1. Over Wintering
By Mr. “Freeze Me” Chapman

2. Over wintering
 Amphibians have developed many different
ways to survive the harsh winters.
 3 different types:
 1. Sleep at bottom of ponds
 2. Sleep underground
 3. Freeze Tolerance

3. Bottom of Ponds
 When weather becomes
cold, frogs like
bullfrogs and green
frogs find a pond.
 They will move to the
bottom of the pond and
sleep/lay at the bottom
until spring.

4. How do they survive?
 The water is cold and will hold lots of oxygen,
so the frog can absorb oxygen through skin.
 Frogs are cold blooded, so their body is cold
and barely functioning, so they do not need
any food.
 Frogs will lay at the bottom of the pond, until
the water warms up and wakes them up.

5. Sleeping Underground
 Some amphibians like toads use their back feet
to dig a hole in the ground to sleep in all
winter.
 They must make sure they bury themselves
below the frost line, or the will freeze and die.

6. How do they survive?
 The air is cold and hold lots of oxygen and the
toad absorbs oxygen out of the air.
 Same as before, they are ectothermic and do
not need any food. Their body is barely
functioning.
 They will stay in the ground until their body
warms up to a specific temperature.

7. Freeze like a Ice Cube
 This is done by wood frogs, grey tree frogs,
and spring peepers.
 These frogs find a good place to hide like
under leaves or bark on trees.
 Then they lay and wait for the winter.

9. Freeze Tolerance
 When the temperature starts to fall these frogs
start to produce glucose (sugar) in their bodies.
 The important thing is that the glucose is not
produced inside the cells, but outside of the
cells in the spaces in between the cells.
 This cause osmosis, which means the majority
of the water in the cells moves out of the cells
and into the area in between the cells.

11. Freeze Tolerance
 The Glucose does 2 things:
 1. lowers the freezing temperature at which the
water would freeze (32 to 16).
 2. Removes water from cells.
 The skin of the frog can withstand the
expanding water and will not burst.

13. Freeze Tolerance
 As the weather warms up the ice inside the
frog will melt and the water will move back
into the cells.
 Then the frog will then wake up and will go
and search for food.