Lecture Slides on Wildlife Habitat - Wildlife Ecology and Conservation | ESRM 450, Study notes of Environmental Science

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ESRM

Wildlife Ecology and Conservation

Wildlife

Habitat

Definition,

Quality,

Use,

and

Selection

The Habitat Concept

Serves

as

a

logical

launching

point

for

class

because

it

is

crucial to our understanding of the distribution, abundance of wild animals

a cornerstone of wildlife conservation and management

What is Habitat?

Term

used

in

a

variety

of

ways

(Hall et al. 1997 Wildl Soc Bull )

The place where an organism lives - An area supporting a particular type of vegetation - These examples are incomplete, don’t foster conservation

What is Habitat?

Manifold

usage

also

counterproductive

Hinders communication among ecologists

Confuses the public - Creates legal messes

Unified Definition of Habitat “areas offering the resources and conditions that promote occupancy by a species”

Definition

Transcends floristic composition; resources include food, cover, shelter, other factors influencing occupancy

Species

specific

Scale

dependent

Has temporal component

Means

that

habitat

is

not

always

“wilderness”

Human activity can both create and destroy habitat (e.g., cottontail rabbits and jackrabbits on the

NA

prairie) Morrison et al. 2006 Wildlife ‐ Habitat Relationships

Cottontails and Jackrabbits

Conversion

of

open

rangeland

to

farmland

has

created

habitat

for

cottontail

rabbits

Sylvilagus

floridanus

Utilize hedgerows, gardens

Seek cover along fences

But

has

constricted

white

tailed

jackrabbit

Lepus townsendii

habitat

Depends on the open prairie

Habitat Quality Morrison et al. 2006 Wildlife ‐ Habitat Relationships

Across

landscape

(geographic region),

some

areas won’t

qualify

as

habitat

Those

that

do

vary

in

quality

Quality:

degree

to

which

area

provides

conditions

that

facilitate

persistence

Continuous variable

High: promote high survival, reproduction over long time periods - Low: promotes occupancy but with low survival, reproduction or for relatively short or intermittent periods - Linked to demographics, not vegetative characteristics

Habitat Use

The

observed

distribution

of

animals

among

habitats

Note,

patterns

of

habitat

use

can

vary

as

a

function

of

behavioral

state

foraging, denning, hiding, resting

So, state

specific habitat use patterns often specified (e.g., “foraging habitat use”)

Habitat

use

is

also

Subject to temporal variability

Scale

dependent

Not

necessarily,

because

they

are

realized

i.e.,

habitat

use

is

influenced

by

constraints

imposed

by

Predators (spatial and temporal patterns of mortality)

Competition (exclusion; e.g., blue mussels Mytilus edulis

Habitat Use

Problematic

Habitats where animals are abundant may not be best (high quality)

Doesn’t allow us to say anything about how animal distributions might change following landscape alteration (e.g., as a result of human disturbance) Management Based on Habitat Use

Habitat Selection

a

hierarchical

process

involving

a

series

of

innate

and

learned

behavioral

decisions

made

by

an

animal

about

what

habitat

it

would

use

at

different

scales

of

the

landscape

Krausman 1999 Some basic principles of habitat use

Habitat Selection

Choice

of

one

habitat

(or

certain

habitats)

over

others

at

a

particular

spatial

scale

Scale

dependent:

animals

select

habitats

at

very

fine

(micro)

to

very

broad

(macro)

spatial

scales

Temporally

variable

a hierarchical process involving a series of innate and learned behavioral decisions made by an animal about what habitat it would use at different scales of the landscape

Studies of Habitat Selection

e.g.,

Defining

random

expectation

(availability)

B A Habitat

*Note,

expectations

also

can

hinge

on

accessibility

Studies of Habitat Selection

e.g.,

Defining

random

expectation

(resources)

B A Foraging habitat Food unit