The effect of familiarity on the temporal dynamics of spatial and affiliative associations in monk parakeets

Claire L. O'Connell, Annemarie van der Marel , Elizabeth A Hobson

To successfully navigate dynamic social environments, animals must manage their relationships by deciding who to interact with, how often, and when. Relationships may develop between familiar group members, but novel relationships can also form as strangers join groups. The process through which relationships form among strangers is not well-known for most species. We used a captive population of monk parakeets (Myiopsitta monachus) with known familiar and stranger relationships to test how novel relationships form among strangers. We established a novel social group by combining 22 parakeets captured from four geographically distinct locations. We quantified how familiar relationships differed from stranger relationships and whether we could detect convergence of the patterning and timing of spatial and affiliative associations across three contexts: general spatial proximity, nearest neighbor identity, and affiliative interactions. We found that familiar networks were consistently more well-connected during the experiment, but stranger birds formed relationships across all three association contexts. Spatial proximity associations formed readily for both familiar and stranger birds, while nearest neighbor and affiliative interactions developed more quickly among familiar dyads, indicating that the rate and patterning of how these relationships were formed differed. We found that the birds consistently preferred familiars across all behaviors with no clear patterns of convergence between familiars and strangers but the degree of preference depended on the social context. Overall, these findings suggest that parakeets recognize and differentiate between birds they might have encountered previously and that relationships with familiar and stranger conspecifics are not interchangeable.  We discuss the differences in the effect of familiarity on spatial associations compared to affiliative contact and the extent to which these results suggest that monk parakeets balance the risks and benefits of associating with familiar and stranger birds.