English and Scientific names:

White-tailed Hawk, Buteo albicaudatus

Number of individuals: 

One, hatch year bird.

 

Locality: LOUISIANA: 

Cameron Parish

 

Specific Locality:

Willow Island, a few? miles west of town of Cameron.

 

 

Date(s) when observed:

October 27, 2007

 

 

Time(s) of day when observed:  

 8:05 AM to 8:23 AM, then briefly at 10:22 AM.

Reporting observer and address:

Paul Conover

Lafayette, LA

 

 

Other observers accompanying reporter who also identified the bird(s):

Phillip Wallace, Curt Sorrells, Dan Purrington, and David Muth and I were birding together but in separate parties. We all independently saw and identified the bird.

Other observers accompanying reporter who independently identified the bird(s):

The Boslers refound and photographed the bird on 10/29.

Light conditions (position of bird in relation to shade and to direction and amount of light):

Morning sun, good autumn light. Seen well with sun low and behind me, and the bird in front of me. 

Optical equipment: 

Zeiss 10x binos, Nikon D50 camera with 55-200 lens.

Distance to bird(s): 

At closest, within 50 yards.

Duration of observation:

15 minutes, then about 1 minute.    

Habitat: 

Overgrown field of hundreds of acres, filled with ragweed and other tall annuals. There were scattered clumps of dead trees and brush-piles overgrown with vines scattered sparsely throughout the large field.

 

Behavior of bird: 

           I first saw the bird hovering over a grassy/scrubby field  a few hundred yards away to the northwest. It hovered with wings held roughly horizontal, perhaps slightly above, about 30 yards over the ground. I could see it was dark, but I couldn’t see the pattern so I started walking toward it. It then flew into a grove of dead trees and landed on a high snag on a dead tree. I thought it might be a White-tailed Hawk or perhaps a light Harlan’s, but that either would be interesting. I expected it to see me coming through the field of weeds, so I kept my camera ready for it to fly and was taking pictures at intervals as I approached. Not too long after I had started walking, my phone buzzed. It was Phillip telling me they were watching an interesting hawk. I let him know that I was getting fairly close to it and had photographed it. At one point a Red-tailed Hawk flew up and the bird defended its perch but didn’t fly. Another time it flew and returned to a nearby perch. It allowed me to approach all the way to the grove—perhaps because it didn’t want to cede its perch to the Redtail--and I began making my way to it through the dead trees. There were a lot of fallen limbs and now and then I snapped dead limbs, but I was able to get to within a few trees of it—perhaps 50 yards but probably a bit closer. The ragweed was so tall in this area that I was enclosed and I wasn’t able to see anything around me, only above me. I stopped and waited for it to fly. Eventually it stood taller and ruffled its feathers and I knew it was about to take off. I got a few pictures of it taking off. At this point, through the weeds and trees, I heard David speaking to me from nearby, and I realized that he had also seen the hawk and made his way to it, also, videotaping the bird. It took me a while to locate David in the tangle. I was glad that everyone in the party was alert to it.

         David and I began walking a nearby treeline hoping for another look at the bird, but we didn’t find it.

        Discussing the ID, we felt it was probably a White-tailed Hawk but waited until we could conclusively eliminate Harlan’s before calling it one.

        Later, when our group had gotten together again, we compared the photos I had taken with the photos in the Clark and Wheeler photo guide and found that our bird’s underwing matched White-tailed perfectly.

        Not long afterwards we saw the hawk fly up from grassy field with a rat in its talons, flying toward the thickly wooded west end of Willow Island. I felt the bird was probably not just a migrant, but had settled in this area for at least the day.

 

Description:

A large hawk, about Red-tailed-size, with bare yellowish legs. Long-winged, with wingtips extending beyond tail. Dorsal surface solidly black, without whitish mottling as in some Red-taileds. Head black, but with paler patches on sides of head. Eyes dark, bill grayish, without yellow cere.

 

Chin, throat, and upper breast blackish with a white blaze on mid-breast.  Black of ventral surface becoming mottled with whitish from belly to legs, and becoming predominantly whitish with scattered small dark marking from legs to tip of undertail coverts.

 

Underwings:

            The outermost (3 or 4) primaries emarginated, with the 2 outermost clear white from base to notch, and blackish from notch to tip. Remainder of flight feathers grayish in ground color with whitish bases and with fine, narrow, regularly spaced dark tranverse lines, some wavy, down length of feather. 

            The overall effect of underwing was a dusky wing with a longitudinal white stripe down the center of the wing, bordered fore and aft by longitudinal rows of black spots.

            Greater coverts evenly barred dark and white, with dark bars becoming wider distally. Median secondary? coverts bright white with wide black chevrons on lower border, narrowly white-tipped, forming distinct blackish underwing bar. Lesser coverts whitish dotted evenly with black. Hind border of lesser coverts bordered by row of black chevrons forming another dark wingbar, then a slightly paler (brown rather than black) wingbar. Median primary coverts barred black and white, same pattern as greater coverts. 

             This description is based on the photos, and some of my perceptions of the feathers and tracts would probably be clearer if I had access to a similar-age specimen. 

 

Tail:

       Feather grayish with fine, dusky bands evenly but narrowly spaced.

        

Voice:

Not heard.

Similar species:

Ferruginous and Rough-legged eliminated by bare legs.

 

Swainson’s, Red-tailed and “Harlan’s” seem to be eliminated by pattern of underwing and tail. The combination of white wing lining with darker lesser coverts and dark flight feathers seems to be unique to juvenile White-tailed Hawk. Tail of this bird doesn’t seem consistent with Harlan’s pattern.

Photographs or tape recordings obtained?

I took digital photos, attached, and Muth took video. Some of the others in the party may have taken images.

Previous experience with this species: 

Fair amount of experience with this species, but not this age group.

Identification aids:

We used A Photographic Guide to North American Raptors Wheeler and Clark

soon after observation to see if Harlan’s could be eliminated and found a photo of WTHA with an underwing closely resembling this bird.

This description is written from: 

Memory, examination of photos

Are you positive of your identification? If not, explain: 

 

Yes. We were careful not to identify this bird at the time without eliminating Harlan’s and other dark Red-taileds, the only real possibilities for confusion. The photos are conclusive.

Reporter: 

Paul Conover

Date and time: 

October 29, 2007