Download Bobcats among state`s most elusive mammals

WALK
ON THE
WILDSIDE
The Minnesota Conservation Federation
December 2013
Bobcats among state’s most elusive mammals
T
he bobcat is Minnesota’s most common wild cat species, but
few people ever see one.
Minnesota represents
the northern limit of the
bobcat’s North American
range and it inhabits mainly the northern forests of
the state, roughly north
and east of a line running
from Hinckley to Warroad.
The bobcat’s Minnesota
population is estimated at
around 2,000.
The bobcat is a close relative of
the Canada lynx, which is found
in the northern most reaches of
Minnesota. Although the two big
cats are similar in appearance, the
bobcat is a bit smaller, and has
smaller feet and a longer tail. Unlike the lynx, which feeds mainly
on snowshoe hare, the bobcat has
a more diverse diet. It eats a wide
variety of small- to medium-sized
mammals and also preys on deer.
A 30-pound bobcat may seem an
unlikely predator for a much larger deer, but bobcats are able to
pounce on the deer and puncture
their jugular vein to bring them
down.
Another prey the bobcat has
been known to attack is porcupine,
which has sharp quills that deter
most predators. Porcupines are
often found in trees so they are
fairly easy prey for the adept
climbing bobcat. The bobcat is not
are not particularly fast runners.
however, immune to the porcupine’s sharp quills. Researchers
have discovered bobcats that were
killed when vital organs were
pierced by the quills.
Bobcats also have been known
to attack other larger mammals
like fishers and coyotes, and even
large birds like eagles and hawks.
As with many predators, the
bobcat feeds mainly during the
low-light hours of dusk and dawn,
but does hunt during the day in the
winter.
The bobcat depends heavily on
its keen eyesight and stealth in
capturing its prey. It often surprises its prey by pouncing on it. In
many cases, the prey doesn’t see
the bobcat until it is too late. If an
animal does spot a bobcat, before
it is attacked, it has a decent shot
at escaping. Bobcats have difficulty chasing down their prey, especially in deep snow, because they
Because bobcats eat a variety
of mammals, they prefer a
habitat with a wide range of
wildlife. They are often
found in aspen and coniferous forests, and cedar
swamps — areas where deer
tend to congregate during the
winter. They prefer a habitat
away from humans, which is
one reason few people ever
see them. However, they
may be lured to rural homes
by easy prey like house cats, small
dogs and poultry.
Bobcats tend to stake out a
large range and hunt within it. A
male bobcat’s range is typically
about 20-25 square miles, while a
female has a range of about 10-15
square miles. This wide range
makes it especially difficult for
hunters and trappers to locate a
bobcat, even when one is nearby.
Bobcat facts
► Bobcat kittens, which typically number two or three, are
born between April and July. They
stay with their mother until the
following winter.
► Bobcats got their name from
their relatively short tail, which
looks like it has been bobbed.
► Bobcats den in hollow logs,
under tree roots, caves or other
secluded shelters.
Listen to chickadee chatter this winter
A
nyone who
has spent any
time watching wildlife
in Minnesota has certainly encountered the
black-capped chickadee.
Often described as
cute, tough, feisty and
cheerful, the blackcapped chickadee is
one of Minnesota’s
most common yearround residents. Most
people know chickadees eagerly visit birdfeeders and
show a remarkable tolerance to
humans, but these cute little birds
have one of the most complex
communal lifestyles of any bird in
the state.
In the late summer and early
fall, chickadees form flocks,
which usually consist of between
six and 10 birds of different ages
and genders. Within the flock
there is a pecking order with the
oldest male as the leader and the
youngest birds at the bottom.
A flock of chickadees carves
out a territory of about 20 acres,
which they move about in looking
for food and shelter. The flocks
stay together until the late winter
or early spring when they begin
breaking up in preparation for the
mating season.
