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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