Age, sex, and temperature shape within- and among-individual space use in black-capped chickadees

Historically, spatial ecology studies have focused on average movement patterns within animal groups; however, recent studies highlight the value of considering movement decisions both within- and among-individuals. Using a marked population of black-capped chickadees (Poecile atricapillus), we used the number of unique feeders an individual visits within our study area as a proxy for space use to assess the causes and consequences of within- and among-individual differences in chickadee space use. We found that as temperature decreased, feeding rate increased. Females, but not males, increased the number of unique feeders used coincident with the temperature-related increase in feeding rates. This may be due to sex-related differences in dominance, where males which are the dominant sex in chickadees, have priority access to feeders, while females increase their foraging areas to meet higher energetic demand. We also found that independent of temperature, juvenile males used more unique feeders than adult males. We suggest that this may be due to age-specific benefits of space use in male, where un-paired juvenile males may increase feeder exploration to gain information about potential mates. Finally, although chickadees showed repeatable differences in space use throughout our study, we found no evidence that space use predicted annual survival. Overall, our results suggest that dominance hierarchies and individual energetics impact within- and among-individual variation in space use. We provide suggestions for future studies to enhance understanding of fitness-related consequences of within- and among-individual variation in space use.