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| Figure
1. The European starling is a medium-sized,
black songbird with short, triangular wings, speckled
plumage, and a short tail. The adult in breeding plumage
has a distinctive yellow bill and speckled black plumage
with purple-green iridescence. The nonbreeding adult has
a black beak and light spots. Juveniles are drab gray-brown
overall. Males and females look alike. |
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It is hard to
imagine now, but European starlings (Sturnus vulgaris,
Fig. 1) were purposefully introduced from Europe into this country.
After two failed attempts, about 60 European starlings were released
into New York’s Central Park in 1890 by a small group of people
with a passion to introduce all of the animals mentioned in the
works of William Shakespeare. The offspring of the original 60 starlings
have spread across the continental United States, northward to southern
Canada and Alaska, and southward into Central America. There are
now an estimated 150 million starlings in the United States.
In 1889 and
1892, the Portland Song Bird Club released 35 pairs of starlings
in Portland, Oregon. These birds established themselves, but then
disappeared in 1901 or 1902. The next sighting of a starling in
the Pacific Northwest was not until the mid 1940s. Presumably these
birds could be genetically linked to the 1890 Central Park introduction.
It is difficult
to reach a consensus on starlings. Some value the species for their
creative adaptiveness and their odd beauty. Many hold a strong dislike
of starlings because of their aggressive behavior at feeders and
nesting sites, and their overwhelming flocks and roosting habits.
There is only one thing on which agreement can be reached regarding
starlings—they are ubiquitous.
Facts
about Starlings
Food and
Feeding Habits
- Starlings
forage on lawns and other areas of short grass, such as pastures,
golf courses, turf farms, and similar places.
- One of
their very favorite foods is the large larva of the leatherjacket,
or marsh cranefly (Tipula paludosa), which eats the roots
of grass plants. Leatherjackets (like starlings) are not native
here, and were unintentionally introduced from Europe.
- Starlings
have unique jaw muscles designed both to clamp shut and spring
open, allowing them to use their bills to pry things open, including
openings in the soil.
- Starlings
also eat fruit, seeds and suet at bird feeders, and food scraps.
Nesting
and Roosting Sites
- Starlings
nest in suitable holes and crevices in buildings, utility poles,
decaying trees, and holes in cliff faces, 6 to 60 feet above
ground.
- Males
establish territories and choose nest sites, then attract females.
- Male starlings
are very aggressive when claiming nest sites, taking over nest
boxes and other cavities even while they are in use by such
native birds as bluebirds, woodpeckers, and swallows.
- The nest
is an untidy collection of grasses, bark strips, twigs, rope,
and other debris. The nest cup is lined with feathers, mosses,
or other soft material.
- In late
summer and fall, starlings form large flocks and roost in large
deciduous trees. In early winter, when trees lose their leaves,
starlings roost in areas that provide protection from wind and
cold, including coniferous trees, areas under bridges, and in
grain terminals and barns.
- During
the night, individual birds change their position in the roost
to minimize energy loss, with older birds maintaining the “best”
positions. (See “Roost Sites”
for more information.)
Reproduction
- Starlings
can be building nests, sitting on eggs, or caring for young
anytime from mid February to early July.
- Four to
six slightly glossy, pale blue eggs hatch after an incubation
period of 11 to 13 days.
- Both parents
take turns with incubation during the day; at night only the
female remains on the nest.
- The young
begin to fly at 18 to 21 days of age, and out-of-nest care by
parents lasts 2 to 4 days.
- A pair
of adults can raise two broods per year. The female typically
starts laying a second brood shortly after the first one fledges.
- Starling
eggs (which are about the same size, shape, and color as robin
eggs) often are found lying on the ground. It is believed that
the females drop eggs if they are ready to lay, but the nest
is not yet complete or has been taken over by another bird.
 |
Figure
2. Starlings lay four to six slightly glossy, pale blue
eggs.
(Photo by Acorn Naturalists.) |
Mortality
- Adult
starlings have few predators, although hawks and falcons occasionally
catch them in flight.
- Loss of
young starlings results from starvation, adverse weather, and
predation by owls, raccoons, rats, domestic cats, and other
predators.
- Humans,
via control programs in agricultural areas, are probably responsible
for most starling mortality.
Viewing
Starlings
Starlings
can be seen almost any time of the year in low elevations throughout
Washington, particularly in areas associated with humans. They
are among the few species of birds that tolerate high human density
and poorly vegetated landscapes such as industrial sites. Starlings
are normally absent only from heavily wooded areas, deserts, and
areas above timberline. They appear to be partially migratory,
but patterns vary regionally and individually. Many birds move
into valleys and urban areas during the winter.
Starlings
are often observed walking or running along on lawns, stopping
to probe for cranefly, moth, and beetle larvae with their powerful
beaks. The short grass makes it easy for them to walk, locate
food, and view potential predators.
