Sunday, 23 September 2012

[cobirds] Broad-winged Hawk kettle, etc., Roselawn Cemetery, Fort Collins (Larimer)

Roselawn Cemetery, founded in 1947, is a newer and lesser known cemetery in the eastern part of Fort Collins (Larimer).  It is just northeast of the intersection of Mulberry (SR14) and Summitview (i.e., east of where the Poudre River crosses Mulberry about half way (1+ mile) to I-25, or another way of putting it would be just east of the Sundance Saloon and just west of the Amish Showroom on the north side of Mulberry accessed by the frontage road).  I have had my eye on this place for a long time and only birded it about 10 times.  Being out on the edge of town, it has the attributes of an autumn migrant trap and considerable promise.  Today some of the promise came to fruition.

Backing up what Scott Severs posted earlier, at about 11am I saw a group of swirling hawks maybe 100 feet up, which apparently had just lifted off from their overnight roost in a row of big cottonwoods just north of Roselawn over a hay field.  Fourteen of the birds were Broad-winged Hawks and I am fairly sure the other 2, believe it or not, were Northern Goshawks!  An amazing sight for Colorado!  The birds were just slightly too far off to confirm the ID of the non-Broadwings.  They quickly gained altitude and moved off to the southwest (that is, toward Boulder).

Also at the north boundary fence of the cemetery and the hay field were, first, a juvenile Red-headed Woodpecker flying from one wooden telephone pole w to another one, followed by a Lewis's Woodpecker flying from the same pole w to the pole where the Red-headed had gone.  Lewis chased off Redhead, then disappeared.  Two Northern Flickers then alighted on the same pole where the other two species had just been.  Then the Lewis's reappeared, chased off the flickers, and then proceeded to go to a big Russian-Olive very nearby for one olive.  It took the olive to the top of the pole, presumably to cache it.  After watching this bird for quite some time, I believe the Lewis's was not caching but rather taking food to the pole, jamming it in cracks on the top of the pole to hold it, then pecking/consuming the food.  The food appeared to consist of individual olives, what I think was a large black beetle (in all likelihood a darkling beetle) captured on the ground in the hayfield, and paper wasps caught on the wing via "flycatching" aerobatics (probably European, but maybe one of our native Polistes).  I believe the other woodpeckers may have been using the pole differently, that is, strictly as a cache.  All in all, quite a show.  The Lewis's may be gettable, as it was still on the pole on the fenceline near the big Russian-Olive w of the very nw corner of the cemetery property (weedy and undeveloped) when I left at noon.

The other cool experience at this cemetery this morning was finally figuring out how the emergence of adult Hackberry Nipplegall Psyllids works.  Emergence is underway.  The nipplelike galls are on the underside of hackberry leaves.  Looking at these galled portions of a leaf from its upper surface, they appear as craters.  So, pale green nipple on the underside of the leaf, shallow depression on the upper.  The psyllid nymphs (little white creatures with light orange wing pads) break thru the upper leaf surface, shed their skin, then begin to dry out, darken up, and expand their wings.  Galled leaves lying on the ground from which emergence of the adult psyllids has been very recent, show holes in the middle of the craters, bright white shed skins (one to a crater, each skin looking like a six-legged shriveled aphid), and maybe a few, motionless, hardening newly-emerged adult psyllids (which could be very pale to dark brownish gray, depending on their degree of "hardening").  As we've talked about before, the adult psyllids will be active in the trees for a period of weeks and will be a source of considerable interest from birds.  The situation in Washington Park in Denver may be an example.  (Somebody help me out here.)  Birds actively feeding on large numbers of adult psyllids often appear very hyper.  If a bird doesn't succeed in nit-picking a perched adult psyllid off the surface of a leaf or branch, and the psyllid takes off, fast-twitch actions are a bird's only hope of capturing the prey.  In the hackberries at Roselawn today were several Yellow-rumped Warblers, one Wilson's, and Black-capped Chickadees.  How many good birds have you seen in flocks of these three species?  It is just a matter of time, and a whole lot closer/cheaper than Crow Valley.

Dave Leatherman
Fort Collins

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