Going
Buggy! Insect-eating Birds
Every spring when the great flood of migrating birds
returns, they feast on the great flood of insects and other cold-blooded
vertebrates returning at the same time. Let's look at some of the tiny
critters that are emerging, and see what kinds of birds eat them.
Earthworms
and Insects on the Ground
Robins are adapted to notice earthworms in their underground
burrows, and pig out on them starting as soon as the ground thaws.
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Like
robins, this American Woodcock eats earthworms and large insects
it finds on the ground. Which species gets worms deeper in
the soil? How can you tell?
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Caterpillars
That Munch on Trees
Rose-breasted Grosbeaks, Scarlet Tanagers, many kinds of warblers, and other "canopy" birds
feed on caterpillars that eat the leaves of trees. As soon as the tiny insects
hatch, they begin feeding on the tiny soft leaves first opening up, and migrating
birds arrive just in time for dinner!
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Scarlet
Tanagers feed on insects in leafy trees, especially oaks. |
Cape
May Warblers thrive on the budworms that sometimes infest spruce
trees. |
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Connecticut
Warblers take a lot of their insects in the low branches of trees.
They forage in dark, dense vegetation.
They walk along the leaf litter and fallen branches and logs,
usually
around a swamp or equivalent, picking off invertebrates |
Cerulean
Warblers like this one are becoming rarer and rarer over most
of their range in the eastern states, barely up to Canada. They
eat insects in the very tops of trees. |
Flying
Insects
Swallows, swifts, nighthawks, flycatchers, some warblers, and Cedar Waxwings
snap up insects flying in the air. Swallows, swifts, and nighthawks fly for
hours at a time, snapping up insects on the wing. Flycatchers, warblers, and
waxwings flutter out from a branch when they spot a succulent insect, and snap
it up!
Aquatic
insects and other tiny swimming invertebrates
Ducks, some shorebirds, kingfishers, and sometimes even crows, robins, and
other songbirds pick at aquatic insects. Ducks can get them in deeper water
than songbirds can, swimming underwater or dabbling in one spot to grab them.
Shorebirds walk in the shallow water picking at them. Kingfishers fly above
the water and suddenly snap their beaks to grab tiny fish and larger insects
near the surface. Songbirds walk along the shore picking up insects that are
pushed toward shore with the waves.
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Crows
notice everything on the ground. In early spring they spend
a lot of time on ice breaking up on lakes and rivers, picking
up dead insects. During spring and summer, crows often walk
on the edge of lakes and streams picking up small aquatic animals
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This
Eastern Phoebe is picking up insects on the mat of vegetation
on the edge of Lake Michigan. Phoebes can also snap up flying
insects from a perch.
Photo Brian Boldt
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Killdeers
are great at noticing insects and worms in grassy fields, but
they also do a lot of feeding on the edge of ponds, lakes,
and streams.
Photo Stephen J. Lang for The
Wisconsin Society for Ornithology
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Tiny
Insects
Hummingbirds get their protein by picking tiny aphids and other chewing insects
from the surfaces of flowers and leaves, and by snapping up very tiny flying
insects like gnats out of midair. Some people feed hummingbirds and small fly-catching
birds by setting out chunks of banana and melon in a small mesh bag. Hummingbirds
zip this way and that snapping up the tiny fruit flies that swarm about this
kind of fruit.
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This
tiny Ruby-throated Hummingbird can chase tiny insects in mid
air, or can slurp them up with its long tongue when it sees
them on flowers or leaves.
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Crawling
Insects and Weed Insects
Many birds feed on the big caterpillars, beetles, grubs,
and other medium and large insects and spiders they find near the ground.
Blackbirds, bluebirds, sparrows, crows, wrens, and other birds get a
lot of protein by hunting out these bugs.
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Red-winged
Blackbirds eat both seeds and insects. During the summer their
main diet is insects, which they get on the ground, and by
searching through weedy plants.
Photo Ann Cook
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This
Eastern Bluebird is eating mealworms from a feeder. In the
wild, bluebirds sit on a fence post or other perch and study
the ground until they see a bug. Then they zip down for the
kill!
Photo by DennisMalueg
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Towhees
eat insects on the ground that they find by scratching at
leaf litter.
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Bobolinks
find their food in grass, weeds, and on the ground in meadows
and prairies. In summer they eat mostly insects.
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Adult
cardinals eat mostly seeds, but during the breeding season
they spend time searching the ground and low plants for insects
to feed their babies.
Photo by Myron "Red" Newton.
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This
Wood Thrush feeds mostly on the ground, walking in the leaf
litter in a forest, pushing aside leaves with its beak to peek
underneath for insects and other tiny creatures.
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Wrens
investigate every corner of their little territories trying
to find enough insects to feed their many babies (often 7 or
8 in a single clutch) and themselves.
Photo Ann Cook
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White-throated
Sparrows may scratch at the ground like towhees. They also
find insects in the branches of low weeds and shrubs.
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European
Starlings walk on the ground and poke their beaks into the
ground. Then they "gape"-that is, open their beaks
to form a bigger hole in the soil to make it easier to notice
insects.
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Insects
in the Crevices of Trees
Chickadees, nuthatches, creepers, woodpeckers, and the
Black-and-white Warbler find insect eggs, larvae, or pupae in the crevices
of tree bark. Woodpeckers can hear bugs chewing within the wood, and
dig them out!
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Yellow-bellied
Sapsuckers eat sap and berries, but also lots of insects that
they hear chewing inside the outer layers of trees trunks.
Photo
Ann Cook
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Chickadees
eat many tiny insects that they find in tree bark. They also
snap up crawling insects from leaves and inside weeds and grasses.
Photo
Ann Cook
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Red-headed
Woodpeckers are also masters at pecking into wood to get the
insects they hear chewing.
Photo
by Stephen J. Lang for The
Wisconsin Society for
Ornithology
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Tufted
Titmice, relatives of chickadees, take insects from many of
the same places.
Photo
by Myron "Red" Newton.
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Generalists: Birds That Eat Many Kinds
of Insects
Some birds can eat a wider variety of insects than
others. These are called generalists. One example
is the Yellow-rumped Warbler.
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Blue
Jays use their intelligence and curiosity to figure out where
bugs are in many places of their territory. They are omnivores
who eat many plant items, too.
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Orioles
can glean for insects in leaves, or can fly out to snatch insects
in mid-air
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This
Yellow-rumped Warbler is versatile! It can eat little caterpillars
on treetop leaves, can flutter out to snap up insects in midair,
can visit bird feeders to take suet or mealworms, and in a
pinch can even eat berries!
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Try
This! Field Study and Journaling
In your field notebook, make 5 columns and label them:
- Insects
on tree leaves
- Insects
on tree bark
- Insects
on the ground
- Insects
in weeds
- Insects
in the air
- Extremely
tiny insects
Take your
notebook outdoors, and spend 30 minutes searching for insects. Whenever
you see a new insect, make a tally mark in the corresponding column
in your field notebook. Which kinds of insects are you best at finding?
What kind of bird's life would you be best adapted for? In your journal,
write what your life might be like if you were that kind of bird. What
new skills would you need? What skills do you have now that wouldn't
help you as this kind of bird?
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