Images of spread wing specimens used for the evaluation of new methods for estimating the total wing area of birds

Authors

Hellen (Yi) Fu
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
hellen.fu@mail.utoronto.ca

Michelle Su
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
michelle.su@mail.utoronto.ca

Santiago Claramunt
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada
Department of Natural History, Royal Ontario Museum, Toronto, Ontario, Canada
Orcid: 0000-0002-8926-5974
<s.claramunt@utoronto.ca>
claramunt.bio@gmail.com

Citation

Fu, H., M. Su & S. Claramunt (2023) Wing images used for testing new methods for estimating the total wing area of birds. Dryad Dataset https://doi.org/10.5061/dryad.cc2fqz6c9

Funding

• Natural Sciences and Engineering Research Council of Canada, Award: RGPIN-2018-06747, Discovery Grant

• Royal Ontario Museum, Canada

Abstract

Images of extended wing preparations of 112 specimens representing 40 avian families were used for testing new methods for estimating the total wing area of birds.

Materials and Methods

Spread wings photographed at the ROM were placed on white paper on a copy stand with a Nikon Z50 mirrorless camera mounted directly above the wing. An L-shaped ruler was placed next to the wing to provide the scale. Two Godox LEDP260C Bi-Color LED light panels on tripods were set at 100% brightness and 5000K color temperature and placed on either side of the camera to minimize shadows. Large wings were photographed in the ROMs photo studio. Wings at LSU were photographed using a hand-held camera and a digital or manual leveler to ensure the camera was directly above the wing. To reduce measurer error, photographs were taken and digitally measured only by H.F. and M.S.

Processed images were obtained using ImageJ v.1.53 (U.S. National Institutes of Health, Bethesda, Maryland). We set the scale using the scale ruler in the image and used the Threshold tool to transform the photo into a binary (black and white) image, sometimes followed by the Fill Holes option. Most images were further edited manually using the Brush tool to fill small border gaps in broken or disarranged feather vanes, or to fill marginal white spots not distinguished from the background by the thresholding tool. Finally, the Eraser tool was used to delete anomalies due to disarranged cover feathers, usually near the shoulder area, and to create a straight proximal border that would represent the root chord (parallel to the axis of the body and perpendicular to the wing leading edge).

References

Fu, H., M. Su, J. J. Chu, A. Margaritescu & S. Claramunt. In press. New methods for estimating the total wing area of birds. Ecology and Evolution link

Data and file structure

The main folder contains the original digital photographs and the subfolder contains the images processed for obtaining estimates of wing area using the ImageJ software; repeated estimates for some wings are included in a subfolder of the later calles :subfolder “Re-measured Binary.” Image are in Joint Photographic Experts Group (JPEG) or Digital Negative (DNG) formats. Image file name convention is as follows: [scientific name] [collection acronym]_[specimen number] [additional information such as shot type (ventral or dorsal), number (e.g. 1 of 2), or whether it is the binarized image (“bin”)].[filename extension: jpg or DNG].