The wings
of starlings have a triangular shape when stretched out in flight.
Their flight is direct and swift, not rising and falling, like
the flight of many “black birds.”
When starlings
spot a perching hawk, falcon, or owl, they will “mob”
it by flying around it and diving toward it, calling loudly. Dense
flocks of starlings will also take flight and perform complex
evasive movements in unison to avoid predators, such as falcons.
Huge, undulating
flocks containing thousands of starlings can be observed during
the winter months flying over towns, water, and fields.
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Figure
3. Two visual displays made by starlings.
(From Stokes, A Guide to Bird Behavior.) |
Displays
Since starlings
are widely distributed and abundant in populated areas, they make
great subjects for bird-watchers interested in wildlife behavior.
The wing-wave
display is performed when the male is perched; the bird spreads
his wings and moves them in a rotating manner.
The fluffing
display is performed by males and females during aggressive encounters.
The displaying bird faces another bird and puffs out all its feathers.
The other bird may do the same.
Starlings
have diverse calls and songs, such as whistles, high-pitched squeaks,
and imitations of other birds’ calls and songs, including
those of bald eagles and other raptors. Just before pairing in
spring and on warm fall days, the male commonly gives a squeal-call
near the nest hole when a female flies by.
As long ago
as the Fifth Century B.C., the Greeks and Romans kept starlings
as caged birds and taught them to imitate human speech.
Roost Sites
Starlings
roost on structures or in trees from late summer until the beginning
of the breeding season. The number of birds using roosts can vary
from a hundred to 150,000 or more. Roosts are largest in late
summer, when composed of newly hatched young, their parents, and
other birds that did not breed. The roosts become smaller, and
may change location, in fall and winter when the adults migrate
or return to breeding grounds.
Each sunrise,
starlings leave their roost site and scatter across the land in
small flocks to feed on nearby lawns, cultivated fields, golf
courses, and similar places, as well as natural areas including
wetlands, tidal flats, and debris rich beaches. Starlings will
fly 30 miles to a productive feeding site.
Up to two
hours before sunset, the starlings farthest from the roost site
begin their return trip to the roost. The birds travel along established
flight lines that are used day after day. Other small flocks join
them and the flock size increases as it approaches the roost site.
Some members will drop out and perch on pre-roosting sites such
as trees, power lines, bridges, and towers, along the way. These
pre-roosting areas are constantly changing in membership as birds
leave and rejoin the main flocks.
Before sunset,
all birds at pre-roosting sites will have left for the primary
roost, where immense flocks will be swarming. The birds make spectacular
dives into the primary roost, flutter about in search of a good
perch, and settle down for the night.
Preventing
Conflicts
The starling’s
long association with humans has strengthened its adaptive characteristics.
Because these birds congregate in large numbers and aggressively
search out food sources and nest sites in and around buildings,
they can come into conflict with people.
The following
are suggestions on how to prevent and remedy conflicts that arise.
In cases where these methods are not practical, contact the Department
of Agriculture Wildlife Services for more information.
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| Figure
4. Starlings can be prevented from roosting on a building
ledge by securing sheet metal, wood, Styrofoam blocks, or other
materials at a 60-degree angle. |
Figure
5. The undersides of rafters can be covered with bird netting
to prevent starlings from gaining access to roosting spots.
(Drawings by Jenifer Rees.) |
Starlings
nesting in buildings: Starlings
are adept at establishing nest sites in nooks or crannies in buildings.
Nesting activity can damage buildings, create fire hazards, and
clog gutters and drainpipes, causing water damage.
Prevent starlings
from nesting or roosting in structures by installing barriers
(Fig. 4, 5) and sealing all potential points of entry. Although
starlings have difficulty entering holes smaller than 1½
inch in diameter, house sparrows, bats and other small mammals
can slip right in. Use wood, ¼-inch hardware cloth, aluminum
flashing, or similar sturdy material. Light material, such as
bird netting or rags, will not keep determined starlings out.
Replace any loose shingles or siding, and repair broken windows.
Install commercially
available vent guards to prevent starlings from entering exhaust
vents and dryer vents. If necessary, cover the ends of elevated
drainpipes with ¼-inch hardware cloth during the nesting
season. All screening should be checked periodically to make sure
it isn’t clogged.
Prevent starlings
from roosting on walls covered with vegetation by removing the
vegetation or draping bird netting over the area. In new construction,
avoid creating small cavities or spaces with access from the exterior
into which starlings can enter and nest.
Starlings
can be evicted from buildings and other sites any time of year.
State and federal laws do not protect this species. A stick with
a 2½-inch angle bracket screwed to it can be used to remove
nests. The nesting material should be collected and removed to
prevent the birds from using it for a new nest. Take immediate
steps to prevent starlings from rebuilding.
