Saturday, December 29, 2012

Christmas day birding

"Pinning down a reliable rosy-finch location can be hard; most are in high-elevation towns where there is a good feeder supply. Cliffy areas can also be good, but it can be harder to scan the flocks at such locales. Often, a spot that is good one winter has few or no rosies the next. The finches are easiest to find during and after mountain snowstorms, when they are forced to feeders to get food."
The feeders behind Red Rocks Trading Post are probably the best location in the metro area to check for rosy-finches after a snowstorm. There are better locations further into the mountains, but Red Rocks is a much more convenient place to check when there's not a lot of time.

Red Rocks Trading Post, Jefferson County. December 25, 2012.

So far this year we have not had a lot of snow in the Denver area. There's been a couple of storms, but nothing that's really stuck around. Christmas Eve we got a nice storm that blanketed most of the area, and took advantage of a lazy Christmas afternoon to check the feeders at Red Rocks.

Song Sparrow, Dark-eyed Juncos (pink-sided and gray-headed), and house finches.
Red Rocks Trading Post, Jefferson County. December 25, 2012.
There were probably a few dozen birds hanging around the feeders, but nothing really out of the ordinary. After five minutes of watching for rosy-finches, we heard a Black-capped Chickadee give a scolding call, and immediately afterward all the other birds started giving warning chip notes, they all stopped feeding, and then an instant later they all burst off the ground and deep into the bushes. Of course we immediately started scanning the sky looking for the offending predator, and spotted a raptor buzzing low over the feeders.

We didn't get a great look as it buzzed by, but did manage to get a picture of it perched on a tree nearly 200 yards away.

Cooper's Hawk (I think?). Red Rocks Trading Post, Jefferson County. December 25, 2012.
I'm not sure of the ID, but I'm thinking it was a Cooper's Hawk, for a few reasons:
  1. In flight, the wings were narrow and tapered to a point, with a silhouette similar to either an accipiter or a falcon. A Peregrine Falcon has nested on nearby Ship Rock for many years, but they don't typically hang around for the winter. The wings didn't seem long enough relative to the body and it seemed too small overall to be a Prairie or Peregrine Falcon.
  2. Looking at the perched bird, the head looks larger relative to the body than that of a Sharpie
  3. As the bird launched from its perch into a dive, we got a good view of the tail feathers, and they appeared to spread into more of a fan shape than a wedge shape.

I'd like to get a better view before I could call it for sure, but I feel comfortable at least nailing it down to either a Cooper's or Sharp-shinned Hawk. Shortly after it flew off, birds started coming back out to the feeders. We enjoyed watching this Black-Capped Chickadee struggle to free a seed from it's hull from it's perch in a bush.

Black-capped Chickadee. Red Rocks Trading Post, Jefferson County. December 25, 2012.
We didn't spot anything out of the ordinary. In fact, our list for the day was nearly identical to our list at our feeders at home. We should have brought some fresh seed with us, which might have helped bring more birds out to the feeders.

Western Scrub-Jay. Red Rocks Trading Post, Jefferson County. December 25, 2012.
Steven Mlodinow checked in on the feeders earlier in the day than we did, and had very different luck. He posted to the Colorado Birds Google Group:
" . . . In any case, we had about 200 rosy-finches come in, breakdown being 20 Black, 40 Hepburn's, and the remainder "standard" Gray-crowned. We saw hundreds of juncos, some of which I still have to scratch my head over, but at least 3 GH x PS Juncos and the WW x PS Junco has returned. The GOLDEN-CROWNED SPARROW did its job and gave us nice views."
Next we headed to Chatfield State Park, which straddles Douglas and Jefferson counties. Chatfield covers a lot of habitat, but our main interest today was finding the Red-necked Grebe or any of the rare gulls that have been reported lately. Most bodies of water in the area have frozen over by now, and Chatfield itself is nearly completely frozen.

Chatfield State Park, Jefferson County. December 25, 2012.
We did manage to find one small stretch of open water in the northwest corner of the reservoir, near one of the boat launches and the dam.

Red star indicating location of open water. December 25, 2012.
Gull numbers were significantly down as compared to prior reports, and all we saw was a lone Ring-billed. Waterfowl were a little better, with a good mix of Canada and Cackling Geese, Hooded Mergansers, Common Goldeneyes, one Ruddy Duck, Pied-billed Grebes, American Coots, and Northern Shovelers.

