Lynx tolerance to anthropogenic disturbance: what are the limits?

26th International Congress for Conservation Biology Baltimore 2013

Yaëlle Bouyer

Anthropogenic disturbance: from wildland to urban environment

Wilderness

City center

Shared space?

Anthropogenic disturbance: from wildland to urban environment

Studies show avoidance of human related features by large carnivores

General belief: large carnivores cannot coexist with humans at fine scale

BUT

Recent studies: LC can tolerate remarkable degrees of human disturbance and very modified landscapes even at fine scale

Gehrt et al. 2009 & 2010; Carter et al. 2012; Dellinger et al. 2013

Anthropogenic disturbance: from wildland to urban environment

Preferance vs. Tolerance

What are the limits of human disturbance that can be tolerate by lynx?

Eurasian lynx (Lynx lynx) is known as a typical forest species which avoids human related landscapes

Range of Eurasian lynx expanding in Europe

Anthropogenic disturbance: from wildland to urban environment

Study the tolerance of lynx to human disturbance: where lynx are instead of where they could be

Lynx home ranges vs. immediate surroundings

Values of human disturbance proxies inside home ranges and their surroundings?

Hypothesis: 1. Human proxies should be less numerous inside the HR than outside

2. Lynx should orient their home range in order to minimize human presence

3. Trade-off between avoidance of people and prey access

Anthropogenic disturbance: from wildland to urban environment

Data

49 lynx

Telemetry data (GPS and VHF) from 1995 to 2012

Kernel estimation : 25, 50, 70, 90 and 95 %

Buffers of 2km width, from the 95% border up to 14 km

Variables: human density (hab/km²); public and private roads (km/km²) and index of roe deer density (pellets/km²) LME to account for individual

heterogeneity

Data : 2 groups

49 individuals

High roe deer density Low roe deer density

Results

High variation in the 95% home range for the 49 individuals

Human density (hab/km²)

Public roads (km/km²)

Private roads (km/km²)

Roe deer density (pellets/km²)

Minimum 1.61 0.15 0.57 0.23

Average ± SD 41±70 0.53±0.31 0.99±0.19 1.24±0.88

Maximum 314 1.54 1.31 4.2

©M.Dalum

Results : Human density

Home range Buffer

1) High roe deer density

Human density acts as a barrier

2) Low roe deer density

Home range Buffer

Trade-off between human density and prey accessibility

Results : Human density

Home range Buffer

Results : Private roads

Correlated with forest presence

No significant effect of public roads

Home range Buffer

Public roads don’t seem to have an effect

Results : Public roads

Results: Low roe deer density

Home range Buffer

core areas = highest roe deer density

Results show: • Avoidance of a high human density but also dependant on roe deer presence Trade-off between access to prey and proximity to humans

• No real impact of roads inside HR

Summary

• Lynx = game species in Norway no possibilities of habituation

• Wide range of tolerances between the different individuals • Very adaptable (from mild wilderness to high disturbed landscape)

Summary

• Landscapes will continue to change or at least won’t come back to a high wilderness areas

Studies of tolerance = reliable results on what large carnivores can support and even their true limits

• Our study area = one of the least modified in Europe we probably don’t have access

to areas extreme enough to test the limits of large carnivores

Can lynx support a human pressure even more important that the one found in

our study?

Summary

Acknowledgments: Johnl Linnell (NINA)

Vincenzo Gervasi (NINA) Emmanuelle Richard

(NINA) Roseline Beudels (IRSNB)

Pascal Poncin (ULG) FNRS