Friday, December 12, 2008

Staying In Touch and Not Getting Lost

Don't forget to bring a FRS Radio if you have one. I suggest channel 7, subchannel 11. Spare batteries are a good idea.

Also your cell phone. There is coverage, at least from hilltops, in much of the circle. My cell number is (520) 325-5310.

And a GPS is a handy tool, especially if your area includes the circle boundary.


Some of us will be out in the predawn darkness (and hopefully without too much wind) to listen and call for owls. Mysteriously, Whiskered Screech-Owl has never been recorded on this count even though it is very common in the more densely wooded areas (such as upper Sycamore and Yanks Canyons, the uppermost part of California Gulch near Ruby Road, and at Peña Blanca Lake). It's not uncommon to get a vocal response from a roosting owl during broad daylight if you use the imitation to attract mobbing flocks of passerines.

Other likely species are Great Horned and Western Screech, though Barn Owl is probably not rare, and if one were to be at Wise Mesa, even Short-eared would be possible. Maybe someone will flush a Long-eared Owl during the day, and there are Spotted Owls in the depths of Sycamore Canyon. Northern Pygmy-Owl is also in Sycamore Canyon, and in the lower drainages, Ferruginous Pygmy-Owl is a distinct possibility.

If you will be camping before or after the CBC day to look for owls, let Jake or me know so we can suggest a place to go.

Avoid Double Counting Large Birds

To avoid two groups counting the same bird, it's a good idea to note the time of day if you see a flyover:

Turkey Vulture
Bald Eagle
Golden Eagle
Peregrine Falcon
Prairie Falcon

Thanks to Laurens Halsey for the suggestion.

CBC Fees Policy

Participant Fees Policy (taken from the NAS CBC website)
• There is a $5.00 fee per U.S. resident field participant per count.
• Feeder watchers and all observers 18 and under may count for free.
• One individual may choose to participate in 4 or more count circles and pay only a flat fee of $20. This discount is available only for participants registering at least 48 hours in advance online.
• If someone registers for 5 counts, pays $20 then one of the counts is cancelled we refund nothing except in the case that if they register for 4 counts and one is cancelled, we have to refund $5.
• Refunds of CBC fees will be issued ONLY if a count is cancelled. In this case, the compilers must notify Audubon of the cancellation of the count for refunds to be issued to pre-registered participants. If a participant does not show up on the day of the count the fee is considered a donation – in this case no refunds are issued. Also the compiler must indicate this no-show status on the site so that the participant’s name is suppressed from reports. Effort information and calculations are NOT affected by data entered/edited in the participant lists by the compiler.
• Persons who pre-register but do not show up on the day of the count must consider their pre-paid fee as a donation to Audubon. No refunds are issued in this case.
• All paying U.S. and Canadian participants, U.S. CBC participants 18 and under, and compilers will receive a copy of American Birds: Summary of the CBC.
• U.S. participants have the opportunity to opt-out of receiving this publication if they indicate this online or if they do not submit their address.

Tricky ID #4 - Eastern and Western Meadowlarks

The Eastern Meadowlark in Southeastern Arizona is a non-migratory, local species of the native grasslands. The form here is also known as "Lilian's Meadowlark," and may be split from Eastern soon. Western Meadowlark breeds as far south as the agricultural fields of Marana, northwest of Tucson, and flocks winter here in all weedy and grassy habitats.

Places that have breeding pairs of Eastern Meadowlarks have pairs in the same place in winter. This indicates a sedentary population and that it is unlikely to encounter large flocks any distance away from breeding areas. The only areas in this CBC circle likely to have Eastern Meadowlark are at the far western edge, on the flat, grassy ridges between Negro and Peck Canyons and Ramanote and Toruno Canyons. But there could be some wanderers, and everyone should carefully scrutinize them.

Eastern Meadowlark has the yellow of the center throat sharply delineated from the white of the malar region, with the feather tract line between the two matching the separation of colors. In Western, the yellow bleeds across the feather tract line into the malar region. This can be hard to see in winter and immature birds when the yellow is more creamy and the white of the face a buffy off-white, obscuring the differences in these colors.

