Dark-Eyed Juncos — Evolution in Action

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.

Slate-colored juncos are dark gray on their backs and heads, and white on their breasts. The line on their breasts between the gray and white forms an inverted ‘U’.

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.

Slate-colored junco also called the “snow bird”.

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.

Oregon dark-eyed juncos have a distinct black hood.

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.

Pink-sided dark-eyed junco.

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.

Gray-headed juncos are gray pretty much everywhere except their backs, which are rusty red. Again, pink or yellow beak, white edge to the tail (you can just see that in this picture) make them a junco.

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.

WHO CARES???

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.

And that is pretty cool.

Turkey vultures have returned to Front Range

Some people watch for the first robin of spring. In Capistrano, they look for the return of the swallows. I know it’s spring when the turkey vultures return to the Front Range of Colorado. (https://amylaw.blog/2013/04/08/it-must-be-spring/)

Turkey vultures are big birds — the biggest you are likely to see, with the exception of an eagle or an American white pelican.

You’re not going to mistake a vulture for a pelican. The others are a little more problematic.

They are big, dark bird with translucent (almost see-through) trailing wing feathers, and a red head.

I have the most trouble telling a turkey vulture from bald or golden eagles. Although golden eagles may hold their wings in a slight “V”, most often they hold their wings flat.

A turkey vulture soars with it’s wings in a slight “V”, often called a “dihedral”.

Turkey vultures are also “tippy” when they fly — they are so light that air drafts bounce them around. Eagles are not “tippy”. It’s beneath their dignity.

And neither a bald or nor golden eagle have the translucent trailing wing feathers.

Swainson’s hawks, or a broad-winged hawks are both tippy and fly in a V. But both these hawks have shorter, broader wings, and are smaller. They also often brownish-red and have white markings on their wings or bodies.

You might confuse it with a black vulture, but black vultures just seem smaller overall — shorter wings, much shorter tail, with a dark grey head. Plus, black vultures are limited to the southern US down into South America. I have to travel south if I want to see a black vulture.

It’s been a long, hard winter. I hope you enjoy your first signs of spring, whatever they are!

Chickadees checking out a home.

I went out to the garden yesterday to see when I could start taking my frustrations out on it planting my spring vegetables in it. As I walked up to the garden, though, I saw movement in one of the trees on the edge of it.

This little gourd birdhouse blew out of the tree during a storm over the winter. We picked it up out of the snow, and re-hung it on the nearest branch. Now, a black-capped chickadee has decided to check it out. The mate sat in the branches nearby.

The gourd seems like a good fit for the little birds. But there is a problem — it is too close to our garden. I think the disruption of us working in the garden will drive them off.

So once the chickadee flitted out of the gourd for a moment, I moved the birdhouse a little further away from the garden. I hated to do it, because the chickadees might not come to it’s new spot. But hopefully this way they have a little time to get used to the new location.

I hope they come back. We’d love to have them as neighbors.

The Day the Dinosaurs Died

I had always wondered how the dinosaurs died out. I couldn’t understand how just getting hit by an asteroid, or having volcanoes spew out ash could wipe them all out. Then I heard about some research that pinpoints the moment the asteroid hit. That seemed like a promising place to start my research.

Scientists still debate the specifics of what happened, but it probably went something like this…

The dinosaurs are dead.

They died sixty-six million years ago when an asteroid the size of the island of Manhattan slammed into the ocean off the coast of Yucatan, Mexico. The asteroid punched a crater 112 miles wide and a dent one mile deep into the Earth’s surface. It caused a magnitude 11 earthquake – one of the biggest ever – to shake the Earth’s crust.

Donald E. Davis, Courtesy commons.wikimedia.org

The intense heat generated by the crash vaporized the asteroid, as well as granite in the Earth’s crust. The silica in the granite turned into molten glass.

The crust rebounded like a trampoline after the asteroid hit it. A cloud of superheated air shot into the sky at twice the speed of sound. The cloud carried the melted particles of glass into the upper layers of the atmosphere.

Within minutes after impact, the larger globs of red-hot glass began to pelt from the sky. The burning rain lasted for several hours. It started fires that burned all over the world. We can still see a layer of ash from these fires in the rocks today.

