Table 1. Summary of sampling across growth stages for each taxon (number of specimens per growth stage), and timing of the first appearance of an incipient OCL (light red) and a distinctly-formed OCL (dark red).
| Neonate | Downy | Pin-feathered | Pre-fledgling | Fledgling | Sub-adult | Adult | |
|---|---|---|---|---|---|---|---|
| California1 Quail | 8 | — | 2 | — | — | — | 2 |
| Wild Turkey1 | 1 | — | — | 1 | — | — | 1 |
| Western Gull2 | 2 | — | — | — | — | — | 2 |
| American Kestrel3 | 2 | — | — | — | 1 | — | 2 |
| Red-tailed Hawk3 | — | 1 | — | 1 | — | — | 2 |
| White-tailed Kite3 | — | — | 1 | 2 | 3 | — | 1 |
| Barn Owl3 | — | 1 | 2 | 2 | 1 | 1 | 2 |
| Great-horned Owl3 | — | — | 1 | 1 | 1 | — | 1 |
| Mourning Dove4 | — | — | 1 | 2 | 2 | 2 | 1 |
| Anna’s Hummingbird5 | — | — | 1 | — | 1 | 3 | 1 |
| Green-cheeked conure5 | 1 | 1 | 1 | 1 | 1 | — | 1 |
| Western Scrub-Jay5 | 1 | — | 1 | 3 | 2 | 1 | — |
| House Finch5 | 1 | — | 1 | 2 | 1 | — | 1 |
Note:
This indicates the first appearance of this structure in each taxon over all, either in the humerus and/or the femur. Developmental mode is indicated by color number superscript: orange1, precocial; yellow2, semi-precocial; green3, semi-altricial 1; blue4, semi-altricial 2; purple5, altricial. Six ostrich chicks also comprise part of the dataset, but are not included here because (beyond neonate an adult) they do not fit into the growth stages used for other taxa.