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Diet
is the most important issue which comes up on
our message board each spring as newcomers arrive
with rescued nestlings. New starling parents are
often unsure what foods to feed baby starlings,
as caring for a wild nestling is a brand new thing
for them. So, on this page I would like to address
some basics about starling nutrition as well as
discuss the suggested dog food based diet commonly
used for wild baby songbirds.
So, what do
baby starlings eat in the wild?
Knowledge about the diet of wild baby starlings
is crucial for all of us to have in order to raise
healthy birds. So, exactly what do wild starlings
feed their nestlings? Seeds, or fruits, or regurgitated
foods? Well, we first need to remember that the
majority of North American wild songbirds (passerines)
feed insect diets to their babies in the nest,
only adding other foods to the diet later. Starlings
are no exception to this and feed a variety of
insects -- mostly softer invertebrates -- to their
nestlings. Even adult starlings eat a diet high
in insects, rounding out their diets with fruits,
etc. depending on the season. Starlings are omnivores
yet because they eat a larger amount of insects
than do most omnivorous birds, they are very close
to being insectivores. Their dietary needs include
animal protein, vitamins (especially vitamin A!),
and minerals such as calcium, etc. Below are two
interesting tidbits about starling nestling diets:
"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." --
Farmers' Bulletin No1571
"Without
seeming to care whether the benefiting farmer
thanks him or reviles him, he hurries with jerky
steps about the farms and gardens in the summer
time, carrying more than 100 loads of destructive
insects per day to his screaming offspring..."
-- Carson, Rachel. "How
about Citizenship Papers for the Starling?",
1939
But why is a dog food mixture better than parrot
handfeeding formula for rescued baby starlings?
We already know that starlings have different
nutritional needs than parrots. But it seems to
be a common assumption that 'wild birds eat seeds
therefore it is okay to feed wild baby birds foods
which were made for parrots who are seed eaters'
(foods such as parrot handfeeding formulas.) Years
ago one company stated on its product labels that
its parrot handfeeding formula was appropriate
"for all baby birds." One company's
label recently still stated this last time I checked.
Unknowledgeable pet store employees are still
recommending parrot formula for wild baby songbirds.
However, the fact is that parrot handfeeding formulas
are specifically formulated for herbivores (birds
who eat seed, fruits, nuts, flowers). Thus the
main protein content in parrot handfeeding mixes
is from plant sources. Plant protein does not
supply adequate amino acids or protein for birds
like starlings who need animal protein
in their diets. Baby song birds are fed an almost
total insect diet the first week or so of life,
the protein content of insects is from 50 to 70
percent, so you can see that parrot food will
not come close to meeting their needs.[More
about proteins farther down.]
To
compare handfeeding formula and dog food ingredients,
simply go to a petstore and read labels. What
you will find is that the main ingredient in parrot
handfeeding formulas is most often corn, followed
by things such as wheat meal, oats, rice flour,
plant protein products, etc. Next look at dog
food labels, and notice not only the protein and
fat level but also the main food ingredient. Some
examples are below:
Zupreem
parrot handfeeding formula is 22% protein with
its main ingredient being corn, and the same
is true for such formulas as "Kaytee Exact"
and "Lafeber's Instant Nutri-Start"
(only two of many more brands). It is interesting
though that Lafeber is the only company that
tells you up front that it is not appropriate
for insect eating birds. This is from their
web site: "Instant Nutri-Start Is Not Meant
To Be Fed To Insectivorous Birds Or Raptors."
Some
of the dog food brands that come closest to
the ratio required by starlings of 33% protein
and 12% fat would be: "Innova Puppy Dry
Food" with 26% protein and 12% fat or "Purina
One Senior Protection" with 28% protein
and 12% fat.
Dog food would provide not only the animal protein
needed for an omnivorous or insectivorous bird
but also additional needed vitamins amd minerals.
For more information about this, please see the
info under the heading entitled, "Food for
Baby Starlings" on the Baby
Starling Care webpage.
Why is a certain type of protein so important
to starlings?
First, a little about proteins in general ----
Proteins are very important for normal growth
in humans and animals. The building blocks of
proteins (or what proteins break down into) are
amino acids. Amino acids are important not only
for growth but also for healing of tissues, for
production of immune bodies and enzymes, for supplying
energy, and for most chemical processes in the
body. There are 20 or so amino acids. Eight of
these cannot be made by the human body and are
referred to as 'essential amino acids.' They must
be gotten through foods containing them.
Proteins
from animal sources supply the most amino acids
and are said to be "complete proteins."
