Date: 1/28/18 10:30 am From: Daniel Scheiman <birddan...> Subject: Red-tailed Hawk Varieties: a word of caution
A word of caution about identifying Red-tailed Hawks to subspecies/variety.
The photo of a Red-tailed Hawk
http://ebird.org/ebird/view/checklist/S40114366 was reported by the observer
as a Kriderıs, but was flagged by another eBirder as a light morph Harlanıs.
See her message below. Brian Sullivan of eBird Central agrees. We tend to
think of Kriderıs as being pale and Harlanıs as being dark, but it is much
more complicated than that. A similar situation recently arose in Memphis
http://ebird.org/ebird/view/checklist/S42064364. Photos of a dark Red-tailed
Hawk left unspecified to subspecies by the observers was flagged by another
eBirder as being a Harlanıs. But the observers and raptor experts decided
the bird had some characteristics that did not jive with Harlanıs. It
appeared to be an atypical individual that may be an intergrade with harlani
and abieticola. It is prudent to leave the bird unspecified for now until
more is understood about this complex species.
³There are a number of features which make this an adult Harlan's over a
Krider's. The easiest to note are the extensive mottling in the remiges,
rather than regular banding on those feathers. The second noticeable
feature are the blackish toned markings and clean whiteness of the belly (no
creamy tones). Generally Krider's will be unmarked, or lightly marked on
the underwings and belly, but if they do have markings they will be warm
toned. The blackish patagials and blackish blobby belly markings are common
on light Harlan's. Even the dark parts of the head on this bird are very
cold toned, and on a Krider's would be warm toned. Please feel free to
double check with Brian Sullivan (ebird admin and raptor expert) if you have
any additional doubts. Also this article may be of some help:
https://hawkwatch.org/images/stories/Learn/Kriders_Birding_ABA_March_2010.pd f with a couple of similar light Harlan's examples shown on the last page."