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Q: Birds that eat forest tent caterpillars ( Answered 5 out of 5 stars,   0 Comments )
Subject: Birds that eat forest tent caterpillars
Category: Science > Biology
Asked by: uzzz-ga
List Price: $20.00
Posted: 12 Mar 2006 15:31 PST
Expires: 11 Apr 2006 16:31 PDT
Question ID: 706497

Blue jays are known to eat forest tent caterpillars. Do crows? or
pigeons? What other birds do the same? I need sources that I can

Thank you

Subject: Re: Birds that eat forest tent caterpillars
Answered By: hummer-ga on 12 Mar 2006 21:42 PST
Rated:5 out of 5 stars
Hi uzzz,

Guess what?  It is past midnight, I was feeling good about having a
list of nine birds for you, and I just now discovered that there are
over 60 species of birds that enjoy a meal of tent caterpillars for

"Other known predators include frogs, mice, skunks and over 60 species
of birds (Witter and Kuhlman 1972). Bird predation of late-instar and
pupal stage forest tent caterpillars has recently been demonstrated to
cause overwhelming mortality of populations at all densities in an
artificial setting, and is hypothesized as the principle regulator of
low density populations between outbreaks (Parry et al. 1997)."
University of Florida
Department of Entomology and Nematology 

Forest tent caterpillar, Malacosoma disstria Hübner

1) White-breasted nuthatch (Sitta carolinensis) 
"Food: A myriad of insects, including larvae of the gypsy moth and the
forest tent caterpillar, beetles, spiders, caterpillars, and ants
comprise the main diet of white-breasted nuthatches throughout the
spring and summer. In the winter, nearly all food eaten is mast
composed of beechnuts, acorns, hickory nuts, maize and sunflower seeds
(Bent 1948). Among the insect foods are several other forest pests
including nut weevils, locust seed weevils, and roundheaded woodborers
(Scott and Patton 1975). Nuthatches may also be attracted to feeders
with suet and sunflower seeds."
USDA Forest Service Northeastern Area

White-breasted nuthatch
"The white-breasted nuthatch is easy to identify, especially since
this stubby-tailed bird often walks down a tree headfirst as it
searches bark for insects. This white-breasted bird has a black cap
and nape that contrast with the white sides of the face and chest. The
call is a loud nasal ?yank, yank.? These birds live around woodlands,
parks, and suburban areas. They eat acorns, moths, tent caterpillars,
and other insects. Easily tamed, they can be handfed foods such as
peanuts and sunflower seeds."
West Virginia University Extension Service

2) Black-billed Cuckoo (Coccyzus erythropthalmus)
"This cuckoo is brown above and white below. The bill is slightly
curved downward, and all black. Adults have a red eye-ring. The long
tail has white spots that are not as distinct as the yellowbilled
cuckoo. Sexes are outwardly similar. The call is "cu, cu, cu." This
cuckoo's diet consists of tent and other caterpillars, hairy
caterpillars, beetles, ants, wasps, flies, and fruits such as grapes.
The nest is of twigs, built in dense thickets or small trees. Often
this bird lays eggs in the nests of catbirds, wood thrushes, and
yellow warblers. It is a fairly common migrant and uncommon to fairly
common summer resident, and it may occur in small numbers in most
West Virginia University Extension Service

3) Yellow-billed Cuckoo (Coccyzus americanus)
"Their habitat is in dense tangles of undergrowth or brushy roadside
thickets by streams. Diet is similar to the black-billed, including
tent caterpillars. The nest, built on a horizontal limb of a small
tree or bush, is flat and flimsy, constructed of short twigs and lined
with grass, moss, or rags. Incubation is by both sexes. Unlike the
black-billed cuckoo, the female rarely lays eggs in other birds'
nests. It is a fairly common migrant and fairly common summer
resident, probably nesting in every county in wooded areas, but it is
not found in dense mature forests."
West Virginia University Extension Service

Yellow-billed Cuckoo
"The Yellow-billed Cuckoo is an unusual bird in that it feeds almost
exclusively on tent caterpillars. It has a long curved bill that makes
it especially adept for reaching in and pulling out tent caterpillar
larvae. Some people call them rain crows probably because they will
call just before a summer rainstorm."
Birmingham Southern College 

"The Yellow-billed Cuckoo is one of the few birds that eat many hairy
caterpillars like Tent Caterpillars or Gypsy Moth larvae."
Georgia Wildlife Web Site

4) Bay-breasted Warbler (Dendroica castanea)
"The Bay-breasted Warbler is one of the species of the state that is
high associated with outbreaks of spruce budworm and generally its
highest densities are found in areas where spruce budworm is found
(Morse 1989)..."
The species is highly insectivorous during the breeding season. Morse
(1989) suggests that the species concentrates most of its activities
on the larger inner parts of the limbs in contrast to the outer
portions of the tree. Sealy (1979) noted that the species also was
associated with forest tent caterpillars, in which it took many of the
smaller sized caterpillars. Greenberg (1979) described the species as
relatively plastic in foraging during the winter."
Minnesota GEIS, Forest Wildlife Technical Paper

