Ridin' at the Refuge

Saturday's mountain snow reached the plains by the overnight hours Saturday, and I awoke to a fresh dusting of four or so inches. After a quick shovel of the drive I headed off to the Rocky Mountain Arsenal National Wildlife Refuge. It's been a while, so I am sorry if you have read my posts on this great location in the past. For anyone who has recently found this blog, or is not familiar with the Arsenal I strongly recommend it. This former farming community, turned weapons plant, turned petrochemical factory, turned Superfund site is quickly becoming a unique treasure of the National Wildlife Refuge system. As the Denver area expands it is becoming an increasingly surrounded oasis of prairie in the midst of human habitation. This spring the Refuge will see the grand opening of its new Visitor Center, and as each year passes the area continues to evolve to a more wild state.

I hadn't been out to the refuge since last summer/fall, and the fresh snow made it seem like an appealing destination. My drive in followed only a single set of tire tracks, and a Coyote welcomed me back as he sat near the side of the road. I approached the Visitor Center, and decided to check out the feeder station from my truck. Before I had even gotten started I had Western Meadowlark, Chickadee, Red-winged Blackbird, Northern Flickers, Black-billed Magpies, Song Sparrow, and scores of Dark-eyed Juncos. Of the Juncos, the White-winged is the race that I have found I see the least frequently.


So, I was happy to find one perching for me. Then, it like the others was drawn to the spilled seed on the snow.


I dropped into the Visitor Center to sign in, and found that the weekend tour was set to leave in fifteen minutes, and with the snow it was likely to be a small group. I decided to ride along. It had been just about a year since the last time I had been over to 'raptor row' or the Bison enclosure and I had hopes of seeing the light and dark Ferruginous Hawks again. (For those who have not been, the trailed area that is open to the public in the refuge is relatively small. The focus is on the animals, and they are able to live their lives more naturally with large areas where humans just don't go. Regular tours take visitors on a shuttle buss to see areas that they are not allowed to visit on foot.) While I had a few minutes to wait I wandered around what had been the Officer's Club (now the Visitor Center) to check some of the plantings and fresh tracks in the snow. Not many birds in the trees, so I completed my walk back at the feeders. Feeding there among the crowd was a first-year Harris's Sparrow.


Suh-weet! I have seen a handful of these largish sparrows, but all of them have been re-finds, where I went in with the hopes of locating a bird I knew had been in the area recently. This was the first that I had just picked out of a crowd - pretty cool.


The top of its head and throat will turn black in adult breeding plumage, and will merge with the necklace patch it has right now to form a backwards black hood. Here is a post that shows an adult bird closer to breeding plumage - note that it is a Harris's Sparrow, not a Harris Sparrow, it is possible to learn a few things over a couple of years. From the birds I have seen, Colorado mostly gets first or second year birds that have gotten a bit off course for winter. Typically this species overwinters just to the south-east, becoming more common into the eastern plains of Colorado.


With a great add to my list, to go along with White-crowned Sparrow, American Goldfinch, and Hairy Woodpecker, I was ready for a tour and some hawks! The group grew to seven, a ten year old boy and his dad, a couple of whom the wife had visited the refuge as a Girl Scout. "Back before they cleaned it up!" She explained to the boy, which was why she still "glows at night" Wink-Wink. There were also another pair of photographers to round out our crew. The stars of our trip yesterday were the Bald Eagles. Even a jaded birder like myself who was out for the hawks had to be impressed with the showing. My conservative count for the tour was a dozen, although I am guessing we had more but couldn't count some assuming they were the same ones that had just relocated as we drove. We had a nice mix of adults and juveniles of all ages. Many were perched in the trees, but we had a chance to see one on the snow over a kill, and others in flight.


My highlight was getting to see both the light and dark Ferruginous Hawks on the trip. The dark morph was just seen in passing, and I had no angle to get shots from the camera portholes on the bus. As seen below, the light-morph was much more accommodating. It appears that this light-morph is a recent addition to the area, last year's birds showed dark irides, a characteristic adults have but younger birds do not.


