migration• Migration is another option for animals that

can move across long distances. They survive by leaving the area for part of the year or part of their life, and move to habitats that are more hospitable.

Why, Where, How??• Animals migrate to change climates and

avoid harsh conditions

• They go some place warmer (usually the same spot, for a given species, each year)

• They fly, swim, walk

• They travel on instinct (birds may use landmarks)

• When temperatures drop, instinct tells them when to begin.

rufuos hummingbird

hibernation• Hibernation is commonly regarded as

passing the winter in a state of lethargy, a defense against cold and food shortages, but it is not quite that simple. During hibernation, animals dramatically reduce their metabolic and heart rates and lower their body temperatures.

More about hibernation

• Animals whose body temperature drops to about 41° Fahrenheit (5° Centigrade) and who go into an inactive state that lasts for weeks or months are the deep, or classic, hibernators. One example is the marmot, which spends six to seven months (longer than any other animal) hibernating in a subterranean retreat with many fellow marmots huddled together for warmth.

Why, Where, How??• Animals hibernate to avoid harsh

conditions and lack of food

• They will either “bulk up” by eating a lot or store food for winter

• Beginning and ending may be different but the signal is temperatures dropping and thawing.

marmot

torpor• Animals which do not reduce body

temperature dramatically go into a state called "torpor" Periods of inactivity range from a few hours to a few days, but may stretch out to several months. Black bears, one of the better known examples of animals which hibernate in a torpor, do not go into true hibernation because of their large size and excellent insulation. Torpid bears can wake up and amble away if disturbed.

black bear

short –term torpor• Short-term torpor is the most common.

Many small desert mammals, such as kangaroo rats, ground squirrels, rock squirrels, prairie dogs and chipmunks respond to food scarcity in winter by slowing down their internal processes for hours to days. This generally occurs after foraging and is more severe than sleep. “Snackers”

kangaroo rat

dormancy• Wood frogs exemplify the first group of freeze-

tolerant animals. As the temperature drops, these frogs produce an antifreeze, which allows them to control where and when ice forms. With this control, frogs can ensure that ice does not form within their cells, which would kill them, and they can prepare their metabolism to be turned off. When frozen, a wood frog neither breathes nor bleeds, and has a barely recordable heart beat. Once temperatures climb, all functions return. The frogsicle becomes a happy hopper.

Arizona toad

What is Estivation?

• Drought/summer time “hibernation”

• During dry or extremely hot periods of time

• Spade foot toad, squirrels, desert tortoise, spiders, and more.

estivation• Just as animals hibernate in order to stay alive in cold

places, animals estivate [or aestivate] in hot, dry places.  The bodies of estivators will slow down.  Breathing and heartbeat get very slow.  The animal doesn't need as much food and water to live since food is fuel for energy and they aren't using much.  Reptiles use 90-95% less energy when they are estivating.  Animals don't move, grow or eat during this time.    When hot and dry times come, estivators will find themselves a safe place to sleep--usually underground.  This is the only way some animals can live through high heat and no water.

• The desert tortoise estivates; it eats cacti, grasses, and wildflowers from March until June, and then retreats to an underground burrow for the heat of the summer. In the cooler fall, the tortoise emerges to eat and drink. Some desert squirrels and spiders also estivate in response to food scarcity.

desert tortoise

Dormancy• Plants way to “hibernate”• Drop leaves• Do not use as much

water• Photosynthesis is

temporarily stopped or reduced.

Annuals

• Annuals live for only one season. They do not come up a second year from roots or crown.

• Must produce seeds before they die

• Wildflowers

Perennials• Live over from year to year, producing leaves and stems for more than 2 years from the same root system.

• Look dead during the winter, come back in the spring

• Verbena• Hydrangea

Deciduous• Deciduous

plants will drop their leaves.

• Maple, oak, cottonwood, aspen, etc.

Evergreens / Conifer

•Stays green

•Has needles rather than leaves

•Tolerate cold