5) Baltimore Oriole (Icterus galbula) 
"Baltimore orioles are attractive songbirds that will come to feeders.
They are generally liked by both serious birdwatchers and casual
backyard enthusiasts for both their appearance and song. They are also
important predators on some insect pests such as forest tent
caterpillars. (Bent, 1965; Parry, Spence, and Volney, 197)"
University of Michigan Museum of Zoology.$narrative.html 

6) Mockingbirds (Mimus polyglottos)
"Forest Tent Caterpillars
Usually gone by this time, they have extended their stay with us; many
trees in the heavily infested areas are void of foliage (oaks, sweet
gum and Bradford pears, to name a few). They are beginning to pupate
now. We should see the last of these caterpillars in the next few
days. Some are rolling up leaves remaining on the trees and puupating
inside the rolled leaf. Others are on the cracks and crevices of the
trunk, and others are on the eaves of homes. Birds, like mocking birds
and blue jays, will feed on the pupal stage and drop the white cases,
cocoons, to the ground. The adults will emerge in a few weeks and will
cluster around lights, mate, lay their eggs on the trees and be gone
until next spring. Homeowners and gardeners can check tree limbs for
the crystalline-like egg cases wrapped around the stems. These can be
easily removed and disguarded and will help to reduce some of the
population for next year."
LSU AgCenter 

American tent caterpillar:

7) Blue Jays (Cyanocitta cristata)
Blue Jays feed tent caterpillar pupae to nestlings.-Although it is
generally known that American cuckoos (Coccyzus americanus and
erythropthalmus) and Baltimore Orioles (Icterus galbuhz) feed on tent
caterpillars (Malacosomu americana), there are few references to the
important activity of Blue Jays (Cyanocitta cristata) in  the control
of this pest (see Forbush, 1929, ?Birds of Massachusetts, etc.,? Part
2, p. 383).
In April and May, one pair of Blue Jays will destroy hundreds of the
cocoons to feed the pupae to their nestlings, thus eliminating
potential thousands of eggs due to hatch on fruit trees the following
spring. I first observed Blue Jays gathering the cocoons in 1948 while
watching a jay nest near my house. As the food brought to the
nestlings was always carried inside the mouth instead of between the
mandibles, it was necessary to watch the adults as they foraged to
find out what they were bringin, c to the nest. With binoculars, I
could see them carry a small white object to a brush pile, hold it
between the toes, and pound it with the bill. Something was then
tossed into the mouth as the white object was released to float off in
the breeze or cling to the twigs. After two or three repetitions of
this performance, the parent jay flew to the nest to feed the young.
Examining the white objects, I found them to be the silky cocoons
woven by the adult tent caterpillar. The birds had opened each one at
the end to extract the developing pupa. Each year since, I have noted
that Blue Jays hunt these cocoons about the wild cherry trees.
AMELIA R. LASKEY, 1521 Graybar Lane, Nashville 12', Tennessee, July 22, 1953.
University of New Mexico

8) Black-throated Green Warbler (Dendroica virens virens)
"Birds eating tent caterpillars.--On May 20, 1935, I twice observed
the Black-throated Green Warbler, Dendroica virens virens, feeding
upon American tent caterpillars, Malacosoma americana, about ten miles
north of Indiana, Indiana County, Pennsylvania. During each
observation, the individual warblers descended from hemlock growth at
the woodland's edge to a grove of young wild black-cherry trees,
Prunus serotina, where they tore open the nests and devoured the small
larvae in some quantities."
J. KEnnETH TEggF.S, Soil Conservation Service, Ithaca, New York.

9) Black-Capped Chickadee (Poecile atricapillus)
"About two-thirds of a chickadee?s diet consists of animal protein:
moth and butterfly caterpillars (including early growth stages of
gypsy moths and tent moths), other insects and their eggs and pupae,
spiders, snails and other invertebrates. In late summer and fall,
chickadees eat wild berries and the seeds of ragweed, goldenrod and
staghorn sumac. In the fall chickadees begin storing food in bark
crevices, curled leaves, clusters of pine needles, and knotholes. The
birds rely on these hoards when other food becomes scarce. Chickadees
also eat suet from feeding stations and fat from dead animals."
Pennsylvania Game Commission - State Wildlife Management Agency 