Shock waves from the impact went through the core of the planet at over ten times the speed of sound. They reached the other side of the Earth in an hour-and-a-half. The energy from these waves punched pulverized rock up twelve feet off the coast of Australia. Volcanoes in nearby India had been erupting for some time, but now their eruptions became extreme. More poisonous gasses and dust spewed into the darkening sky.

In North America, the shock waves hit the shallow, narrow gulf that stretched to the Arctic. Waves of water higher than a thirty-story building flooded the nearby land. Close on the heels of the floods, gale-force winds knocked down trees, and the molten glass began to rain onto the devastated land. Stranded fish sucked some of these glowing sand-sized particles into their gills as they gasped for breath in shallow puddles. The flood waters finally crested, then reversed course. The water rushed back, covering the dying trees, fish, and animals with mud.

An almost-mile-high tsunami raced away from the impact crater at nearly ninety miles per hour. The waves spread to every ocean in the world. They threw fish and sediments onto land. Any animals in their path were drowned.

In the next few days, the vaporized rock and volcanic ash blanketed the globe in acidic soot and dust. The toxic clouds completely blocked out the sun. Plants couldn’t photosynthesize, and died. Global temperatures dropped.

The finer dust particles remained in the atmosphere for a decade. Rain finally deposited the acidic dust into the sea. The oceans became more acidic. The acids killed most animals that required hard shells, from ammonites down to plankton. The ocean ecosystems collapsed, as well.

Seventy-five percent of all life — plant and animal — died as a result of the impact.
That was the end of the dinosaurs.

Or maybe not.

The burning winds, earthquakes, floods and fires left a few survivors scattered across the globe. But these survivors had to deal with great hardships.

The Earth was a cold, dark, hungry place in the first years following the impact. Without sunshine, plant life, including forests, died. Animals that needed trees for part of their life-cycles died, too.

The fires and darkness left little to eat – rotting trees, fungus, insects, seeds. And of course, survivors had to be able to find the food in the dark. At first, meat-eaters feasted on dead and dying animals. But soon they suffered, too, as their prey died off. Only smaller animals made it through the hungry times of the long cold night.

A decade after the asteroid hit, the skies cleared enough for shade-tolerant ferns to grow again. Eventually other plants and trees sprouted, too. The few animals who made it through the impact and years of starvation and cold finally had something to eat besides fungus, decaying trees and a dwindling number of ten-year-old seeds.

Who survived?

Sea life was impacted least. Creatures who lived deeper in the oceans suffered less than those closer to the surface.

On land, survival was more random. Those who made it through had two common traits — they were small, and they lived on the ground. This included some frogs, turtles, crocodiles, snakes and lizards. These cold-blooded animals probably survived in the tropics. It was warmer there, even in the dark.

Almost as many mammals died in the extinction as dinosaurs. Mammals evolved at the same time as the dinosaurs. But mammals had always been mouse-like creatures. They never grew to the enormous sizes of the dinosaurs.

Their small size meant that mammals required fewer calories. Being small helped them live through the hungry time. And they were used to eating more different foods than most dinosaurs, including seeds, and maybe fungi.

Early mammals lived in many different environments. The mammals that lived in trees died out when the asteroid hit. But a few scurried through the plant litter on the ground, retreating to burrows in times of danger.

As they evolved, many mammals came out in the cool night, when the cold-blooded reptiles slowed. This gave the mammals several adaptations that helped them stay alive when the asteroid hit. They had bigger eyes to see in the dark. Warm blood let them stay active in the cooler hours, and fur insulated their bodies to retain body heat. After the asteroid, their fur also may have protected the mammals from the razor-sharp edges of shattered volcanic glass that littered the ground.

Courtesy Norbert Brugge, http://www.b14643.de/Chicxulub_event/index.htm

As plant life slowly returned, mammals rebounded quickly. They adapted and filled the empty niches left by the extinction of so many other animals.

Mammals were joined in the empty landscape by a few other creatures. One tiny group of dinosaurs was able to solve the same problems that plagued mammals.
Some of these creatures were ground-dwellers, so they survived the loss of trees. They learned to lay their eggs in protected areas such as rocky ledges or hidden depressions in the soil. They had fingernail-like beaks instead of skin-covered muzzles. The hard beaks may have helped them to find seeds in the razor-sharp layer of ash laid down by the explosion.

In many ways, these animals were like mammals. They were warm-blooded. They became smaller. They made it through the decades long cold spell with a layer of insulation — feathers — that had evolved before the asteroid.

