{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T13:16:49Z","timestamp":1785417409555,"version":"3.56.0"},"reference-count":54,"publisher":"Cambridge University Press (CUP)","issue":"5","license":[{"start":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T00:00:00Z","timestamp":1774310400000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0"}],"content-domain":{"domain":["cambridge.org"],"crossmark-restriction":true},"short-container-title":["Parasitology"],"published-print":{"date-parts":[[2026,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>\n                    Ricinid lice are exceptionally large-bodied relative to their hosts and tend to form small infrapopulations. They exhibit a more pronounced female bias (predominance of females) than most other lice. Sex ratios (SRs; the proportions of males) of 10 hummingbird-ricinid species pairs collected from South and North America were examined. There was a significant positive relationship between infrapopulation size and SR in 5 cases, and similar non-significant tendencies in 4 cases. Two formerly constructed hypotheses had been considered to explain this relationship. First,\n                    <jats:italic>Wolbachia<\/jats:italic>\n                    infections may account for the female bias, but male aggression during mating could elevate female mortality resulting in higher male proportions in large infrapopulations. Second, the Local Mate Competition (LMC) Hypothesis predicts that highly inbred infrapopulations should exhibit female-biased SRs. Small infrapopulations are likely to be inbred because of stronger genetic drift and are also more likely to originate from single infestations. Conversely, multiple infestations can generate larger and more outbred infrapopulations that are less affected by genetic drift, leading to a shift towards more balanced SRs. This results in a positive correlation between infrapopulation size (infestation intensity) and SR. Both hypotheses provide explanation for the positive association between infestation intensity and the proportion of males, although the LMC aligns more strongly with the actual values of the observed SR bias. Notably, the former hypothesis refers to the physiological mechanism, whereas the latter refers to the adaptive value of the SR bias. These 2 hypotheses are not mutually exclusive.\n                  <\/jats:p>","DOI":"10.1017\/s003118202610184x","type":"journal-article","created":{"date-parts":[[2026,3,24]],"date-time":"2026-03-24T06:04:26Z","timestamp":1774332266000},"page":"646-653","update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":0,"title":["Alternative hypotheses to explain the relationship between infestation intensity and sex ratio of ricinid lice (Psocodea: Phthiraptera: Ricinidae) infesting hummingbirds (Apodiformes: Trochilidae)"],"prefix":"10.1017","volume":"153","author":[{"given":"Yoshika","family":"Oniki-Willis","sequence":"first","affiliation":[{"name":"Independent Researcher"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edwin O","family":"Willis","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00987cb86","id-type":"ROR","asserted-by":"publisher"}],"name":"Institute of Biosciences, State University of S\u00e3o Paulo (UNESP)"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3481-5673","authenticated-orcid":false,"given":"Old\u0159ich","family":"Sychra","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/04rk6w354","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Veterinary Sciences"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Terry","family":"Galloway","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/02gfys938","id-type":"ROR","asserted-by":"publisher"}],"name":"University of Manitoba"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9470-0934","authenticated-orcid":false,"given":"Lajos","family":"R\u00f3zsa","sequence":"additional","affiliation":[{"name":"HUN-REN Centre for Ecological Research"},{"id":[{"id":"https:\/\/ror.org\/00rb16m44","id-type":"ROR","asserted-by":"publisher"}],"name":"National Laboratory for Health Security"},{"id":[{"id":"https:\/\/ror.org\/02rmd1t30","id-type":"ROR","asserted-by":"publisher"}],"name":"Babe\u015f-Bolyai University"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2026,3,24]]},"reference":[{"key":"S003118202610184X_ref34","doi-asserted-by":"publisher","DOI":"10.1186\/s40168-023-01462-9"},{"key":"S003118202610184X_ref32","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-294X.2004.02409.x"},{"key":"S003118202610184X_ref11","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1098\/rspb.1994.0072","article-title":"Ectoparasite virulence is linked to mode of transmission","volume":"256","author":"Clayton","year":"1994","journal-title":"Proceedings of the Royal Society B: Biological Sciences"},{"key":"S003118202610184X_ref24","doi-asserted-by":"publisher","DOI":"10.1111\/evo.13147"},{"key":"S003118202610184X_ref1","first-page":"129","article-title":"Biologie und \u00d6kologie der Amselfederl\u00e4use","volume":"9","author":"Baum","year":"1968","journal-title":"Angewandte Parasitologie"},{"key":"S003118202610184X_ref36","doi-asserted-by":"publisher","DOI":"10.1038\/sj.hdy.6800760"},{"key":"S003118202610184X_ref52","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.ento.42.1.587"},{"key":"S003118202610184X_ref21","volume-title":"IOC World Bird List (v15.1)","author":"Gill","year":"2025"},{"key":"S003118202610184X_ref5","doi-asserted-by":"publisher","DOI":"10.2307\/3284227"},{"key":"S003118202610184X_ref48","doi-asserted-by":"publisher","DOI":"10.2307\/5727"},{"key":"S003118202610184X_ref2","doi-asserted-by":"publisher","DOI":"10.1007\/s00265-024-03533-9"},{"key":"S003118202610184X_ref18","doi-asserted-by":"publisher","DOI":"10.1016\/0040-5809(86)90013-4"},{"key":"S003118202610184X_ref16","first-page":"333","article-title":"Von Alexander Koenig gesammelte Federlinge. 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Published by Cambridge University Press.","name":"copyright","label":"Copyright","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}},{"value":"This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike licence (http:\/\/creativecommons.org\/licenses\/by-nc-sa\/4.0), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the same Creative Commons licence is used to distribute the re-used or adapted article and the original article is properly cited. The written permission of Cambridge University Press or the rights holder(s) must be obtained prior to any commercial use.","name":"license","label":"License","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}},{"value":"This content has been made available to all.","name":"free","label":"Free to read"}]}}