Chinook winds blow when warm moist air crosses a range of mountains. As the air mass crosses the mountains, it rises; as it rises, it dries.
As it crosses the ridge of the mountains, the now warm very dry air mass is held down by a strong jet stream. The warm dry air is trapped between the ground below and the jet stream above.
As the air moves from cold to warm, the clouds form and evaporate.
When the now warm very dry air hits the ground, we can have winds from 30-90 mph (48-145 km per hour). Chinooks blowing at these speeds can blow over semi-trucks. In the 1970s, extremely violent chinooks hit the National Center for Atmospheric Research, just west of Boulder, and pegged their anemometer (wind meter) at 120 mph (193 km per hour).
Chinooks can raise the air temperature 40o (4o C) in minutes. Because they are dry winds, they can evaporate and sublimate (evaporate directly from snow or ice, without melting into water) snow at an astonishing rate. This is nice for getting ice off sidewalks, but chinooks have caused us to go from having a comfortable amount of snow in the mountain snowpack to needing water restrictions within the space of a day. This is why the Blackfeet Indians of Montana call it “snow eater.”
Chinooks blow on the lee side of mountains all over the world. In Europe, they are called Fohn winds; in California, Santa Anas. Loo winds blow off the Kirthar Range in Pakistan east onto the Indo-Ganges Plains in summer, making a hot season hotter.
Once I had a fancy camera that held bird images still so that I could figure out what I was looking at, I began to learn a lot more about LBJs — Little Brown Jobbies — little birds that are around us but we really don’t pay much attention to. And one of the first LBJ birds I learned about was the Dark-eyed Junco.https://amylaw.blog/2015/03/05/spring-is-coming-really/
If you look at a lot of bird books, the generic entry Dark-eyed juncos says that they are a type of sparrow with pink to orange bills and legs, and white edges on their tails; they winter south to Mexico, and breed from Alaska and southern Canada all the way to the arctic tundra. Colorado is lucky that they can live here year-round.
But reality is much more complex.
If you are from the Eastern US, the slate-colored junco is probably the dark-eyed junco you are most familiar with. They breed in Canada, and winter in the continental United States. I don’t have very good photos of the slate-colored because they usually show up at my feeders when it’s snowing. They flit in for some seeds then dart back into the trees. This behavior is typical enough that dark-eyed juncos are called the “snow bird”. Humans have co-opted the nickname to mean elderly folk who show up in warm climates in winter.
As it turns out, Juncos were a tough species for me to use to start learning about LBJs. Dark-eyed Juncos come in a huge variety of subspecies — five subspecies with three subspecies having even smaller ‘races’ within them. And the most amazing thing about all this variety is that it seems to have developed just in the last 10,000-13,000 years — since the last Ice Age! https://www.audubon.org/news/dark-eyed-juncos-backyard-gems-come-dazzling-array-colors
eBird has this to say about juncos: “…incredible variation between populations. All have short pink bills and white outer tail feathers. Often in flocks in winter, foraging on the ground for seeds. Visits feeders. Subspecies include: Slate-colored (widespread), Oregon (West), Pink-sided (Rockies), Gray-headed (Rockies), Red-backed (central Arizona and New Mexico), and White-winged (Colorado in winter).” https://ebird.org/species/daejun
This is the classic Oregon dark-eyed junco — pink or yellow beak, black hood distinct from brown back or red sides, white breast, white edges of the tail. At first glance, it doesn’t look anything like the slate-colored dark-eyed junco, above. But it still has the pink beak and white-edged tail of a dark-eyed junco.
The Oregon junco breeds in the Pacific Northwest, but they winter throughout the west and the Great Plains, which is why I get to see them.
This bird looks like a pale version of the Oregon junco above. Often pale versions are females while bright versions are males, but in this case, it’s just another sub-species of dark-eyed junco. The above bird is called a pink-sided junco because of the orangish-pink sides. This seems like a small difference to call out, especially when the big difference I see between it and the Oregon is that it has a pearly gray head.
