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The missing lynx - restoring Scotland’s
forgotten cat
By Dr David Hetherington
Peter Cairns
European distribution
of Eurasian lynx
Karl Weber
Natural
Populations
Reintroduced
Populations
Why consider reintroducing lynx to Scotland?
• Ethical
Moral responsibility to restore species that we as
humans, made extinct
• Legal
The UK is obliged by Bern Convention, Rio
Convention & EU Habitats Directive to consider
the feasibility of reintroducing extinct species
• Ecological
Restoring top predator to ecosystem may help to
reduce damage by deer
• Economic
Reducing deer densities can reduce damage to
forestry and agriculture. Lynx could contribute to
wildlife tourism
When and how did the lynx become extinct in
Scotland, and have conditions improved for lynx
since then?
IUCN Guidelines for Re-introductions
“Identification and
elimination, or
reduction to a
sufficient level,
of previous causes
of decline…”
The distribution of historic
and prehistoric remains of
lynx in Britain
Historic
Post-glacial
Late Glacial
Undated
The distribution
of lynx in Europe
around 1800
After Curry-Lindahl (1951)
and Kratochvil (1968)
Decline of Forest Cover in Scotland
• 75% forest cover in mid
Holocene
• Permanent deforestation
occurred in far north and west
3700-3900 BP due to wetter
climate
• Anthropogenic clearance
begun by mesolithic
communities but occurs on
large scale during Bronze
and Iron Ages
• >50% of forest cleared by year 1 AD
• Destruction, helped by woodland grazing of livestock, continued
until last area of extensive forests, in the Grampians, were all but
cleared from 1600-1700
Forest cover by the late 18th
and 19th centuries for selected
European countries
Hungary
30%
Switzerland 19%
France
14%
Scotland
4%
Modern Scotland
• 20th Century afforestation means forest
cover now 20% for Scottish mainland
• The aim is to have 25% forest cover for the
whole of Scotland by 2050, with a focus now
on Forest Habitat Networks
• Roe, non-native sika and red deer now
widespread and numerous in woodland
• All 3 species occur at high densities, often
creating problems for ecology and for forestry
• All 3 species are potential prey for lynx
Study by Breitenmoser & Haller (1993) in the Swiss Alps
showed:
• Lynx at colonising front had much smaller home ranges
than lynx in the established core distribution
• One male and one female made 75% of their kills in a
8.5km2 area at the colonising front, while a male and female
in the established core made their kills over a 142km2 area
• Local chamois population at the front decreased from
800-300 within 6 years
Prey spectrum of lynx in the Swiss Jura
(from Jobin et al., 2000)
Prey species
Roe deer
Chamois
Red fox
Brown hare
Marmot
Pine marten
Badger
Domestic cat
Wild cat
Capercaillie
Number
of kills found
428
133
37
13
1
1
1
1
1
1
%
of prey items
69.3
21.5
6.0
2.0
0.2
0.2
0.2
0.2
0.2
0.2
Sheep production
in Scotland
• High densities in southern
Scotland, but low densities in
the north and west
• Vast majority of sheep now
grazed in open pasture
Lynx depredation on sheep in
Switzerland
Number of sheep killed
250
200
150
100
50
0
1999
2000
2001
2002
2003
2004
2005
Peter Cairns
Peter Cairns
• The extinction of lynx in Scotland was not caused
by climate change, and probably occurred during
the Middle Ages
• Early and severe deforestation, a decline in deer
populations and persecution due to predation on
woodland-grazed livestock are likely to have been
the most significant factors
• These factors no longer operate in the modern
Scottish landscape
How many lynx could Scotland support?
Analysis of Habitat
• Conducted using a Geographical Information
System or GIS
• Most habitat data was drawn from the Swiss Alps
due to the high quality of data available and the
environmental similarity to much of Scotland.
•
45-74 km2
•
74-550 km2
One female territory only
Total area = 366.7 km2
At least one male and one
female
Total area = 3,172.4 km2
100km
•
550 km2 +
Could support >20 lynx
Total area = 17,139.3 km2
Connectivity Analysis
Northern Scotland
14,994.4 km2
Southern Scotland
5,327 km2 (6,144.4 km2
if including Kielder Forest)
Scotland
20,321.4 km2
100km
Wild ungulate biomass and lynx
densities from selected areas in Europe
Source area
Ungulates
km-2
Ungulate biomass
available to
lynx (kg km-2)
Lynx
100km-2
Central Norway
0.2 roe, 1.6 reindeer, 0.8 sheep
142
0.3
Swiss Jura
7.2 roe, 1.6 chamois
192
1.0
Swiss Alps
7.7 roe, 5.0 chamois
289
1.7
Bialowieza, Poland
4.7 roe, 6.4 red deer
517
2.9
Scottish Highlands
7.4 roe; 3.1 red deer; 1.6 sika, 0.1 fallow
453
-
Southern Uplands
5.5 roe; 0.9 red deer; 0.1 fallow
183
The relationship between lynx density and wild
ungulate density for four areas in Europe.
3.5
3
y = 1.99Ln(x) – 9.53
R sq. (adj.) = 0.996
Scottish
Highlands
Bialowieza
Forest
Lynx 100km-2
2.5
2
Swiss Alps
1.5
1
Swiss Jura
Southern
Uplands
0.5
Central Norway
0
100
200
300
400
Ungulate biomass kg km-2
500
600
Average lynx population
densities of 2.63 and 0.83
100 km-2 are predicted for
the Highlands and Southern
Uplands respectively.
Giving:
Highlands
394 lynx
Southern Uplands
51 lynx
100km
Scotland total
445 lynx
Population Viability Analysis (PVA)
What is the Minimum Viable Population (MVP) size for lynx?
• Used RAMAS/age software
• Model employed good quality
life history data from real lynx
populations across Europe
• The risk of extinction during
100-year period after reaching
carrying capacity was explored
for a range of theoretical
population sizes
• An extinction risk of 5% or less was considered acceptable
Probability of persistence over 100 years for a range of
population sizes at carrying capacity
Population
Pessimistic
Intermediate
Optimistic
50
35.6
66.0
84.4
100
76.8
90.4
95.8
150
85.8
93.0
97.4
200
90.8
96.6
97.4
250
90.8
97.0
98.2
300
93.4
96.8
98.6
350
92.0
97.0
98.2
400
96.0
98.2
99.0
450
93.4
97.6
99.0
500
95.0
96.8
98.4
550
97.0
96.6
97.2
600
96.0
98.4
99.0
Average lynx population predicted for
the Highlands and Southern Uplands:
100km
Highlands - 394 lynx - VIABLE
Southern Uplands - 51 lynx – NON- VIABLE
Wildlife corridor – for lynx
Andreas Ryser
Conclusions
• Lynx are native to Scotland, but humans made them
extinct by the late Middle Ages
• Large amount of well-connected potential
habitat available
• High densities of prey suggest habitat could
support around 450 lynx in two populations
• A Southern Uplands population must be connected
to the Highlands population
• The Highlands could support a viable lynx population
 Urs Breitenmoser
Acknowledgements
• Dr Martyn Gorman, University of Aberdeen
• The Highland Foundation for Wildlife
• KORA Carnivore Research, Switzerland
• Northshots