Blackcapped Chickadee
"On the morning of April 23, 1938, I again observed at close range the
destruction of these caterpillars, this time by a Blackcapped
Chickadee, Penthestes atricapillus atricapillus, in a brush-grown
field in Broome County, near Nanticoke, New York. When first seen, the
chickadee was busily engaged in visiting a number of the newly started
nests of the American tent caterpillar located in a nearby wild-apple
tree, Malus pumila. Using an eight-power binocular at twenty feet, I
observed the chickadee dosely while it visited three caterpillar nests
in succession. It would first tear open the web, then pick up the
small worms (on this date about three-eighths of an inch long and a
sixteenth of an inch in diameter) and devour them rapidly. After
visits to three nests during my presence, it apparently had its fill
and flew off. On ex- amining these nests a conservative estimate
showed that 75% of the contents of each had been eaten. Estimating an
average of 70 to I00 worms in each (rough count in an untouched
caterpillar nest) the chickadee must have consumed at least 170 tent
caterpillars at one meal. The chickadee was apparently feeding before
my approach, so that it had possibly eaten many more. Tent
caterpillars are so tiny at this time of year that they are attractive
prey for warblers and chickadees before noticeable destruction of
foliage has begun. This suggests that these birds are especially
important checks on tent caterpillars at a time that presages their
more destructive development.-
J. KEnnETH TEggF.S, Soil Conservation Service, Ithaca, New York.

I'm sure you won't mind if I post this now and I'll see what I can
find out about those 60 species tomorrow. In the meantime, you can
have a look at my measley 9 birds and see what you think.

Talk to you tomorrow,

Google Search Terms Used:
"birds that eat" "tent caterpillars"
blue jays "tent caterpillars"
crows "tent caterpillars"
birds eat lasiocampids
"predators of tent caterpillars"

Clarification of Answer by hummer-ga on 13 Mar 2006 08:44 PST
Good morning, uzzz. 

I thought you would enjoy this little titbit:

"The bears can and do eat up to 25,192 forest tent caterpillars in a
twenty-four hour period."
[?The Trumpeter,? the publication of Wild and Free, a wild animal
rescue organization based in Garrison Minnesota,] 

Here are two birds to add to my list:

10) Agelaius and Brewer Blackbirds (Ezqhagus cyanocephaks) 
"Blackbirds Feeding on the Forest Tent Caterpillar.-At Rollings Lake,
British Columbia, on June 5, 1925, it was observed that Red-winged
Blackbirds (Agelaius and Brewer Blackbirds (Ezqhagus cyanocephaks)
were busily feeding on the forest tent caterpillars that partly had
defoliated the poplar trees along the lake shore. Both species nested
in the vicinity; the redwings in two small tule marshes that fringe
the lake shore; the Brewer Blackbirds in stumps, on the ground, or in
crevices of dead poplar trees that stood close to the lake. Blackbirds
of both species also were seen flying from the infested trees to their
nests and back again, presumably carrying the larvae to their young. -
J.A. MUNRO, Okanagan Landing, B. C., January 15, 1929"
University of New Mexico

11) Red-Winged Blackbird (Agelaius phoeniceus)
"Diet and eating habits: Year round, the red-winged blackbird's diet
consists of about 73% vegetable matter and 27% animal. Eats mayflies,
caddis flies, moths, beetles, caterpillars of gypsy moths, forest tent
caterpillars, geometrid moth caterpillars, cankerworms, grubs in
plowed fields, grasshoppers, spiders, myriapods, mollusks, snails;
also blackberries, blueberries, and other fruit. Will also eat bread
and bird seed mixtures in backyard feeders. Feeds on the ground,
walking or hopping to keep up with the feeding flock. In late summer
and fall, the red-winged blackbird mixes with grackles, cowbirds, and
starlings to feed in open fields on weed seeds and waste grain."
The Columbus Zoo and Aquarium of North America 

Check your library for this:

Ontario Birds: The 55-page August 2001 issue (19:2) includes:
"Forest Tent Caterpillars and Birds by Dave Elder."

Have gone through all of the books we have here (for one, "The Audubon
Society Encyclopedia of North American Birds") and can't report
anything substantial:

"In McAtee's report, 200-300 stomachs of birds of 8 species held
caterpillars - downy woodpecker, blue jay, red-winged and Brewer's
blackbirds, warbling vireo, black-cappped chickadee, hermit thrush,
and eastern bluebird - and caterpillars were in 300-400 stomachs of
the red-eyed vireo and American robin. About 75 species, including the
tiny chickadees, eat the hairy tent caterpillars; 46 species eat the
caterpillars of the gypsy moth; 31 species eat the caterpillars of the
brown-tailed moth...", etc. but no mention of the forest tent
"The Audubon Society Encyclopedia of North American Birds"
NY: Alfred A. Knopf (©1987). P557

How long a list were you hoping for?   : )

