Verification of Unusual
Rec. # 2010-14
|Scientific name:||Corvus cryptoleucus|
|Date:||April 16, 2010|
|Length of time observed:||20 Minutes|
|Location:||Canyonlands National Park - Island in the Sky District - Mesa Arch Parking Area|
|Distance to bird:||10-15 Feet|
|Optical equipment:||Leica 10x42 Ultravid HD|
|Weather:||Thin, high overcast all day with light wnd gusts and no precipitation|
|Description: Size of bird:||Large and robus|
|(Description:) Basic Shape:||Like that of other North American crows or ravens|
|(Description:) Overall Pattern:||Entirely black|
|(Description:) Bill Type:||Not sure how you'd classify bill type, but it was elongated, yet thick and somewhat stout|
Field Marks and
[see note of explanation below]
From the dates of April 14-18, 2010, Victor Emanuel and I(and John Fitzpatrick, Director of the Cornell Laboratory of Ornithology) were leading a Chairman's Council trip for the Lab of Ornithology in Southeast Utah. We were staying at the Sorrel River Ranch on Hwy. 128 approximately 17 miles northeast of Moab but taking daytrips into the nearby national parks for the purpose of birding and sightseeing.
On the day of April 16, we escorted our group to Canyonlands National Park for the aforementioned activities. By 2:30 p.m. we had been in the park for several hours and had begun the lengthy ride back to the ranch. For a grand finale to our activities, I led the group on the loop trail to view the Mesa Arch. By the time the sightseeing was finished, and the return trip to the parking area complete, it was 3:30 p.m. Victor and I were in the lead as we reached the parking lot. We were each driving 15- passenger Econoline touring vans (the classic bird tour mobile)and were walking toward the vans to unlock them and get the group ready to board. Approaching the van I saw a raven sitting on a short post (about 3 feet tall) at a distance of about 3 feet from the van. I pulled up short of getting too close to the bird and stopped Victor and the group so that we could view it. As anybody from the West can tell you, ravens and other corvids will often make themselves remarkably at home in areas where they think food is available. Ravens in particular can be unnerving as they will often approach to within a few feet of people in and around picnic areas. My intention upon stopping was to simply have people enjoy exceptional views of a raven at very close range. By the time the entire group was off the trail and back in the parking lot, a couple more minutes had elapsed, yet the raven remained atop its post perch decidedly unconcerned with our presence. With all of us clustered at a distance of only 15 feet, we all enjoyed excellent views of the bird.
Frankly, for the first couple of minutes of viewing, I was still not "on" to the fact that we had a Chihuahuan Raven before us. As we were losing interest in the bird and ready to move toward the vehicles, a gust of wind descended on the area. Still watching the bird, I was immediately treated to the sight of the bird's neck feathers jostled in the wind and the exposure of unquestionably white bases to the feathers of the neck. In fact, the white featherbases extened up to the head. I immediately stated something to the effect of "Wait a minute, this bird is displaying white feathering on the neck and head." It was at that point that the possibility of Chihuahuan Raven was raised.
As if starting from scratch, we began viewing the raven anew, with emphasis on the neck feathering, bill size and shape, and length and appearance of the rictal bristles that extended forward from the base of the bird's bill. Victor and I took the entire group, step-by-step through the features that make a raven either Common or Chihuahuan. John Fitzpatrick stated that Chihuahuan Raven is 15% smaller than Common, but without direct comparison, that feature of this species was not clearly detectable. I do think that the bird seemed smaller to me, but I couldn't prove that it was without direct comparison.
Unfortunately the bird shifted its position so that even though it retained its perch, ensuing wind gusts did little more than slightly ruffle the bird's neck feathers. Nevertheless, the bird remained exceedingly easy to study and we focused on features of its bill, particularly the rictal bristles.
The bird's rictal bristles appeared long and slightly unkempt looking. As they extended forward from the bill base, they covered a little more than half of the bird's bill and appeared somewhat shaggy. Ravens have thick bills anyway, but this bird's bill appeared somewhat stout. John Fitzpatrick photographed the bird at a range of between 10 and 15 feet.
