Zhang, YixuanJiang, XinyiAplin, Lucy M.Wang, DaipingFarine, Damien R.2026-06-122026-06-120962-8452PubMed:41057005ORCID:/0000-0003-2208-7613/work/217157595https://hdl.handle.net/1885/733811243Social network structure plays a key role in shaping processes in animal populations. However, our understanding of how individual-level social decisions scale up to population-level social structures remains limited, particularly outside mammals. Here, we used continuous, fine-scale tracking of four large captive colonies of zebra finches (Taeniopygia guttata), revealing that zebra finches consistently maintain 1-2 closest contacts, 6-7 close contacts and 22-24 intermediate contacts, with the identities of these contacts remaining stable across days. By separating spatial co-occurrence from social preferences using null models, we demonstrate that closest and close partners are maintained by social choice, while intermediate partners are shaped by spatial affinity. These results suggest that zebra finch egocentric networks are made up of at least three different tiers of consistent, differentiated relationships. Importantly, we show that these tiers - when combined across individuals - form a multitiered social structure at the colony level. Finally, we review literature on egocentric animal networks, highlighting similarities in patterns to other species, and discuss the distinctions between multitiered and multilevel societies. Our results suggest that fundamental constraints in time, cognition and spatial organization may drive common structural properties in animal social networks across taxa.D.W. is funded by the Chinese Academy of Sciences (CAS Pioneer Hundred Talents program), the Third Xinjiang Scientific Expedition Program (Grant No. 2022xjkk0801), and the National Natural Science Foundation of China (32270452). D.R.F. was funded by the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 850859) and an Eccellenza Professorship Grant of the Swiss National Science Foundation (grant no. PCEFP3_187058). L.M.A. was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract number MB22.00056. AcknowledgementsenPublisher Copyright: © 2025 The Author(s).animal social networksegocentric structurefractal patternsrelationship differentiationsocial spatial interfaceTaeniopygia guttata2025-10-0810.1098/rspb.2025.0978105017946837