angela watkins jason noble and c. patrick doncaster
TRANSCRIPT
An agent-based model of jaguar movements through
conservation corridorsAngela Watkins
Jason Noble and C. Patrick Doncaster
Background Aims Methodology The Model Results Conclusion Current Work
Order of Events
Background
The most important threats to global biodiversity
Less habitat means fewer individuals
Populations become increasingly isolated
Habitat loss and fragmentation
Pictures taken from advocacy.britannica.com, dailyreckoning.com.au, king.portlandschools.org
respectively.
Connect local sub-populations Reduce the risk of local extinctions
Effective conservation requires the description of a landscape from an
individual species’ perspective in order to measure, understand and conserve
‘functional habitat connectivity’
Corridors, Connectivity and Conservation
Largest cat in the Americas, third largest in the world
Apex predator and keystone species Territorial and solitary Preferred habitat:
◦ Tropical rainforest◦ Subtropical rainforest
Jaguar
Jaguar range
Historic Range
Current Range
Link between two protected areas
Critical area linking populations to the north and the south
Subject to urban expansion
Central Belize Corridor
Jaguar Corridors
Jaguar Populations
Aims
Build a simple agent-based model of jaguar movement
Explore the effect of landscape structure on the population
Investigate how corridors can connect discrete habitat patches
Methodology
Individual agents represent individual organisms
Interactions between individuals
Interactions between individuals and the landscape
Agents encoded with rules that mimic simplified real behaviours
Agent-based simulations
Least-cost models
Habitat maps used to ‘cost’ the landscape
Species-specific
‘Organisms use a route of least resistance’
Taken from: Rabinowitz, A. & Zeller, K. A. (2010) A range-wide model of landscape connectivity and conservation for the
Jaguar, Panthera Onca. Biological Conservation 143: 939-945.
The Model
Model landscapes
3 controls
3 non-connected
3 connected
Cost Values
Habitat Cost
Forest 1
Edge 5
Non-forest 25
9-cell Moore neighbourhoods
Sex-specific movement rates◦ Males - 100%, females – 70%
Sex-specific territoriality◦ Pheromones add a cost to the cell
5% random moves
Model parameters
Results
Clearly identified territories and habitat choice
No strong difference in average landscape cost value
Map Layout
Connected corridors promote movement between patches
Map Layout
Conclusions
Plausible territorial behaviour
Not all corridors are the same
Critical feature for cost: amount of habitat
Key difference:
capacity to promote migration from one patch to another
Current Work
Integrate model with real-world GIS data Validate agent movement with empirical
data
Aims
Least-cost route choice Pheromones Male preference for trails Female avoidance of males? Difference in movement inside vs.
outside Cockscomb? Male vs. female movement rates
Key Parameters
SupervisorsJason Noble and C. Patrick Doncaster
Jaguar Corridor InitiativeBart Harmsen and Rebecca Foster
This work was supported by an EPSRC Doctoral Training Centre grant (EP/G03690X/1).
Acknowledgements
Any questions?