Biology Reference
In-Depth Information
What's On the Menu?
Q Someone told me that bird seed mixes aren't good for birds — that I should
be feeding them just sunflower seeds. But wouldn't mixtures give a more balanced
diet?
A
AccordingtoresultsoftheSeedPreferenceTestconductedbytheCornellLabofOrni-
thology, black-oil sunflower seeds attract the widest variety of species. Sunflower seeds
haveahighmeat-to-shellratio;theyarehighinfat(animportantenergysourceforbirds);
and their small size and thin shell make them easy for small birds to handle and crack.
(Striped sunflower seeds are larger and have thicker seed coats.)
Most mixtures include less expensive “filler” seeds such as millet and milo, which are
often left behind as birds eat the good stuff. When these and other seeds in a mixture are
left uneaten, they can start molding and can contaminate fresh seed. The Seed Preferen-
ce Test showed that millet is popular with sparrows, blackbirds, pigeons, and doves but
ignored by other birds; milo is preferred only by jays, pigeons, and doves. Nyjer seed at-
tracts goldfinches, redpolls, and siskins.
Q I was told that it is bad to feed birds in the spring when they are feeding their
young because the adults will feed the babies the sunflower seeds from the feeders
rather than the more varied diet they should be feeding them. Is this true? Do I have
to give up my feeders in the spring?
A
That all depends. If goldfinches or siskins are bringing sunflowers to the babies, it
won'thurtthem—thosenestlings orfledglings areprettymuchvegetarians anyway.But
once summer is underway, it might be bad to let cardinals, Rose-breasted Grosbeaks, or
most other birds feed their babies too much sunflower seed or grape jelly, which don't
have enough protein for growing babies. As long as the families are only coming to the
feeders once or twice a day, they should be getting plenty of other proper food.
Sadly, a few bird parents are as clueless as a few human parents are about their re-
sponsibilities. A 2009 study by researchers at Binghamton University showed that some
urban crows overfeed their young junk food, preferring items that were easier to obtain
