Vulnerability of moose and roe deer to wolf predation in Scandinavia- does habitat

matter?

International Master Programme International Master Programme Applied Biology, 2007Applied Biology, 2007By: Lisette FritzonBy: Lisette Fritzon

• Ungulates important prey for wolves

• Threat against wolf recovery

• Dramatic growth of prey populations

• Important species, both for hunters and for forestry production

• Need for more knowledge of how habitat and spatial factors may affect the vulnerability of prey

Introduction

• Examine if there are high-risk areas for moose and roe deer in a wolf territory

• Null hypotheses; habitat and spatial variables at kill sites did not differ when compared to control and random sites

Aim

• Moose (n=177)

• Roe deer (n=76)

• Habitat and spatial features compared

• 11 territories in Sweden and Norway

• Field work, Narrow scale

• Arc View, Broader scale

Method

Territory number

Territory No. Moose No. Roe deer

1 Djurskog 37 5

2 Forshyttan 10 2

3 Glaskogen 6 3

4 Halgån 19 0

5 Hasselfors 16 36

6 Jangen 14 2

7 Stadra 4 16

8 Tyngsjö 24 3

9 Ulriksberg 9 6

10 Uttersberg 23 3

11 Nyskoga 15 0

Total 177 76

1

3

5

10

11

72

4

6

8

9

Study area showing the 11 wolf territories on the Scandinavian Peninsula.

Field Reconnaissance• Summer 2006• 253 kill sites• 253 control sites• Summer and winter • 27 variables analysed

Field Reconnaissance

1. Visibility

2.Slope

3. Habitat class

4. Forest class

5. Distance to the nearest edge

6. Forest age

7. Stem diameter

8. Height of undergrowth

9. Height of forest

10. Distance to nearest largest stem

11. Number of stems

24 variables

30 m 30 m500 m

Kill site Control site

•Habitat and landscape variables were recorded •253 kill sites and 253 control sites

Random direction

• Coordinates from carcass and control points (total 506)

• Wolf home ranges, minimum convex polygon (MCP) method

• Random points (total 253), compared with kill, control

• Two buffer zones added, 250 meter and 1000 meter buffer

• 24 variables analysed

Geographic Information System spatial analysis

Object variables (Buffer 250, 1000)

• Building (N), a• Building (N), b • Road (m), a• Small road (m), a

Area variables(Buffer 250, 1000)

•Antrophogenic area•Deciduous forest•Coniferous forest•Clearcut•Young forest•Wetland•Water

Distance variables• Distance small road (m) • Distance building (m

Topographic variables•Slope•Meters above sea level (m)

Density variables(Buffer 250)

•Relative moose density

Statistical analyse

• Logistic Regression Field Data• Moose summer vs control• Roe deer vs control• Logistic Regression GIS Data• Moose summer vs random• Roe deer vs random

Test Variable Higher Lower Percentage correct

Significance

Moose kill

vs contol

Height of undergrowth

X 60.5 0.002

Proportion of meadow

X 60.9 0.05

Average stem diameter

X 61.9 0.030

Proportion of spruce

X 61.3 0.033

Field data

Test Variable Higher Lower Percentage correct

Significance

Roe deer vs control

Number of stems

X 60.5 0.004

Field data

Test Variable Higher Lower Percentage correct

Significance

Moose kill

vs random

Number of buildings (b)

X 62.6 0.005

Meter above sea level

X 65.2 0.032

Proportion clear-cuts (a)

X 66.0 0.027

GIS Data

Test Variable Higher Lower Percentage correct

Significance

Roe deer vs random

Proportion coniferous forest (b)

X 58.6 0.002

Average meters above sea level

X 61.2 0.021

GIS Data

Discussion•Habitat and spatial variables differs between kill, control and random

•Ungulates have a variety of

anti-predator strategies

High predation risks in open

areas (Kunkel & Pletcher 2000)

• In this study,moose seems to choose more open areas, both for field data and for GIS data

• Same pattern as for many other studies (Seip 1992; Singer & Mack 1999; Dussault et al 2005)

