Image 1: Oregon form, male, first individual
Images 2: Oregon form, male, second individual
Image 3: Oregon form, female, third individual
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Oregon Junco (Junco hyemalis oreganus) - Oregon form (Dark-eyed Junco)
23 October 2015: Our visit to Tualatin River National Wildlife Refuge (TRNWR) gave us the opportunity to photograph one of the five different forms of the Dark-eyed Junco (Junco hyemalis) (considered a sparrow) that are known to exist in North America, the “Oregon” form or Thurberi. We’ve now photographed two of the five forms (the Slate-colored Junco being the other). There are 12 known subspecies of Dark-eyed Junco in North America grouped into the five major categories mentioned that also include besides the Oregon form, Gray-headed (Canceps), Gray-headed (Dorsalis), White-winged (Aikeni), and the Slate-colored (Hyemalis), which is the most common of the five and is found throughout the eastern half of the United States and eastern parts of Canada. The Oregon form of Dark-eyed Junco that we photographed at the TRNWR has five subspecies of its own with the southernmost such subspecies being generally paler in color than those found farther north all the way to southern Alaska and along the Pacific Coast of Canada and throughout the West Coast of the United States. The range map found at All About Birds makes clear that Dark-eyed Junco is strictly a North American bird since it generally breeds throughout Canada from coast to coast and is found throughout the United States from one end to the other either as a permanent resident or a wintering one, and then again it ranges into northern Mexico and is found all along the US-Mexico border from California to Texas or the Pacific Ocean to the Gulf of Mexico respectively but does not range beyond the northern tier of Mexican states farther to the south. Because of its extensive range throughout North America and the great variety of forms that it presents, Dark-eyed Junco is one of the original and authentic residents of the Western Hemisphere.
Here’s this very useful extended quote from the National Geographic site on Dark-eyed Junco (and whose link is listed in our Sources section below): “The distinctive “white-winged junco,” aikeni, is mostly pale gray above, usually with 2 thin white wing bars; it is also larger, with more white on its tail. It is most similar to the “Slate-colored” (which can rarely have narrow wingbars) but is larger and paler, with contrasting blackish lores and more extensive white in the tail. The male “slate-colored junco” has a white belly contrasting sharply with a dark gray hood and upperparts, usually with very little contrast between the hood and back; immatures can have some brown wash on the back and crown. In the female, the amount of brown on the head and at the center of the back varies; it’s more extensive in immatures. The “slate-colored junco” comprises 2 subspecies: the widespread nominate and the larger, bluer-billed carolinensis, which is resident in the Appalachians from Pennsylvania to northern Georgia. An additional subspecies, cismontanus, is often grouped with the “slate-colored.” It breeds from the Yukon to central British Columbia and Alberta and may winter throughout the West; it is casual to the East. Cismontanus is intermediate between the “slate-colored” and the “Oregon,” with males showing a blackish hood that contrasts with a usually grayish back (occasionally with some brown). Females and immatures are very similar to the “Oregon” juncos, but are less distinctly hooded. The male “Oregon” junco has a slaty to blackish hood, contrasting sharply with its rufous-brown to buffy-brown back and sides; the female has duller hood color. Of the 5 “Oregon” subspecies, the more southerly subspecies are paler. The “pink-sided” junco, mearnsi, has broad, bright pinkish cinnamon sides, a blue-gray hood, a poorly defined reddish brown back and wings that do not contrast markedly with the flanks, and blackish lores. Females duller, but retain basic pattern; they can resemble “Oregon” females closely. In the “gray-headed” junco, the pale gray head and dark lores resemble the head pattern of the “pink-sided,” but the flanks are gray rather than pinkish, and the back is marked by a very well-defined patch of reddish hue that does not extend to the wings and that contrasts sharply with the rest of the body. A distinctive subspecies, dorsalis, is sometimes known as the “red-backed” junco and is resident from northwestern Arizona through New Mexico to the Guadalupe Mountains of western Texas. It differs from the more widespread, migratory, northerly breeding caniceps in having an even paler throat and a larger, bicolored bill that is black above and bluish below. Intergrades between some subspecies are frequent. Common intergrades are: “pink-sided” x “oregon” and “pink-sided” x “gray-headed.” Cis¬mon¬tanus may be a broad intergrade population of “Ore¬gon” x “slate-colored” juncos. Identification to subspecies group thus requires caution to eliminate the possibility of an intergrade; for intergrades, look for intermediate characteristics: For example, a darker, more contrasting hood on a “pink-sided” indicates the influence of “Oregon” genes; reduced pink sides and a well-defined reddish back on a “pink-sided” indicate “gray-headed” parentage.”
Sources:
“Dark-eyed Junco,” All About Birds, Cornell Lab of Ornithology, range map, photographs, description, songs, accessed 11.11.15, https://www.allaboutbirds.org/guide/dark-eyed_junco/id
“Dark-eyed Junco,” Audubon, Guide to North American Birds, photographs, description, range map, accessed 11.11.15, https://www.audubon.org/field-guide/bird/dark-eyed-junco
“Dark-Eyed Junco,” National Geographic, description, photographs, range map, accessed 11.11.15, http://animals.nationalgeographic.com/animals/birding/dark-eyed-junco/
