| Clue | Source | Date |
|---|---|---|
| Their voices echo in the mountains | ||
| Some long-distance callers | New York Times | 14 Sep 2024 |
| They sing in the Alps | Newsday | 01 May 2024 |
| High-range singers? | Universal | 27 Aug 2015 |
| High-range singers? | ||
| Some Alpine singers | ||
| Alpine singers | ||
| Alpine songsters | ||
| High-range singers? | ||
| "The Lonely Goatherd" performers, e.g. | ||
| Swiss warblers. |