Box 1. Carnivores as variable seed dispersal agents
Carnivores can be important agents of directed, long-distance dispersal (Herrera 1989; Willson 1993; Rost et al. 2012; López-Bao et al. 2015; Hämäläinen et al. 2017; Shakeri et al. 2018), and rodent aversion to carnivore scat promotes the survival of scat-dispersed seeds (Bartel & Orrock 2021). Individual niche specialization (i.e., where intraspecific variation in seed dispersal effectiveness should be most pervasive) is most common in upper trophic levels (Araújo et al. 2011), and many carnivore species exhibit high intraspecific variability in diet composition (Dumond et al.2001; Darimont et al. 2009; López-Bao & González-Varo 2011; Cypher et al. 2014; Davis et al. 2015; Newsome et al. 2015; Manlick et al. 2019). For carnivore populations with dominance hierarchies, rank can constrain individual resource access (Zimen 1976, 1981; Tilson & Hamilton 1984; Gese et al. 1996) and space use (Gese 2001; Henry et al. 2005; Dorning & Harris 2017; Kamler et al. 2019), which likely produces predictable intraspecific variation in the quantity and distance of seeds dispersed. Below, we describe two carnivore species where recent work on social behavior indicates that social structure may predict individual seed dispersal effectiveness.