Although these longer dispersals may be infrequent, they are critical for sustaining a stable population over a large area. Wolves in the Bow Valley, for example, may be dependent on the influx of wolves from beyond the park's boundaries for replacing their losses due to vehicle collisions and deaths from other causes. The ideal width of a corridor depends on the type and size of animals using it. A corridor 250 -350 metres wide is the minimum requirement for large carnivores. The length of a corridor, or the distance between quality habitat patches, should be as short and direct as possible.
Vegetation is required by many animals for warmth and security.
Both cougar and black bear prefer continuous forest cover. Darkness also provides natural cover. For this reason, cougars prefer to travel at night. Secondly, and perhaps more importantly, is the shy, discreet nature of large carnivores. A result of protecting corridors is that wildlife will not be forced into more developed areas.