Survival Strategies for Plants and Animals

Peter Marchand Founder of the Winter Ecology classes at the College level. “Life in the Cold” Premier researcher and teacher of Winter Animal/Plant Adaptations.

Three Options for Overwintering Success Migration Hibernation Resistance

Migration The instinctive seasonal movement of animals. Ex. = birds, whales, elk.

Resistance Animals and plants develop strategies to live in the cold. Special characteristics and adaptations. Musk Ox

Resistance Examples Evergreens - push water into extracellular spaces. Prevents freezing and bursting of living cells. Ice crystals can then form between cells.

Resistance (cont.) Maple Trees –Transfer sugar water to the roots in the winter. –Travels back up in the spring to provide energy for bud development.

Resistance (cont.) Spruce Grouse - has extra scales to hold onto icy branches. Caribou, snowshoe hare, lynx - large feet. Ptarmigans - feathers covering feet.

Resistance (cont.) Lynx –large feet, act like snowshoes. –Can keep up with prey better.

Resistance (cont) Wolverine in winter.

Resistance (cont.) Porcupines –more quills to trap heat in quills, close to body. –Strip trees of bark.

Hibernation Inactive, sleeplike state. Why? Cold Prevention Reduce the need for food Symptoms: –Body temp. lowered –heartbeat lowered –breathing lowered (Reducing Metabolism)

Hibernation Requirements: –Need very little energy. –Need very little oxygen. “Trigger” : Hypothalamus- part of the brain. Adrenal Gland - located on top of kidney.

Hibernation Black Bear in Den.

Hibernation Black Bear

Hibernation Homeotherms –Warm blooded –Energy reserves: respiration periodic arousal –All hibernating mammals arouse periodically and body temp’s change.

Hibernation Poikilotherms –“cold blooded” –seek underground burrows. –Ex’s: Snakes, frogs, toads, salamanders, turtles. (frogs, toads, sal., turt. Will burrow in soft mud near streams and lake bottoms) Overwintering success of reptiles and amphibians is best assured by avoiding subfreezing temp’s.

Reptiles and Amphibians Wood frogs – hibernates just below surface and freezes solid –Produce glycogen which is stored in the liver then when they start to freeze it is converted to glucose and cells are filled with the glucose (acts like an antifreeze) Turtles shift from breathing Oxygen to osmosis

Types of Hibernation 1. True –W–Warm blooded animals Bats, squirrels, hamsters, swifts. –B–Body temp. reaches temp’s close to surrounding air. –A–Arouse themselves to keep warm.

2. Pupa –Cold Blooded animals –Insects –Larvae and grubs in Galls, Dead leaves, Rotting wood.

Types of Hibernation 3. Carnivorean Lethargy –Bears, Skunks, Opposums –Body Temp. doesn’t drop much (88 F) Don’t lose as much body heat. –Heart rate drops 40%

Types of Hibernation 4. Diurnal Torpidity –Bats active at night dormant- day –Hummingbirds active- day dormant- night

Types of Hibernation 5. Diapause –Insects Find sheltered places to stay away from freezing temps. And elements.

Fatness and Hibernation 1. Fattest animals remain dormant the longest. 2. Species that fatten up early will hibernate sooner.

Migration

MIGRATION The instinctual movement of animals. Animals are specialized and must migrate. Migrate by air, water, land.

Migration Routes Elk migrating through Greater Yellowstone Area. Mississippi Flyway for waterfowl. Whales along West Coast of N.A.

Migration CONS Energy cost is HIGH Must build up 50% of body weight as fat. Flying over water Hunting for waterfowl Once south/north: –New Parasites, diseases, predators, and food.

Migration: TRAVEL Easier by AIR than by LAND. Mammals expend 10x Energy by running than a bird of SAME WT flying same distance. Water travel (Whales), Energy cost is LOW.

Migration: Breeding Grounds Northern Hemisphere –shift from northern breeding grounds to a southern non-breeding ground. –Breeding grounds have more/better resources for caring for young. –Practically NO species is known to breed in both areas it inhabits.

Migration: Navigation Instinctual movement. Mapping of landmarks (learned) Some direct themselves by sun (Own compass) Triggered by weather, seasons, winds.

Migration: Navigation Groups migrate together. –By air, water, and land. –Herds of Elk –Flocks of Birds –Pods of Whales –LOST?