Mixed waterfowl. Chatfield State Park, Jefferson County. December 25, 2012.
The highlight was finding the Red-necked Grebe mixed in with the other waterfowl. For the 15 minutes or so that we were there, he spent the majority of the time with his head tucked in his back, directly behind a bush, or close enough to the shoreline that the view was obstructed by rocks, but at one point he came out in open view and lifted his head at the same time.

Red-necked Grebe. Chatfield State Park, Jefferson County. December 25, 2012.
We saw a Red-necked Grebe in Idaho during spring migration a couple of years ago, but Red-necked was still new to our Colorado list. Not a bad way to spend a lazy Christmas afternoon!

Thursday, December 27, 2012

Golden-crowned Sparrow at Red Rocks Trading Post

Last weekend we stopped by the trading post at Red Rocks Park. Red Rocks is most famous for the outdoor amphitheater that hosts musicians, comedians, and other performers, but the feeders behind the trading post are the big draw for us.

Red Rocks Amphitheater. Image via
The red sandstone formations are a remnant of the Ancestral Rocky Mountains. According to Wikipedia:
"The red sandstone found throughout Red Rocks Park is geologically identified as belonging to the Fountain Formation.[2] Other Colorado examples of Fountain Formation geology include nearby Roxborough State Park, Garden of the Gods near Colorado Springs, and the Flatirons near Boulder. The rocks were formed about 290-296 million years ago when the Ancestral Rocky Mountains were eroded during the Pennsylvanian epoch. Later, uplift during the Laramide orogeny tilted the rocks to the angle at which they sit today."
The park is beautiful year-round, but the gardens behind the trading post are particularly stunning in the spring, as seen in the photo below from one of our trips last spring.

Feeders at Red Rocks Trading Post, Jefferson County. April 13, 2012.
For the past couple of winters, there has been a Golden-crowned Sparrow hanging out at the feeders. Golden-crowneds are common on the Pacific coast, spending the summers in Canada and Alaska, and the winters in Washington, Oregon, and California. During the winter, some Golden-crowneds wander further east, some going as far as New England.

eBird range map for Golden-crowned Sparrow.
They have been showing up in Colorado at least once a year for some time, and for the past couple of years they have been showing up reliably at a couple of feeders in Boulder and Jefferson counties.

eBird bar chart for Golden-Crowned Sparrows in Jefferson and Boulder counties.
Last winter Golden-crowneds wintered at two different easy-to-get-to locations around the Denver metro area. Teller Farms in Boulder County, and Red Rocks Trading Post in Jefferson County. We made three or four attempts at each location last winter, but failed to find them on any of our trips. Most of the people who did find them saw them early in the morning, and my theory is that since both of these locations see quite a bit of human traffic, the sparrows retreated out of view as soon as very many people started to be out and about.

This winter Golden-crowneds have shown up at both locations again. Teller Farms had a Golden-crowned for just a few weeks at the end of October and beginning of November. He stuck around just long enough for us to add him to our life list (along with lifer White-throated and Harris's Sparrows) on November 11. Another has been seen erratically at Red Rocks since October, but we weren't too concerned about finding him since we had already found the one at Teller Farms.

Last Saturday, we went to Red Rocks Trading Post to check for rosy-finches that occasionally visit the feeders after snowstorms blanket the higher elevations. We dipped on the rosy-finches, but unexpectedly found a Golden-crowned Sparrow instead.

Golden-crowned Sparrow. Red Rocks Trading Post, Jefferson County. December 22, 2012.
As most birds you really want to get a picture of tend to do, he tried his best to avoid letting us take an obstruction-free picture of his glowing crown.

Golden-crowned Sparrow, pulling a Wilson. Red Rocks Trading Post, Jefferson County. December 22, 2012.
It was nice to finally see the Golden-crowned at a location we had tried so many times, and even nicer to find it unexpectedly during a different winter. Other birds we enjoyed on this trip were typical of the habitat and season: Western Scrub-Jays, Black-Capped and Mountain Chickadees, a Spotted Towhee, and Dark-eyed Juncos were the most prominent.

Western Scrub-Jay. Red Rocks Trading Post, Jefferson County. December 22, 2012.
Others staked out the area longer and reported seeing Common Redpolls, which are having quite the irruption this year. We did not see any on our trip.

Tuesday, December 25, 2012

Post-snowstorm feeder birds

Last winter, I took a few "snow days", where I worked from home instead of the office to avoid the messy commute after a storm. Working from home is a great excuse to focus more on what's at home, rather than what you can go find elsewhere. However, this winter has been a little more mild so far, and I've not yet been able to use the snow as an excuse to stay home and watch birds all day. Luckily my wife (Ellen) has been keeping the feeders full and took some wonderful photos of our recent visitors.

