Have your vole and eat it, too

The Valmont Great Horned Owls are seemingly doing well- I surmise by last night's activity that the female is being kept well-fed by the male. He delivered a plump vole at 8:37 last night, and she didn't just gulp it down right away. Instead, she saved it for most of the night, not eating it until dawn was lighting up the sky at about 6 am. She takes short breaks throughout the night, maybe to sit out on the perch or maybe to stretch her wings a little, but none seem to exceed an hour. Last year, she would leave for hours on end, even in bitterly cold weather, and the first clutch failed. After the eggs were removed, however, she laid more and pulled off a successful, if not late batch of chicks. Perhaps with a year of experience under her belt everything is on track this year.
Not all of the local Great Horneds are on eggs yet, though. I was at the local Wild Bird Center today, and ran into Wendy Stuart, an outstanding bird photographer who has been watching her favorite pair at Walden Ponds Wildlife Habitat in Boulder all spring. The female there is staying near the nest but not incubating yet. Guess there's room for variability in this area depending on the owl in question- Wendy says this pair has laid eggs in March every year she has studied them, this being the fifth.

The Eggs Are Down

Let the owl-camming commence! I haven't been watching the Valmont Power Plant Owl Cam too closely, but the last time I checked (about a week ago), an Owl had been coming and going but I figured there would be a bit of a wait for incubation, since the Great Horned Owls there laid eggs February 24 and 28th last year. The owl abandoned those eggs for some reason, but had another clutch going by March 24 with chicks still in the box in early June.

Now I see that there was an egg already laid this year on February 9, and two are there now, with the female spending most of her time incubating. Papa owl is bringing treats now and then, too- check out the vole (or whatever it is) in the second pic below. All good news- I hope they succeed at their first try this year..
Many of you already know about this cam, but if not you'll find it interesting to know that the nesting box is 260 feet up the side of a retired smoke stack at Xcel Energy's Valmont Station in Boulder, Colorado. The stack overlooks the Valmont Reservoir complex (see above), an Important Bird Area especially known for the wintering waterbirds there that take advantage of the open water created by the warm water discharge of the power plant. The box was placed to attract nesting Peregrine Falcons but has had Great Horned Owls use it for years now instead. On the annual Boulder Bird Club mid-winter trip to the reservoir complex, plant engineer Dave Madonna described the difficult efforts that the owls go through when they fly up heavy prey like rabbits or ducks. It takes them multiple stops on ladders on their smokestack or the other two smokestacks nearby, laboring up until they can finally heave the prey into the box for their voracious chicks. I have commented on it before, but I still get a funny mental image of the chicks going through their branching stage, clinging to the perch outside the box or grabbing the ladder 260 feet off the deck. When they finally decide to go for it and fly out, that must be quite the leap of faith.

Not too light, not too dark, just... intermediate

I found another interesting Red-tailed Hawk last weekend at Cherry Creek State Park in the SE Denver Metroplex. At first glance it had some Rough-legged Hawk traits, particularly the look of a black belly band with dark breast streaking above and lots of white on the head. Getting it scoped, however, quickly dispelled that ID- the bare legs, for example, immediately rule out Rough-legged. I recognized the bird as a Red-tailed Hawk, and suspected it was a Harlan's Hawk (the harlani subspecies that breeds mostly in Alaska and the Yukon.)

The undertail coverts and leg feathering were pretty rufous, and the distal half or so of the tail was pretty reddish, but the base of the tail had the classic mottled gray color of a Harlan's. Also, the belly and breast streaking were blackish, not dark brown of other Red-tails. The goggled look, big-looking eyes and relatively smaller bill, vertical white/black streaking of the breast, and near lack of pale highlights in the scapulars all pointed to Harlan's Hawk as well. Just to be sure, I consulted with some of my pro raptor-id buddies and they agreed that the bird is an intermediate-morph Harlan's Hawk. It seems like some distant calurus (the western Red-tailed subspecies) influence may be present, but then again maybe not- this topic seems tricky and may not be resolvable without DNA analysis. The main thing that seems to confuse people is that Harlan's Hawks can have red in their tails- they just can't have predominantly red tails like adults of most other RT subspecies. I've been birding with folks who immediately write-off a potential Harlan's Hawk because of this, but both Brian Wheeler and Jerry Liguori discuss the eminent possibility of red in Harlan's Hawk tails in their excellent raptor ID books (and in personal email exchanges.)

