| There are two color forms of the Northern
Flicker (Colaptes auratus), the "Yellow-shafted" of east of the
Rocky Mountains (C. a. auratus, hereafter YSFL) and the "Red-shafted"
of west of the Rockies (C. a. cafer, RSFL). The most obvious
difference is the flight feathers (wings and tail): YSFL have yellow shafts
and undersides to these feathers, while the RSFL's are red. RSFL
also lack the red patch on the nape present in YSFL, have brown rather
than gray crowns, and gray rather than tan throats. Male RSFL have
red "mustaches" while male YSFL have black ones.
A stable hybrid zone extends along the
east slope of the Rockies from southern Alaska to the Texas panhandle.
Here, these two forms freely interbreed. Resulting offspring can
show a wide variety of traits, including a number of combinations of traits
of either or both parents, or intermediate forms of individual traits.
Occasionally, hybrids (more correctly,
intergrades) wander out of range. On 9 Oct 2002, RRBO captured one
of these intergrades. |
