Understanding the Relationships between Landscape Connectivity and Abundance of Ixodes ricinus Ticks
The density of Ixodes ricinus ticks in a heterogeneous landscape of northern Spain was determined and associated with some aspects of habitat topology. The habitat mosaic was used to quantify connectivity between patches of different tick density. The analysis revealed that patches with high tick abundance are ‘stepping-stone’ territories that, when removed from the landscape, cause large changes in connectivity. Sites with medium tick abundance do not cause such a critical transition in connectivity. Patches with low tick abundance, but optimal abiotic conditions for survival are located within the minimum cost corridors network joining the patches, while those sites where the tick has been intermittently collected are located at variable distances from this network. These results suggest that tick distribution in a zone is highly affected not only by abiotic variables (vegetation and weather) but also by host movements. Whether these high-density ‘stepping-stone’ patches occur in other tick species needs to be evaluated because of the potential implications of these foci for human health.
- Daniel, M. and Dusbábek, F. 1994. Micrometeorological and microhabitat factors affecting maintenance and dissemination of tick-borne diseases in the environment. In: 'Ecological Dynamics of Tick-borne Zoonoses', D.E. Sonenshine and T.N. Mather (eds), pp. 91-138. Oxford, New York.Google Scholar
- Gray, J.S., Kahl, O., Robertson, J., Daniel, M., Estrada-Peña, A., Gettinby, G., Jaenson, T.G.T., Jensen, P. and Jongejan, F. 1998. Lyme borreliosis habitat assessment. Zentbl. Bakteriol. 287: 211-228.Google Scholar
- Keitt, T.H., Urban, D.L. and Milne, B.T. 1997. Detecting critical scales in fragmented landscapes. Conserv. Ecol. (online) 1: 4. URL: <http://www.consecol.org/vol1/iss1/art4>.Google Scholar
- Patton, D.R. 1975. A diversity index for quantifying habitat "edge". Wild. Soc. Bull. 3: 171-173.Google Scholar
- Stauffer, D. and Aharony, A. 1985. Introduction to Percolation Theory. Taylor & Francis, London.Google Scholar