Clarification of Answer by hummer-ga on 13 Mar 2006 10:14 PST
Nice link -

12) Rose-breasted Grosbeak (Zamelodia ludoviciana)
"It proved an active enemy of the Rocky Mountain locust during that
insect s ruinous invasions, and among the other pests it consumes are
the spring and fall cankerworms, orchard and forest tent caterpillars,
tussock, gipsy, and brown-tail moths, plum curculio, army worm, and
chinch bug. In fact, not one of our birds has a better record.(See
Biol. Survey Bul. 32, pp. 33-59.)"
National Geographic Magazine, VOL. XXIV, No. 6, 1913

Clarification of Answer by hummer-ga on 14 Mar 2006 08:14 PST
13) Pine Grosbeak (Pinicola enucleator)
14) Evening Grosbead (Coccothraustes vespertinus)
Forest Tent Caterpillar in 2002: What's On The Menu?
"3. Some people think FTC are for the birds. Lure in birds with bird
feeders, especially the pine and evening grosbeaks, and they'll do
some of the work by eating the caterpillars."
Minnesota Department of Natural Resources

15) American Crow (Corvus brachyrhynchos) 
"It is reported that crows consumed approximately 20% of forest tent
caterpillar pupae during outbreaks in Minnesota."
Wisconson Department of Natural Resources

Northern Prairie Wildlife Research Center
Caterpillars of Eastern Forests
"Helpful Literature on Caterpillars"

Clarification of Answer by hummer-ga on 14 Mar 2006 10:36 PST
16) Ring-billed gulls (Larus delawarensis)
TITLE:  Ring-billed gulls, Larus delawarensis, feeding in flight on
forest tent caterpillar, Malacosoma disstria, cocoons.
AUTHOR: Blomme, C. G.
SOURCE: Can. Field-Nat. 105-:280-281
DATE: 1991
KEYWORDS: foraging/behavior/diet

17) Least Flycatcher (Empidonax minimus)
18) Yellow Warbler (Dendroica petechia)
Rose-breasted Grosbeak (Pheucticus ludovicianus)
Northern Oriole (Icterus galbula)
{C916} Perry, D., J. R. Spence, & J. A. Volney. 1997. "Responses of
natural enemies to experimentally increased populations of the forest
tent caterpillar, Malacosoma disstria."
Reared forest tent caterpillars in upland and lowland aspen forests in
Alberta, Can. simulating various population densities. The [Least
Flycatcher, Rose-breasted Grosbeak, Yellow Warbler and Northern
Oriole] preyed on late larvae and were the chief source of pupal
mortality at all prey densities.
Dept. Entomol., 243 Nat. Sci., Michigan State Univ

Not a scholarly link -

Preventing Tent Caterpillars Next Year
"Songbirds eagerly probe the bark of trees and gobble up as many tent
caterpillar eggs as they can find. Among the most helpful egg hunters
are bluebirds, blue jays, tufted titmice, and chickadees. Black and
yellow-billed cuckoos, Baltimore orioles, redwing blackbirds, phoebes,
red-eyed vireos, robins, and downy woodpeckers will eat the
caterpillars, too."

Thank you for your kind words and generous tip, as usual you posted an
interesting and challenging question!  I have your question #2 locked
and will post an answer as soon as possible.


Clarification of Answer by hummer-ga on 05 Apr 2006 05:29 PDT
"Food: Waldo L. McAtee (1926) gives the following comprehensive
summary of the cedar waxwing's food:
The Cedar-bird in some places is called Cankerbird, on account of a
marked fondness for cankerworms, and it has a great reputation also as
a foe of the elm leaf beetle. In New England it has several times been
observed to clean up local infestations of this pest. The species has
been observed to clear orchards of the tent caterpillars and to feed
also on larvae of the forest tent caterpillar, the willow sawfly, the
basket-worm of cedar, and the spotted willow leaf beetle."

Pine Siskin (Carduelis pinus)
[cited by Parry]
Grant, J. (1959) Pine siskins killing forest tent caterpillars
(Malacosoma disstria Hbn.) Proceedings of the Entomological Society of
British Columbia, 56, 20.

Larval ontogeny and survivorship of eastern tent caterpillar colonies
"While at least 56 species of birds have been reported as predators of
tent caterpillar larvae and pupae (Witter and Kulman 1972), few birds
will regularly feed upon mature larvae, presumably due to setae and
toxicity. Young larvae, however, are poorly defended and relatively
conspicuous, and it is likely that insectivorous birds are responsible
for much early-instar mortality. This is especially likely since the
temporal occurrence of young colonies of eastern tent caterpillars
coincides with the spring migration and breeding season of many
insectivorous birds in eastern North America (Witter and Kulman
uzzz-ga rated this answer:5 out of 5 stars and gave an additional tip of: $20.00
Wow! What an answer. I leave my computer for a few of days and
'Voila!' a great answer by hummer-ga.  As usual you exceeded my
expectations. Thank you.

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