Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Ornithology

Danish dairy farmer delivers data coup

Neither the name Peder V. Thellesen nor the Danish Ornithological Society Journal will resonate with most Nature readers. In a striking example of citizen science, the Danish journal has just published 45 years of Thellesen's breeding data from his studies of starlings (Sturnus vulgaris) in 27 nesting boxes on his dairy farm (P. V. Thellesen Dansk Ornitol. Foren. Tidsskr. 111, 87–95; 2017). As far as we know, this data set provides a world-class example of the effects of climate change on the natural world.

The starlings advanced the date of their egg-laying by 1 day every 5.0 years for the first clutch and every 4.7 years for the second clutch. Thellesen found that this change in breeding onset significantly correlated with the mean rise in local April temperatures over those periods. Clutch size and hatch rate remained constant, although nesting-box occupancy has fallen by 40% since 2004, in line with the bird's decline nationally and regionally.

Thellesen ringed a total of 12,450 starlings, or 1 in 16 of all starlings ever ringed in Denmark. Although he has no formal scientific training, his patient and systematic observations far exceeded the duration of any funded research project. As the language gap between scientists and the public widens, we find this work an inspiring reminder of the might of human curiosity.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Tony Fox.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Fox, T., Heldbjerg, H. Danish dairy farmer delivers data coup. Nature 550, 333 (2017). https://doi.org/10.1038/550333b

Download citation

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing