Credits & Licences

Maps and the Alderwing landscape

Map tiles: OpenFreeMap. Map design and schema: © OpenMapTiles (CC BY 4.0). Geographic data: © OpenStreetMap contributors, available under the Open Database Licence.

Burbz adapts the map colours and presentation and adds game scenery. Trees and buildings in Alderwing are game illustrations, not surveys of individual objects. The map renderer is MapLibre GL JS (BSD 3-Clause).

Elevation © Mapterhorn, combining Copernicus and regional terrain data. The full terrain credits and required source notices include Copernicus, the Environment Agency, Scottish and Welsh sources, with the complete contributor catalogue linked there.

Map credits can also be opened with the ⓘ control on each map.

Burbz Quest

bgm-burbz-quest-v2.mp3 is the original two-minute instrumental Burbz Quest, generated with ElevenLabs on 26 July 2026 for the game's crossfaded background-music loop. It replaces the original one-minute bgm-birbs-quest.mp3 runtime track, which remains in the pack for provenance.

Bespoke Burbz sound design

ambience-empire-treetops.mp3 and the twelve sfx-*.mp3 files were generated specifically for Burbz with ElevenLabs on 26 July 2026. They form a warm woodland palette of polished wood, parchment, feathers, wind magic, restrained chimes, battle feedback, rewards, and a seamless Empire-view treetop ambience.

Their use remains subject to the Burbz project owner's ElevenLabs account and applicable service terms.

The night sky

The stars, constellation figures and star names over Alderwing come from d3-celestial by Olaf Frohn (BSD 3-Clause), built from the HYG star database by David Nash (CC BY-SA 2.5) and the Yale Bright Star Catalogue. Burbz works out where each one stands from the date, the clock and your place, with the Sun, Moon and planets from published almanac formulas. Nothing leaves your phone.

Weather

Alderwing makes its own weather: fair skies with drifting cloud, and now and then a passing shower. It needs no weather service, and your position never leaves your phone for it.

Calm walking and camp sounds

The campfire, chopping, dusting and eating sounds in camp/ were generated specifically for Burbz with ElevenLabs on 24 September 2026. They keep quiet moments soft and close.

The footsteps in footsteps/ were generated for Burbz with ElevenLabs on 27 September 2026: steps on grass, pavement and wood, wading steps and a splash for stepping into a river.

bard-lute-loop.mp3 is Pip Marrow's lute tune, generated for Burbz with ElevenLabs Music on 7 October 2026 and cut into a 15-second seamless loop. It plays when you walk near a travelling bard.

Their use remains subject to the Burbz project owner's ElevenLabs account and applicable service terms.

Nature sounds

The frogs, rising fish, lapping waves, grasshoppers, far sheep, rutting stag, foxes, twig snaps and other small voices of Alderwing's quiet places, the leaf and shingle footsteps, and two battle sounds were generated for Burbz with ElevenLabs Sound Effects v2 on 29 September 2026. They are made sounds, not recordings. Each plays as a single event from a place near you; none loops.

Their use remains subject to the Burbz project owner's ElevenLabs account and applicable service terms.

British birds

Every bird you hear on a walk was checked with BirdNET before it went in, so a British wood sounds like a British wood. ElevenLabs made all or some of the crows, ravens, geese, rooks, blackbird chinks and robin ticks. Where ElevenLabs could not make a bird that BirdNET recognised, Burbz uses a real recording by a British birder, shared on iNaturalist and found through GBIF. Each is cut to one call or phrase, filtered, faded and levelled. Thank you to every recordist.

Blackbird chinks: blackbird-alarm-01 by Jose Gutierrez Higa, 2026-09-25, source, CC BY 4.0; blackbird-alarm-02 by xwarli, 2023-11-17, source, CC BY 4.0; blackbird-alarm-03 by Kathryn, 2024-11-09, source, CC BY 4.0; blackbird-alarm-04 by Claire T., 2022-09-21, source, CC BY 4.0.

Blue tit: bluetit-song-01 by Iona Cowell, 2026-01-12, source, CC0 1.0; bluetit-song-02 by Richard M, 2026-03-04, source, CC0 1.0; bluetit-song-03 by Sara Scorey, 2026-03-01, source, CC0 1.0.

Goldfinch: goldfinch-twitter-01 by Andrew Thomas, 2026-02-09, source, CC0 1.0; goldfinch-twitter-02 by Thames Valley Environmental Records Centre, 2026-03-10, source, CC0 1.0; goldfinch-twitter-03 by j_bur, 2026-04-25, source, CC0 1.0.

Wren: wren-song-01 by Bettina Grieser Johns, 2026-03-06, source, CC0 1.0; wren-song-02 by Diane Hornsby, 2026-03-20, source, CC0 1.0; wren-song-03 by Ollie Davis, 2026-02-23, source, CC0 1.0.

Common buzzard: buzzard-01 by Jo Roberts, 2026-04-14, source, CC0 1.0; buzzard-02 by Sara Scorey, 2026-03-02, source, CC0 1.0; buzzard-03 by Mathew Robinson, 2025-09-22, source, CC0 1.0; buzzard-04 by Richard Lowry, 2025-08-31, source, CC0 1.0; buzzard-05 by Richard M, 2025-08-24, source, CC0 1.0.

