Dynamic network partnerships and social contagion drive cooperation

Abstract

word limit) 44Both reciprocity and positive assortment (like with like) are predicted to promote the evolution of cooperation, yet how partners influence each other's behavior within dynamic networks is not 46 well understood. One way to test this question is to partition phenotypic variation into differences among individuals in the expression of cooperative behavior (the "direct effect"), and

Reciprocity and behavioral heterogeneity govern the stability of social networks

“…Manakins were captured using mist-nets and each male was outfitted with unique color bands and a coded nano-196 tag transmitter (NTQB-2, Lotek Wireless; 0.35 g). To record the social network at a given lek, proximity data-loggers (SRX-DL800, Lotek Wireless) were deployed in each territory to record 198 all tag detections within the territory from 06:00 to 16:00 for ~6 consecutive days (± SD 1 day), which comprised a single recording session (26,39). Territory ownership was assigned using 200 direct observation of color-banded males at the display sites (22), and was subsequently verified in the proximity data.…”

“…Data processing All data processing and statistical analyses were performed in R 3.5.1 (45). Male-male 210 cooperative interactions on the display territories were determined using spatiotemporal overlap of tag detections in the proximity data (26). Specifically, a social interaction was defined as a 212 joint detection of two males within approximately 5 m on a territory during the breeding season (26).…”

“…Male-male 210 cooperative interactions on the display territories were determined using spatiotemporal overlap of tag detections in the proximity data (26). Specifically, a social interaction was defined as a 212 joint detection of two males within approximately 5 m on a territory during the breeding season (26). This spatial range corresponds to the visual and acoustic contact required for a typical 214 display interaction in this species (22,46).…”

“…Because both individuals in a social 310 partnership can contribute to its fate, and because they both had other partnerships in the dataset, we modelled persistence using a multiple-membership structure in a binomial mixed-effects 312 regression model, fit with the brms package (55). This method can be used to account for multiple partner identities within a single random effect (26,(55)(56)(57). In our analysis, the two 314 identities were weighted equally, because we assumed they could both determine partnership persistence.…”

“…Cooperative partnerships are a key part of the manakin social system (5, 22, 23), 58 similar to humans (24). Male wire-tailed manakins cooperate by forming display coalitions which are the basis of dynamic social networks (25,26). Cooperation occurs on display 60territories that are clustered into spatial aggregations called leks.…”