ArticleProceedings of the National Academy of Sciences of the United States of America2025
Rapid morphological change in an urban bird due to COVID-19 restrictions.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 4 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
4 citing papers in PubMed.
- Unexplained rapid bill-size changes in an urban bird during the COVID-19 anthropause.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- Reply to Acoca-Pidolle and Mathieu: Rapid phenotypic change in an urban bird likely driven by resource changes during COVID-19.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- Human action shapes the beaks of backyard birds.Proceedings of the National Academy of Sciences of the United States of America · 2026Article
- Rapid morphological change in an urban bird due to COVID-19 restrictions.Proceedings of the National Academy of Sciences of the United States of America · 2025Article
Corrections and comments
- Commented on by
Authors and funding
2 authors.
Funding
Abstract
The COVID-19 pandemic provided a natural experiment to test the impacts of human activity on urban-dwelling wildlife. Urban dark-eyed juncos differ in bill shape and size in Los Angeles in comparison to local wildlands. We measured juncos that hatched before, during, and after COVID-19 restrictions at a Los Angeles college campus. Birds that hatched during and soon after COVID-19 restrictions had bills that resembled those of local wildland birds. Yet, bills rapidly returned to pre-COVID-19 morphology in birds hatched in the years following pandemic restrictions. Thus, human activity (and lack thereof) underlies rapid morphological change in an urban bird.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.