Discussion

• GIS data; Roe deer avoid open areas proportion coniferous forests higher

•GIS data; Moose open areas

•Roe deer same pattern as moose for elevation

•Field data; Roe deer avoid open areas number of stems higher

•Field data; Moose more open areas

• Studies linked predation risk to landscape attributes

• Summer and winter

• Chasing distance

• Important management and conservation implications

• Better predicting impacts of wolves on prey

Discussion

Conclusion• Patterns in which habitats moose and roe deer are being killed by wolves

•Habitat does matter

•Moose tendency seek open areas

•Roe deer tendency avoid open areas

Acknowledgements Håkan Sand, Camilla Wikenros, Mats Amundin, Sabrina Muller, Undine Knappwost, Grzegorz Miskulisnki, Lasse Jäderberg, Johan Jakobsson and Sam. Thank you all for making this thesis possible!

Thank You For Listening!

Questions?

•More studies are needed

•GPS radio collars on both wolves andmoose/roe deer that record their locations at intervals over two winters and summers

•The aim would be to test whether moose/roe deer locations differs on days when wolves are present or absent

•With this test the advantage is that the movements of wolves can be used to test the behavioural responses by resident moose/roe deer

Further research

Anthropogenic rea; Buffer 250m and 1000m(2) Discontinuous urban fabric with more than 200 inhabitants with minor areas of gardens and greenery(3) Discontinuous urban fabric with more than 200 inhabitants with major areas of gardens and greenery(4) Discontinuous urban fabric with less than 200 inhabitants(5) Solitary houses with property(6) Industrial or commercial units, public services and military installations(10) Sand and gravel pits14) Green urban areas(15) Sport grounds, shooting ranges, motor, horse and dog racing tracks(17) Ski slopes(18) Golf courses(19) Non-urban parks(20) Camping sites and holiday cottage sites(30) Arable land(32) Pastures

Deciduous forest; Definition: Tree-covered areas consisting of a total crown cover of >30%, whereof >75% of the crown cover is made up of broad-leaved trees. Tree height is >5 meters Buffer 250m and 1000m(40) Broad-leaved forest not on mires(41) Broad-leaved forest on mires(48) Mixed forest not on mires(49) Mixed forest on mires(50) Mixed forest on open bedrock

Coniferous forest; Definition: Areas consisting of trees with a total crown cover of >30%, whereof >75% of the crown cover is made up of coniferous trees. Tree height is >5 meters Buffer 250m and 1000m(43) Coniferous forest on lichen-dominated areas(44) Coniferous forest 5-15 m(45) Coniferous forest >15 m(46) Coniferous forest on mires(47) Coniferous forest on open bedrock

Clear-cut; Definition: Open and re-growing clear-felled areas where trees/bushes have a rough height of <2 meters. Buffer 250m and 1000m(54) Clear-felled areas

Young forest; Definition: Bushes with a total cover of >30% and a height between ca. 1 and 5 meters and younger forest with a cover of >30% and a height between roughly 2 and 5 meters. Buffer 250m and 1000m(53) Thickets(55) Younger forest

Wetland; Buffer 250m and 1000m(70) Inland marshes(71) Wet mires(72) Other mires

Water; Buffer 250m and 1000m(80) Water courses(81) Lakes and ponds, open surface(82) Lakes and ponds, surface being grown over

Building; Buffer 250m and 1000m(732) Mansion(735) House, size class 1 < 150 square metre(736) House, size class 2 > 150 square metre(741) Church(797) Hostel

Road, Buffer 250m(5022) Road > 7m, not national road(5024) Road 5-7m, national road(5025) Road 5-7m, not national road

Small road, Buffer 250m(5029) Road < 5m, not national road(5061) Public road, good standard(5071) Public road(5082) Public road, poor roadDistance small road

(5029) Road < 5m, not national road(5061) Public road, good standard(5071) Public road(5082) Public road, poor road

• TestSignificant VariableHigherLowerMoose kill vs controlHeight of undergrowthXProportion of spruceXProportion of meadowXAverage meters above sea levelXRoe deer vs controlNumber of stemsXMoose kill vs randomProportion clear-cutsXNumber of buildingsXAverage meters above sea levelXRoe deer kill vs randomProportion coniferous forestXAverage meters above sea levelX