If the birds
are caring for young, one approach is to wait until the young
can fly out of the nest, then remove all nesting materials and
cover all openings.
Starlings
at feeders: Starlings are attracted to both seed and suet
feeders, and their aggressive habits can deplete food supplies
and keep smaller birds from approaching. By choosing the right
bird feed, style of bird feeder, or modifying an existing feeder,
you can discourage starlings.
Because starlings
have difficulty cracking the commercially available black sunflower
seeds, these can be offered in feeders.
Because starlings
have difficulty landing on a small perch, making the perches on
a feeder smaller by sawing them, or removing the perches altogether,
can keep starlings off (Fig. 6). Most songbirds do not need a
perch to access the seed.
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Figure
6. To reduce waste, prevent crowding at the feeder, and
keep starlings away, remove all perches and cover all but
one lower feeding port with duct tape or electrician’s
tape.
(Drawing by Jenifer Rees.) |
Figure
7. A hanging pine cone stuffed with peanut butter or suet
will prevent starlings from accessing this simple feeder.
Smaller birds will have no trouble landing and feeding. (From
Link, Landscaping for Wildlife in the Pacific Northwest.) |
Figure
8. Wire placed over a platform feeder to allow small birds
in and keep large birds out.
(Drawing by Jenifer Rees.) |
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Figure
9. Before and after pruning of a coniferous tree to reduce
its attractiveness to roosting starlings.
(Drawing by Jenifer Rees.) |
Starlings
may also be deterred by small feeders that swing and twirl whenever
the heavy birds land on them (Fig. 7).
Because starlings
have trouble clinging upside down, a suet feeder that requires
the birds to clasp the feeder from below will discourage starlings.
Your local bird specialty store can give you information on suet
feeder designs to deter these birds.
Wire mesh
placed over a platform feeder will prevent starlings from accessing
the seed (Fig. 8). Don’t place large amounts of birdseed
on the ground or on an uncovered platform feeder.
Starlings
roosting in trees: In fall and winter, the communal night
roosts of thousands of starlings create accumulations of droppings
below the roost. When a health official deems this a health risk
to the public, steps need to be taken to disperse the flock. Options
include installing visual and auditory scare devices, and thinning
30 to 50 percent of the branches of roost trees—or removing
trees from dense groves—to reduce the availability of perch
sites and to open the trees to the weather (Fig. 9). A tree service
company can provide this service.
Experience
has shown that the best results occur when the pruning of trees
is combined with scare tactics. (See Canada
Geese for information on visual, auditory, and other scare
devices.)
| Protecting
Native Cavity Nesters from Starlings |
| Although
starlings can be interesting to watch in highly built-up areas
where few other bird species thrive, they are a serious problem
in areas where native birds exist. These introduced species
compete with native, cavity nesting birds for nesting spots,
which are becoming increasingly less plentiful as trees are
cut down.
Male
starlings are especially aggressive in their search for nest
sites: They will peck holes in eggs laid by other birds, throw
out their nesting material, and kill their young. Starlings
will build nests on top of existing nests containing eggs,
and can evict the larger wood duck from its nest boxes.
To
prevent problems:
- Don’t
attract starlings. (Follow recommendations under “Preventing
Conflicts.”)
- Install
nest boxes designed to exclude starlings (Fig. 10). Many
native songbirds can use an entry hole smaller than the
11/2 inches needed by starlings (Table 1). Be alert to hole
enlargement by flickers and rodents, and replace or add
a new front with the proper hole size. To reduce the size
of an existing entry hole, attach a piece of wood to the
front of the existing box and drill the appropriate size
hole. File down all rough edges. It is also possible to
buy a pre-drilled metal plate that can be attached over
the entry to a nest box.
- Don’t
install nest boxes that have perches. Perches are used by
starlings, but are not necessary for native species.
- When
observing a starling building a nest in a nest box, repeatedly
remove the nesting material, or plug the entry hole for
a few days or longer to prevent them from entering. Carefully
monitor the box throughout the breeding season for use by
starlings.
- If
starlings have laid eggs in a nest box, vigorously shake
the eggs and return them to the nest. The adults will incubate
them, but the eggs will not hatch. Because state and federal
laws don’t protect these birds, it is legal to remove
their nests and destroy the eggs or the birds themselves.
- Clean
out nest boxes each year. When not cleaned out, birds will
build new nests on top of old ones. This raises the new
nest close enough to the entry hole so starlings or other
predators can pull out the occupants.
