{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T12:28:44Z","timestamp":1777984124752,"version":"3.51.4"},"posted":{"date-parts":[[2025,5,31]]},"group-title":"Animal Behavior and Cognition","reference-count":38,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2025,5,31]],"date-time":"2025-05-31T00:00:00Z","timestamp":1748649600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,3,3]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                <jats:p>\n                  Infanticide, the killing of dependent young by adult conspecifics, is an extreme form of conflict that remains poorly understood. Previous studies suggest that it is associated with reproductive benefits, either by making breeders newly available for reproduction or by increasing offspring care and reducing competition for resources. In addition, infanticide may result from a reproductive trade-off, where parents kill their offspring if environmental conditions compromise their reproductive value. Here, we combine video, genetic and individual-level reproductive data collected over 12 years to describe infanticide in a highly social, cooperative bird, the sociable weaver\n                  <jats:italic>Philetairus socius<\/jats:italic>\n                  and to establish whether direct reproductive benefits or life-history trade-offs are possible motivators for this behaviour. We documented 50 cases of infanticide and identified 27 aggressors with known histories. These were mostly born outside the colonies where they committed infanticide (63%) and there was a bias towards younger individuals. Aggressors were usually not part of the victim\u2019s breeding group (74%), but in two cases infanticide was committed by the breeding female, and in five by helpers. In most cases, aggressors were not reproducing at the time of the infanticide, were not recorded mating with any of the breeders or helpers from the attacked nest, nor occupied the nest from where the chicks were evicted. Only 13 of the known aggressors were confirmed as breeders after the attacks, and these mostly reproduced at the colony where the attacks were committed. Overall, we found no evidence for direct reproductive benefits of infanticide in sociable weavers. However, the younger age of aggressors, lack of genetic relatedness to the victims and future breeding at the colony suggest that competition between breeding groups, and hence indirect reproductive benefits, could provide motivation for infanticide in this population. Additional work over longer periods is needed to identify these possible indirect fitness benefits of infanticide.\n                <\/jats:p>","DOI":"10.1101\/2025.05.27.656097","type":"posted-content","created":{"date-parts":[[2025,5,31]],"date-time":"2025-05-31T16:35:17Z","timestamp":1748709317000},"source":"Crossref","is-referenced-by-count":2,"title":["Infanticide in a colonial cooperative bird is not associated with direct reproductive benefits"],"prefix":"10.64898","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7130-144X","authenticated-orcid":false,"given":"Rita","family":"Covas","sequence":"first","affiliation":[{"name":"CIBIO-InBio, Centro de Investiga\u00e7\u00e3o em Biodiversidade e Recursos Gen\u00e9ticos, Laborat\u00f3rio Associado, University of Porto, Campus Agr\u00e1rio de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"},{"name":"BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"},{"name":"FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7701, South Africa"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4475-8035","authenticated-orcid":false,"given":"Liliana R.","family":"Silva","sequence":"additional","affiliation":[{"name":"CIBIO-InBio, Centro de Investiga\u00e7\u00e3o em Biodiversidade e Recursos Gen\u00e9ticos, Laborat\u00f3rio Associado, University of Porto, Campus Agr\u00e1rio de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"},{"name":"BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0454-1053","authenticated-orcid":false,"given":"Andr\u00e9 C.","family":"Ferreira","sequence":"additional","affiliation":[{"name":"CIBIO-InBio, Centro de Investiga\u00e7\u00e3o em Biodiversidade e Recursos Gen\u00e9ticos, Laborat\u00f3rio Associado, University of Porto, Campus Agr\u00e1rio de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"},{"name":"BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"},{"name":"Department of Evolutionary Biology and Environmental Science, University of Zurich, Zurich 8057, Switzerland"},{"name":"CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4095-6088","authenticated-orcid":false,"given":"Pietro B.","family":"D\u2019Amelio","sequence":"additional","affiliation":[{"name":"FitzPatrick Institute of African Ornithology, University of Cape Town, Rondebosch 7701, South Africa"},{"name":"CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6049-3690","authenticated-orcid":false,"given":"Rita","family":"Fortuna","sequence":"additional","affiliation":[{"name":"CIBIO-InBio, Centro de Investiga\u00e7\u00e3o em Biodiversidade e Recursos Gen\u00e9ticos, Laborat\u00f3rio Associado, University of Porto, Campus Agr\u00e1rio de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"},{"name":"BIOPOLIS Program in Genomics, Biodiversity and Land Planning, CIBIO, Campus de Vair\u00e3o, 4485-661 Vair\u00e3o, Portugal"},{"name":"Department of Biology, Norwegian University of Science and Technology, Norway"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-3467-751X","authenticated-orcid":false,"given":"Delphine","family":"Duval","sequence":"additional","affiliation":[{"name":"D\u00e9partement de Biologie, Ecole Normale Sup\u00e9rieure de Lyon, Lyon, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1182-2299","authenticated-orcid":false,"given":"Matthieu","family":"Paquet","sequence":"additional","affiliation":[{"name":"Centre National de la Recherche Scientifique (CNRS), Station d\u2019\u00c9cologie Th\u00e9orique et Exp\u00e9rimentale, Moulis, France"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1893-3960","authenticated-orcid":false,"given":"Claire","family":"Doutrelant","sequence":"additional","affiliation":[{"name":"CEFE, Univ Montpellier, CNRS, EPHE, IRD, Montpellier, 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