ML116674531

Age

Not specified

Sex

Not specified

Media notes

A juvenile Broad-winged Hawk at Gilman Park, Fullerton. 25 September, 2018.

Observation details

Around 11am, while Shawn and I were birding towards the eastern end of the park, along the slope bordering the south edge, we began hearing chips coming from understory shrubs below the Eucalyptus trees that sounded like that of a MacGillivray's Warbler. While we were trying to get views of the warbler we had a smallish bird of prey come flying in (from behind us), and proceed through the trees, and soon land in trees just up ahead of us. My impression was that of a Red-shouldered Hawk (RSHA; although very little was seen of the bird while it was in flight). Looking at the now perched bird, it was clear the bird wasn't an adult RSHA, and something didn't seem quite right for it being a juvenile RSHA either. We had a side view of the bird, with it facing to our left. With binoculars, I couldn't really see much in the way of any details that helped to confidently ID the hawk. So we both began taking photos of the bird, and after a short time tried moving up to get a better angle on it. However, the hawk took off before we'd gone too far, unfortunately, and vanished almost instantly--apparently going further upslope into the fairly dense grove of Eucalyptus. When looking at our photos, I was a bit surprised to see it appeared to show some feature of a juvenile Broad-winged Hawk. But since we had lost the bird, and it looked hopeless to refind it, I just decided to return to looking for the chipping (probable) MacGillivray's Warbler. Afterall, I figured once I had a chance to look at the pics on a monitor, we’d see that the hawk was just a RSHA. Well, checking the photos again, while eating lunch, it began looking more and more interesting. Decided to go back to Gilman Park after finishing lunch, but had no luck in refinding the Broad-wing type hawk (did see an adult RSHA). Later in evening, looking at photos on a monitor, and pulling out some raptor guides, I could see pretty much everything was a good match for a juvenile Broad-winged Hawk! One of the first features noticed (in the photos of the perched bird), was that the secondaries and greater wing coverts were solidly brown, and not showing pale barring as would a RSHA. Although the viewing angle we had of the bird didn't show much of the underparts, what we could see showed a clean white background color here, with relatively sparse, but large/coarse markings on the sides of the breast and flanks (dark blackish-brown, oblong to anchor shaped markings). This was notably different than what a RSHA juvenile (or adult) would show. In comparison to a HY RSHA, the upperparts were a bit darker brown, being a more uniform dark brown, having much less pale spotting and blotching. The dorsal surface of the tail showed broader, pale brown bands (versus thin blackish-brown banding), which would be the opposite on HY RSHAs. The Gilman Park hawk showed less light-to-dark contrast on the dorsal surface of the tail than what is shown by juvenile California (elegans) subspecies of RSHAs. The tail also appeared slightly shorter, relative to the bird's size, than the relative long tail length shown by RSHAs. The bird's tarsi also appeared relatively short, in comparison to the fairly long tarsi shown by RSHAs. The facial features looked better for a Broad-winged Hawk (BWHA), in showing more contrast, with a vertical, blackish-brown "malar" line, a buffy wash to the pale auriculars, a light buffy supercilium, and a bright white throat (which, as seen in the photos, showed a narrow, dark vertical stripe in the middle of the throat). I didn't get the feeling the size of the hawk was much different than a RSHA (though certainly smaller than that of a Red-tailed Hawk). Though BWHAs are smaller than RSHAs, there was nothing to really compare it to at the time, to get a feel for relative size. No vocalizations were heard from the bird, and when I went back in the late afternoon, I could not relocate it.

Technical information

Model

Canon PowerShot SX50 HS

ISO

800

Focal length

215 mm

Flash

Flash did not fire, auto

f-stop

f/6.5

Shutter speed

1/160 sec

Dimensions

1842 pixels x 1599 pixels

Original file size

509.58 KB