Variations in House Finches
often report seeing strangely colored House Finches.
Clay Gascoigne hosts lots of House Finches at his
feeders in Jackson, Tennessee. He reported that
in the 2001-2002 FeederWatch season, "the daily
count of house finches exceeded 100 frequently and
occasionally was as high as 140."
|With that many House
Finches he was bound to see some variation,
as his photos, displayed on this page, demonstrate.
||House Finch coloring
varies widely, and research shows that most
of the variation is caused by diet. All
male House Finches have the same potiential
for yellow, orange, or red coloration. Researchers
who kept House Finches in captivity found
the red plumage replaced by yellow unless
a carotenoid pigment was mixed in with their
food during molt. The pigment was mixed
in for experimental purposes, to determine
the cause of the color variation.
|In the wild,
three carotenoid pigments found in natural
foods give House Finches their color. Beta-carotene
produces yellow to orange colors, isocryptoxanthin
produces orange colors, and echinenone produces
|Yellow House Finches are frequently
seen in the southwest and Hawaii where natural
foods are low in some of these carotenoids.
In the east birds often feed on the high-carotenoid
fruits of ornamental plants.
|Research verifies that
the color variation often found in House
Finches is caused by pigments in food, but
this finding in no way suggests that it's
necessary or even desireable to affect a
bird's color by manipulating the food source.
Gascoigne said that
yellow colored birds made up 4 or 5% of
the total population of House Finches in
his yard and that their coloring ranged
from yellow to bright yellow-orange to faded
yellow-pink. Individual birds in this group
apparently fed at different food sources
during their previous molt.
In addition to
variation in the shade of a House Finch's color,
there is variation in the pattern of coloration.
The size of red patches or the amount of coloration
on the head, chest, and rump varies by subspecies
rather than by access to pigments.
To learn more
about House Finches, visit the Lab's
Bird of the Week page. To learn about the
Lab's study of House Finch Disease, visit the House
Finch Disease Survey web site.
Photos taken by Clay Gascoigne.