(Eggs supply all essential amino acids, and meats
are high in them too.) Proteins lacking in some
essential amino acids are said to be "incomplete
proteins", and these incomplete proteins
originate from most plant sources. It is known
that a lack of amino acids lead to deficiencies
which adversely affect health.
The
"biological value" of a food is one
way of evaluating a source of protein. Biological
value is "the measurement of the amino acid
completeness of the proteins contained by the
food." The info below was taken from a biological
value chart saved years ago off of the Internet,
and it illustrates that plant sources are lower
than animal sources in complete proteins. (Online
searches yield more info about this.)
| Biological
Value |
| Eggs
100% |
| Fish
Meal 92% |
| Beef
78% |
| Milk
78% |
| Wheat
69% |
| Corn
54% |
| Wheat
Gluten 40% |
Animal protein is necessary for European starlings!
Different
animals have varying amino acid requirements:
herbivores such as rabbits will get all the amino
acids they require from plants (or from incomplete
proteins), whereas carnivores will get none of
their essential amino acids from plants. Starlings
are not herbivores, and studies have shown that
animal protein is necessary in their diet. Below
are a couple of quotes about the importance of
animal protein to starlings (taken from The
Starling by Christopher Feare --an invaluable
book for starling owners to read!)
"Starlings spend most of their time feeding
in grassland throughout the year. During the
breeding season, and especially when feeding
young in May and June, their diet consists almost
entirely of invertebrates obtained from the
surface or from the upper few centimetres of
the soil of grass fields. Should this source
of invertebrate food disappear for some reason,
for example during a particularly dry spell,
the chances of survival of the chicks are much
reduced when they are given alternatives such
as bread, cereals, and cattle food. This happened
in 1975 at Worplesdon and it resulted in the
total failure of all of the late broods. In
addition to being presented with plant proteins,
which are less readily asimilated than animal
proteins, the absence of invertertebrates in
the diet deprived these late chicks of practically
their only source of water."
"Most
omnivorous birds eat invertebrates at most times
of year and Berthold (1976) found that plant
foods constituted a reserve that could be exploited
when invertebrates were less readily available.
The nutrient provided by the invertebrates is
animal protein and its absence from the diet
leads to weight loss and death (Berthold 1976).
Only specialist herbivores such as pigeons and
Waxwings are able to survive without this animal
protein. The effects of the absence of invertebrate
food on male Starlings were clearly shown by
Al-Joborae (1979) who found that while the testes
of birds fed on insects grew normally in spring,
the testes of those Starlings maintained on
a plant diet did not develop at all."
Reference:
Feare, Christopher. (1984). The Starling.
pages 56-57 and 204-205
To feed or not to feed the suggested dog food
diet?
Feeding an improper diet to wild baby songbirds
results in unhealthy birds. Rehabbers learned
through firsthand experience that feeding parrot
handfeeding formula to wild songbird babies resulted
in poorly developed feathers and poor weight gain.
Some birds who were raised on it were unable to
fly, while others died. We already know that wild
baby songbirds need animal protein in order to
develop properly, and that is where the dog food
based diet comes in. This diet which is suggested
on this website is one commonly used by wildlife
centers across the country. In fact, when doing
an online search about what to feed a wild baby
bird, it is amazing how many wildlife rehabber
sites show up listing variations of the dogfood
diet or a cat food diet for baby songbirds.
Perhaps
the thought of feeding baby birds a diet mixture
based on a food formulated for canines may seem
strange to new starling owners. But the dog food
mixture has been found to supply the protein,
vitamins, and minerals necessary for healthy baby
songbirds. This diet has had very good success
with thousands of birds under rehabbers' care.
Also, countless pet starlings, some whose owners
post at the Starling Talk Message Board, have
been thriving on this diet (supplemented with
fresh veggies) for years. Until much more research
has been done, possibly leading to a food formulated
specifically for captive European starlings,
it seems wise to stick with the dog food diet
proven to raise healthy starlings.
Ultimately
everyone will choose what to feed their own starlings.
But before choosing a diet for a captive baby
or adult starling, it is necessary to have a basic
knowledge about the bird's nutritional needs.
Where to find more info about diets for baby and
adult starlings--
Please
read the article, "Diet
of the Wild European Starling", for
detailed information about starlings' diets in
the wild.
Info about the suggested diet for starling nestlings
is at the following webpage: Starling
Talk's Baby Starling Care
A webpage giving complete info about diet for
adult pet starlings is here: Starling
Talk's Adult Starling Diet
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