Spacing systems in mammals: is territoriality always what it seems?

1. Is mammalian territoriality a process or a result?

   Comment on territories as "defended areas" vs. territories as "exclusively used" areas. Use bannertailed kangaroo rats as example of the problem. Radiotelemetry shows very little overlap, also virtually no use of periphery; animals are aggressive towards intruders at den but no data elsewhere. Is aggression maintaining the home range exclusivity? Could it be a side effect of central-place foraging?

   
   
2. Does mammalian territoriality involve defense of space or defense of resources?

   The more interesting definition is defense of space, even space that does not include resources at the moment. But some apparent "territoriality" may just reflect defense of resources. example: gray-cheeked mangabeys, groups show large exclusive core areas, but playback experiments show no evidence that aggression is site-specific, rather they suggest that mangabey groups simply avoid close proximity; could exclusive areas be a byproduct of this behavior plus site attachment?

   
   
3. Is it reasonable to expect mammalian "intruders" to be detected and evicted, or could there by "defense by exploitation"?

   For many mammals, home ranges are large and mobility is relatively low. Is it likely that animals will detect intruders? If not, why shouldn't intruders be more common? Example: white-tailed mongoose, solitary foragers that live in nonoverlapping areas. Animals scent mark wherever they are, but encounters never seen. Why not? How frequent or how damaging would encounters have to be to ensure that it's in an intruder's interest to think twice? Could territory-holders be manipulating resource levels at the home-range periphery to deter intruders?

   
   
4. Are the "territorial" interests of individuals in mammalian social groups necessarily coincident?

   In white-tailed mongooses, females sometimes forage independently within joint "territories". It seems as if they would benefit from some form of shared patrolling of boundaries, but no evidence that they do. Could "coordinated patrolling" evolve? In the agile mangabey, a comparison with the gray-cheeked mangabey produced a puzzling result: males of different groups responded aggressively to playbacks of their neighbors' calls, but groups nevertheless sometimes formed peaceful "supergroups". How can we predict spacing patterns when the interests of males and females in a group differ?