Pawnee National Grassland is 193,000 acres mostly comprised of native shortgrass prairie in north central Colorado. Pawnee is a well known birding location because it is one of the best places in the world to see three localized and declining prairie species: Mountain Plover, Chestnut-collared Longspur, and Thick-billed Longspur as well as other common prairie species. It is also the best place in the state to find Sharp-tailed Grouse. Our goal for the day was to find all four of these species.
April is my favorite time to bird in Pawnee National Grassland. The combination of minimal biting insects, pleasant spring temperatures, and displaying Sharp-tailed Grouse make for incredible birding!
Our first target bird of the day was Sharp-tailed Grouse. The very northern part of Pawnee is the most reliable place in the state to find these birds. They had been lekking in the area but the only birds we saw were perched in a dead tree.One of my favorite hawks of the prairie, the Ferruginous Hawk. The largest hawk in Genus Buteo, these powerful predators feed mainly on medium sized mammals. I often see them around Prairie Dog towns.The most common bird on the grassland in early spring is undoubtedly the Horned Lark. These small birds can be found in almost any open habitat in the state. While the Horned Lark may be the most common sight on the prairie the song of the Western Meadowlark is a sound synonymous with any open habitat in the western United States. Although this robin sized songbird may look harmless, the Loggerhead Shrike is a ferocious predator. Although in summer their diet consists mostly of large insects, in winter they will eat rodents and small birds. They are famous for skewering uneaten prey on thorns or barbed wire fences to eat later.One of the strangest sights on the dry shortgrass prairie is the profile of a distant shorebird. The Mountain Plover is a unique shorebird spending almost none of its life along the shores of oceans and lakes. They spend summer on the short grass prairie of the western great plains. Like many prairie birds Mountain Plover are declining with the world population around 20,000. The fragmentation of native shortgrass prairie and decline of prairie dog towns which provide excellent nesting habitat contribute to the decreasing numbers. Pawnee is one of the remaining strongholds for this species in Colorado. Another local prairie breeding species is the Thick-billed Longspur. They breed in native shortgrass prairie from Montana to northern Colorado. Over the last 50 years these birds have declined by almost 90%. Pawnee National Grassland is the best place in the state to find these birds during the summer months. The last of our four target birds, the Chestnut-collared Longspur. They are found in native shortgrass prairie. Since 1980 these longspurs have declined by more than 80%. Of all the Longspurs in North America the Chestnut-collared Longspur has by far the most accurate and descriptive name of any of these small prairie birds.
Every year as the days grow longer and the temperature increases a wide variety of birds migrate through Colorado. Although many migrating birds regularly travel through Colorado, the birds in this post are all rarely seen in the state. These rare birds, or rarities as birders call them, are often a cause for excitement for anyone attempting to grow their Colorado list.
As it turned out this spring an exceptional number of rare birds were reported in Colorado. Most of them were from the Eastern United States or birds from Southern States that overshot their breeding grounds. These birds are unpredictable, only showing up in Colorado a few times a year. Several of the birds were even more rare!
Thanks to the many Colorado birders who found and reported these rarities!
April Rarities
Neotropic Cormorants like this one are identified by their equally proportioned neck and tail. The common cormorant in Colorado, the Double-crested Cormorant, has a much shorter tail.Female Vermilion Flycatcher.Glossy Ibis can be differentiated from the much more common White-faced Ibis by their purple facial skin and red knees. Yellow-throated Vireo.Easily the rarest bird I saw this spring was this Louisiana Waterthrush. It was just the seventh ever reported in the state and a lifer for me.In this flock of Franklin’s Gulls is a Caspian Tern. It is slightly larger with a long orange bill.American Golden-Plover in non-breeding plumage.This Yellow-throated Warbler sang loudly the entire time we observed it making him easy to locate. White-eyed Vireo with its white eye clearly visible. Three Dunlin in breeding plumage, part of a small flock of six. Their red backs, black bellies and long down-curved bill are key field marks. Whimbrel. These incredible shorebirds migrate mostly along the coast, although very small numbers move through Colorado every year. They spend summer in northern Alaska and winter along the coast of the southern United States and Central America.Male Hooded Warbler hopping along the ground.Black-and-white Warbler is the only warbler in North America that behaves like a nuthatch, climbing up tree trunks in search of food.
May Rarities
Palm Warblers like this one can be identified by their tail pumping behavior.A Chestnut-sided Warbler showing its namesake chestnut side.A Black-throated Blue Warbler. This small eastern warbler is rare in Colorado and was a lifer for me this spring. A Broad-winged Hawk flying over. These raptors migrate though Colorado every spring and are almost always seen in flight.Male Summer Tanager. They are one of the only all red birds in Colorado.A Gray-cheeked Thrush. Although this species is very similar to Swainson’s Thrush it lacks the clear eye ring and other subtle details of the face pattern. It was confirmed by its distinctive song. This bird was special because it is one of the best rarities I have found.Rose-breasted Grosbeak foraging in the top of some tall trees.A female Northern Parula. Although this warbler is normally a regular eastern migrant in Colorado, this was the only one I saw this spring.Female Cape May Warbler moving up the tree. They can be identified by the dense gray streaking on their sides and their gray cheek patch.A female Golden-winged Warbler foraging just feet away from me. Another lifer!A roosting Yellow-crowned Night-Heron. This bird would hunt and roost on the shores of this small lake every morning but would disappear, presumably to nearby bushes during the day.
May Continued
One of the most common eastern warblers in Colorado is the Blackpoll Warbler, one of many I saw this spring.One of the rarest eastern warblers I have seen this year is the Worm-eating Warbler. A female Painted Bunting, identified by its overall greenish color.A male Pine Warbler. These birds often forage and sing from the tops of trees, but this one landed on the ground providing excellent views.A male Kentucky Warbler, another lifer. This skulky warbler never got more then three feet off the ground. It was only visible for several seconds while hopping between bushes. A Blue-winged Warbler hopping around in some dense bushes.This bright golden warbler is a Prothonotary Warbler. It is identified by its long bill and blue gray back.Female Blackburnian Warbler sitting in a tree close to me. It was by far the most cooperative Blackburnian I have ever seen. No, your eyes are not deceiving you, this bird’s tail is longer than its body! The clear pink sides and fully gray head confirm this bird is a Scissor-tailed Flycatcher.A Magnolia Warbler, probably a young male, hopping around in a distant tree.My lifer Scarlet Tanager. This bird was still transitioning into breeding plumage. This is evident because of the green patch on the back. Eastern Wood-Pewee. Western and Eastern Wood-Pewees look so similar that they can only be confidently identified by hearing their song. Thankfully, this bird was singing continually from a tree right above us.
