Sources & media
Bird image, field note, and recording sources.
Every licensed bird image used by Bird Tone is credited here with its original source, license, and modification record. Field-note and recording sources follow in the same ledger.
Identification sources
- American Robin identification guide ↗
American Robins have warm orange underparts set against a dark head and gray-brown back.
- Blue Jay identification guide ↗
Blue Jays show blue, black, and white patterning, including strongly barred wings and tail.
- American Goldfinch identification guide ↗
Breeding male American Goldfinches are bright yellow with a black forehead and black wings.
- House Sparrow identification guide ↗
Male House Sparrows combine a gray crown, dark bib, and warm chestnut-brown wing and back patterning.
- Eastern Bluebird identification guide ↗
Male Eastern Bluebirds are vivid blue above with a rusty or brick-red throat and breast.
Photo sources and licenses
- American Robin photo by Rhododendrites ↗
CC BY-SA 4.0 · resized to a 1200px maximum edge; target color neutralized for Field Marks; reviewed whole-bird alpha reused for the silhouette; background removed for the Color Memory reveal; no crop or anatomy reconstruction.
- Blue Jay photo by Rhododendrites ↗
CC BY-SA 4.0 · resized to a 1200px maximum edge; target color neutralized for Field Marks; reviewed whole-bird alpha reused for the silhouette; background removed for the Color Memory reveal; no crop or anatomy reconstruction.
- American Goldfinch photo by Omaksimenko (EXIF credit: Oleg Maximenco) ↗
CC BY-SA 4.0 · resized to a 1200px maximum edge; target color neutralized for Field Marks; reviewed whole-bird alpha reused for the silhouette; background removed for the Color Memory reveal; no crop or anatomy reconstruction.
- House Sparrow photo by Rhododendrites ↗
CC BY-SA 4.0 · resized to a 1200px maximum edge; target color neutralized for Field Marks; reviewed whole-bird alpha reused for the silhouette; background removed for the Color Memory reveal; no crop or anatomy reconstruction.
- Eastern Bluebird photo by Dehaan ↗
CC BY-SA 3.0 · resized to a 1200px maximum edge; target color neutralized for Field Marks; reviewed whole-bird alpha reused for the silhouette; background removed for the Color Memory reveal; no crop or anatomy reconstruction.
Field recordings and licenses
- American Robins in North Carolina by G. McGrane ↗
Public domain (author dedication) · Original recording; Bird Tone made no audio edits. Bird Tone keeps a verified copy for reliable, on-request playback.
- Blue Jay “queedle” call by Jonathon Jongsma ↗
CC BY-SA 3.0 · Original recording; Bird Tone made no audio edits. Bird Tone keeps a verified copy for reliable, on-request playback.
- American Goldfinch call by U.S. Fish and Wildlife Service ↗
Public domain (U.S. federal government work) · Original recording; Bird Tone made no audio edits. Bird Tone keeps a verified copy for reliable, on-request playback.
- House Sparrow “tschilp” call by Joseph Sardin ↗
CC0 1.0 · Original recording; Bird Tone made no audio edits. Bird Tone keeps a verified copy for reliable, on-request playback.
- Eastern Bluebird song near a nest box by Jonathon Jongsma ↗
CC BY-SA 3.0 · Original recording; Bird Tone made no audio edits. Bird Tone keeps a verified copy for reliable, on-request playback.
Project-owned interface art
The Bird Tone logo, favicon, and decorative SVG shapes are project-owned interface artwork. Social previews use the licensed American Robin photograph credited in the photo ledger above.
Interface icons
Navigation and action icons come from the open-source Lucide icon set, distributed under the ISC License.
How to use these materials
The photograph exercise teaches attention to one mark. It should not be treated as a complete identification authority. Identification guidance is linked and paraphrased. Bird Tone redistributes only the individual photographs and recordings listed above under their stated licenses.
Questions from the field
Using credited media
Can I reuse the bird photos or recordings from Bird Tone?
Check the license for the specific item before reuse. Each photograph and recording keeps its own creator, source, and license link here; Bird Tone does not replace those license terms.
How were the practice images and calls changed?
Each photo entry states the resize, field-mark neutralization, silhouette, and background-removal work used for practice. Each recording entry states whether Bird Tone made an audio edit and links to the original source.