Lecture 4

Question 1

Breeding range of birds; where is this confined to in the tundra?

Answer 1

Southern limits of where they nest; Hudson Bay coastline

Question 2

Most birds in the tundra are ground-dwelling, such as these birds with a long toenail for digging up seeds & invertebrates

Answer 2

Longspurs (Smith’s, Lapland)

Question 3

Birds sing while _____ to ____

Answer 3

flying to mark their territory

Question 4

Most birds head south for the winter, except for ____, which stays year-round

Answer 4

Willow ptarmigan, a northern grouse; feathered legs/feet/toes help them stay warm

Question 5

Challenges for plants growing in the tundra

Answer 5

Abrasive wind
Cold, permafrost
Lack of nutrients
Short growing season (<140 days)

Question 6

This plant is dominant in the tundra:

Answer 6

Saxifrages

Question 7

Plant adaptations in the tundra

Answer 7

Cold hardiness (ice forms in structure)
Small size
Low/creeping/sprawling growth
Clump growth
Retains leaves year-round
Dark colours
Hair to absorb/trap heat
Growing in sheltered sites (e.g. crevices)

Question 8

3 trees that exhibit dwarfism

Answer 8

Dwarf Birch, Arctic Willow, Labrador Willow

Question 9

Genotypic Dwarfism

Answer 9

Fixed genetically to be a certain size (e.g. Dwarf Labrador Tea wouldn’t grow larger if planted further south)

Question 10

Phenotypic Dwarfism

Answer 10

Size depends on environment (e.g. Dwarf Birches grow larger if planted further south)

Question 11

These formations protect plants from harsh conditions

Answer 11

Raised beach ridges

Question 12

Thicket

Answer 12

area where shrubs form a dense growth pattern; habitat for insect-gleaning birds (e.g. warblers) and migratory songbirds that don’t nest on the ground

Question 13

Layering + cold temperatures

Answer 13

Tree branch touches the ground, and a new tree grows from it - spruces (e.g. white spruce)

Layering at the base of a tree is covered by snow, while the dead top part is the only part exposed to the harsh conditions

Question 14

Tundra-nesting birds (4):

Answer 14

Blackpoll Warbler (also in HBL)
Common Redpoll (live in willow thickets)
Hoary Redpoll
American Tree Sparrow (at the tree line)

Question 15

Small mammals that depend on thickets (2)

Answer 15

Meadow voles

Northern bog lemming

Question 16

Why aren’t deer mice found in the tundra?

Answer 16

Long tail & big ears aren’t suited for cold temperatures

Question 17

Why are meadow voles & northern bog lemmings able to survive in the tundra?

Answer 17

Short tail/ears, plump bodies

Question 18

Bergmann’s Rule

Answer 18

Larger species are found in colder environments

Question 19

Gloger’s Rule

Answer 19

Species with less pigment (i.e. white colouration, inc. in winter) are found in colder environments

Question 20

Allen’s Rule

Answer 20

Animals in cold environments have smaller extremities

Question 21

What is the long-tailed mouse species found in the tundra, and how does it survive?

Answer 21

Meadow jumping mouse, survives by burrowing into beach ridges and hibernating

Question 22

Name an animal (other than meadow jumping mouse) that survives by hibernating in the tundra

Answer 22

Groundhog

Question 23

Meadow vole population cycles

Answer 23

Meadow voles are very rare in some years and abundant in others; this affects the populations of their predators (arctic fox, short-eared/snowy owls, northern harriers)

Question 24

Snowy owls

Answer 24

• Dense feathers, turn white with age
• Feathers over bill protect from winds
• Females are larger and tend to have dark markings
• Most northern owl in the world
• Kill lemmings and pile them around nests to feed babies when they hatch

Question 25

Do lemmings actually purposefully run off cliffs?

Answer 25

no

Question 26

Endemic

Answer 26

any plant/animal species found only in one small geographical area

Question 27

Example of a Hudson Bay endemic

Answer 27

Lepage wild flax

Question 28

Life ‘rebounding’ as a storm ends and it gets warmer:

Answer 28

plants grow, animals return

Question 29

The HBL physiographic region contains two forest regions:

Answer 29

Tundra, HBL

Question 30

HBL forest region - northern boundary

Answer 30

edge of the tree line

Question 31

HBL forest region - southern & western boundary

Answer 31

boreal forest

Question 32

HBL forest region - eastern boundary

Answer 32

James Bay

Question 33

T/F: the HBL forest region is one of the wildest/most unexplored parts of North America

Answer 33

True

Question 34

T/F: the HBL forest region is very dry

Answer 34

False