Skip to main content

Table 1 Examples of naturally occurring, unintentional and deliberately created human made factors that may promote isolation

From: Field site selection: getting it right first time around

  Natural isolating factors Human activity with incidental effects Artificial and deliberate methods
Physical barriers Sea, large rivers and lakes, mountains and hills, desert and barren or poor terrain Buildings, roads, railways Insecticide, drainage
Vegetation Unsuitable habitat type, excessive shade, no shelter Large monospecies plantations Land use change e. g. clearing and planting
Distance Between suitable habitats, to nearest host Sparse human presence, no farm animals, no plumbing or irrigation Zones with no host, no natural or human-made breeding sites etc.
Time Seasonal events, flood, animal bird migration Crops, animal movement Time limited or interrupted water supplies
Temperature Seasonal changes, latitude, altitude   
Competition Neighbouring habitat zones favour a competitor   Promotion of benign competitor or predator