver and his colleagues describe the overall appearance of the prairie, season by season, and discuss the relationship between the ability of species to withstand drought conditions and their rooting depths and architecture.  Also of interest, Weaver published a follow-up paper in 1936, describing the way prairie plant communities looked in 1935 – one year after the big drought.

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