uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Thermal emissivity of avian eggshells
Show others and affiliations
2016 (English)In: Journal of Thermal Biology, ISSN 0306-4565, E-ISSN 1879-0992, Vol. 57, 1-5 p.Article in journal (Refereed) Published
Abstract [en]

The hypothesis has been tested that evolution has resulted in lower thermal emissivity of eggs of birds breeding openly in cold climates than of eggs of birds that nest under protective covering or in warmer climates. Directional thermal emissivity has been estimated from directional-hemispherical reflectance spectra. Due to several methodological difficulties the absolute emissivity is not accurately determined, but differences between species are obvious. Most notably, small waders of the genus Calidris, breeding in cold climates on the tundra, and in most cases with uniparental nest attendance, have low directional emissivity of their eggshells, about 0.92 when integration is carried out for wavelengths up to 16 mu m. Species belonging to Galloanserinae have the highest directional emissivity, about 0.96, of their eggs. No differences due to climate or breeding conditions were found within this group. Eggs of most other birds tested possess intermediate emissivity, but the values for Pica pica and Corvus corone cornix are as low as for Calidris. Large species-dependent differences in spectral reflectance were found at specific wavelengths. For instance, at 4.259 mu m the directional-hemispherical reflectance for galliforms range from 0.05 to 0.09, while for Fratercula arctica and Fulmarus glacialis it is about 0.3. The reflection peaks at 6.5 and 11.3 mu m due to calcite are differentially attenuated in different species. In conclusion, the hypothesis that evolution has resulted in lower thermal emissivity of bird eggs being exposed in cold climates is not supported by our results. The emissivity is not clearly related to nesting habits or climate, and it is unlikely that the small differences observed are ecologically important. The spectral differences between eggs that nevertheless exist should be taken into account when using infrared thermometers for estimating the surface temperature of avian eggs.

Place, publisher, year, edition, pages
2016. Vol. 57, 1-5 p.
Keyword [en]
Avian eggs; Birds; Heat dissipation; Egg cooling; Thermal emissivity; Incubation; Seabirds; Thermal radiation; Waders
National Category
Other Biological Topics Bio Materials
URN: urn:nbn:se:uu:diva-284493DOI: 10.1016/j.jtherbio.2015.11.008ISI: 000374359800001PubMedID: 27033033OAI: oai:DiVA.org:uu-284493DiVA: diva2:920459
Available from: 2016-04-18 Created: 2016-04-18 Last updated: 2016-06-22Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textPubMed

Search in DiVA

By author/editor
Roos, ArneNilsson, Annica M.
By organisation
Solid State Physics
In the same journal
Journal of Thermal Biology
Other Biological TopicsBio Materials

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 156 hits
ReferencesLink to record
Permanent link

Direct link