Common
Loon
The Common Loon in summer is very striking with its
black-and-white
checkered
back,
glossy
black
head,
white
belly
and
wing
lining,
and
characteristic
white
necklace
around
the
throat.
All
loons
have
grayish
feathers
in
the
winter,
and
immature
birds
tend
to
resemble
adult
birds
in
winter
plumage.
The
white
feathers
of
the
belly
and
wing
linings
are
present
year-round.
Loons'
habit
of
swimming
low
in
the
water
helps
to
distinguish
them
from
other
water birds,
such
as
ducks
and
geese.
Loons
most
resemble
the
grebes,
but
can
be
identified
by
their
larger
size,
thicker
necks,
and
longer
bills.
In
flight,
loons
can
be
recognized
by
their
humpbacked
profile,
with
head
and
neck
held
low
and
feet
pressed
back
towards
the
body
and
projecting
beyond
the
tail.
Both
males
and
females
look
the
same,
although
males
are
generally
larger.
Adults
are
large-bodied,
weighing
from
2.7
to
over
6.3 kg
and
measuring
almost
a
meter
from
bill
tip
to
outstretched
feet.
The
bill
is
quite
large,
averaging
75 mm
in
length,
and
is
black
in
color
throughout
the
year.
The
skeleton
and
muscular
system
are
designed
for
swimming
and
diving.
Loons
are
streamlined.
|
 |
Their
legs
are
placed
far
back
on
their
body,
allowing
for
excellent
movement
in
water
but
making
them
ungainly
on
land. The
head
can
be
held
directly
in
line
with
the
neck
during
diving
to
reduce
drag,
and
the
legs
have
powerful
muscles
for
swimming.
Many
bones
of
the
loon's
body
are
solid,
rather
than
hollow
like
other
birds',
aiding
in
diving
ability.
During
dives,
the
large
webbed
feet
provide
all
of
the
propulsion
and
the
wings
are
held
tight
unless
they
are
used
to
help
make
sharp
turns
while
chasing
prey.
Daily
life
Loons
spend
their
time
hunting,
feeding,
resting,
preening,
and
caring
for
young.
They
are
predators;
their
diet
in
summer
consists
of
fish,
crayfish,
frogs,
snails,
salamanders,
and
leeches.
Adult
loons
prefer
fish
to
other
food,
and
seem
to
favor
perch,
suckers,
catfish,
sunfish,
smelt,
and
minnows.
The
life
expectancy
of
the
loon
may
be
15-30
years.
The
bird
spends
long
rest
periods
motionless
on
the
water.
It
may
rouse
itself
to
stretch
a
leg
or
wing
at
intervals,
occasionally
comically
waggling
a
foot.
When
swimming
on
top
of
the
water
it
will
sit
erect
with
neck
slightly
curved.
The
loon
will
peer
underwater,
moving
its
head
from
side
to
side
to
locate
prey.
It
then
aims
and
dives
quickly.
It
will
stay
underwater
for
almost
a
minute
and
can
dive
to
depths
of
80
m.
During
the
dive,
feathers
are
compressed
and
air
is
forced
from
between
the
feathers
and
from
the
air
sacs
in
the
body.
Loss
of
air
from
the
air
sacs
also
allows
the
loon
to
quietly
sink
below
the
water
surface
to
avoid
danger.
| Adult
loons
may
fly
to
different
lakes
to
feed.
The
adaptations
that
make
loons
such
efficient
divers
also
make
them
heavy
and
slow
to
take
wing.
To
take
off
from
a
lake,
loons
run
along
the
surface
into
the
wind.
The
distance
needed
to
gain
flight
depends
on
wind
speed;
in
calm
times
the
birds
may
run
as
far
as
several
hundred
meters
before
they
gain
enough
speed
to
take
off. |
 |
Once
in
the
air,
the
loon's
relatively
small
wingspan
(130-140 cm)
carries
it
at
average
speeds
of
120 km
per
hour
during
migration.
The
wings
beat
quickly
to
carry
the
large
body
and
have
a
high
degree
of
curvature
to
provide
lift.
Common
Loons
spend
little
time
on
land
and
have
to
pull
themselves
onto
land
to
nest.
They
generally
move
one
foot
at
a
time
to
walk,
shuffling
along
with
their
breast
close
to
the
ground.
On
return
to
the
water,
the
loon
slides
in
along
its
breast
and
stomach.
