In another approach, Goldstone et al. [22] and Goldstone and Robert [55] studied the nature of collective behavior of human crowds in forming trail system patterns in the compound topology of origin and destination nodes.
Once locations along a trail degrade to this condition, ORV users may deviate from straight-trail courses, creating new trails to one side or the other, thus forming trail braids.
Consequently, human footprints and formed trails in an open space can fade or disappear if the track or trail is abandoned for a long period of time or is blocked and is not used by the pedestrians frequently due to different physical, social or economic factors.
Nests are considered "nonforaging" if they do not form trails to any trees; this does not necessarily mean that the nests perform no foraging at all, simply that they do not form foraging trails directly to aphid-bearing trees.
Fig. 19 A formed trail under a passable obstacle in summer, Ferdowsi University of Mashhad, Mashhad, Iran.
The panel said exhaust contributed to global warming by emitting carbon dioxide and nitrogen oxides at high altitude and by forming condensation trails; it did not say jet engine exhaust depletes the ozone layer.
It is also important to note that our definition of nonforaging nest does not necessarily mean that a nest is not foraging at all, just that it is not forming foraging trails to trees.
As the surface starts to crumble, dust and debris are expelled from the body, forming a trail along the orbital trajectory of 3200 Phaethon.
As their highly elliptical trajectories take them near the sun, some of that ice starts to sublimate, forming a trailing cloud of gas and dust that is illuminated by sunlight.
Polydomous wood ant colonies form distinct trails of ants travelling between these nests: workers carry food, nesting material, brood, and queens along these trails in both directions (Rosengren and Pamilo 1983).
