South Dakota Species Highlight: Chestnut-collared Longspur

There are some species I instantly think of as being iconic northern Great Plains species when I hear the name. Marbled Godwit. Baird’s Sparrow. Lark Bunting. Greater Prairie Chicken. When I think of driving west and north from my home in far southeastern South Dakota, and heading to the central or western part of the state, away from the mosaic of corn and soybeans that dominates my area, I think of wide open grasslands, few people, and a unique ecosystem of iconic bird species. In my mind that also includes the Chestnut-collared Longspur, a gorgeous bird with a unique dark plumage (breeding plumage males) that I almost see when I heard the name, hanging out on a barbed wire fence with nothing but grassland for miles around.

Chestnut-collared Longspur - Calcarius ornatus
Harding County, SOuth Dakota
Chestnut-collared Longspur from July 22nd, 2011 in Harding County, South Dakota. This. This is what I think of when I hear the name, a gorgeous breeding plumaged male Chestnut-collared Longspur hanging out on a barbed wire fence in a rolling grassland environment.

Yesterday I was processing bird photos (still a few years behind) and working on my website. I was working on a directory of photos I got last July in Hyde County, in the east-central part of the state, and got to one photo, and one photo only, of a Chestnut-collared Longspur. It’s not a great photo, and in fact, if it were another species where I had an abundance of photos, I might have thrown it out. I was shooting photos of shorebirds at a small wetland I’d stumbled across, when the lone longspur flew into my vision and plopped down to grab a quick drink. It was mid-day, the lighting was poor, but I grabbed a quick shot, surprised I’d seen one here, as I usually think of them as being a bird I’d find further to the east and north.

Then, as what tends to happen, I downloaded all the photos from that day, and they sat there unprocessed. I’d forgotten about that photo and encounter until processing photos yesterday, and knowing my collection of Chestnut-collared Longspur photos was sparse, I decided to keep the photo and work on the associated species pages on my website. As I was doing so, it brought to light just how rare an encounter the sighting was for me.

Chestnut-collared Longspur - Calcarius ornatus
Hyde County, South Dakota
Chestnut-collared Longspur July 5th, 2020 Hyde County, South Dakota. One quick photo grab, and the bird was gone.

Two. TWO. That’s how many “decent” photos of the species I’ve managed to grab in South Dakota in the 21 years I’ve been birding. Despite my internal impression of the species as an iconic Northern Prairie species, both my actual sightings and photographs of the species have been extremely limited.

As I started working on my dedicated species page for the Chestnut-collared Longspur, I got to the “Conservation Status” section of the page and started doing some research, beefing up my current (very sparse) content. When I first created the page for the species some 20 years ago, there seemingly weren’t any worries about the status of the species. But when I looked at the IUCN (International Union for Conservation of Nature) web page on the conservation status of the species, it was immediately clear it was a species in trouble. The species has been downgraded in status twice in recent years as numbers have started to dwindle.

IUCN Redlist status for the Chestnut-collared Longspur.
From the IUCN page for the Chestnut-collared Longspur, a history of the official status of the species in their eyes. The species status has been downgraded twice in recent years, and numbers continue to decline.

It’s wasn’t a cheery exercise reading more about the status of the species. The Breeding Bird Survey (BBS) data, the gold standard for rigorous, systematic tracking of population trends over time, indicated a startling decline in the species of almost 90% from 1966 (Sauer et al. 2016). Other data sources show equally shocking declines, with estimates of >95% species loss in the Canadian portion of the Chestnut-collared Longspur range in less than 40 years, from 1971 to 2017 (COSEWIC 2019). A species that was once a common breeding bird in Nebraska, Kansas, and Minnesota has nearly been extirpated from those states, and previously robust populations elsewhere in its historical range are now gone. Clearly, it’s a species in serious trouble.

So what’s the cause of the trouble? Most sources agree that habitat loss is the primary factor in their decline. The Northern Great Plains used to be a mosaic of natural grasslands, wetlands, and riparian corridors with woodlands. Davis (2004) studied habitat needs for the Chestnut-collared Longspur and found that they required quite large, contiguous blocks of grassland to successfully breed. They avoided even what might be considered “prime” grassland habitat if the size of that grassland patch were anything less than 100 acres. With vast swaths of former Great Plains grassland converted to agricultural land uses in the last 150 years, grassland communities have been devastated, and remaining grassland patches have been heavily fragmented. In short, Chestnut-collared Longspurs can’t find enough suitable large patches of grassland on which to breed.

That downward spiral of suitable habitat continues currently, and in fact has recently intensified in parts of the Great Plains. That includes right here in South Dakota, where demand for corn and soybeans, including the uptick in demand due to biofuel use, has resulted in massive swaths of grassland and prairie land being plowed under for the first time in just the last 15-20 years. South Dakota itself is a hotspot of this habitat loss, particularly eastern and north-central South Dakota, where the rate of grassland habitat loss in recent years is actually higher than that of the well-publicized loss of tropical forest in parts of South America.

From a well-publicized study from Wright & Wimberly (2013), a graphic showing hotspots of grassland loss in recent years. The eastern Dakotas have been a hotspot of habitat loss as grasslands are plowed under and converted to soybean and corn fields.

It’s not just agriculture that’s driving habitat loss in the northern Great Plains. Energy development is front and center in parts of that range, as new methods for extracting fossil fuels have been developed in the last 20 years. The image below depicts the “nighttime lights” dataset for a portion of the northern US. These data record visible light energy from the Earth’s surface at night. Larger cities are clearly visible in the data, but…what’s the massive blob of light in sparsely populated western North Dakota?

Image from the Defense Meteorological Satellite Program’s Operational Line Scan System (DMSP-OLS), generally referred to as the “Nighttime Lights” dataset. Depicting areas of visible light at night, lights from urban centers clearly dominate. However, one of the biggest signals is a sparsely populated, massive swatch in western North Dakota. Those are flaring natural gas associated with hundreds and hundreds of oil wells, as fracking technology made extracting oil possible in this region.

North Dakota is now the 2nd largest oil producing state in the country, thanks to fracking technology developed in the 2000s that has allowed companies to extract a difficult to access, but massive resource of oil in the region. There are hundreds upon hundreds of oil wells in the region, wells that may be spaced out across the massive prairie landscape, but…each well requires access, each well requires energy sources. None of this was there even just 15 years ago, but now the network of wells, roads, and powerlines has severely fragmented grassland habitat in the region.

Range map of the Chestnut-collared Longspur, overlaid with general are of Bakken Oil Formation
The species range map for the Chestnut-collared Longspur, with the general area of the Bakken Oil Formation in the cross-hatched area. The red color on the underlying map represents the breeding range of the Chestnut-collared Longspur. The location of the Bakken formation? Smack dab in the middle of it.

As the map above shows, the Bakken formation is smack dab in the middle of the breeding range for the Chestnut-collared Longspur. The area in North Dakota was developed SO incredibly rapidly, with economic considerations overwhelming any thought for habitat or environmental considerations. But for a species such as the Chestnut-collared Longspur that’s been declining precipitously and needs large, intact grassland patches to breed, oil and gas activity in the Bakken couldn’t have come at a worse time, or in a worse place.

Two. Perhaps it’s not a surprise I only have to photos of Chestnut-collared Longspurs, a species that’s “vulnerable” and fading fast. Get out there and enjoy this species while you can, as your chances of seeing it in the future may be fading.

What are your thoughts? Comment here!

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