To close, I am guessing that this will be the highlight bird for everyone on the trip who wasn't floored by an eye-level Ferrug or a feeding Harris's Sparrow....


...the just above eye level Bald Eagle. This bird was 10-15 yards from the shuttle bus, and just sat as we stopped and then slowly rolled past. Beautiful, and a great reminder of just how large these birds are. Our tour did get to see a handful of Bison, although they were distant and fairly well hidden in the downslope area of their range. By the time the bus got back I needed to be heading out, but I didn't regret taking the ride. I did notice someone birding from a vehicle at the feeders, and walked over to say hello and ask about the Harris's Sparrow. The man said he hadn't seen one himself that day but that there had been two around, a first and second year. Impressive little feeding station they have going there.

If you are in the area and remotely interested in wildlife do check this location out. The tour ride is a great experience for anyone interested in wildlife or history, regardless of your knowledge level. The ride is really great for kids, but parents be warned that it can run almost two hours. Be aware that the refuge isn't a park. It is a wildlife refuge, and there are a handful of differences for the visitor to be aware of - so check out the site or give them a call during visiting hours.

I can't wait to get back for a hiking day, although at the >95% of the water is frozen, so waterfowl are very limited. On the flip side this normally quiet site is in its off season, so you will have an even more intimate experience during the coming weeks than you will once migration heats up.

2011 Count: 64
Lifetime: 252

Cool Down

After an early morning that featured two, three mile, down then up hikes I was ready for an afternoon cool down, somewhere that offered flat terrain. I decided to spend a couple of hours at the Rocky Mountain Arsenal National Wildlife Refuge.



This was a limited intensity birding hike for me. Doing anything on a windy expanse of plains at mid-day is a challenge. Even so, the refuge offers so much to see that even at during admittedly quiet birding hours I still knocked together a 27 species list. The gulls had descended on Lake Ladora, but a contingent were always airborne, riding the gusts and keeping the usually quiet plains fairly noisy.
My effort was rewarded by a few personal first-of-season sightings, including the Horned Lark below.


Against a windswept, grassy, background the horns of a lark can be difficult to pick out. For this bird my ID started in the field and was confirmed before I had zoomed in or cropped this image. Look for the three colors in the tail. The Horned Lark features a tail that has narrow white edges, and a brown central stripe, on otherwise black feathers. It is a good sign, and one that once recognised can be used at highway speeds as these flocks take flight from the roadside.

The Refuge always seems to have a group of Mule Deer somewhere in sight. On this visit I had to make a detour to avoid coming between a lone male and two youngsters who had left the shade of a copse where the rest of the herd was resting. Taking the roads that led the longer way around showed me this deer who did a couple of cuts between mom and the rest of the herd as I tried to remain as far away as possible.


Good thing they carry around their own pair of sun visors!

One positive from strong sunlight is that it can make some markings stand out.


The roufus and white patches on the male Gadwall are much more visible in this light than at dawn or dusk.

Finally, with the least quality is a Franklin's Gull in breeding plumage. This gull is similar in appearance to the Laughing Gull (non-breeding plumage), that I saw in Baltimore last fall. The easiest way to tell these two apart is that the Laughing Gull localizes to the Eastern U.S. seaboard, while the Franklin's Gull migrates north through the plains to Canada in the spring, and back south to Peru in the fall.


Hopefully I get a few more shots to improve the quality this spring.

2010 Count: 97
Lifetime: 210

Rocky Mountain Arsenal Raptors

Every DFO birding trip I have attended has been taught me something, and yesterday's trip to the Rocky Mountain Arsenal National Wildlife Refuge was no exception.

The highlight of this trip came early, in the form of Ferruginous Hawks. The more common 'light' form is pictured above. That individual had apparently had a messy breakfast before we arrived. As is often the case though, a well fed hawk is a content hawk, and this one remained perched as our 10 person group got good looks from fairly close range. Just down the road we had another Ferruginous, this one was the first of the dark variety that I had seen.

