Mute Swan was introduced to the United States in the late 19th century
(1), primarily for its
ornamental value. Like many such actions, it has manifested into unintended
consequences and has become viewed by many as an invasive species due to its
increasing population and aggressive behavior. Mute Swans
have affected not only native bird species by displacing them but also
aquatic animals due to their feeding on large amounts of aquatic vegetation
used by fish and invertebrates.
Growing up on Long Island, NY, I had plenty of
opportunities to view these birds. They can be very aggressive – I have
watched Mute Swans chase dogs, geese and people not only from their nests
but just because their “space” was invaded. These are easy birds to observe
since they are use to people – yet they need their space. Even if you are
motionless a bird that approaches should be treated with a lot of respect.
The male Mute Swan is known as a “cob” while the female
is known as a “pen”.
Mute swans become sexually mature when they are two
years old, but often will not begin breeding until they are three, four, or
even five years old.
The Mute Swan is reported to mate for life. However,
changing of mates does occur infrequently, and swans
remate if their partner dies. If a male loses his mate and pairs with a
young female, she joins him on his territory. If he mates with an older
female, they go to hers. If a female loses her mate, she remates quickly and
usually chooses a younger male.
In spring Mute Swans build nests that look like large
mounds with waterside vegetation. Female Mute Swans lay an average of 6
off-white to pale green eggs but can produce as many as 11
(2). Incubation takes about 35 days. The hatchlings are
called “cygnets”. Within a few days they leave the nest and are able to feed
themselves. They stay with the parents for a few months. Cygnets can fly at
about 4-5 months of age and are considered "juveniles" at that time.
Mute Swans are unmistakable; there is really no bird in the eastern US that
look like it. They are the largest birds on the water measuring 50”–60” long
with a wingspan that is between 80”-94” long (over 7’). They are also heavy
weighing between 12 – 30 lbs. The coloration of a mature bird is all-white
with an orange bill (with some scant black markings) and a black front to
their face. Their legs are black.
They have a black “knob” on the top of their bill.
Immature mute swans can be dirty gray or white. Their
legs are gray to pink. The bill is gray or tan
Lakes, Ponds, shallow coastal ponds, estuaries, ponds, bogs, and streams
flowing into lakes.
The natural range of the Mute Swan is in temperate areas of Europe across
In its natural range, Mute Swans do migrate to a point.
on a wide range of vegetation, both submerged aquatic plants and grasses and
grains such as wheat.
Audubon Society Field Guide to North American
NYS Dept. Of Environmental