By 3:50 our group was getting restless and the raven showed no sign of impending departure. In an attempt to get the bird to respond, I played back vocalizations of both raven species. Despite my attempts, the bird seemed oblivious to my efforts and remained silent. In fact, the bird emitted no vocalizations the whole time we were there.
As we boarded the vehicles and began our departure from the area, the bird jumped off the perch and onto the ground, which is where we left it as we drove away.
For a final stop before exiting the park, we let the group out at the visitor center. John Fitzpatrick and Victor Emanuel crossed the park highway to the canyon overlook on the opposite side of the road while the group was occupying itself inside. At the canyon rim Fitzpatrick came across two more ravens sitting on the rocks, which he proceeded to photograph from a distance of about 15-20 feet.
We returned to the ranch that afternoon and Fitzpatrick retired to his room to review his images. That night we gathered in one of the ranch's conference rooms for a recap session of the day's events, a session that included a viewing of the raven images. Using PowerPoint, John displayed images of the different ravens in succession. To us, it was definitely clear that there were differences between the two sets of images, and they are as follows:
1) The first bird (the Mesa Arch Parking Area bird) possessed a slightly shorter but stouter bill with rictal bristles that appear more unkempt and longer than those of the Visitor Center bird.
2)The Visitor Center bird shows a longer bill with rictal bristles extending no more than halfway up the length of the bill from the base and appearing shorter, "tighter," and more "clean cut" than the Mesa Arch Parking Area bird.
3)Although we never could photograph the white base to the bird's neck feathers, we did at least get a hint of it in one of the images. The image showing this feature actually shows a hint of white feathering extending on to the head.
In conclusion, I feel the first bird, the bird I refer to as the Mesa Arch Parking Area bird, was a Chihuahuan Raven and that the Visitor Center bird, and probably most of the other ravens in Canyonlands National Park are Common Ravens. I also think that while the differences between the two species are subtle, the photographs taken by John Fitzpatrick manifest the important and critical differences. I am in the process of procuring the images from Fitzpatrick and will submit them to the UOS asap.
|Song or call & method of delivery:||None|
|Behavior:||Perched for 20 minutes atop a three foot post before hopping to the ground, which is where we left it.|
|Habitat:||Pinyon/Juniper woodland interspersed with shrubs, flowers, and grasses atop one of SE Utah's elevated plateaus.|
were they eliminated:
|Common Raven (Corvus corax). Please read my complete description above.|
this & similar species:
|I have led many tours in SE Arizona and south Texas where Chihuahuan Ravens occur rather commonly. I atteneded the University of Arizona as a student in the early 1990s, where I had many other opportunities to study and learn this bird. I have seen thousands of Common Ravens throughout western and northern North America.|
|References consulted:||National Audubon Society's The Sibley Guide to Birds, 2000.|
|Description from:||From memory|
|Observer:||Barry Lyon, Victor Emanuel, Dr. John Fitzpatrick, et. al.|
|Observer's address:||2209 Southern Oaks Drive, Austin, Texas 78745|
|Observer's e-mail address:||firstname.lastname@example.org|
|Other observers who independently identified this bird:||[Victor Emanuel tour group]|
|Date prepared:||April 22, 2010|
Dr. Fitzpatrick photographed the bird. I am currently obtaining the
him and will submit them as soon as possible.
Note of explanation: With your patience I would like to begin this description with an explanation of why this bird was not immediately reported. My name is Barry Lyon and I am a long-time tour leader for Victor Emanuel Nature Tours. Victor Emanuel and I were leading a donor trip to SE Utah for the Cornell Laboratory of Ornithology from April 14-18. At the time the bird was discovered, we were in the middle of our tour and I simply didn't know any other birders in the state of Utah to contact. Upon returning home (Austin, Texas), I immediately got sick and have not felt up to submitting this report until now. In preparation for the submission process, I started with the Google search engine to find a Utah ornithological society. That's how I found this website and ultimately this report form. In researching your site, I discovered that there is only one prior report of Chihuahuan Raven for Utah, a single sight record submitted by Tim Avery in August 2007 from Monticello. As this report will likely represent the first documented record of this species in the state, I suppose my delay in submitting this report will make a lot of people very unhappy with me. All I can do is offer my apologies to anybody who feels snubbed. [Barry Lyon]