Post on 31-Jan-2023
Lynx tolerance to anthropogenic disturbance: what are the limits?
26th International Congress for Conservation Biology Baltimore 2013
Yaëlle Bouyer
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
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
2) Low roe deer density
Home range Buffer
Trade-off between human density and prey accessibility
Results : Human density
No significant effect of public roads
Home range Buffer
Public roads don’t seem to have an effect
Results : Public roads
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