Our apartment complex is adjacent a 65 acre open space with a small creek running through it. We've had a lot of fun watching the seasonal changes in our "back yard" over the past year and a half. Last spring we had breeding Bullock's Orioles, Western Meadowlarks, and Say's Phoebes, just to name a few. We also had an impressive Cliff Swallow colony that nests in the eves of the units facing the creek, and when the Common Grackles are here, their creaky-swingset-like calls fill the air all day long. In the late fall, American Goldfinches increase in numbers and devour the sunflower seeds that grow along the creek. In the winter, we occasionally hear a Great-horned Owl pass through. My favorite part of the winter, however, is the action we get at our bird feeders.

Our porch, Adams County. December 19, 2012.
We have a fairly simple set up, with a couple of feeders strung on a wire over our patio. We sprinkle seed on the ground and on a couple of old bar stools, which double as platform feeders. When we first started feeding, we mostly just had house finches and house sparrows. However, it wasn't long before a few other birds started to join them. Some of our more frequent visitors are White-crowned Sparrows.

White-crowned Sparrow. Our porch, Adams County. December 19, 2012.
These dashing little birds are quite hardy, and we have often been serenaded by dozens of them at a time on our high-altitude trips above the treeline in the Colorado Rockies. According to Birds of North America, perhaps the most exhaustive encyclopedic reference for North American birds, White-crowned Sparrows are quite the popular research subject:
"In the first formal treatment of the White-crowned Sparrow in 1772, J. R. Forster described it as an “elegant little species.” So many others have found this species to be elegant that Luis Baptista (1989) described it as the “best studied songbird” and as one of the best studied of all nongame bird species. Among the characteristics that make this species so attractive to ornithologists are its wide distribution, its abundance over much of its range, and its conspicuousness during most stages of its annual life cycle—all help to make this sparrow an ideal subject for studies of behavior in the wild. In addition, it thrives in captivity on a simple diet."
 After a big snowstorm last Wednesday, we had our first Song Sparrow visit our porch. We've seen and heard these little guys on our open space quite regularly, but until now have not seen them stray far enough from the creek to find our feeders.

Song Sparrow, caught in the act. Our porch, Adams County. December 19, 2012.
Song Sparrows exhibit incredible diversity across their range, with a total of 52 named subspecies, 24 of which are diagnosable. As the name implies, this sparrow's song is one of its most important assets. According to All About Birds, male Song Sparrows are under a lot of pressure to impress the ladies:
"Like many other songbirds, the male Song Sparrow uses its song to attract mates as well as defend its territory. Laboratory studies have shown that the female Song Sparrow is attracted not just to the song itself, but to how well it reflects the ability of the male to learn. Males that used more learned components in their songs and that better matched their song tutors (the adult bird they learned their songs from) were preferred."
Another new addition this year is a Spotted Towhee. We had not seen a Spotted Towhee at our feeders or anywhere on our open space in the 18 months we've lived here until last week, and since he first showed up this guy has made regular appearances every day for a week.

Spotted Towhee. Our porch, Adams County. December 19, 2012.
While we've seen these colorful guys quite a few places, they seem to be most prominent along the foothills of the Front Range. We've seen them everywhere from Garden of the Gods, to Roxborough State Park, to Gregory Canyon. According to All About Birds  male Spotted Towhees seem to have just one thing on their mind when they sing:
"Early in the breeding season, male Spotted Towhees spend their mornings singing their hearts out, trying to attract a mate. Male towhees have been recorded spending 70 percent to 90 percent of their mornings singing. Almost as soon as they attract a mate, their attention shifts to other things, and they spend only about 5 percent of their time singing."
House Finches were one of the "spark" birds that got me to start looking twice at little brown birds (who knew that something so brightly colored was so common?), so even though they're one of the most common birds in North America, I still have a soft spot for them.

House Finch. Our porch, Adams County. December 19, 2012.
Any time you find a flock of House Finches you're bound to spot a couple sporting peachy or yellow colored heads and breasts, rather than the typical cherry red. According to All About Birds, their pigment comes directly from their diet:
"The red of a male House Finch comes from pigments contained in its food during molt (birds can’t make bright red or yellow colors directly). So the more pigment in the food, the redder the male. This is why people sometimes see orange or yellowish male House Finches. Females prefer to mate with the reddest male they can find, perhaps raising the chances they get a capable mate who can do his part in feeding the nestlings."
While the passerines might be attracted to the sunflower feast, the accipiters are attracted to the passerine feast. We've had both Cooper's and Sharp-shinned Hawks stop by hoping for a meal, but so far they have not had any success at our feeder.