Wait … warm-blooded, beaked, egg-laying, feathered animals … sound like birds.

Red-faced mousebird, Urocolius indicus, at Pilanesberg National Park, Northwest Province, South Africa. Courtesy Wiki Creative Commons, Derek Keats, https://flickr.com/photos/93242958@N00/28386328890

Yes, birds are dinosaurs, the only group of dinosaurs to survive the asteroid extinction. Dinosaurs didn’t die out, after all.

What we’ve learned from the asteroid extinction is both reassuring and terrifying. Life can survive huge changes that happen in an instant. But there is no way of predicting who will make it through. And the life that survives won’t be the same as it was before.

The asteroid impact was the fifth global extinction the Earth has seen. We are entering the sixth, carbon dioxide global extinction. If we take action now, we can limit the loss of species, and prevent global ecosystem collapse.

But we must take action now. We must do everything we can to limit carbon dioxide production. And it must be all of us, together.

Or we can expect to go the way of the dinosaurs.

Birds coming back

We’ve been following the Bald Eagles at Fort St. Vrain power plant closely this spring. But other birds are showing up, too.

Male Spotted Towhee

Spotted Towhees scratch in the soil for insects. But in the spring, you can hear the males calling “tche-tche-tche-cheee!”as they perch on the tips of trees. (https://amylaw.blog/2014/06/02/spotted-towhee/)

Chickadee gathering hair from an old suet feeder.

A pair of black-capped chickadees spent the winter in the neighborhood. It looks like they might nest here this summer, too. Actually, we’ve had chickadees around for a couple of years. https://amylaw.blog/2018/05/03/a-little-housekeeping/

Red-tailed Hawk sitting on the railing of a fence in the yard of the people behind us. They keep chickens and have cotton-tailed rabbits living under the porch.

Last fall there was a Red-Tailed Hawk cruising through the neighborhood. https://amylaw.blog/2018/12/13/red-tailed-hawk/

I don’t know for sure that this is the same bird, but as I pointed out last fall, it is a little unusual for them to be hunting in the semi-wooded suburbs.

And this bird is hunting. Another neighbor said that he came out to get the morning paper, and it was ripping up a rabbit it had caught in his front yard. He said it didn’t fly off as he approached, so he decided to get the paper later.

Today I heard a Crow burbling as it flew fast overhead. It joined another to harass the Red-tail, at times almost driving it into the ground.

With all that drama going on overhead, I almost missed the ringing zipping sound of a Broadtailed Hummingbird heading west into the mountains. https://amylaw.blog/2018/05/09/summer-cant-be-far-away/

I always wonder what they eat this early in the spring. https://amylaw.blog/2017/05/18/hummers-in-snowstorm/And then I go make up some sugar water to put in the feeders for them.

Ten days of growth…

April 4, 2019

Mama eagle shades the chicks. At this point, they are 9 days old.

April 4, 2019

Up until this day, I hadn’t seen them out of the central depression, where the failed egg remains. But once they started exploring, they rambled all over.

April 5, 2019

I’m a little annoyed, because Mama eagle is in the way of a nice shot of the little ones. There were two cameras on the nest, but the bomb cyclone took out one of them, so I can’t switch for a better view.

April 6, 2019

Oh! I get it now! Mom providing shade for the chicks while they sleep. Now that I understand what she’s doing, I see that she actually shades them a lot.

You can see the remains of a fish at her feet. The failed egg is still in the nest, too.

April 9, 2019

She spends a lot of time feeding them.

April 11, 2019

The last couple of days, the male has been covering the chicks up with nest material. I have no idea why.

April 11, 2019

The male has covered the chicks up. The female finally took nesting material out of his beak and put it back where he had picked it up. Hah! I could practically hear her saying “Will you just stop?”

April 11, 2019

Not only have the chicks grown, they are beginning to lose their downy feathers, and their beaks and talons are turning from black to grey.

April 11, 2019

Above: The female has already fed the right hand chick the first half of the fish in her beak. A previous fish is in the left foreground.

I always thought that it was kinda a free-for-all at feeding time for birds — the chicks opened their beaks as wide as they could and the adult dropped food into the biggest mouth. That hasn’t been the case with the eagles — one chick is fed until it is full, then the other is fed. This could be a problem in lean years, but the male has kept the nest full of fish this year.

