54 Nebraskaland • June 2020
of cygnets produced each year was
declining. Therefore, locating swan
nests was the other part of this study.
We needed to determine how many
nests resulted in eggs being laid, how
many eggs hatched and how many
cygnets made it to flight stage.
Capturing, collaring and following
these birds would help us answer
these questions.
Biology and Background
Trumpeter swans are the largest of
waterfowl, and even claim the title of
largest native bird in North America.
Males, also known as cobs, typically
weigh between 24 and 28 pounds and
stand about 4 feet tall, with females
being only slightly smaller. Their
corresponding wingspan is also large,
reaching up to 8 feet. Trumpeters are
solid white except for their bills and
feet. Cygnets have grayish plumage,
which they keep for a year. On rare
occasions, cygnets will display white
plumage similar to their parents.
Trumpeters can be distinguished
from their close cousins, the tundra
swan, by having a totally black bill,
with a little pink or red on the bottom
jaw. Tundra swans have a yellow
marking at the base of their bill,
just in front of the eye. Non-native
mute swans have pinkish bills and a
distinctive head shape, with a bulging
knob at the base of the beak.
Swans are long-lived and known to
have reached age 24 in the wild and
age 33 in captivity. They will pair for
life, but most will obtain another mate
if one perishes. They don't breed until
they are 3 to 6 years old. Their nest sites
are located overwater and typically
start with muskrat huts on which
adults build the nesting structure.
Swans are quite territorial and only on
the largest lakes or marshes will there
be more than one pair nesting. Despite
being big white birds, they are adept at
hiding themselves and their nesting
sites among the cattails and bulrushes.
Females will lay 4 to 6 eggs during
late April or early May and incubate
them for about 35 days. It takes
Mark Vrtiska, waterfowl program manager with the Nebraska Game and Parks Commission, prepares to net a swan
from an airboat on Ballards Marsh Wildlife Management Area in Cherry County.
