Winter Ecology
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Transcript of Winter Ecology
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