Approach Social status estimation Seed dispersal measurements
Experimental: Wild populations
Social interactions: Remote cameras to video-record behavior of individuals in social context at foraging stations Each station has 2 food items: primary resource (e.g., carrion) and secondary resource (fruit) Direction of aggressive/submissive behaviors indicates relative dominance among individuals in a dyad or group Food item selection by solitary individuals confirms a preference for primary resource and role of social interactions in frugivory Link individual behavior to scat collection: Food items are tagged with fine glitter or fluorescent dye (unique color for each station) Hair snags near each food item to capture DNA samples to ID individual genotypes Dispersal distance: Presence/color of glitter or dye in scat indicates distance and direction of movement from station Quantity of seeds dispersed: Count number of seeds per scat deposit Germination trials to estimate # viable seeds per scat Sequence DNA from scat to link individual genotypes from scat and feeding station assay Quality of seed dispersal: Estimate rates of seed removal (see Bartel & Orrock 2021 for seed removal tray design) in microhabitats where scat is found
Experimental: Captive populations
Human observers record direction of aggressive/submissive behaviors to estimate each captive group’s dominance hierarchy Each group is given 2 food items: primary resource (e.g., carrion) and secondary resource (fruiting shrubs) Dispersal distance: Observations of individual gut retention times can be used with published estimates of movement distances in wild populations to estimate potential dispersal distance Quantity of seeds dispersed: Count number of seeds per scat deposit per individual Germination trials to estimate seed viability
Observational: Remote sensing Remote cameras to video-record behavior of individuals in social context at primary resources (e.g., carrion or fruiting trees) and secondary resources (e.g., fruiting shrubs) Direction of aggressive/submissive behaviors indicates relative dominance among individuals in a dyad or group Individuals may be distinguished either visually in photos or with radio-collars Dispersal distance: Published estimates of gut retention times and movement distances can be used to estimate potential dispersal distance Quantity of seeds dispersed: Visually estimated through video recordings at fruit sources (# of visits and # of seeds consumed per visit)
Observational: Molecular analyses Extensive scat collection may be done in systems where social status carries a molecular signature. Identify individuals through genetic analysis of scat. The following molecular approaches may be used estimate individual social status: Fecal glucocorticoid concentration is related to dominance in some cooperative breeding species (Creel 2001) Reproductive hormone concentrations may be used in systems where reproductive status affects dominance Genetic analyses to identify sex may be used when sex affects dominance Average mass of scat per individual may provide estimation of individual size when size affects dominance Quantity of seeds dispersed: Count number of seeds per scat deposit Germination trials to estimate # viable seeds per scat Quality of seed dispersal: Estimate rates of seed removal in microhabitats where scat is found