Hyperabundant Deer Management:

the Parks Canada Experience

Impacts and Monitoring

Dr. Emily Gonzales, Ecosystem Scientist

Parks Canada Hyperabundant Wildlife Directive

1. Confirm hyperabundancy

2. Report hyperabundancy (State of Park Report, Management Plan)

3. Consultation

4. Hyperabundant Management Plan

a) Appropriate Methods for Management

b) Monitoring, Assessment and Reporting

c) Animal Care/Environmental Assessments/CEO Approval

5. Partnerships, Education and Communication

6. Implementation – Operations – TUESDAY @ SLINP

Gw

aii H

aanas

Nati

onal Park

Few deer Many deer

Where have all the flowers gone?

(Martin, Allombert

Stockton)

Gulf

Isl

ands

Nati

onal Park

Widespread problem

Few deer

Many deer

(Gonzales & Arcese 2008,

Gonzales & Clements 2009)

Problem WORSE in Parks

From 1950 to 2000 - Wisconsin

• 10% plant diversity lost outside of Parks

• 50% plant diversity lost inside Parks

Predation is occurring

outside of Parks

(Rooney & Waller 2003)

3 Reasons for Hyperabundant Deer

Too many deer 1. Too few predators

2. Mild winters

3. Habitat Change: abandoned farms & logging increased

resources. Landscapes still changing. (Côté et al. 2004)

Since 1971, population in

Thousand Islands: +22%

dwelling density: +117%

Landscape Change

• Deer a host for ticks, which carry Lyme

disease

• Car crashes

• Garden raids

• Disease (chronic wasting disease – not in

Ontario yet – active monitoring)

Too many deer, many problems

Too many deer, many ecological problems

Deer change plant composition:

• Palatable plants decrease (trillium)

• Less palatable plants increase (fern forests)

Change forest structure:

• Seedlings consumed – no new forest to

replace old

Densities of deer can exceed ability of

palatable plants to persist

(Augustine & Frelich 1998)

Solution: Reintroduce Predation

Has ecological benefits but

introduces human conflicts (Ripple and Beschta 2003, 2004) Ye

llow

stone W

olf

Rein

troducti

on

Top-d

ow

n E

cosy

stem

Carnivores

(wolves)

Herbivores

(deer)

Plants

(Hairsto

n e

t al. 1

960)

How many deer? – not a bad question,

but problematic

Monitoring deer: no good

options

Expensive Methods: aerial,

thermo = moderate quality

Cheap Methods: pellet counts (Marques et al. 2001),

Trillium height (Koh et al. unpublished) = poor to

moderate quality

Aerial survey

(Patrikeev 2008)

No “magic number” of deer

Depends on the plants and

the landscape

Depends on behaviour

Monitor plants (# seedlings)

to assess ecosystem

recovery

Plants tell us how we’re doing

(Latham et al. 2009)

(4 deer/km2)

2m 4m EMAN

FOREST

PLOT

20m x 20m Quadrat

2m x 2m Seedling

recruitment

Soil Decomposition

5m

Tree species, crown condition,

stem defects, DBH, height

Woody D

ebri

s

Woody Debris

Avian Diversity

Stand condition Condition

Monitoring

Program

Tree Seedlings = indicator of deer impacts

# of tree seedlings: can use to identify which sites are overbrowsed

(Morellet et al. 2007,

Sweetapple & Nugent 2004)

Exclosures: Don’t provide reference conditions

• Fenced vs. Open Plots: How much biomass is removed

by deer?

• Fenced Plots: What plants emerge when protected

from deer?

• Open Plots: What plants emerge when deer are

reduced?

(Horsley et al. 2003,

Wisdom et al. 2006)

Building Relationships…

…with Community of Akwesasne, OMNR, Hill

Island Residents

Deer meat used in mid-winter ceremony

Mentoring for youth

Awareness workshops

Local resident community walks and meetings

Next steps…

Citizen Science Initiative: monitoring

Emily’s Questions

• How can we increase efficacy as deer

become more wary and at lower deer

populations?

• How can we maintain safety?

• Are more elegant plant monitoring methods

needed as deer populations decline?

• Are there efficient, economical monitoring

measures for deer impacts on other species

(non-plants)?