Birds
Woodpecker Skull from Hilton Pond Center
Since Greg rarely posts and I am spending most of my time pushing pre-masticated food down the gullet of my main blog, nothoo, this poor blog has languished. Fear not, for here is an awesome link to an awesome blog that you really should be reading. I have linked previously to this blog from nothoo in reference to the Montauk Monster. Enjoy.
Purple Martin Show, originally uploaded by CritterQueen.
Wow. A spectacle of purple martins in Richmond. I wish I had the time to drive down there and gawk. A stop here would, of course, also be in order.
Stuart Merrell posted an interesting question on the VA-Bird list recently. In short his question was:
Why do we rarely, if ever, see Warblers or Thrushes (excluding Robins) crossing the road.
As I pondered this question I was reminded of an experience I had last fall (September 2007).
While driving down a back road the car in front of me nearly hit a bird that flew across the road. The road is not a very busy one and since I was birding it was only naturally that I stopped to see what it was. The glimpse I got of it while it was crossing the road and veering away from the car set off my thrush-GISS alarm. Scanning low in the tress and on the ground I located the bird. The bird was walking along a fallen branch and was that most thrush-like of warblers a Connecticut Warbler!
That was my one anecdote involving warblers and the road. Here is my possible theory:
Warblers tend to nest in areas where there are large unbroken areas of appropriate habitat. Roads fragment habitat and lead to fewer warblers. The fragmentation also enables nest predators (raccoons, corvids, etc…) and brood parasites (BHCO) to access the nest, thus creating fewer successful nests and in turn fewer warblers near the fragmented habitat. The warblers that chose to nest near a road failed and did not “win” at the game of life. This creates evolutionary pressure that keeps the birds away from the road fragmented habitat.
I think that in general the same theory applies to the Catharus thrushes (Veery, Swainson’s, …) and the Hylocichla thrush (Wood Thrush). The other North America thrushes that I am familiar with, Robins and Bluebirds, thrive in fragmented habitat. Robins need grassy areas for food as well as worm casings for nests and Bluebirds perch hunting technique virtually mandates some fragmentation to have an appropriate area for hunting.
The past few days have brought fledgling Song Sparrows, Gray Catbirds, Northern Cardinals, and American Robins to my yard. This summer has been special for yard (well neighbor’s yard actually) breeders. There is an Eastern Bluebird pair that set up shop in the neighbor’s bluebird box. The parents come to my Red Maple and perch hunt insect goodness (like miniature Red-shouldered Hawks) to bring back to the nest. They are on their second brood though I am unsure if the first brood was a success or not. It is surprising to me that the Bluebirds nested here. We are in a pretty densely populated area with no real open space (which I usually associate with Bluebirds) and the neighbors have a Black Lab that has run of the backyard and barks at the nest box with some frequency.
The other pleasant surprise this Summer was a late and very vocal Wood Thrush setting up shop. We used to get Wood Thrushes breeding every year but some yokel neighbor let their cats loose and the Wood Thrushes went absent for two years. This year they are back. I guess that my hurling of logs, sticks, rocks, etc… at the cats when I see them has helped. Before you get all up in arms, I have two cats myself and I only hurl items near the cats not directly at them. My cats are both strictly indoor cats as I want to enjoy my cats as long as possible and not worry about dogs, coyotes, cars, other cats, disease, storm drains, etc… I already looked into the possibility of trapping/otherwise eliminating the cats but the animal trespass laws where I live explicitly exclude domestic cats. Oh well.
After a long hiatus, in which I was too lazy to fix my broken server, Fairfax Birding is back!
Some researchers from Germany have found that “migratory birds use their visual system to perceive the reference compass direction of the geomagnetic field and that migratory birds “see” the reference compass direction provided by the geomagnetic field.”
You can also hear an interview with one of the researchers on NPR.
