Winter Ecology

Why is it cold in winter?

• We’re farther away from the sun?

NO!!

• We’re tilted away from the sun?

YES!!

Scranton, PA

Scranton, PAWeather Records

Types of Snow Crystals:

The most basic snow crystal is a hexagonal prism and can come in many shapes and sizes.

The prism has 8 sides: 2 surfaces known as basal facets and 6 prism facets.

How does a dull hexagonal ice crystal make such beautiful and elaborate flakes? The intricate flakes come from the condition in which the ice crystals are formed.

Types of Snow Flakes

Simple Prisms

Plates

Stellar Dendrites

Fernlike Stellar Dendrites

Columns, Needles and Capped Columns

Triangular Crystals

12 Sided Snowflake

Life History of a Snowstorm

• Powder

• Destructive metamorphism

• Constructive metamorphism

• Melt metamorphism

Powder

Destructive Metamorphism

Quin-zhee- Athabascan origin

Constructive Metamorphism

• Temperature gradient in snowpack…where is it warmer, top or bottom?

• Ice sublimates, vapors moving up• Warmer top melts a little, joining grains as it refreezes• Lower sublimation continues, leaving depth hoar

• Creates subnivean zone• Destabilizes snow pack…avalanche danger!

Scranton, PA….

A Winter Vacationland?

Northern Shrike

Common Redpoll

Evening Grosbeaks

“Flying Pigs”

Short-eared Owls

Rough-legged Hawk

What Do Organisms Do in Winter?

• Die

• Migrate

• Hibernate

• Stay and tough it out!

DIE?

DIE?

Why Migrate?

The Pro’s

?The Con’s

• DANGEROUS! (more than half never return)

• DANGEROUS!! (going to unknown area; hiding places, food sources, etc.)

• DANGEROUS!!! (already inhabited with competitors)

Who Migrates?Many organisms do . . .

. . . Even Mammals

Stay and Tough it Out

http://www.youtube.com/watch?v=D2SoGHFM18I

Freeze

What do ‘herps’ do in winter?

Avoid Freezing

Garter Snake hibernaculum in Canada

Winter Insects

Winter Insects and Invertebrates

Animal Tracks in the Snow.

Opossum

Pacer

Beaver

Black Bear Tracks

• Pacer• Front 5 in. L X 5 in. W

• Hind 7 in L X 5 in. W

Bobcat

• Notice you don’t see any claws.

Diagonal Walker

Coyote

• Diagonal Walker • Notice the claws

Raccoon• Pacer

Gray Squirrel

• Gray Squirrel are Hoppers.

Wild Turkey

Diagonal Walker