Eastern has blacker head stripes and paler background color to the face, but this is comparative and takes eperience.

More of the outer tail feathers in Eastern are purely white, so when seen well in flight, it appears that only the central two tail feathers are dark. On Western, you might be able to see the brown edges on the outer feathers, but they also usually appear totally white; the central brown area of the tail is larger and appears more as a triangle, rather than just the narrow two central feathers. Keep in mind that this is very hard to see well in the field, best viewed when a bird flying away from you and then lands at close range.

Call notes are a great clue. Western actually calls out its own four-letter banding code, "weme," often in flight. It also can give a "chuck" while perched. Eastern is usually silent in flight and gives a rough, rising, fart-like "brzzzit" when perched.

Tricky ID #3 - Bendire's & Curve-billed Thrashers

I was surprised that Bendire's Thrasher was even on the cumulative list for this Christmas Bird Count. In my experience, in Southeastern Arizona there are a few places where Bendire's Thrasher occurs. They are in those locations all year, and I have never bumped into the species in any other location that does not closely match the same habitat. This indicates to me that the species is resident and does not wander in this part of the state. Populations to the north of us are apparently migratory, but it's not clear where they go. Places where I've seen them include northern Avra Valley north into the Santa Cruz Flats, the Whitewater drainage of the Sulphur Springs Valley, and the San Simon Valley east of the Chiricahuas.

The species appears to prefer very flat topography with sandy or loose soils and patches or rows of mesquite with a grassy, weedy understory. An absence of cholla cactus seems to be a unifying characteristic too, and my guess is that this keeps out Curve-billed Thrasher (which usually builds its nest in cholla). Curve-billed is a large, aggressive species that would displace Bendire's.

The best field mark is the smaller bill on Bendire's. With a good profile view (close range or through a spotting scope), the lower edge of the bill appears straight, while both the upper and lower mandible in a Curve-billed are curved. Supporting field marks are the more clearly defined spots across the breast on Bendire's (somewhat arrow-shaped with very good view), a pale base to the bill, paler eyes, and a vaguely warmer color to the lower face. Earlier in the year, immature Curve-billed Thrashers have all of these exact same field marks and are very frequently misidentified as Bendire's in urban Tucson and Phoenix.

Bendire's is usually silent, sometimes giving a slight "chuck," while Curve-billed has the very familiar upslurred double whistle.

Tricky ID #2 - Chihuahuan & Common Ravens

Everyone realizes these birds are very difficult to tell apart. The main difference is size, but individuals are variable, and size is the most difficult character to judge properly in the field. Said another way, size is the most frequently misjudged field character in birds. It's almost purely a comparative feature, and if you have nothing of known size to compare it to, you should not rely upon it.

Size can be inferred from speed of wing beats, with smaller birds flapping faster. But then speed of flight varies with conditions too – wind direction and the purpose of the bird's flight, for example.

HABITAT is a great clue. Chihuahuan Raven prefers wide open, flat country with scattered bushes and lots of grass or open ground. They are not normally found in hilly canyon country. So unless your area is in the far eastern or northern parts of the circle, you are unlikely to encounter the species.

BEHAVIOR is moderately useful. Chihuahuan Raven is more likely to be found in large winter flocks, roosting and feeding in groups that can number over 100. They are much like crows in this regard. But if it's a feeding concentration, such as at a dump (there is not one in our circle), both species can be found in the same large flock together. And sometimes groups of 20 or more Common Ravens will gather to feed in fields or frolic in the updrafts on a mountain peak.

FIELD MARKS for Chihuahuan Raven include a more rounded and less wedge-shaped tail and a shorter bill with the culmen curving down to the tip just beond the nasal bristles. Common Raven has a very wedge-shaped tail (you have to see it well from below, such as in soaring behavior) and a culmen that continues horizontally for some length beyond the end of the nasal bristles before dropping down to the tip. Common also has longer wings. If it's windy, the ruffled neck feathers of a Chihuahuan Raven will show bright white bases, but the pale gray bases of Common's neck feathers can be misjudged as being white.

