Future Directions
While centuries of research have been devoted to characterizing and understanding animal social behavior, there is a surprisingly limited amount of knowledge of how social behaviors affect trophic interactions to generate patterns in communities. Since animal social status has predictable, well-documented effects on individual diet and movement, investigating how animal social behaviors contribute to intraspecific variation in seed dispersal effectiveness may explain much of the unresolved variation in seed dispersal and plant recruitment. There is an important lacuna in non-primate systems for understanding how social status may explain intraspecific variation in diet and space use, and consequently seed dispersal effectiveness. While a few studies show that social status explains individual diet composition in some potential seed-dispersing vertebrates (e.g., pampas foxes and pronghorn; Dennehy 2001; Castillo et al. 2011), there is limited knowledge of how it may explain the well-documented dietary variation in omnivorous species where social status is known to determine resource access, such as many carnivore species (Box 1). Since this current lacuna is likely due to the difficulty of tracking both seed fate and the behaviors of cryptic animals, we suggest methods for systems where animal behavior and seed fate cannot be measured by direct human observation of wild animals (Table 1).
Our framework also highlights that individual social status may play an unappreciated role in determining post-dispersal seed survival and recruitment when individuals of different social statuses utilize different habitat types. We therefore strongly suggest that future research measuring individual behavior, social status, and seed movement also evaluate the quality of seed-deposition sites by measuring rates of post-dispersal seed predation and seedling establishment (Table 1). We predict that this framework will be most important in systems where plant species are dispersal limited, animal social status affects individual diet and movement, and fleshy fruit is an essential dietary supplement for subordinate individuals (e.g., carnivore and folivore populations). Understanding how social status affects seed dispersal may be most critical in systems where animal social structure is modified or destabilized, illuminating cryptic hotspots of seed dispersal loss.