To exist within the flock, the
chickadees have developed a language or series of calls that help
keep the flock together, warn of
danger, assert dominance or show
aggression. In all ornithologists
have identified about 15 different
calls used by chickadees. Among
the most commonly heard call is
chick-a-dee-dee, which is used in
a number of situations, including
when a bird is separated from the
flock, when food is found or when
where they quickly hop
from branch to branch and
can even be seen hanging
upside-down on a branch
eating insects, seeds or berries.
danger is past.
Another common call is feebee, which the dominant male uses to lead the flock or during territorial disputes.
If you listen closely you can
also hear the tseet call, which is a
contact call used to keep the flock
together.
When a chickadee give a rapidly repeated high see sound, it
means danger is approaching and
the flock should beware.
If you spot a flock of chickadees, sit down quietly nearby and
listen to their chatter. Watch their
actions and try to figure out what
they are talking about.
Identification
In contrast to some of Minnesota’s other year-round birds like
the goldfinch or cardinal, it is difficult to distinguish male chickadees from females. Males are
slightly larger than females, but
without close inspection, it is
nearly impossible to tell the difference between the two genders.
It is often easy to identify
chickadees, even from a distance,
by their flight pattern, which is
ungulated with rapid wing beats.
They also are easy to spot in trees
The black-capped chickadee belongs to the titmouse
family, which also includes
a variety of other chickadee
species that live in other
portions of North America,
including the Carolina
chickadee.. The blackcapped chickadee’s closest
relative in Minnesota is the tufted
titmouse.
Foods
During the winter months
chickadees eat both animal and
plant matter in equal parts. They
eat insects, caterpillars, spiders,
seeds and berries.
During the autumn, chickadees
will store food for the winter in
bark, knot holes, leaves, conifer
needles and dirt, but no storage
site is used for more than one food
item. This method of storage is
called scatter hoarding. It may
seem amazing, but chickadees
have an incredible memory that
helps locate the dozens upon dozens of places they have stored
food. They also remember the
storage sites they have taken food
from and which ones still hold
food.
Life span
The average chickadee lives
just 2.5 years, but some live much
longer than that. The oldest chickadee ever recorded was more than
12 years old.
The most common causes of
death for chickadees are starvation
during the winter months and predation.
Birds adapt to survive in cold and snow
S
ome people love
Minnesota’s winter,
while others try to escape it
by traveling to warmer climates. The same is true for
birds.
thing they can find that is
edible. Crows will eat anything from dead animals to
human garbage to survive.
Many of Minnesota’s
bird species have adapted to
life in the cold and snow,
while others migrate south
for the winter.
Most of the birds that
leave Minnesota during the
winter are driven to warmer
climates in search of food, which
is no longer available when the
cold and snow move in. A good
example is the barn swallow,
which feeds primarily on flying
insects. When it becomes too cold
for the insects, flies south.
Birds that winter here can be
divided into three categories. The
first lives in the same region
throughout the year. These include
chickadees, nuthatches, cardinals,
bluejays and gold finches.
The second group is found in
our state only during the winter
months. They spend the rest of the
year in the far north and migrate
south to Minnesota during the
winter to escape even worse winter conditions. This group of birds
includes the junco, common redpoll and snowy owl.
The third category of winter
birds includes those that stay here
only as long as food is available
and the weather remains favorable. Mallard ducks and Canada
geese, for example, will stay here
as long as they can find open water. Robins, mourning doves,
hawks and bald eagles are among
the other birds that will remain in
Minnesota as long as food is still
available.
For the birds that do spend the
winter months in Minnesota, finding a source of food is the most
important factor in survival. The
food available to birds also can be
divided into three categories.
The first type of winter food,
and the most plentiful, are seeds
and berries. Tree and plant seeds
and dried berries are everywhere
and provide reliable sources of
food until spring arrives. Gold and
purple finches, chickadees, sparrows and nuthatches are just a few
of the birds that depend heavily on
seeds and berries to survive the
winter.
Another source of food is other
creatures. Insects, although rarely
seen by humans during the winter,
also provide a stable source of
food for birds. Many insects hibernate in the bark of trees and birds
like woodpeckers, chickadees and
nuthatches remove the insects
from their hiding places.
Other birds eat small mammals
or other birds. Owls and hawks eat
mice, voles, rabbits and squirrels.