VOICE is good. You can sing the call note of a Chihuanhuan Raven, as it is nasal and tonal. Common Raven's voice is extremely variable but is lower and more croak like, usually descending and not on a single tone.

Thursday, December 11, 2008

CBC Circle on Google Maps

Thanks to Andrew Core, I figured out how to make a link to a Google Map with all the areas:

Click Here to see the map in your web browser.

If you want to view the circle in Google Earth (download the program for free first),

Click Here to download the most updated file.

Check Those Tanks!

A Tank in southern Arizona is a small pond, dammed to catch rainwater and provide for cattle. With the fantastic Monsoon this past summer, all are full this year and present a great opportunity for water birds. This is especially crucial this year since Peña Blanca Lake has been drained for a toxic cleanup this year.

Please make an effort to check them thoroughly. Walking around the edges might flush a Wilson's Snipe that at first isn't obvious. (Though it's unlikely that we'll miss that species; it has been missed only 3 times in 34 years.) They could also harbor a Spotted Sandpiper or a duck or two, maybe something rare like a waterthrush.

Tricky ID #1: Eastern and Western Bluebirds

This is a big year for Western Bluebird in the Atascosa Highlands. It seems that every team has a good chance of seeing a bunch, and we could even surpass the record of 334 seen in 1980 (each team would have to see an average of only 17).

There will likely be a corresponding chance of getting a very large – but erroneous – number of Eastern Bluebird unless we are very careful of our IDs. Eastern Bluebird may be the most over-reported bird in southeastern Arizona by unwitting observers who simply look at the range maps and think the two species must be of equal status.

The reality is that Eastern Bluebird is one of the more local and sedentary southeastern Arizona specialties, our local subspecies being called "Azure Bluebird." They occur in only a very few areas in the southeastern corner of the state and with only some down-slope movement in some winters. Otherwise, they appear to remain in pairs or small family groups in the same small area all year. This is in strong contrast to Western Bluebirds which wander hundreds of miles in groups of sometimes dozens of birds. There are indeed records of flocks of Eastern Bluebirds in lower valleys every few years, but these appear to be irruptions from populations of the migratory eastern North American forms. It's a rare occurrence.

The only place in this CBC circle that I have seen Eastern Bluebird is at the Sycamore Canyon trailhead, and they are there almost every time I visit. There are surely more territories in the circle, and I would appreciate very much knowing where you find these. But please be sure you are identifying them correctly.

The voices are very different. Western Bluebird has a single, soft "whew" or doubled "weh-whew" whistle, also often mixed with a couple "chuck" notes or short rattle if perturbed. Eastern has a multisyllabic warble mixed with soft "chuck" notes.

Westerns will be in roving flocks, usually in mistletoe. Eastern will probably be only in a small groups or pairs.

Color is a clue in good light and views. The blue of our Easterns is really a bright azure blue. Western is a dark, luscious blue.

The pattern on the throat can be hard to discern in female and winter birds. If you don't see a blue throat, don't automatically assume that it's an Eastern. The throat color of Eastern will be either whitish in the female or bright orange in the male, but the key feature is that this orange color extends high on the sides of the neck and even curves up behind the ear covers. Western is uniformly blue or bluish gray on the sides of the head from the face down to the shoulder.

Tuesday, December 9, 2008

New Circle Center Coordinates

I totally forgot about map datums! I had taken the latitude and longitude off the USGS topographical map, which is based on 1927 North American Datum. So, converted to the WGS 84 datum (which is what Google Earth uses), the current latitude and longitude are 31.470006° N, 111.172780°W.

The change in coordinates only affects the circle image I sent out as a .kmz file, moving it some 50 yards to the west. Not a huge difference. The circle as shown in blue on the topo map printouts is correct, as I used Photoshop Elements to draw the circle based on the topo map scale and the actual center ("Center of Section 36 of T 22 S, R 11 E").

Google Earth is a free program you can download to view the earth via satellite photos. It's like an animated version of Google Maps (which uses a simple web browser). If you click the bottom most option in the left column, change your angle with the up arrow on the dial in the upper left part of the screen, then zoom in, it's truly amazing. It's like being able to fly over the terrain.

Download it at Google Earth.