Add xeno-canto to Animals (#3059)

README.md

@@ -182,6 +182,7 @@ API | Description | Auth | HTTPS | CORS |
 | [RescueGroups](https://userguide.rescuegroups.org/display/APIDG/API+Developers+Guide+Home) | Adoption | No | Yes | Unknown |
 | [Shibe.Online](http://shibe.online/) | Random pictures of Shiba Inu, cats or birds | No | Yes | Yes |
 | [The Dog](https://thedogapi.com/) | A public service all about Dogs, free to use when making your fancy new App, Website or Service | `apiKey` | Yes | No |
+| [xeno-canto](https://xeno-canto.org/explore/api) | Bird recordings | No | Yes | Unknown |
 | [Zoo Animals](https://zoo-animal-api.herokuapp.com/) | Facts and pictures of zoo animals | No | Yes | Yes |
 
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