At
night,
loons
sleep
over
deeper
water,
away
from
land
for
protection
from
predators.
Family
and
social
life
Loons
arrive
in
pairs
on
northern
lakes
in
the
spring
as
soon
as
the
ice
thaws.
Loons
are
solitary
nesters.
Small
lakes,
generally
those
between
5
and
50 ha,
can
accommodate
one
pair
of
loons.
Larger
lakes
may
have
more
than
one
pair
of
breeding
loons,
with
each
pair
occupying
a
bay
or
section
of
the
lake.
Until
recently,
loons
were
thought
to
mate
for
life.
Banding
studies
have
shown
that
loons
will
sometimes
switch
mates
after
a
failed
nesting
attempt,
even
between
nestings
in
the
same
season.
Courtship
and
mating
are
a
quiet
time,
with
the
pair
swimming
and
making
short
dives
together.
Eventually
the
male
leads
the
female
to
a
suitable
spot
on
land.
Nest
building
then
begins.
| Loons
build
their
nests
close
to
the
water,
with
the
best
sites
being
completely
surrounded
by
water,
such
as
on
an
island,
muskrat
house,
half-submerged
log,
or
sedge
mat.
Generally
the
birds
can
slip
directly
from
the
nest
to
water.
The
same
sites
are
often
used
from
year
to
year.
Loons
will
use
whatever
materials
are
on
hand
to
build
their
nests:
tree
needles,
leaves,
grass,
moss,
and
other
vegetation
have
been
found
under
loon
eggs.
If
material
is
not
handy,
loons
will
lay
their
eggs
directly
on
the
mud
or
rock
substrate.
Sometimes
clumps
of
mud
and
vegetation
are
collected
from
the
lake
bottom
to
build
the
nest.
Both
the
male
and
female
help
in
nest
building
and
with
incubation,
which
lasts
until
hatching,
usually
26-31
days.
If
the
eggs
are
lost,
the
pair
may
renest,
often
in
the
same
general
location. Usually
two
eggs
are
laid
in
June,
and
towards
the
end
of
the
month
loon
chicks
covered
in
brown-black
down
appear
on
the
water. |
 |
Loon
chicks
can
swim
right
away,
but
spend
some
time
on
their
parents'
backs
to
rest,
conserve
heat,
and
avoid
predators
such
as
large
carnivorous
fish,
snapping
turtles,
gulls,
eagles,
and
crows.
After
their
first
day
or
two
in
the
water,
the
chicks
do
not
return
to
the
nest.
|
Chicks
are
fed
exclusively
by
their
parents
for
the
first
few
weeks
of
life,
and
up
until
eight
weeks
of
age
the
adults
are
with
them
most
of
the
time,
providing
most
food.
After
this
time
the
chicks
begin
to
dive
for
some
of
their
own
food
and
by
11
or
12
weeks
of
age,
the
chicks
are
providing
almost
all
of
their
own
food
and
may
be
able
to
fly.
Chicks
are
fed
small
food
items
early
in
their
life
including
snails,
small
fish,
crayfish,
minnows,
and
some
aquatic
vegetation.
|
 |
As
they
grow,
they
require
more
protein,
and
usually
are
fed
more
fish,
if
available.
At
migration
time,
the
young
are
able
to
look
after
themselves,
and
the
adults
generally
leave
first,
with
young
following
soon
after.
The
voice
of
the
loon
Perhaps
one
of
the
most
fascinating
things
about
Common
Loons
is
their
haunting
and
variable
voice.
Loons
are
most
vocal
from
mid-May
to
mid-June.
They
have
four
distinct
calls
which
they
use
in
varying
combinations
to
communicate
with
their
families
and
other
loons.
These
are
the
tremolo,
wail,
yodel,
and
hoot.
The
tremolo
sounds
like
a
crazy
laugh
and
is
used
for
a
variety
of
purposes,
such
as
to
signal
alarm
or
worry
and
to
denote
annoyance
or
greeting.
The
wail
is
one
of
the
loveliest
of
loon
calls.
It
is
used
frequently
during
social
interactions
between
loons
and
may
be
used
to
regain
contact
with
a
mate
during
night
chorusing
and
in
answering
other
loon
tremolos.
The
yodel
is
given
only
by
the
male.
It
is
a
long,
rising
call
with
repetitive
notes
in
the
middle
and
can
last
up
to
six
seconds.
