Canvasback and parasitic redhead egg identity data
Data files
Mar 10, 2026 version files 7.49 KB
-
egg_dat_for_archive.csv
5.96 KB
-
README.md
1.53 KB
Abstract
Validating the accuracy of protocols and field observations is important to maintain consistency amidst changing observers or study sites. To aid inferences on interspecific brood parasitism, we validated 200 field observations of egg identification to the species level against mitochondrial DNA sequencing for nests where interspecific brood parasitism was suspected. Of the samples submitted for sequencing, 29 failed to sequence resulting in 171 DNA verified samples of canvasback (Aythya valisineria) and redhead (Aythya americana) eggshell membranes. We found observers were highly accurate at differentiating eggs between the two species despite experience level, and hatched eggshell membranes contained the best quality tissue samples for sequencing success when compared with eggshell tissue samples from earlier in incubation. Our investigation showcases the utility of non-invasive molecular techniques to validate field protocols and rejects egg identification as a major source of uncertainty when trying to account for interspecific brood parasitism in parasitized canvasback nests.
Dataset DOI: 10.5061/dryad.r4xgxd2t4
Description of the data and file structure
Data was collected to compare field identification of duck eggs with DNA validated species identification. We also tested assumptions about observer experience, sample quality, and sample structure to improve future non-invasive sampling efforts. Data is uploaded as .csv file.
Files and variables
File: egg_dat_for_archive.csv
Description: Data was collected to compare field identification of duck eggs with DNA validated species identification. We also tested assumptions about observer experience, sample quality, and sample structure to improve future non-invasive sampling efforts. Analysis was performed in Program R using R2jags package.
Variables
- Sample.ID: unique sample ID
- Spp: species of egg from visual observations (canv = Aythya valisineria, redh = Aythya americana)
- age.bin1: 0-9 days incubation (hatched membranes as reference group)
- age.bin2: 10-24 days incubation (hatched membranes as reference group)
- conc: sample DNA concentration (ng mL-1; continuous)
- correct.id: egg species confirmed by mtDNA sequencing
- succ.seq: sample sequenced successfully (0 - no, 1 - yes)
- redh: "1" if confirmed spp is Aythya americana, "0" if Aythya valisineria
- obs.bin1: first year observer (3+ year as reference group)
- obs.bin2: second year observer (3+ year as reference group)