I'm noticing that if a Harlan's Hawk has red in its tail, it is often more extensive in the outer tail feathers, with the gray going farther out in the middle feathers. (By the way, in any RT subspecies the red is mostly on the top of the tail, not the bottom, so from underneath you won't always see it- the bird in this post shows both the underside and top of the tail for comparison. To get the tail lit up red from underneath, the bird usually needs strong light coming from above- see this bird as an example.) I thought I'd cobble together a little comparative matrix, showing adult light-, intermediate-, and dark-morph Harlan's Hawks perched and in flight. There is essentially an unbroken continuum between the light-morphs and dark-morphs, but I've tried to choose good matches for the end members and a pretty middling intermediate bird. Birds that are more darkish-light, light-intermediate and dark-intermediate, and lightish-dark are out there, too, but I'm not including them in this comparison. You'll note that good, dark Harlan's still have at least a wee bit of white streaking on the breast, something that calurus dark-morphs lack. Also note the cold, blackish steaks on even the light-morph individual, not brownish like on light morphs of other RT subspecies. Maybe I'll do a similar matrix sometime for juveniles, but they largely follow the pattern, differing mainly in eye color and tail pattern.

The Power of Suggestion

Denver-area winter birding spot Cherry Creek Reservoir has been hopping with good birds over the last few days, including reports of 9 species of gulls. The keys at big lakes like Cherry Creek are patience and good glass, and it also doesn't hurt to spend the hours with good birding buddies, either. Having one or more friends around helps a lot with bird spotting as one sifts thousands of Ring-billed and Herring Gulls for the goodies, and helps to pass the time during lulls (like yesterday, when nearly all of the gulls departed for a couple of hours in mid-afternoon.)

Another bird of note at Cherry Creek has been a juvenile swan. Swans can be deceptively tough to ID when you don't have up-close field guide looks at adults. The open patch of water that has been the base of operations for this bird is about 500 meters out from shore, and often the air gets quite distorted over the ice. As if that wasn't enough of a problem, young swans don't develop some of the most important field marks until they mature- things like the shape of their bill or the shape of the junction with the bill and forehead can be unpredictably out of whack on first-winter birds. Lots of indicators pointed to Tundra Swan, including black legs and a concave upper bill edge. So for a couple of days, the RBA and state list serve were reporting it as such. Yesterday, though, a competing ID theory developed with its own supporters pointing out features like the immense size, all-dark lores, and long neck as indicative of Trumpeter Swan.

I didn't arrive until about noon, and soon got onto the swan, which was standing near and completely dwarfing a Canada Goose (a large subspecies, too- not a lesser Canada Goose.) The bird stretched, craning its neck, which was amazingly long. Seeing this for myself, and with the arguments for Trumpeter fresh in my mind, I had no problem agreeing with the call- Tundra would be bigger than a Canada Goose but not that big. Throughout much of the afternoon I happily shared my scope with other birders and casual passers-by, telling them it was a young Trumpeter Swan.

How wrong I was.

So were the Tundra Swan folks right? Nope.



