September 26, 2009
Richard Stevens:
Jerry Petrosky and I arrived at Rocky Mountain Arsenal (Adams County) just as it opened at 6:00 am. Sunrise was 6:52 am; Civil Twilight 6:25 am. By the way, hours change on October 1st, when the arsenal and Visitor's Center will open at 7:00 am and close at 4:30 pm. Guess they are not going to pay for a guard at the front gate this winter; too bad, it was nice to wander the grounds until dark in the winter looking for owls and sparrows.
As I expected, when I played a Barn Owl recording at one of the larger groves of Mexican Locust trees mixed with sparse cottonwoods, a Barn Owl called back. It answered for about 2 minutes before becoming quiet.
I then played a Long-eared Owl recording (at 6:40 am). To our surprise (though I did suspect that Long-eared Owls were here/there) two Long-eared Owls circled over our heads for about 20 seconds before returning to the thick Locust trees!
We then hiked about 6.2 miles of the public trails. What a beautiful fall day. Winds were a little strong, blowing the leaves and making picking out birds a little difficult (steady 10+ mph, gusts to 18 mph), but we enjoyed the hike.
Highlights:
A Cassin's Vireo was in the cottonwoods below the Lower Derby Lake dam. As we watched the vireo, a Cooper's Hawk flew through the trees after a rather scared and quick flying Ruddy Duck.
The northern side of the Lake Ladora trail was closed at Lower Derby (due to construction) so we were not able to check the canal between Lakes Derby and Ladora.
We turned around and hiked to the Rod and Gun Club trail. This year there is a good amount of water east of the Bird Blind. Ruddy Ducks, American Coots, Gadwalls and a few Canada Geese were taking advantage of the ponds that have been dried up for years. We saw our first shorebird of the day, one Killdeer.
A vireo which avoided identification fluttered about with 4 Yellow-rumped Warblers above the bird blind. The vireo (which turned out to be a Cassin's Vireo) eventually flew to the Mexican Locust trees just west of the cottonwoods surrounding the blind.
We chased after it so as to finally identify it. While watching the vireo, my binoculars caught two eyes staring back at me. It turned out to be our third Long-eared Owl of the day! Two Sharp-shinned Hawks circled, more interested in each other, than us!
We headed back toward our car and noticed a new mobile bird blind at Havana Ponds; we so detoured 0.4 miles south to have a look. Several additional Killdeer and a Greater Yellowlegs walked the northeast shore of Havana Ponds. There were quite a few Ring-billed Gulls and common ducks. Another pair of Sharp-shinned Hawks was in the few cottonwoods south of the ponds.
We scoped through the 14 Franklin's Gulls looking for a Sabine's Gull or Laughing Gull; without success.
A side note to the Ranger who decided to use the side of the blind for a restroom, never assume in today's world that you are alone when outside. We debated as to whether to knock on the blind's window, but did not. I do not believe she figured out we were in the blind.
A leisure walk back to the Visitor's Center found 5 Rock Wrens wandering around the Prairie Dog Village south of Havana Ponds. Several of the Rock Wrens dove down into the mounds; guess a good place to find insects/fleas. Can Rock Wrens carry "bubonic plague virus"?
There was a nice collection of sparrows along the southeast side of Lake Ladora. White-crowned, 2 Song, 4 Chipping, and a Lincoln's. A Green-tailed Towhee used one of the higher and thicker bushes for cover.
Our trek ended with a quick circling of Mary's Lake. House Finches and many Red-winged Blackbirds were along the south side. On the south side, we encountered a "strange" little dark sparrow like bird. Very dark back, no white in tail, wings, head, back, anywhere. It flew, but dove back onto ground in thick cover each time. Very short tailed, very small, definitely no white in fanned tail (saw it fly and land four times). No idea what it was? If it was an "ammodramus", ouch, we missed identifying it. The grasses were wet, which could have made it look darker than normal.
The trail back to the Visitor's Center leads through a "cottonwood grove". Two Black-capped Chickadees caught our attention. They lead us to a Black-and-white Warbler wandering along the branches.
While I had a two hour meeting at Riverside Cemetery, Jerry walked the west side sparse "riparian area". He found an Orange-crowned Warbler, several Rock Wrens, and another mixed sparrow flock.
We then decided to head west to Two Ponds National Wildlife Refuge (Jefferson County) as it was the last day it is open in 2009 (May to September, Tuesday through Saturday). At 72.2 acres, it maybe the smallest National Wildlife Refuge in the country, sixty three point two acres of uplands and 9 acres of wetlands.
A Gray Catbird was along the south side of the wetlands area. A Townsend's Warbler was high in the cottonwoods just inside the north entrance. Perhaps one could relocate this bird from outside of the entrance, but I would not count on it.
Our birding day ended with a two hour search for the Northern Parula found yesterday by Sue Ehlmann and Rebecca Kosten near mile marker 3.0 at Barr Lake (Adams). We had no luck, but did find a Cassin's Kingbird at mm 3.2. What's up with all the Cassin's Kingbirds this year? Traditionally they appear to migrate later than Western Kingbirds; there sure seems to be many of them along the front range this year (or is it more birders out)?
We did pass the Burrowing Owl site at 3.4 miles east of Tower Road and 96th Avenue. Still at least two Burrowing Owls there. No Short-eared Owls along the DIA Owl Loop (that's Denver International Airport).