- If
you have just a couple of boxes, take them down each year
(or block the entrance holes) after the breeding season
and do not put them back up until the native species are
seen or heard the following spring. Note: Since starlings
do not migrate for the winter, they will be looking for
nesting sites long before the migrants return in the spring.
| Table
1. Entry hole dimensions needed by some small native cavity-nesting
birds |
Click
image to enlarge. |
| Figure
10. A nest box designed to provide a safe nesting
site for native cavity-nesting songbirds. (From
Link, Landscaping for Wildlife in the Pacific
Northwest.) |
|
| Bird
species |
Diameter
of entrance |
| Chickadees |
1
to 1~ in.* |
| Tree
swallows |
1¼
in. |
| Violet-green
swallows |
1~
in. |
| House
wren |
1
in.* |
| Nuthatches |
1¼
in. |
| Western
bluebird |
*1½
in. |
| Hairy
woodpecker |
1~
in. |
| Downy
woodpecker |
1¼
in. |
| *
This species will also use the diamond-shaped entry hole
shown in Figure 5. |
|
Starlings
eating fruits and vegetables: A small flock of starlings can
quickly ruin or remove the year’s fruit or young vegetable
crop.
Protect fruit
crops with flexible bird netting, which can be purchased in a
variety of lengths and widths at garden and hardware stores; professional
quality materials and hardware are available from bird-control
companies and over the Internet. Secure the base of the shrub
or the tree to prevent starlings from gaining access from below
(Fig. 11). Individual small branches containing fruit can be protected
with an onion sack or similar mesh covering.
 |
Figure
9. Protect fruit crops with flexible bird netting. Secure
the netting at the base of the shrub or tree to prevent starlings
from gaining access from below.
(Drawing by Jenifer Rees.) |
Row crops,
such as strawberries, can be completely covered during the fruiting
season. If the netting is to be used for several harvest seasons,
it may be worth the extra effort to construct a frame to support
the netting.
Scare devices,
such as pie tins and commercially available Mylar balloons or
Mylar scare tape, are known to provide temporary protection. Suspend
balloons at least 3 feet above trees or bushes, or from lines
between posts. Use tethers at least 3 feet long.
Attach special
red and silver bird-scare tape to stakes and stretch it 18 inches
above the areas that need protection. Twist the tape several times
before attaching it to stakes so that the visible interval of
red/silver is 16 inches. The tape should move freely, so that
when a slight breeze blows it will flash in the sun. The space
between tapes will have to be no more than 5 feet to be effective.
Because most
birds will fly into a strawberry patch, land on the ground between
the plants and eat the ripe strawberries from there, scare devices
placed above the patch are not effective. Instead, place the scare
tape between the rows. The tape should sag slightly but should
not be less than 3 inches or more than 5 inches from the ground.
Scare devices
need to be moved weekly (daily if possible) so birds don’t
become accustomed to them; they are also most successful if put
in place before the birds become a problem. Always harvest ripe
fruit immediately.
Protect germinating
corn plants and other crops with bird netting until plants are
about 8 inches tall. Large plastic trash bags attached to 6 to
7 foot wooden stakes, along with the above-mentioned scare tactics,
can be used in areas with lots of air movement. Cracker shells
and propane cannons may be needed in larger plantings. Ultrasonic
devices are not effective at frightening starlings.
Other
Control Techniques
Trapping
Research has
shown that intensive trapping and euthanizing can temporarily
reduce starling numbers and damage. This may be worthwhile in
some situations, such as at a winter cattle-feeding operation
or at airports. However, it has no effect on the number of starlings
returning the next year unless it is done repeatedly and over
50 percent of the population is removed each time.
Small-scale
traps are available from enterprises over the Internet. Check
the trap every two hours for non-targeted birds.
Do not trap
starlings and release them elsewhere, because they will easily
return or cause problems somewhere else. If you cannot humanely
kill them yourself, find a falconer or wildlife rehabilitation
center that will accept live starlings to feed to birds of prey.
(See “Trapping Wildlife”
for information on euthanizing birds.)
Shooting
Shooting is
not an effective way to manage starling populations overall. The
number of birds that can be killed by shooting is small relative
to the size of the flock. However, shooting may be helpful where
only a few birds are present, and in supplementing or reinforcing
other dispersal techniques. First check with the local ordinances
regarding discharging firearms.
Public
Health Concerns
Although health
risks from birds are often exaggerated, large populations of roosting
starlings may present risks of disease to people nearby. The most
serious health risks are from disease organisms growing in accumulations
of starling droppings, feathers, and debris under a roost. This
is most likely to occur if roosts have been active for years.
Precautions
need to be taken when working around large concentrations of starling
droppings. Contact the Department
of Health for recommendations.
Legal
Status
Starlings
are exempt from the Migratory
Bird Treaty Act (MBTA) of 1918, which was passed for the protection
of migratory birds. Their nests, eggs, young, and/or adults may
be removed or destroyed at any time. No permit is required.
Internet
Resources
Centers
for Disease Control and Prevention
Prevention
and Control of Wildlife Damage
Seattle
Audubon’s Birds of Washington State
Washington
Department of Health
Washington
Department of Fish and Wildlife
Wildlife
Control Supplies
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