You see, Trumpeter and Tundra Swans are the only species on the state list, and we all fell into the trap of trying to make the bird one or the other. But while I was happily pointing out the bird to folks, Bill Maynard had gone home and was studying his digiscoped pictures to try and settle the issue. His conclusion was that the bird was a young Mute Swan, which explained the seeming contradiction of field marks. Coincidentally, just after he posted his thoughts to the state list, Mike Freiberg and I were photographing the bird as it flew over us, heading off beyond the dam for about ten minutes before thinking better of the sojourn and flying back to its hangout in the middle of the lake. I didn't look at the photos at all, though, until my dad called me to tell me about Bill Maynard's post. Mike and I grabbed our Nikons and zoomed in on the flight shots, and essentially smacked our foreheads with the realization that it indeed was a Mute Swan.

So what are some things that I take away from the experience?
• This is an example of why the birding lifestyle is cool- healthy, friendly ID debates and sometimes surprising resolutions.
• A great example of seeing what one expects to see instead of seeing what one is actually seeing.
• A reminder to keep the mind open to possibilities beyond the expected, particularly when a bird isn't quite "right."

So at this point I hand it off to the Colorado Bird Records Committee. I don't think there will be any debate about the ID, but with people around the country keeping Mute Swans in their ponds, the provenance of the bird will be debatable. On the other hand, established wild populations of this Eurasian species exist up and down the East Coast and through the Great Lakes, and perhaps in Missouri and Montana as well, so making the flight to Colorado from one of these wild populations wouldn't be too much of a stretch for such a bird. It doesn't show obvious signs of aviculture (like a band or clipped or oddly worn wing feathers), but not all waterfowl enthusiasts band their birds, I suppose. Whatever the eventual verdict, it is a very interesting bird and sure to generate much more discussion before the whole episode is over.

Well, the 4th quarter of Super Bowl XLII just got underway with a punt by the Patriots- neither team is doing much offensively and the score is New England 7, New York 3. Why mention the Super Bowl on a birding blog, you ask? Because of the schweet bird-themed FedEx ad featuring giant carrier pigeons. Gotta love it when a company pulls out all the stops like this. Check it out:

Running Across an Old Friend

My little birding buddy Garrett & I hit the trail today in search of an Iceland Gull that's been bopping around Boulder County. My dad & I saw it for a few minutes yesterday, but it got real camera shy and departed as soon as I began training my digiscoping rig onto it. How do birds know when you're about to photograph them? It sat there calmly enough while we were just looking at it...

Anyway, Garrett will have to wait for another chance at his ICGU lifer since it didn't show during our time looking. Not all was lost, though, as we found this inky dark-morph calurus Red-tailed Hawk on our way home. It was at the exact same location where I saw it last winter holding court on a power line along 95th and Valmont east of Boulder. I'm positive it is the same bird, as dark-morph birds like this are really scarce. It would be just too much of a coincidence to have another at the same spot. Needless to say, I was pretty excited to see the bird again- I get pretty geeked about dark buteos (in case you haven't noticed.) My excitement grew when the bird decided to stay put as I pulled off on the shoulder of the road instead of bolting directly away. When it finally launched it flew parallel to the road north of me, keeping in good light and in profile. A clear blue sky would have been peachy, but I'm not complaining! I guess this unusual exhibition of cooperation is a bit of payback for all of the birds that fly straight away at their first inkling that I'm slowing down to look at them.

I got some shots I really liked of the bird last winter, but this time the light was a lot better for the perched shots, and I got a series of flight shots showing the deep red upper tail surface (aka the deck.) Even really dark Harlan's Red-tailed Hawks wouldn't have a complete red deck like this. Although they can have some red in their tails, if present it is usually near the base and the rest of the deck is banded grayish white. A Harlan's would also have at least a few white streaks on its breast.

Waxwings & Waxlesswings

I had the good fortune to change a mundane errand into a photo frenzy a few weeks ago when I heard the high, shrill zreees of Cedar Waxwings outside the local PostNet shipping store. The little strip mall housing the shop had a few crabapples heavily laden with winter-shriveled fruit, and the waxwings were thronging to the trees in waves as the reserves sat back higher in bare cottonwoods waiting for their turns. Using the trusty BrdPics mobile as a blind, I parked near one of the trees with the light at my back, rolled down the window, and set about trying to catch some of the action.

