What do Energy Pyramids tell us?

The importance of the Spotted Owl

Energy Pyramids show the flow of energy through an ecosystem

Ecologists study energy pyramids

3rd level consumers mostly carnivores & some omnivores

2nd level consumer carnivores & omnivores

1st level consumer herbivores

Producers: green plants make their own energy from sunlight

10,000 Kcal

1000 Kcal

100 Kcal

10 Kcal

1 Kcal

An energy pyramid from the Andrews

10,000 Kcal

1000 Kcal

100 Kcal

10 Kcal 0.1%

1%

10%

100%

1 Kcal 0.01%

When an owl eats a flying squirrel it uses about 90% of the calories to live—

move, digest, produce body heat, reproduce and escape from predators.

When a frog eats a cricket or a cricket eats a plant, they use 90% of those calories to move, digest, produce

body heat, reproduce and escape from predators.

Bushy tailed

wood rat

Red-backed

voles

Deer Mouse

Chipmunk

Red Tree Vole

Flying Squirrels are about half the owl’s diet

Spotted Owls need a largehome range. Home range is

the name ecologists give the amount of living area animals need to hunt enough prey to survive.

You can tell how healthy an ecosystem is by the number of 3rd level consumers living there. If there is not enough energy (prey) inan ecosystem

the area won’t be able to support 3rd level consumers.

Brush Rabbit

Snow Shoe Hare

Spotted Owls are 3rd level consumers

Spotted Owls mate for life. They live about 10 years. Mating pairs usually return to the same nest every summer to raise their young. When winter comes, the young leave the nest and mating pairs separate to find their own home range because prey is scarce.

Young Spotted Owls are born in nests at the top of tall snags.

They become fledglings when they

are old enough to leave the nest and fly

After two months the fledglings leave home

and find their own mate and home range.

around the nest area.

Northern Goshawk

Great Horned Owl

Barred Owls

Spotted Owl predators and competitors include the Northern Goshawk and the Great Horned Owl and The Barred Owl. These birds attack Spotted Owls, prey on their young, compete for prey and try to drive them out of their home range.