The sharp-shinned hawk, for example, depends heavily on small
birds as a food source.
A third source of food available
during the winter is sought after
by scavenger birds. Crows and
gulls, for example, feed on any-
Most of the birds that winter
in Minnesota know how to
survive in the cold and snow
and do quite well, even in the
most unbearable conditions,
but some birds ability to survive is directly connected to
the severity of the winter.
Pheasants do not survive well
in harsh winters with heavy
snow, because it makes it difficult
for them to find food. Wild turkey
also have difficulties finding food
when snow becomes too deep.
But not all birds dislike the
snow. The ruffed grouse depends
on snow to survive. The bird burrows down in the snow and uses it
as insulation to protect it from the
cold when it sleeps.
Other species of birds use different resources for shelter during
the winter. Chickadees or juncos,
for example, find shelter among
the thick branches of spruce trees,
which protect them from the wind
and cold. Some birds roost in the
hollows of old trees to protect
them from the elements, while
others like mallard ducks and
Canada geese depend on their
warm feathers.
A helping hand
Minnesota’s bird species can
survive winter pretty well on their
own, but providing another source
of food in your backyard helps
assure their survival, especially if
you live in areas where natural
foods are in short supply.
Seeds, suet, corn and peanuts
are among the best foods to offer
birds during the winter.
Where do frogs and turtles go during the winter?
D
uring the winter when
temperatures drop and
the snow flies, humans can
keep warm by putting on a
coat, hat and gloves. Because
humans and other mammals
are warm-blooded, meaning
we produce heat, we can
maintain our core temperature
by adding insulation. For humans it is clothes, for a hare,
deer or fox, it means growing
a thick winter coat.
Reptiles and amphibians are
different. They are cold-blooded
creatures, meaning they don’t produce any heat of their own and are
dependent on the air, water or
ground to stay warm. During the
Minnesota winter, it is impossible
for reptiles and amphibians to stay
warm enough to remain active.
When they get cold, everything in
their body slows down, even the
heart and lungs. When it gets so
cold they can no longer eat or digest food, reptiles and amphibians
go into hibernation.
Turtles
If you live near a pond or lake,
you may see turtles everyday during the spring, summer and fall,
but where do they go in winter?
When winter approaches, turtles swim to the bottom of a lake
or pond and plant themselves at
the bottom in the mud and leaves.
Their heart slows to the point
where it is only beating once eve-
ry few minutes. Breathing nearly
stops, but the turtle is still taking
in oxygen. During the summer, a
turtle must rise to the surface to
get oxygen, but in hibernation, it
gets the oxygen from the water.
Oxygen is absorbed through special cells in the linings of their
mouth and throat. The turtle
doesn’t need to eat anything during the winter, because its metabolism is nearly shut down.
This process helps water turtles
survive the winter in most cases.
However, if the ice on a pond
freezes all the way to the bottom
turtles can freeze and die. Also,
turtles can die when decomposing
plants beneath the ice use up all of
the oxygen, which causes fish, turtles and other aquatic creatures to
suffocate.
Frogs
Like turtles, frogs spend the
winter at the bottom of a pond or
lake. Like the turtle, the frog’s
vital systems slow to almost
nothing. Frogs take in the little
oxygen they need through their
skin. However, while turtles burrow into the mud at the bottom
of the pond, frogs cannot. If they
did, they would suffocate, because they would not be able to
take in enough oxygen to survive. Frogs usually just lay at the
bottom throughout the winter.
Snakes
As with the turtle, a snake’s
metabolism slows down to near
nothing in the winter.
Snakes spend the winter
months in underground dens, usually with a group of other snakes.
The dens are usually far enough
underground that the temperature
remains just above the freezing
point.
Salamanders
As winter approaches, the salamander finds a place underground
to hibernate. Usually this is an old
burrow dug by a mammal. In
some cases, the salamander digs
its own burrow. The burrow must
be beneath the frost line in the
ground in order for the salamander
to survive.
Salamanders usually emerge
from their winter dens when they
feel the first rains of spring.
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