Example Application of the
Late Summer Elk Nutrition
and Habitat Models
Mount Emily
Topics to Discuss

Describe the elk management situation in
the Mt. Emily area.

Present results of a hypothetical
management option to illustrate how the
models operate to evaluate changes to elk
habitat.

Summarize some observed strengths and
weaknesses of the models in relation to
results for this case example.
Mt. Emily Area
128,863 acres
Management Situation

The Mt. Emily area straddles a zone where
the moisture gradient shifts from wetter to
the north and drier to the south.

This moisture gradient is reflected in
patterns of increasingly wet forests to the
north and east, and increasingly dry forests
to the south and west.

This spatial variation in precipitation drives
the potential for elk habitat enhancement
across the area.
Management Situation

Mt. Emily Management Objective for elk –
5,700
 Current population estimate – 3,400

The Mt. Emily WMU is managed for mature
bulls

Distribution of elk is not a major issue in
the Mt. Emily area, but localized issues
exist (E.g. Hunter Road)

Predation
Management Situation

Most of the area is composed of National
Forest System lands, that function
primarily as summer range for elk.

The area is administered by two National
Forests, with strikingly different approaches
to motorized access management.

Small amounts of winter range exist on the
southern and eastern portions of the area
on a mix of National Forest, state, and
private lands.
Management Questions

What potential exists for enhancing elk
habitat use during late summer (pre-hunt
period) in the area?

How do road closures change the
probability of elk use at the regional scale,
and at local scales?

How does forage enhancement effect
probability of elk use?

How do road closures and forage
enhancements combined change elk use?
Management Options
Option 1: Identify road and motorized trail
closures across the Mt. Emily area to improve
summer range conditions for elk.
Option 2 (not fully developed): Nutrition
enhancement through reducing canopy
closure in wet forests (just in Green/Huckle
local area).
Scales of Analysis
Mt. Emily (regional landscape)
Green/Huckleberry (local landscape)
Walker/Pelican (local landscape)
Nutrition Model Results

Predicts dietary digestible energy (DDE) for
elk during late summer (August) across
entire landscape of interest (regional
landscape) and for any smaller areas (local
landscape) within the larger area.

Model developed from tame elk grazing
trials conducted in Blue Mountains, as
described earlier.

Estimates of DDE vary strongly with the
potential vegetation types occuring in a
given area and associated precipitation.
Percent Area in DDE Class
Habitat Model Results

Predicts the relative probability of elk use
across a landscape of interest (regional
landscape) and for any smaller areas (local
landscape) within the larger area.

Model based on 5 covariates (predictor
variables).

Can be used to evaluate habitat conditions
and how management actions can influence
elk use on regional or local landscapes.
Habitat Model (5 covariates)
1.
Dietary Digestible Energy of Forage.
2.
Distance to Class 1 or 2 Open Roads.
3.
Distance to Class 3 or 4 Open Roads.
4.
Slope.
5.
Percent Area in Forest Vegetation Types.
Percent Increase in Elk Use
from Existing Condition for Option 1
60.0
53.0
% Change
50.0
40.0
30.0
20.0
10.0
11.0
1.5
0.0
Regional Landscape
Local 1
(WalkerPelican)
Local 2
(GreenHuckle)
Relative probability of elk use increased by 11% for the regional
landscape under option 1, and most of this increase occurred in the
Green/Huckle local area (53%).
General Observations of Model Results

The nutrition and habitat model evaluations
of late summer conditions appear to be
realistic for the Mt. Emily Area.

Nutrition and predicted habitat use are
substantially higher in the north and east,
which reflects local knowledge about
habitat conditions.

Late summer nutrition is more limited in
the south, which also reflects local
knowledge.
General Observations of Model Results

The potential for enhancing habitat use is
greater in areas with more wet forests,
owing to the higher background nutritional
conditions in these areas.

Road closures focused in areas of higher
nutrition will increase elk use substantially
more than road closures in areas of lower
nutrition.

Areas with more wet forests provide an
opportunity for enhancing nutrition in
combination with road closures to further
enhance elk use.
Model Strengths

Many possible types of summaries in space
and time, particularly public vs. private
lands questions regarding predicted elk
habitat use.

Ability to summarize at regional and local scales

Calculating the change in relative probability of
use over time
Model Strengths

Calculating percentage of the landscape
by condition classes (nutrition or relative
use)

Summing the relative probabilities of elk
use for any specified area—the entire
regional landscape or any areas within it
(local landscapes)
Model Weakness

Limited season of application. Spring and
hunting season models would address
other critical time periods for elk.
Management Questions

What potential exists for enhancing elk
habitat use during late summer (pre-hunt
period) in the area?

How do road closures change the
probability of elk use at the regional scale,
and at local scales?

How does forage enhancement effect
probability of elk use?

How do road closures and forage
enhancements combined change elk use?
Questions?