But that the gray-headed junco is another dark-eyed junco. They do indeed have a gray head, so that works out. In fact, gray-headed dark-eyed juncos are all gray, except for a rusty patch on their backs, and the white edges on their tails.
They are residents of the Rocky Mountains, and move up and down the mountain elevations more than north and south, so these are the juncos I’ll see in the mountains in the summer.
And these are just the birds that have come to our feeder! The white-winged, the red-backed, Guadeloupe — even more subspecies of dark-eyed junco are sprinkled around in Canada, the U.S. and Mexico.
Well, I do.
I care for a couple of reasons.
First, I always feel like once I can identify a bird, and know where it’s found, I know that bird a little better — it’s now a friend.
Second, it fascinates me that dark-eyed juncos are splintering into all these different forms in just 13,000 years. To give you an idea of how fast their changes are happening, dogs split off from wolves 15,000-30,000 years ago. So when these birds finally become separate species, they will be the youngest species in the world. That’s evolution in action.
We’ve had a huge red-tailed hawk hanging around the neighborhood this week. I assume it is a female, because female raptors are bigger than males. And she was big.
And I knew she was a red-tailed hawk (Red-Tailed Hawk), even without seeing her tail, because 1) she was big, 2) she had a stocky body with a short tail, which meant that she was an open country “buteo” hawk, as opposed to an “accipitor” that hunts in the trees. 3) she had a “belly band” of rust colored feathers across her tummy, with a white patch above. (For more about identifying a red-tailed hawk https://amylaw.blog/2020/04/25/hawk-conflict/)
She really didn’t like me photographing her. There was another group standing a few feet away, and I never got a photo of her looking at them at all. But she glared at me — a lot.
In between glares, she was kinda fidgety. She stretched…
… and turned around. Did I mention that she was a red-tailed? She had the reddest tail I’ve ever seen on a red-tailed hawk.
Earlier this week, we saw a female broad-tailed hummingbird feeding on the last of a neighbor’s Rose-of-Sharon flowers.
Then we had three more forest fires start in the mountains to the west. It’s October! It is time to cool off.
But this morning we woke to cold temperatures and even a little sleet on the ground. And that brought in the birds. House and goldfinches, a northern flicker, chickadees and a couple of red-breasted and white-breasted nuthatches.
But among these frequent fliers, I saw two dark-eyed juncos.
Dark-eyed juncos have between four and five different color schemes — ornithologists have changed how they classify them. They used to all be called different forms of Oregon juncos, now just some are called Oregon-form juncos, along with slate-colored, white-winged and pink-sided. Very confusing. https://amylaw.blog/2018/03/31/hawk-nest-monitoring-begins/
But as we were enjoying the all little birdies, we noticed one we couldn’t quite place.
A finch that was striped all over, not just on her chest. After a flurry of thumbing throw bird books, we decided a female or juvenile Cassin’s finch — they look the same until the males molt. The clincher was the white ring around her eye. Cassin’s finches are usually found in the foothills or lower mountains. I have no idea why she decided to come visit us. But she is welcome anytime.
In late August, my husband and I went up into the mountains of the Front Range to monitor pika as volunteers for the Front Range Pika Project in conjunction with the Denver Zoo. At that time, we were shocked at how dry the high country was. Last week, we went on Pika Patrol for a second time this year, this time to a spot in the Sawatch Range. It was a beautiful day for a hike — clear skies and temperatures in the 60s.
Pika habitat is always high in the mountains — right at or above tree line. This site is in the bare rocks within the trees in the center of the picture. There was an avalanche chute to the right. This wasn’t the steepest chute we’d ever seen, but when we turned around we saw the results of an avalanche that had roared down it in the recent past.
This is the scene 180 degrees from the the photo above. You can see the downed trees in the background — all had been snapped off. The trees in the center of the photo were lucky to survive, but they had a lot of damage from the debris the avalanche carried. The trees at their bases were broken when they hit the survivors.
In spite of the irrational feeling of unease that the avalanche chute created — there was no snow anywhere around us — my husband and I decided the easiest way to get to the site would be to hike up it, then cut across to the site. As we made our way up the chute, my husband pointed out some trees that had been somewhat protected from the avalanche by a small outcrop of rock.