Of course we get some mammalian visitors to our feeders as well, such as this squirrel, who kept holding one paw against his chest, switching back and forth, presumably to preserve heat on this cold morning.

Squirrel, trying to keep his paw warm. Our porch, Adams County. December 19, 2012.
I realize squirrels come in a variety of species, but I have thus far failed to learn all but the most unique of them. While I would never be satisfied with leaving a bird name at finch sp., duck sp., owl sp., etc. without giving a proper identification my best shot, I just can't seem to find the interest to nail down a specific identification for most non-avian species we encounter. Perhaps another day, Mr. squirrel sp.

Monday, December 24, 2012

Sunday afternoon raptors

Last week we had just an hour or so before sunset to go birding, and headed to look for raptors in Adams County. We focused on part of the DIA Owl Loop just south of Barr Lake State Park.

Our raptor run indicated in red. Adams County. December 16, 2012.
Right off the bat we got great looks at a beautiful Rough-legged Hawk. The light was a little dull, so we were pushing our camera to the limits with 3,200 ISO. Some cameras handle high ISO conditions better than others, and our Canon SX40 HS certainly does a better job than any of our previous cameras, but it's still grainier than I'd like.

Rough-legged Hawk. 128th Ave between Tower Rd and Picadilly Rd, Adams County. December 16, 2012.
Rough-legged Hawks and Ferruginous Hawks are the only buteos that have feathered legs, which is a necessary adaptation for these Arctic raptors, and their nests sometimes contain the bones of caribou.

eBird animated occurrence map for Rough-Legged Hawk.
In flight, one of the best field marks for identification is the dark wrist patches that are clearly visible in flight, though they can be a little harder to make out on dark-morphs.

Rough-legged Hawk, showing off its characteristic wrist patches.
128th Ave between Tower Rd and Picadilly Rd, Adams County. December 16, 2012.

Rough-legged Hawk. 112th Ave between Chambers Rd and Potomac Rd, Adams Count. December 16, 2012.
We also got great looks at a beautiful Prairie Falcon, which took flight and disappeared off into the horizon before we could get the camera on it. It was probably the best perched view we've had, so despite the lack of pictures, we were still thrilled at the view.

 American Kestrels are perhaps the most common raptor we see on a regular basis, but they're so colorful and entertaining to watch, their common-ness doesn't make them any less enjoyable. We watched this Kestrel devour his supper from a power line.

American Kestrel eating rodent intestines.
128th Ave between Tower Rd and Picadilly Rd, Adams County. December 16, 2012.
The light was not great for showing off the Kestrel's beautiful plumage, but we enjoyed watching it enjoy a meal. We've seen Kestrel's on literally hundreds of occasions, but this is the best view we've ever had of one actually devouring its prey.

American Kestrel, with the last bite of its dinner going down the hatch.
128th Ave between Tower Rd and Picadilly Rd, Adams County. December 16, 2012.
American Kestrel, with the last bit of the rodent's tail visible sticking out of its mouth.
128th Ave between Tower Rd and Picadilly Rd, Adams County. December 16, 2012.
Although American Kestrels are still quite easy to find across most of North America, their numbers have been in serious decline over the past 50 years. Luckily the American Kestrel Partnership is keeping tabs on these little guys, and working to protect their numbers.
Borrowed from Matt Giovanni's guest post over at

Other raptor highlights of the day included a Great-horned Owl, a Bald Eagle, a Northern Harrier, and of course no raptor run would be complete without a Red-tailed Hawk.

Northern Harrier, looking particularly owl-like at sunset. Barr Lake State Park, Adams County. December 16, 2012.
Red-tailed Hawk. 128th Ave between Tower Rd and Picadilly Rd, Adams County. December 16, 2012.

Monday, December 17, 2012

Homemade digiscope test run

Last Thursday I put together a cheap digiscope adapter for my smartphone using a $20 phone case, the eyepiece protector from my spotting scope, and some super glue. On Saturday, we got a chance to test it out.

The first test subject was Bald Eagle perched atop a power pole near Boyd Lake State Park (Larimer County). The pictures below were taken with the scope set to 20x zoom, and with my smartphone camera not zoomed in at all (left) and zoomed in to reduce the vignetting (right).

