• QUESTION BOX
BY KEVIN J. COOK
Q: I had a yellow cardinal show up at my feeder and
thought it might be of interest.
How unusual is this? MiriaM
Saye, DenniS, KanSaS
A: Simply explained, your northern cardinal looks yellow because it’s not red enough.
This answer seems glib for lack of
context, so let’s build context.
You can bird for years, even
decades, and see millions of birds
and never see a single case of
xanthochromatism. This treatment
preserves xanthism for a different
application. Definition is one thing,
but application is another.
Birds that are normally yellow
are not typically described as xanthochromatic; we just say they are
yellow. In zoological practice the
term is reserved for an exceptional
condition in which yellow coloration appears in an individual of a
species that is not ordinarily yellow.
Xanthochromatism has been
documented in insects, fishes,
amphibians, and birds; and it probably occurs in other groups as well.
The exceptional rarity of xan-
thochromatism and the lack of
apparent health problems associ-
ated with it likely prevent it from
becoming a research priority.
Consequently, xanthochromatism
in bird-related literature mostly
addresses the condition’s applica-
tions in aviculture, both poultry
production and novelty pets.
Among wild birds, the literature
mostly documents which species
have been seen to exhibit xantho-
chromatism.