Unfortunately, I couldn’t get a good picture of another tree 100 feet down slope of these that was snapped off at about the same height. That suggests that the avalanche was moving fast enough at this point that it didn’t drop very much in the next 100 feet.
At about this point, we turned to the left and headed into the trees to get to the talus slope within them. This small area of broken rocks in the forest didn’t seem very promising as pika habitat, but it wasn’t long before we heard the squeaky-toy call of a pika.
This little guy scampered over the rocks around us.
I wonder if it had been tagged by researchers at some point, because it had a hole in one ear.
The pika stayed about twenty feet away from us as we made our measurements of its habitat. It was respectful of us a big creatures, but it never really seemed too afraid of us.
One of the measurements we are supposed to make as part of the Pika Patrol is whether or not the pika have made their signature “haystacks” (Pika Patrol, Part One). It concerned me that we didn’t see any as we were scrambling over the talus where we saw the pika. But as we made our way down the treacherous rocks, we literally fell onto one. It was very small — evidently it had just been started. And there were plants around (like the grasses in the foreground) that the pika could harvest and dry. But it didn’t seem like much for as late in the year as we visited.
A month ago I was alarmed by the dry conditions we found on Berthoud Pass (2020 Pika Patrol) . This site looked in better shape, but it had several things going for it — it was surrounded by trees that would raise the humidity, and we had that freak snowstorm in early September that dropped a fair amount of moisture. But it was still a warm day in the subalpine, and there wasn’t much evidence of foraging for the winter.
Colorado went from 93o on Monday September 7 to 32o Tuesday September 8, 2020 — a change of sixty-one degrees in 24 hours. Prior to that, On September 6, Denver reached 101o making it our latest 100o day. That gave us a 48 hour change of 68o.
This weather whiplash was a result of the fact that fast-moving cold weather fronts push in behind slow-moving warm weather fronts, compressing the warm air and making it even warmer. When the cold front finally arrives, the temperature drop is dramatic. Few are as dramatic as what we saw yesterday — this was almost a record-breaker for Denver (the record being a change of 63o).
The temperature drop gave us much needed moisture, first as rain, then as snow. Although we are all glad to be out of the forest fire smoke that has plagued us for a month, it has been hard on the birds.
Before the storm hit, my husband and I made sure to fill the bird feeders. The little cheepies appreciated it this morning.
The hummingbirds, almost totally dependent on flower nectar for food, were particularly hard hit. Hummingbirds rely on their incredibly fast metabolism to keep warm. If the night is too cold, they can literally starve to death.
But we had a plan! I have a hummingbird feeder that sticks to the sliding glass door, and so is under the house eaves and would remain snow-free. The little birds completely ignore if there is any other food source available. But this morning, nothing else was clear of snow.
The picture above was taken with natural light, because I didn’t want to startle the starving bird and scare it off it’s energy sources. But for some reason, my camera used the flash for the picture below.
The resulting photo shows off the bird’s iridescent feathers. Bird feathers create color not with pigment, but with prisms in the feathers themselves, and so change depending on the angle of the light.http://Hummer colors
Over the weekend, my husband and I went up to the mountains for the first time this summer. We’ve been trying to isolate ourselves, and the mountain trails have been busy with people trying to get out of their houses while being safe.
We headed up to do our annual Pika Patrol for the Denver Zoo and the Front Range Pika Project. (Pika Patrol, 2019 Edition) We both really enjoy these trips because they force us to get out away from cell phones and cars and the internet, and just be.
It was smokey as we stepped out of the car at the trail head. Colorado is in a drought, and we have four major forest fires burning in the mountains right now. There was a forest fire just west on the other side of the mountain — literally. It produced clouds of smoke that plagued us the entire hike.
But the hike started out well, in spite of the smoke. We were delighted to see these white columbines in the rocks at the side of the parking area. My trusty plant books say that white columbines are a normal, if rare, variation on our more common Colorado columbine.