April 11, 2019

It took her 8 minutes to feed the second half of the fish to the left chick. By the time she finished, all that remains of the fish are under her talons — not much. She feeds them several times a day, not always as much, but a lot.

As of April 12, 2019, the chicks are 17 days old.

Bald Eagle Egg #3, Day 1

The Fort St. Vrain Bald Eagles have been busy. They’ve added more sticks to their nest…

Male brings another stick to the nest — this seems to be an ongoing remodeling project, kinda like our bathroom renovation.

… they are eating well…

… and as of this morning, they’ve laid a third egg.

If I’ve counted correctly, we should start seeing eaglets around March 20.

Bald Eagle Egg #2 Day 1

The Fort St. Vrain Bald Eagles fussed about their nest again today. Those sticks just aren’t quite right!

The eagle in the foreground stood up when the smaller eagle in the background flew in. The smaller eagle is fussing with the sticks that make up the nest. Photo courtesy Excel Bird Cam.
Moving the stick. Photo courtesy Excel Bird Cam.

The larger eagle, in the foreground, flew off, and left us with a view of the smaller eagle — and two eggs.

Eagle with two eggs, as of sometime today. Photo courtesy Excel Bird Cam.

Of concern: snow and single digit night time temperatures for the next few days…

Bald Eagle Egg #1, Day 1

The Bald Eagles at the St. Vrain Power Plant in Platteville, Colorado laid their first egg of the season sometime last night or early this morning.

When I checked in on them around 10:00 this morning, one of the eagles was sitting in the depression they had carefully created in the nest.https://amylaw.blog/2019/02/10/eagle-cam/

This eagle is exhibiting typical brooding behavior — sitting in one spot for long periods of time.

I wasn’t sure she had an egg there, but she didn’t move for a very long time.

Just as I was getting ready actually get to my work, the eagle stood up. I was able see the egg just to the side of her tail.

Newly laid bald eagle egg to the left of eagle’s tail.

Moments after she stood up, the other eagle returned, with a branch in it’s beak.

The stick needed to be placed in just the right place.

I was surprised at how much they dragged that stick around, and that they didn’t hit the egg.

Excel has two cameras on the eagle nest at St. Vrain. The rest of these images are from a different perspective, because I switched to the other camera.

The stick was repositioned several times, and some of the branches trimmed with a quick snip of the beak. Finally, it was in a good spot.

Stick is in the right place

The eagles touched beaks, and one, presumably the male took off. I have no idea if the beak-touching is a frequent thing, or was just for Valentines Day. Sorry. A little anthropomorphizing.

Eagles touch beaks before one flies off.

The remaining eagle fluffed the nest a little, rolled the egg, and settled in

Parent eagle fluffing the nest.
She rolled the egg…
… and settled in.

Most of the egg-brooding is done by the female. She has 35 days to go before this chick hatches out. Bald Eagles lay between one and three eggs, so we’ll have to keep watching to see if more eggs appear.

Eagle Cam

Many years ago, the local power company, Public Service of Colorado, placed a nest box on the smokestack of one of their power plants. They put a camera inside, and watched what happened.

What happened was that a pair of Great Horned Owls moved in and raised a family. The public got to watch. Very cool.

Fast forward several decades. PSC merged with two other power companies in 1995 to form Excel. One of the other companies also had bird cams (which is the story you read in their “Information” page.) Excel now has at least five raptor cams, three in Colorado and two in Minnesota. https://birdcam.xcelenergy.com/cams

Both Bald Eagles and Great Horned Owls begin nesting in January, if you can believe it. Right now, I’ve only seen activity in the Bald Eagle nest. https://birdcam.xcelenergy.com/cams/xcel_energy_eagle_cams/eagle_cam_two

The male, in the foreground, has a bloody beak, after eating a rabbit, the remains of which are just to the left of his head. The female is rearranging the sticks to her liking. Courtesy Excel Energy Bird Cam

I saw them mating earlier, and interestingly, in this pair, the male seems to be the larger. In raptors, usually, it is the female who is bigger.

The female continues to rearrange sticks. Courtesy Excel Energy Bird Cam.

I have two monitors on my computer and have one on the bird cam permanently. I look forward to watching the nest cams through the spring and summer. I hope you enjoy them, too!