That one did fly more quickly, giving me a great view through my bins, showing its white tail and wrists on the upper wing, and the light crescent underneath that forms between the Ferruginous' telltale wrist comma, and the dark leading edge of the under-wing present in this variety. Good looks on both, and chances to become familiar with identification points that I knew would come in handy in the future. Little did I know that I would get the chance later on that same trip.

This bird is a juvenile, light, Ferruginous Hawk. One other birder spotted it on distant branch, but its perch was obscured by branches, and we ended up walking a good distance around the tree to get an unobstructed view. We had eliminated immature Bald Eagle and Red-tail Hawk fairly quickly, but were trying to determine if this could maybe be a Rough-legged Hawk - (which would have completed our area buteo trifecta for the day). The light coloring of the head was what was throwing us off, and we couldn't get a look at the feet, or discern the line of the gape as we approached to make an ID. In the picture the gape is visible, but in the field it was not. The bird decided it had had enough of the people walking a semicircle around it, and flew showing us its wrist commas and confirming its identity for us. It was a great chance to practice checking the field marks we had studied only a few hours before.

In addition to the Ferruginous Hawks there were a number of other raptors on display, including Red-tails, Northern Harriers, American Kestrels, Bald and the Golden Eagle above. The pictures of both the Golden and juvenile Ferruginous had to be brightened a bit after the fact, but show id points well. For the Golden, note that the bill progresses from black at the tip, to grey, and then a yellow base. This individual was close to a pair of Bald Eagles and allowed a chance to compare the two species. The Balds perch at an angle, where the Goldens tend to be more vertical and have a shape like that of a perched hawk.

Birding at the Arsenal is always productive, 27 square miles of refuge in an urban area guarantees that. An added bonus of a group trip like the one I joined yesterday was the potential to get outside the small area of public trails and see the Bison herd on the premises. Each time I visit I think too much time has passed since the last, and can't wait for the next. It is one of my favorite spots, and has a story that shows that even the most devastated environments can not only be repaired, but can become treasures for wildlife.

Afternoon at the Arsenal

In addition to wondering about the possibilities and prevalence of leucism I saw a good variety of full color birds at the Rocky Mountain Arsenal National Wildlife Refuge on Sunday.


The Common Yellowthroat popped into the top of a willow thicket as I walked by and posed while singing for me to take a few shots.

A young Red-tailed Hawk flew along the edge of a wood, and paused for a moment to check me out from the perch it had found. It then called once, took off towards and then over me, before flying on to a more distant grove of trees. I guess it wanted a closer look.

Another young bird, this one a juvenile Snowy Egret, moved from perch to perch as I returned along the lake shore. I used my photo processing software to take a bit of the edge off the mid-day sun. In its altered the photograph shows the key indicator for the age of the Snowy, its bi-colored legs. Eventually the legs will darken, leaving the yellow feet at the end of long black legs. The trademark of an adult Snowy Egret.

As I was leapfrogging the Snowy's perches I was accompanied by a pair of Belted Kingfishers. They were more secretive, preferring to remain on the far side of leafy trees, but their calls give them away. At one point the foliage broke, giving me this view.

Just as I reached the dam road I spotted this flight of Double-Crested Cormorants using some concrete as a communal perch. The two in the back were playing king of the hill with the lone remaining perch, very entertaining.

While scanning the lines I did pick up Bank Swallows as well, which was a new species for me. The back of one is visible in the picture at the top of the previous post.

2009 Count: 168

Lifetime: 178

Was I seeing things?

I had an interesting trip to the Rocky Mountain Arsenal National Wildlife Refuge yesterday afternoon. I'll have a photo report up later, but there were some birds along the way that had me head scratching and possibly seeing more than was really there.

Shortly after I arrived I scanned a large group of swallows on some hanging wires, it didn't take long to pick the one that was not like the others....


That is one white swallow...technically it is leucistic...a true albino would have the pink eye indicating a total lack of pigment.

