Animals over Winter How do habitats change Temperature

Animals over Winter

How do habitats change? • 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) • Food supplies may be harder to find

American bison in summer habitat

http: //www. arkive. org/american-bison/bison-bison/video-bi 02. html American bison in winter

Brrr – it’s cold! What do animals do in winter?

Animals can… • Migrate • Hibernate • Stay in the area and: - Store food - Change their appearance - Change their behaviour Polar bear sleeping in the snow

Complete the worksheet

Answers!

Migration • 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 Snow geese migrating: flying in a ‘V’ formation Snow geese being taught to migrate by following a microlight aircraft

Snow goose: Migration case study • 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 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

Hibernation • 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 Brown long-eared bat hibernating

True hibernation • Body temperature drops • Metabolic rate slows • Breathing and heart rate decreases • Live off stored fat reserves • Can lose up to 40% of body weight Common dormouse hibernating

True hibernator: Arctic ground squirrel • 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 Arctic ground squirrel

True hibernator: 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 Painted turtle

Partial hibernation • Body temperature drops (but often not as low as true hibernators) • Breathing and heart rate slow (but often not as slow as true hibernators) 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

Resident animals Animals which stay in the same area and change their behaviour or appearance rather than hibernating or migrating. Reindeer in winter coat

What can resident animals do? • Store food • Change their diet • Change their coat colour • Grow a thicker coat • Lay down a thick layer of fat • Decrease their metabolic rate 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 skin Cold feet! Huddle together for warmth Thick layer of fat (blubber) under the skin for insulation Large body size (loses less heat) Tightly overlapping feathers for waterproofing and warmth

Light-coloured fur Hollow fur to trap air for insulation Thick layer of fat under the skin Black skin (retains heat) Large body size to minimise heat loss Large feet to spread weight on ice/snow Small ears and tail to reduce heat loss Stiff hairs on feet to protect from the cold and ‘Waking hibernation’ provide grip

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?

Species to choose from • • • Bar-headed goose Grey squirrel American bison Stoat Arctic tern Dormouse • • • Garter snake Blue whale Arctic fox Skunk Brown bear Swallow