City birds are smaller but noisier: morphology, body condition, and song variation between Rufous-collared Sparrows (Zonotrichia capensis) from urban and wild environments in Central Chile

City birds are smaller but noisier: morphology, body condition, and song variation between Rufous-collared Sparrows (Zonotrichia capensis) from urban and wild environments in Central Chile | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article City birds are smaller but noisier: morphology, body condition, and song variation between Rufous-collared Sparrows (Zonotrichia capensis) from urban and wild environments in Central Chile Juan David Arévalo, Carlos E. Valeris-Chacín, Sebastián Maya-Miranda, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9004083/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Urban environments impose challenges for wildlife survival, yet some populations show morphological and behavioral adaptations to these novel conditions. The Rufous-collared Sparrow, Zonotrichia capensis, is a neotropical bird that successfully inhabits both urban and wild environments. This study evaluated morphological and song variations of populations in Central Chile and their association with food availability and anthropogenic noise. We measured 34 individuals from the urban and 64 from the wild environment and recorded 46 songs during the breeding season. Food availability and fragmentation were evaluated through primary productivity (NDVI), alongside environmental noise levels. Results show that individuals inhabiting the urban environment have a smaller size, lower body mass, and lower body condition than their conspecifics from wild environments. Furthermore, song structure shows an increase in the minimum frequencies in the urban population, where we registered higher noise levels. These findings suggest that continuous food availability, higher fragmentation, and anthropogenic noise in the city explain the morphological and vocal divergence observed in urban populations compared to wild ones. Anthropogenic noise fragmentation morphology urban environment vocalization Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 05 Apr, 2026 Reviewers invited by journal 31 Mar, 2026 Editor assigned by journal 03 Mar, 2026 Submission checks completed at journal 03 Mar, 2026 First submitted to journal 01 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9004083","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":615082487,"identity":"2ca7f59a-e233-4db7-9116-580d967e0846","order_by":0,"name":"Juan David Arévalo","email":"","orcid":"","institution":"University of Chile","correspondingAuthor":false,"prefix":"","firstName":"Juan","middleName":"David","lastName":"Arévalo","suffix":""},{"id":615082488,"identity":"2509f32f-8ef1-4e72-b33b-b14ff634466a","order_by":1,"name":"Carlos E. 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