Animals over Winter
• Temperature decreases
– As low as −50°C in the
Arctic! Sometimes even
colder!
• Hours of daylight decrease
– In some places it is dark for
over four months!
• Increased rain and snowfall
– (especially in the northern
hemisphere)
How do habitats change?
• Food supplies may be harder to find
American bison in summer habitat
http://www.arkive.org/american-bison/bison-bison/video-bi02.html
American bison in winter
Brrr – it’s cold!
What do animals do in winter?
• Migrate
• Hibernate
• Stay in the area and:
- Store food
- Change their appearance
- Change their behaviour
Polar bear sleeping in the snow
Animals
can…
Complete the worksheet
Answers!
• This means: to move from one region, country or climate
to another
• In winter, migrating animals normally move from a colder
climate to a warmer one
Migration
Snow geese being taught to migrate by following
a microlight aircraftSnow geese migrating: flying in a ‘V’ formation
• Migrate to a warmer
climate in winter
• Spend spring and
summer in the Arctic
(Alaska, Greenland, Canada)
• Fly south to a warmer
climate in autumn
• Overwinter in Mexico and the Gulf Coast
• Some birds fly all the way in one flight!
- 1,700 miles in 70 hours
Snow goose: Migration case
study
Snow geese migrating
Monarch butterfly: Migration
case study
• Longest known insect
migration
• North American and Canada
populations migrate southward
to overwinter
- Up to 3000 miles!
- Cover 80 miles per day!
• Millions of individuals roost
throughout winter in a state of
relative inactivity
• This means to go into a
dormant (torpid) state
over winter
• Sliding scale of hibernation:
- Some animals hibernate
throughout winter
- Some animals wake up to
feed
Hibernation
Brown long-eared bat hibernating
• Body temperature drops
• Metabolic rate slows
• Breathing and heart rate
decreases
• Live off stored fat reserves
• Can lose up to 40% of
body weight
True hibernation
Common dormouse hibernating
• Unique amongst mammal
hibernators as their body
temperature drops to -3ºC!
• Every few weeks they warm up
slightly by shivering
- Possibly to prevent brain
damage
• Risky strategy:
- Some Arctic ground squirrels
never wake up
True hibernator: Arctic
ground squirrel
Arctic ground squirrel
True hibernator: painted turtle
Painted turtle
• Spend winter
hibernating at the
bottom of a river bed
• Can hibernate for
up to six months
• Use a ‘natural
antifreeze’ to prevent their blood from
freezing
• Body temperature drops
(but often not as low as true
hibernators)
• Breathing and heart rate
slow (but often not as slow
as true hibernators)
Partial hibernation
Brown bear: a full and partial hibernator
• Can be more easily woken than true hibernators (can
wake up in case of danger)
• Awake to feed, drink and even walk around
Animals which stay in the same area and change their
behaviour or appearance rather than hibernating or
migrating.
Reindeer in winter coat
Resident animals
• Store food
• Change their diet
• Change their coat
colour
• Grow a thicker coat
• Lay down a thick layer of fat
• Decrease their metabolic rate
What can resident animals do?
Skunks change their diet in winter
Arctic fox: Adaptations to
the survive the winter
Arctic fox in winter coat Arctic fox in summer coat
What about species that live in even
colder places?
Thick layer of fat
(blubber) under the
skin for insulationThick skin
Huddle
together for
warmth
Tightly overlapping
feathers for waterproofing
and warmth
Large body
size (loses
less heat)Cold feet!
Light-coloured
fur
Thick layer
of fat
under the
skin
Black skin
(retains heat)
Large body size to
minimise heat
lossLarge feet
to spread
weight on
ice/snow
Stiff hairs on feet to
protect from the cold
and provide grip
Small ears
and tail to
reduce
heat loss
Hollow fur
to trap air
for
insulation
‘Waking
hibernation’
Any Questions?
Let’s move on to the activity…
Activity
• Choose one of the species from the list.
• Make a poster about your species. What is it called? Where does it live?
• Using the ARKive website and other websites, find out about the different adaptations your species has to survive winter.
• Draw a picture and explain the different adaptations your species has to survive… – Does it migrate?
– Does it hibernate?
– Does it grow a thick coat?
– Does it store food?
• Bar-headed goose
• Grey squirrel
• American bison
• Stoat
• Arctic tern
• Dormouse
• Garter snake
• Blue whale
• Arctic fox
• Skunk
• Brown bear
• Swallow
Species to choose from