Bald Eagle, digiscoped with my Samsung Galaxy SII and Barska Blackhawk 20-60X60 spotting scope.
Boyd Lake State Park, Larimer County. December 15, 2012.
I put the adapter together on an impulse after getting home from work late, and bought the first case I could find that fit my phone. I don't even remember what brand, and I'm sure I could have found something for half that price if I'd been a little more patient. I had originally hoped for a hard case that would provide greater rigidity while shooting, and the one I found was only semi-rigid. So far it doesn't seem to be a problem though, as it fits the phone snugly enough that the phone itself provides the needed rigidity.

Stoddard (hey, that's me!) wishing something exciting would show up on the phone's screen.
Boyd Lake State Park, Larimer County. December 15, 2012.
We didn't find anything great at Boyd Lake State Park. Despite many of the nearby ponds being frozen over, there was no real concentration of waterfowl as we were hoping for.

There had been some recent reports of a Brant hanging out with a flock of Canada and Cackling Geese at nearby Lake Loveland (Larimer County). We were unable to re-locate the Brant, since it had wandered to a nearby golf course where a couple of other birders tracked it down during a Christmas Bird Count. We spent some time practicing with the digiscoping rig on some Cackling Geese, Mallards, Ring-billed Gulls, and a few escaped domestic waterfowl instead.

Cackling Goose. Pond north of Lake Loveland, Larimer County. December 15, 2012.
Overall, the birding was quite slow. We meandered around a few other hotspots nearby, hoping something out of the ordinary might show up. Surprisingly low bird volume all around.

Red-tailed Hawk. Intersection of CR 17 and CR 18 in Loveland, Larimer County. December 15, 2012.
It's nice to have a new photography toy to try out on days when the birding is a little slower. It adds a different dimension to the day, and gives me a reason to slow down and pay more attention to more common species that winter in the area.

Great Blue Heron. St. Vrain State Park, Weld County. December 15, 2012.
Overall, I'm pretty happy with the digiscope adapter. I need to take it out again on a day with better light to try for better pictures, but I'm getting better pictures than I've been able to get with previous digiscoping setups.

The best bird of the day was probably this Ross's Goose that was kind enough to hang out just 10-15 feet away from the road, gleaning corn from a field. This photo was taken with our regular camera, rather than my new digiscope setup.

Ross's Goose. CR 20 between Wilson Ave and Namaqua Road, Larimer County. December 15, 2012.
As we drove through one neighborhood, we spotted this Northern Flicker enjoying a feast of Russian-olives. Northern Flickers typically enjoy a diet of ants and beetles, which they supplement with fruits and seeds in the colder months. Dave Leatherman points out why Northern Flicker's love Russian-olives in an excellent article in Colorado Birds:
"The normal focal point of bird interest in Russian-olive is the fruit, which botanists classify as an achene. The pulpy coating that surrounds the hard, striped seed is mildly sweet (try it — it tastes not unlike a weak watermelon). Birds like flickers are strictly after the coating when they feed on these fruits, but they also ingest the seeds and then excrete them; in fact, nest boxes used by flickers often contain several inches of excreted Russian-olive pits."
Northern Flicker dining on Russian-olives. Near Loveland Reservoir, Larimer County. December 15, 2012.

Friday, December 14, 2012

Homemade smartphone digiscoping adapter

High up on my wish list for this Christmas (and for the past couple of Christmas's) is a decent digiscoping rig. Just this morning, I was browsing the internet looking for reasonably priced digiscoping setups (I would need a new point and shoot as well as a good adapter), I saw Bill Schmoker's article on the ABA Blog about his custom modification of a PhoneSkope adapter that allows you to digiscope using an iPhone.

I've certainly seen some high quality images on other people's blogs that were captured using smartphones, and I've toyed around with my own phone (Samsung Galaxy SII) but have never been able to capture anything worth sharing. Also, it seems like most of the adapters meant for digiscoping with smartphones are designed for iPhones, and the selection of accessories for other types of smartphones is a little slim.

Looking at Bill's images for how the PhoneSkope adapters work, and how he created his own custom piece, I realized that conceptually, these adapters are basically just a smartphone case with a tube the size of a scope eyepiece attached. I decided that I could probably just buy myself a cheap smartphone case, and glue a tube onto it to create my own adapter on the cheap!