When I first started birding I saw, or at least thought I saw, a good deal of rarities. The longer I have birded the fewer rarities I see. Did I actually see a goodly number of rarities in my birding infancy? Hardly. Instead I bootstrapped myself without a more experienced birder to guide and correct me. As a result I convinced myself, usually while thumbing through a field guide not actually looking at the bird, that I was seeing something rare or at least relatively so when in fact I most certainly was not. Instead, I was seeing one of the large percentage of birds that does not conform exactly to the pictures in a field guide (no matter how good the guide). In this early phase I was not plugged into the birding community and had no outlet to vet my identifications. If I was convinced, and especially if I managed to also convince my poor non-birding wife, then by golly that Western Spindalis at Huntley Meadows is a Western Spindalis. Ok, so I was never that far off!
This naivety, I think, is quite typical of a budding and eager new birder. As the vast world of nature opens up to one’s heightened perceptions and the realization comes that there is so much damn cool stuff right under your nose, eagerness, reliance on non-perfect tools, and over-confidence lead to many a rare birds that are not. With community support, via both kindness and skepticism, a budding birder can become a better birder.
It is hard to be wrong, more so for some than others (looking at myself), but this is the key to growth both as a birder and as a person.
Jeff and I have both been trying to use the weather and local radar to predict how many migrants we’ll see. We talked Saturday night after the sun had gone down and compared some radar images from central Pennsylvania where most migrants would come from. This radar image from 9:00 PM Saturday night shows the density of stuff in the air…
and this one from the same time shows the velocity of that stuff in the air.
The colors in the first one are consistent with birds over the radar station. How do you know that they are birds? Well, it’s not so cut and dried, but the shape is different from, say, clouds or rain. The colors in the second picture indicate that the (probable) birds are moving toward the station from the north (the cooler bluish-grayish part for negative velocities) and away from the station to the south (the hotter yellow-orange-red section for positive velocities). Most weather this time of year will move from the west or southwest, so it’s a safe bet that birds are on the move.
The next morning, I got up early and checked the radar again, this time for northern Virgina where we were going to bird. The radar shots from 5:00 AM showed that we had a lot of birds coming into the area.
Sure enough, we went to the NY monuments at Manassas Battlefield on Sunday morning and had a good fall migration day. We had the area all to ourselves even though it is touted as a great fall migration hotspot.
We birded there for about two hours, and had species feed in front of us as if they were on a schedule. Is it 7:00 yet? OK, send out all the black-throated green warblers. 7:15? Alright, time for the flycatchers to get busy. Parulas, black-throated greens, redstarts, yellow-bellied cuckoos all came out at a certain time, then melted back into the trees as if on cue.
We also had good luck with just the number of each species in a couple of cases. We counted 25 brown thrashers around us at one point, by far the most either of us had seen at one time. Five cuckoos also flocked for us. As we left the battlefield, we saw a single eastern meadowlark perched on the monument nearest the road.
The biggest treat of the day was by far the Connecticut warbler we saw on Bull Run Post Office Road. We saw a small songbird nearly collide with a car and stopped to check it out in the roadside brush. Jeff called it, and I got to bask in the glow of his superior bird-fu. The powerline cut was closed, locked, and covered with Posted signs, sigh. We had had some good luck down there. We also heard and then saw a raven.
Finally, we tried Sully Woods. When we weren’t gagging on the stench of something very big and very dead, we saw two sharp-shinned hawks playing with each other in a thermal, and a single broadwing. We also had an immature white-eyed vireo to round out our beautiful day out.
Yesterday was a beautiful day, but I was stuck all day staring at the unhealthy blue glow of my monitor. Yet, I had a few spare moments to step out into the backyard to see what there was to see. The sky was a brilliant blue. Staring into the sky I caught glimpses of 2 Broadwing Hawks and 3 Monarch Butterflies. The blue of the sky made it extremely hard to stare for long but Nature is still there… Hopefully today I can actually get out and wander about.
On a final note, while making a peach and blueberry cobbler, the windows of course being open on a day like today, I saw no fewer than 7 Titmice, at once, in my apple tree.
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