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Excerpts
from The US Department of Agriculture's: Farmers'
Bulletin No1571.
"The starling
is one of the most effective bird enemies of terrestrial insect pests in
this country. More than half (57 percent) of the annual food of the adult
starling consists of animal matter, including insects, millipedes, spiders,
mollusks, a few crustaceans, and bits of suet and carrion. In April and
May such food constitutes more than nine-tenths of the bird's diet, and
even in February, when the opportunities for obtaining animal food are few,
it forms more than 28 percent of the total. Nearly three-fourths of the
animal food of the starlings, or more than 42 percent of its entire diet,
consists of insects. October is the month of greatest consumption of insects,
when they form nearly 58 percent of food, but in June, August, September,
and November they also provide more than half of the starling's sustenance.
Nearly half
the starling's insect food consists of beetles –– weevils, ground
beetles, and plant-feeding scarabaeids predominating. Conspicuous among
such items is the clover-leaf weevil, a European pest imported into the
Eastern States. The starling must be classed as one of the most effective
bird enemies of the Japanese beetle. Other beetles eaten by starlings
are wireworms and leaf beetles, among which was the Colorado potato beetles.
Grasshoppers and crickets furnish about an eighth of the yearly food of
the adult starling. From August to November these insects form the bulk
of the animal matter taken. When hayfields are being cut and raked in
the latter part of August and early in September, flocks of young starlings
obtain practically all of their sustenance from these insects, supplementing
it with wild black cherries and elderberries. Conspicuous among the grasshoppers
eaten were the red-legged locust and others of the same genus.
The terrestrial
feeding habits of the starling limit the variety of caterpillars eaten,
but this restriction has permitted the bird to distinguish itself as a
most effective enemy of that notorious pest, the cutworm. The European
corn borer also has not been overlooked by the starling.
From the
viewpoint of the farmer the insect-feeding habits of the starling leave
little to be desired. In its diet are some of the worst pests of garden
and field. These it takes in surprisingly large quantities during the
growing season, and even in winter it eats many hibernating individuals.
Cultivated
cherries form 2.66 percent of the adult starling's annual diet, but, of
course the consumption of such food is restricted to June and July when
it forms approximately 17 and 15 per cent, respectively. Some idea of
the extent of the starling's activities may be gained by comparison with
the food habits of the robin. From the examination of 1,236 stomachs,
it has been found that the robin feeds on cultivated fruit about twice
as much as does the starling, and during June and July, robins obtain
about 24 and 23 percent, respectively of their food from cultivated cherries.
As in the
case of men, however, who are often judged by the company they keep, the
starling has been accused of deeds perpetrated largely by the species
with which it associates. Not only is it generally accredited with eating
as much corn as the grackle and the red-winged blackbird, an assumption
that has been disproved, but many farmers confuse it with these species,
with the result that flocks of juvenile redwings are often considered
to be starlings and their depredations charged against them. Corn formed
0.77 of 1 percent of the yearly food of starlings. By far the largest
part of the corn eaten by starlings is waste grain obtained during winter
and early spring.
The demand
of food (insects) by nestlings is greatest during May, June and July,
a time when growing crops are benefited most by a suppression of their
insect enemies. Few birds are more voracious than young starlings, and
it requires the most strenuous efforts of the naturally active parents
to supply the constant needs of their offspring. More than 95 percent
of the nestling's food is animal matter, largely insects. Cutworms are
especially attractive to the young birds, caterpillars as a group forming
more than 38 percent of their diet.
Most of the
starling's habits are either beneficial to man or of an economically neutral
character. Field observation has established the fact that the time spent
by starlings in destroying crops or in molesting other species of birds
is extremely short compared with the endless hours they spend searching
for insects or feeding on wild fruits. There is no question that the influence
of the European Starling in the United States is beneficial. As a destroyer
of such pests as the clover-leaf weevil, the Japanese beetle, May beetles,
cutworms, and grasshoppers, it is even more energetic than some of our
protected native birds".
SFU
News
Oct. 17, 2002
Starlings
Beating Bad Rap
By
Marianne Meladahl
Oliver
Love (left), on the Davistead farm, checks his starling boxes with David
(center) and Hugh Davis
They are
birds with a bad reputation, but an SFU researcher studying the reproductivity
of starlings on a Langley dairy farm may be proving that wrong.
Biology graduate
student Oliver Love, who set up 250 bird boxes on the sprawling 200-acre
farm earlier this year, is using the site's abundant starling population
to investigate the role of a hormone known as corticosterone in bird reproduction.
Owners of
the fifth-generation farm say damage by pests to their fields has been
notably reduced since the birds, numbering in the thousands, began making
their springtime rounds about a decade ago.
Despite their
penchant for targeting blueberry crops and displacing some native bird
species, Love says starlings can also have a flip side. They attack leatherjacket
larvae, which typically infest and destroy huge patches of forage. Farm
owner David Davis says letting nature take its course has replaced the
need for pesticides.
The farm,
with its sprawling natural setting, became an ideal site for Love and
biology professor Tony Williams to study the birds. They were initially
stationed at a field site in Agassiz and found the Davistead farm through
the local field naturalists club. "This is not only a great natural
environment, but the owners are so willing and agreeable to let us carry
out this research," notes Love.
The Davis
family doesn't mind the daily appearance of the PhD student and colleague
Allison Clark, who are continuing their observations until the birds retreat
for winter. "We're happy to participate," Davis says. "What
they learn might eventually help us."
During the
nesting season, from mid-April until late June, the researchers do daily
egg counts and obtain blood samples from the birds. The samples enable
Love to study hormonal variation within the species and how variation
shapes the evolution of traits, such as the number and size of eggs that
are laid and the health of chicks. Love is also monitoring what effect
the hormone has on the mothering skills of birds.
During this
year's nesting season, Love says about half of his boxes were occupied
and 88 offspring were produced.
Starlings
came to North America about a century ago, when 100 of the European birds
were released in New York City. Their population in North and Central
America today is estimated to be more than 200 million.
To
read the original story please click here:
SFU News Story
My sincere thanks to SFU for permission to use
this article.
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