It
is
used
by
the
male
to
defend
territory
and
can
be
stimulated
by
another
male
entering
a
loon's
territory.
Studies
of
recordings
have
shown
that
the
yodel
is
different
for
each
bird
and
can
be
used
to
identify
individual
loons.
The
hoot
is
a
one-note
call
that
sounds
more
like
"hoo."
It
is
mainly
used
by
family
members
to
locate
each
other
and
check
on
their
well-being.
Click
on
the
links
below
to
listen
to
these
sounds.
Conservation
All
loons
are
protected
by
federal
law
and
may
not
be
hunted.
Although
loons
still
nest
in
large
numbers,
recent
studies
have
shown
cause
for
concern
about
low
breeding
success,
especially
of
the
Common
Loon.
Because
this
loon
nests
in
populated
areas
of
Canada
and
the
United
States,
it
is
susceptible
to
the
effects
of
pollution,
development,
and
disturbance.
Historic
data
show
that
loons
have
abandoned
some
of
their
former
nesting
areas
in
the
southern
parts
of
Canada
and
the
northern
areas
of
the
central
United
States.
Loss
of
breeding
habitat
and
disturbance
are
probably
the
main
causes
of
this
reduction
in
the
original
breeding
range.
Loss
of
habitat
results
from
lakeshore
development
and
spills
of
oil
and
other
pollutants.
Physical
interference
with
nests
or
young
and
increased
boat
wake
on
lakes,
which
may
swamp
or
destroy
nests,
also
cause
loons
to
abandon
some
nesting
sites.
Recent
studies
have
indicated
that
loon
nesting
success
and
survival
of
young
may
decrease
with
increased
lake
acidity,
the
result
of
acid
rain.
Acidity
can
result
in
decreases
in
fish
and
other
foods,
causing
loon
chicks
on
very
acid
lakes
to
starve.
Acidification
of
lakes
may
also
increase
the
rate
of
methyl mercury
production
by
microbes
in
lake
sediments
and
water,
resulting
in
higher
concentrations
of
mercury
in
the
food
chain.
A
significant
proportion
of
loons
found
dead
in
the
U.S.
and
Canada
has
high
concentrations
of
mercury
in
their
tissues.
Loon
die-offs
on
wintering
habitats
off
the
Gulf
Coast
of
Florida
have
been
linked
to
poor
body
condition
and
elevated
mercury
concentrations;
and
Canadian
research
has
demonstrated
that
loons
nesting
near
industrial
sources
of
mercury
pollution
occupy
few
potential
territories
and
lay
few
eggs,
resulting
in
poor
reproductive
success.
Increased
methyl mercury
concentrations
in
fish,
the
loon's
main
food
source,
is
the
result
of
environmental
mercury
pollution,
acidification,
and
flooding
of
forested
land
for
hydroelectric
development.
These
activities
pose
a
threat
to
the
health
and
reproductive
success
of
loons
in
many
locations
throughout
their
range.
Loons
are
also
dying
of
lead
poisoning
after
eating
fish
with
lead
sinkers,
and
possibly
after
picking
up
discarded
sinkers
from
lake
bottoms.
The
lead
is
partially
dissolved
in
the
loon's
gizzard,
then
absorbed
into
the
blood
and
body
tissues.
The
absorbed
lead
causes
nerve,
kidney,
and
other
tissue
damage.
North
American
studies
indicate
that
a
significant
proportion
of
adult
loon
deaths
on
the
breeding
grounds
is
attributable
to
lead
poisoning
from
ingestion
of
sinkers.
Abandoned
or
unattended
fishing
line
and
hooks
also
cause
loon
injury
and
death.
To
protect
the
loons
on
lakes
we
visit,
boats
should
be
kept
well
away
from
swimming
birds,
particularly
when
they
are
with
chicks
that
are
too
young
to
dive
or
fly.
Some
shoreline
areas
should
be
left
undisturbed
to
accommodate
loon
nests,
and
boaters
passing
these
areas
should
travel
at
speeds
that
do
not
cause
wash.
Seaplanes
should
come
and
go
as
far
from
nesting
areas
as
possible,
taxiing
to
other
parts
of
the
lake.
Anglers
have
the
responsibility
of
using
non-lead
sinkers
and
of
ensuring
that
no
hooks
or
lines
are
left
unattended
or
abandoned.
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