Lucky for me, our spotting scopes have threaded eyepiece protectors that screw on to the scope during storage. I re-purposed one of our eyepiece protectors, cutting it down in length so that I could glue it to a phone case, taking advantage of the eyepiece protector's threads to maintain a solid connection to the scope.

After cutting the eyepiece protector down to size, I super-glued a cheap smartphone case in place, making sure to line everything up for a nice view.

My phone just pops into the case and I'm ready to shoot!

Although I have not yet had a chance to take it out (I just finished it a couple of hours ago) it does seem to be quite stable, the camera lens and scope eyepiece are well aligned for a clear shot, and I can eliminate all vignetting by using a little bit of the phone's zoom capability. A few indoor, low-light test shots showed that the set up can achieve tack-sharp focus, even in poor conditions. I can't wait to test it out this weekend on some distant waterfowl! This will be a fun addition to our photography arsenal.

Sunday, December 9, 2012

Dark-eyed Juncos - a photo study

Although Dakota Ridge Trail in Boulder County is getting a lot of attention right now for the Northern Cardinal that's been hanging out for the past month, it's also had a tremendous abundance and variety of Dark-eyed Juncos on each of our recent visits.

Dark-eyed Juncos are a unique species, as they are actually made up of a large number of subspecies which can be grouped into 6 (or 5, depending on who you ask) groups that can be readily identified in the field. Each group has distinctive field marks, and there are also noticeable differences in size and song. Each group occupies a different range, with lots of intergradation where their ranges overlap. I've found Sibley's Field Guide to Birds to provide the best overview on each group, with excellent identification tips and helpful range maps.

SLATE-COLORED - Junco hyemalis hyemalis group

Slate-coloreds may be the most widespread group, breeding from coast to coast above the U.S. - Canada border, and wintering from coast to coast in the lower 48.

Dark-eyed Junco (slate-colored). Female on the left, male on the right.
Dakota Ridge Trail, Boulder County. December 8, 2012.
eBird range map for slate-colored Dark-eyed Junco.

OREGON - Junco hyemalis oreganus group

Oregon's may be the second most widespread, living year-round on most of the Pacific Coast, wintering in the western half of the United States and some of Mexico, and regularly straying through the rest of the lower 48, except for the south east.

Dark-eyed Junco (Oregon).
Dakota Ridge Trail, Boulder County. December 8, 2012.
eBird range map for Oregon Dark-eyed Junco.

GRAY-HEADED - Junco hyemalis caniceps

Gray-headeds are somewhat of a south-west specialty. They breed in Nevada, Utah, Colorado, and New Mexico, winter in Arizona, New Mexico, and some of Texas and Mexico, and regularly stray to surrounding states. For the past few weeks, they have been by far the most abundant subspecies at Dakota Ridge Trail.

Dark-eyed Junco (gray-headed).
Dakota Ridge Trail, Boulder County. December 8, 2012.
eBird range map for gray-headed Dark-eyed Junco.

PINK-SIDED - Junco hyemalis mearnsi

Pink-sideds occur mainly in the intermountain west, breeding in Idaho, Montana, and Wyoming, wintering in Colorado, New Mexico, Arizona, and parts of Texas and Mexico, and regularly straying into nearby states. They were also quite abundant at Dakota Ridge Trail.

Dark-eyed Junco (pink-sided).
Dakota Ridge Trail, Boulder County. December 8, 2012.
eBird range map for pink-sided Dark-eyed Junco.

WHITE-WINGED - Junco hyemalis aikeni

White-wingeds are perhaps the least common, and have a very limited range. They live year-round in an area surrounding the intersection of Montana, Wyoming, and South Dakota, winter south into Colorado, and occasionally stray a little further south or north. We were lucky enough to spot one on two trips out of the last three.

Dark-eyed Junco (white-winged).
Dakota Ridge Trail, Boulder County. December 8, 2012.
eBird range map for white-winged Dark-eyed Junco.

You have to be careful distinguishing slate-colored from white-winged in areas where they overlap, as about 1 in 200 slate-coloreds have white wing bars that are about as strong as the white-winged. White-wingeds should be distinguished on the combination of all characteristics (and not just one alone), including having darker lores, and a paler shade of gray, particularly on the throat.

RED-BACKED - Junco hyemalis dorsalis

Red-backeds live year round in central Arizona and New Mexico, and stray or winter just a little further south. None were found at Dakota Ridge trail. They are very similar to gray-headed, except that they have a bicolored bill, with the upper mandible a darker color than the lower.

eBird range map for red-backed Dark-eyed Junco.