What I really wanted was a shot showing the namesake tertiary tips. Seems like most of my pics of these birds are looking up at them- nice, but no waxy wings showing here:
There was a lot of gratuitous feeding-frenzy action to keep me busy while I watched for a good pose showing a bird's upperparts:
You didn't see that slip, did you?

I noticed an interesting feature in some of my pics- when the birds gulp down a whole fruit, their tongue helps push the thing down with a neat harpoon-like tip that presumably doesn't easily let the fruit slip back forward:
And down the fruit did go!Frustratingly, though, lots of the birds lacked the colorful waxy feather tips. These are first-winter birds, and won't get the tips until their adult plumage molts in:
Finally, though, I had color showing on a bird's back and commenced to firing. I only got a few frames but finally had at least a few waxy tips to enjoy looking at.

Horning In On The Action

The highlight of my birding outing today wasn't a bird at all.

This morning, my buddy Nathan Pieplow & I met Ted Floyd and Christian Nunes up at the Fawnbrook Inn at Allenspark, Boulder County's renowned Rosy-Finch locale. Rosies came in two waves of 150-200 birds early, only staying for a few minutes total, making photo opps few and far between. Brown-capped Rosies were in the majority, with a good showing by Gray-crowned (including some Hepburn's) and a spanking male Black, escorted by one or two females. For most of the two sorties the birds stayed up high, and when some dropped down for chow it wasn't for long. Still, getting all three species for the year is always a nice thing that shouldn't be taken for granted.The other few hours that Nathan & I spent waiting were punctuated with some other nice mountain birds and some good conversation. Nathan did some sound recording with his slick new parabolic mic and I cycled my shutter a few times.Heading back down, we trolled around some on the back road through Raymond (town sign: Everyone Loves Raymond!) and Riverside (the scattering of homes where Whitey the Steller's Jay made waves in 2004) with hopes of a Northern Pygmy Owl or Northern Goshawk but the only new bird that we added was a Red-breasted Nuthatch. Thinking that was about it, we regained Highway 7 and headed down towards Lyons.

On our way down we noticed some interesting wildlife. Not hard to notice since the wildlife consisted of half-a-dozen 250-lb Bighorn Sheep rams standing in the middle of the pavement licking road salt, and a couple more enjoying the sunshine on the hillside above the road. Cool!! Thinking back, I think this is the first time I've seen this species in Boulder County. We enjoyed the big mammals for quite a while, watching them graze, lick road salt, and get a drink from the St. Vrain River below the road. Nathan pointed out an adult Golden Eagle soaring above and around the granite cliffs above us, but soon we turned our attention back to the sheep.Besides enjoying the rams, I saw a really funny thing transpire right in front of me. Obviously, Bighorns on the road induce a bit of a traffic jam, with some folks pulling off the road where possible and others just stopping right in the traffic lane. One car, heading down, had slowed way down to enjoy the show. Another car in a big hurry quickly caught up to it just as it went by me. As it went by, I saw the driver in mid-curse, road-raging over the impediment. The amazing thing, though, was the instant that the road rage transformed into awe as the driver saw the rams alongside the road. Lip reading, I swear she said, "DAMMIT! WHAT THE HE... WOWWWW!!!" as a smile blossomed across her face. Glad she had an attitude adjustment. I know I enjoyed the encounter- here are some of my favorite shots.

Wing Shooting

Pueblo City Park is a fantastic place to work on waterfowl photography- the ducks wintering there are super tame, thanks to the succession of folks bringing their kids laden with bags of stale bread to feed the birds. I'm not coming down in favor of the practice, mind you, but they feed the birds whether I approve or not, so I figure I might as well get some snaps out of the deal.