The first notably leucistic bird I have found in the wild, and I did it all by myself! Ok, not that major of a feat when there are hundreds of birds all hanging out together and all in plain sight. What became more interesting was what I saw later....

Am I right, is this a partially leucistic Bullock's Oriole? I only have my Peterson Guide to Western Birds with me this morning, but I do not see anything else to match what I am seeing here.

Then to make a strange coincidence even more unlikely, I saw this bird at the far end of the lake.

I can't say for certain if they were or were not the same individual - although the first one appears to have more white where the Bullock's should have the black eye-band - but differences in time and light angle make it impossible to tell.

Once again nature throws so many questions my way...

Do Bullock's Orioles go through a light molt? This young Oriole seems to suggest otherwise, but that one may have been further along....

If it (they) is (are) leucistic how uncommon would it be to have two in the same area? Are multiple leucistic individuals in the same brood possible? Common? Rare?

I don't think it likely, but can environmental factors increase the emergence of recessive genes?

Finally, am I just seeing these species because this is the season for hatches? Since I have really only been doing this since last October it is entirely possible that each summer hundreds of pale individuals are born, and then due to natural selection are weeded back out of the flocks by the time fall migration rolls around.

As always, if anyone has insight please feel free to comment or email me at daveabirding@gmail.com.

Recovery at the Refuge

After my very enjoyable first day skiing this winter I had some lactic acid that was screaming to get out of my calves. So I headed over to the Rocky Mountain Arsenal National Wildlife Refuge to do some walking. I love the drive in almost as much as anything about the Refuge. I head north from I70, through some light industrial area with warehouses and train-tracks. The four-lane road hits a "T" intersection at the gatehouse, and after pulling through the road is transformed into a two lane road in the prairie. Granted there is still a mountain of rubble left from the old Stapleton Airport runways, but even that is shrinking. The best part about the road is that generally you can take your time driving down it, and you never know what you are going to see before you even reach the visitor center. In the past I have seen Bald Eagles, herds of Deer, and Coyotes just as a kind of appetizer for what awaits in the refuge proper. Today I was looking left as I drove along slowly, and spotted a nest with what may have been a lump in it. I dug out my bins and sure enough there was a Great Horned Owl nesting within sight of the road. I grabbed my camera and got a few quick shots, but the nest was to far to be more than a large blob in a tree.
Being in my car I decided to try something that I haven't done much in the past. I pulled my 2X extension tube out and attached it to my lens. I was able to use my door frame as a solid rest for my arm and got a much more satisfactory image.





After getting a few frames I headed on to begin my actual walking part of my recovery effort. I started off in the same general direction that I normally follow, heading out across a floating bridge on Lake Mary, and then popping up to the road that overlooks Lake Ladora to see what there is in the way of waterfowl. Being mid-day it was not the bird paradise I have seen in the early mornings, but I did see large numbers of both Common Goldeneye and Canvasbacks, with a handful of Common Mergansers thrown in for good measure.





While watching the Lake I enjoyed a Northern Harrier hunting on the far side, out of camera range, but a fun show through the bins. I walked South and East away from the lakes and through open fields and low shrubby growth. There was not much bird activity, but I did see two Bald Eagles ascending a thermal, and two Red-tailed Hawks perched at the top of a large tree. As always I was surrounded by deer, near the lake I had six Mule Deer casually walk behind me through an open field, and later I passed another group lounging under trees.






I crossed back to the East and returned to my car via the Prairie Trail. Unfortunately the clouds were filling in, and aside from the Prairie Dog town there wasn't much activity to be seen. It was a beautiful day for a hike though. I love that in Colorado you can be carving turns in fresh snow one day, and be warm on an easy hike the next. Spring is close at hand in our urban prairie refuge.





Finally as I drove back out I caught site of a Kestrel with prey. I made a quick stop to soak in another great moment at the Rocky Mountain Arsenal.


2009 Count: 61
Lifetime: 91