We walked a few paces and found a nice group of beautiful traditional blue and white Colorado Columbines as well.
The trail up to the site we that we monitor is off of US 40 near Berthoud Pass. Starting at 10,500 feet, the trail is steep — a 50% grade, which means that for every 2 steps forward, we took one up. We did this for about two hours. Every year, I tell my husband, this is it. This is the last time we do this site.
This year, the hike was even harder due to smoke polluting the thin air.
After plodding up the mountain, we reached the meadow that is the beginning of the pika observation site. Last year, as we approached, we could hear the pika’s squeaky-ball chirps. We did this year, too. But instead of a chorus, there only were a few isolated calls.
Instead, we saw chipmunks on the alpine tundra, something I have only rarely seen before.
We took a few minutes to dig out our data sheet, and start recording our observations. It was hot for the alpine — 75o — and so dry the plants crunched beneath our boots.
As we puttered around, we began to see a few pika dashing over the rocks. They went out to the nearby meadow, and came back with a mouthful of forage. But we didn’t find any hay piles yet. It may be too early — they still have a month or so before the snow usually falls.
We found a few places where the pika had left their scat, and collected some for DNA analysis by FRPP.
But compared to last year, there just weren’t many of the little critters around. We speculated on why there were not as many pika as there were last year. We came up with several possibilities:
We came up a month earlier this year. The pikas may not be very active gathering forage for their hay piles yet.
We came up a month earlier, and it was too warm for the pikas. While we were in the alpine, it was 75o, the upper limit of the temperature range that pikas can operate in.
It was just too hot for them, and they had died.
We are hoping that it is either possibilities one or two, or both. But it was hot, and dry. Alpine plants are not tall, but they are usually green and lush. This year, they have taken a beating with the drought, and that will probably impact how much forage the pika can gather.
Even before we became concerned about the conditions we found at the pika site, we had planned to visit another pika site in the Upper Arkansas Valley (that hopefully won’t be so much of a death march). We’ll go up a month from now, when it is hopefully cooler. And we’ll hopefully see plenty of pika building plenty of hay piles for the winter.
I had to zoom out to get an idea of what’s going on with the smoke situation, but it looks like we are being smoked by a fire on the Utah-Colorado border.
It took me a little while to figure out their key: Circles are permanent air quality monitors, triangles are temporary air quality monitors. Green means good air quality, yellow not so good, and orange really horrible. The little flames, of course are the fires.
It is interesting to note that the air quality along the Front Range has got a lot of yellow circles, and one red triangle. Our air quality, 200 hundred miles away and across a mountain range 10,000 feet high, is worse than it is in Grand Junction, 30 miles away.
When I look at the Fire and Smoke Map (above) as well as the InciWeb site https://inciweb.nwcg.gov/, I can see that the Pine Gulch Fire is about 21,000 acres, and at 7% contained, is still growing. We could be in for a smokey couple of days.
The other fires north of the Pine Gulch Fire have been contained. They won’t be declared “out”, however, until the first snow falls, and puts out the last smoldering roots underground.
We have just about every type of bird feeder in our backyard — tube feeders, sock feeders, platform feeders, house feeders, hummer feeders. The one that the birds don’t really pay much attention to are the suet feeders. I have spent a lot of time trying to get them interested, but no luck.
So I have taken to stuffing the hair I get from grooming the dogs into the suet feeders. That, the smaller birds pay attention to. They use it to build their nests.
Last week, it was a female lesser goldfinch who came to fill her beak with as much hair as would fit into it.
Goldfinches are some of the last birds to nest. That makes sense — they have to get the eggs laid, hatched, and the nestlings fledged, all while there are enough late-blooming sunflowers to feed them.
Gathering the hair often involved some contortions. It didn’t bother the goldfinch, though, they are used to hanging upside down to get seeds from sunflowers, and similar plants. Goldfinches at lunch
But it didn’t take her long to get enough to fill her bill, and she flew off. She made a lot of trips to the suet feeder/dog hair dispenser, so I’m hopeful that she nested. I can hardly wait to see the fledglings!