For me the best method is to get the light at my back, wait for a bundled-up kit to come trundling along, bun-bag in hand, and to hang out at the periphery of the gathering horde of hungry ducks and geese to pick off individuals as they arrive for the hand-out. The big, aggressive domestic goose varieties usually push to the center of the throng, but lots of wild American Wigeons, Mallards, and Wood Ducks(!) gather for their chance at the bread delivery, too. There is even a Snow Goose that hangs around. It probably was injured but found its way to this refuge. Ever wonder what the term, "Grin Patch" means? Check out this close-up and I think you'll see the grooved black thickening where the bill halves meet- nice goth look, dude!. Snow Geese have 'em, Ross's Geese don't...
I also like the corrugated effect of the neck feathers.

Wood Ducks usually seem shy and hard to photograph, but they come running (& flying) when the bakery delivery arrives at the pond...
This provides an unusual opportunity for detailed photos without resorting to hiding in a blind. They also don't feel threatened or freak out when you get down at ground (or ice) level, since the kiddos feeding them are down low to begin with. Dropping down gets a much more natural angle on the birds than shooting them looking from above.

American Wigeon outnumber the other ducks there, even Mallards. Great looking ducks, wigeon are! For a few years, a stunning male Eurasian Wigeon held court at the park, too, but for now Americans are all 'ya get.
The challenge I enjoy the most, is trying to get birds coming in on the wing. It is a low-yield game, but every now and then I get a frame I like. Hope you like them, too.

Beware the Abominable Snow Squirrel

Caught on film- the legendary, near-mythical Abominable Snow Squirrel, AKA Yeti Sciurus. Don't get too close- they will attack without provocation.

Yeller Feller

My dad Jim & I went down to Pueblo and Cañon City, Colorado to start the year's birding. Heading that far south in the states opens up some possibilities that aren't around the Denver area, like having most of Pueblo Reservoir ice-free & hosting a nice selection of waterbirds and gulls (we ended up with 7 gull species!) There's also a host of good birding spots around Pueblo & Fremont Counties, plenty to keep us busy for a couple of days' worth of birding.

One specialty of the area is Rufous-crowned Sparrow. A colony is located on the west side of Cañon City, about 45 minutes west of Pueblo. This is pretty much as far north as the interior population of the species gets, although California birds range a bit farther north. I've seen the bird once before in Colorado but not very well, and the birds I've seen in Arizona have been pretty cool, but I finally got some pics to write home about:
As counterpoint to this desert-scrubland specialist, we found a handsome White-throated Sparrow along the Arkansas River in Cañon City. These are rare but not unexpected winter visitors to Colorado, but breed in the Boreal Forest of Canada and the Great Lakes States, so it came a good distance to winter in Southern Colorado:

The best surprise of the trip, though, was a juvenile Yellow-billed Loon that some buddies of mine spotted out on Pueblo Reservoir. We had been playing birding tag with them most of New Year's Day, running into them as they were heading off to another stop. Near the end of the day, my dad & I were in W. Pueblo cruising some neighborhoods looking for White-winged Doves (& earning the hairy eye of a sherrif's deputy) when my phone rang with the news. The sun was about down, but luckily we were only about 5 minutes from the lake, and we headed up with no delay. As we bounced along the rutted rocky road to the vantage point where my friends were, a few of them waved us in- a good sign. Sure enough, a few scopes were on the bird and we just stepped up to view it in the waning light. Some birds are easier than others- thanks, amigos!!

Anyway, we saw the bird again the next day, in better light and much closer. I digiscoped it and took some digiscoped video through my Leica rig. I like the second half of the video where it is swimming with a Common Loon. In comparison to the Common Loon, you can really see the Yellow-billed's size difference (YBLOs are about 30% larger than COLOs), the larger & more upswept yellowish bill, the paler overall coloration (with a bit of straw-yellow tint), the more pronounced scaly pattern formed by the pale edges of the back feathers, the blockier head with the bump over the eye, and the darker patch behind the eye.


If you haven't birded in this part of Colorado, you could jump-start your list by attending the 2008 CFO Annual Convention in Cañon City, 16-18 May.