Pink-footed geese: geese-01 by olmagon, 2025-12-21, source, CC BY 4.0; geese-02 by Andy Donegan, 2024-12-19, source, CC BY 4.0; geese-03 by Barry Stewart, 2026-09-17, source, CC BY 4.0; geese-04 by Paul Round, 2025-02-03, source, CC0 1.0.

Jay: jay-01 by Eleanor, 2025-10-12, source, CC0 1.0; jay-02 by Kieran Roy Powell, 2024-03-22, source, CC0 1.0; jay-03 by Stephen James McWilliam, 2025-04-20, source, CC0 1.0; jay-04 by Em Calam, 2025-09-20, source, CC0 1.0; jay-05 by Chris Procter, 2026-02-05, source, CC BY 4.0.

Moorhen: moorhen-01 by A Emmerson, 2025-02-06, source, CC BY 4.0; moorhen-02 by Charlie Farrell, 2022-04-27, source, CC0 1.0; moorhen-03 by Alison JC Brown, 2025-02-23, source, CC0 1.0; moorhen-04 by plant512, 2021-06-19, source, CC0 1.0.

Raven: raven-02 by Phil Miller, 2023-03-19, source, CC0 1.0; raven-04 by Bardia, 2025-04-28, source, CC0 1.0; raven-05 by Sarah Adamson, 2024-11-10, source, CC0 1.0; raven-06 by Beth King, 2026-05-08, source, CC0 1.0.

Woodpigeon: woodpigeon-01 by Dave Shenton, 2025-03-04, source, CC0 1.0; woodpigeon-02 by James Feehan, 2026-05-22, source, CC0 1.0; woodpigeon-03 by Africa Gomez, 2026-07-15, source, CC0 1.0.

Grey heron: heron-01 by A Emmerson, 2021-04-17, source, CC BY 4.0; heron-02 by Andrew Skotnicki, 2025-03-08, source, CC BY 4.0.

The ElevenLabs sounds remain subject to the Burbz project owner's ElevenLabs account and applicable service terms.

Legacy medieval UI and reward sounds

ui-book, ui-lock, ui-coins, ui-wood, ui-metal, and ui-spell are adapted from 80 CC0 RPG SFX by rubberduck. Source · CC0 1.0.

reward-level-up is adapted from Rise03 in the Level Up sound pack by WobbleBoxx Workshop. Source · CC0 1.0. These files are retained as legacy assets and are no longer the default interaction sounds.

Real bird recordings

Burbz never plays these to you. A recorded call coming out of the game would sound like a bird you had just heard, so the two clips below serve only as test fixtures for the sound-identification self-check on the server.

Common Blackbird song (Turdus merula) by Diana Tudor, source recording, licensed under CC BY 4.0. Burbz excerpted 17.2–19.4 seconds, downmixed, filtered, normalized, faded, and re-encoded the clip.

Tawny owl calling at night in Tuntorp, Brastad, Sweden by W.carter, source recording, licensed under CC BY 4.0. Burbz excerpted 69.7–71.9 seconds, downmixed, filtered, normalized, faded, and re-encoded the clip.

Owls and night birds

The tawny owls of Alderwing and the birds you hear after dark are real recordings from xeno-canto, found through GBIF. Each file is one call or phrase. Burbz cut it, filtered it to the bird's own range, took out a little hiss, faded it and set its level. Every recording is CC0, CC BY or CC BY-SA; the CC BY-SA cuts are shared under CC BY-SA 4.0. Thank you to every recordist.

Tawny owl: tawny-hoot-01 from XC707096 by Sonothèque ADVL, France 2021, CC0 1.0; tawny-hoot-02 from XC835723 by Grégoire Chauvot, France 2023, CC0 1.0; tawny-hoot-03 from XC758790 by Alvaro Ortiz Troncoso, Germany 2022, CC BY-SA 4.0; tawny-kewick-01 from XC684111 by Lewis Kratky, England 2021, CC0 1.0; tawny-kewick-02 from XC1136032 by Christian Kahle, Germany 2026, CC0 1.0; tawny-kewick-03 from XC797480 by Grégoire Chauvot, France 2021, CC0 1.0; tawny-trill-01 from XC583836 by Alvaro Ortiz Troncoso, Germany 2020, CC BY-SA 4.0; tawny-trill-02 from XC707096 by Sonothèque ADVL, France 2021, CC0 1.0; tawny-trill-03 from XC835723 by Grégoire Chauvot, France 2023, CC0 1.0.

Barn owl: barnowl-screech-01 from XC707104 by Sonothèque ADVL, France 2021, CC0 1.0; barnowl-screech-02 from XC433736 by Joost van Bruggen, the Netherlands 2018, CC BY-SA 4.0; barnowl-screech-03 from XC1090740 by Noé Ferrari, France 2026, CC BY 4.0.

Little owl: littleowl-keeew-01 from XC1095903 by Petr Holecek, Czech Republic 2026, CC0 1.0; littleowl-keeew-02 from XC432927 by Joost van Bruggen, the Netherlands 2018, CC BY-SA 4.0; littleowl-keeew-03 from XC1089094 by Noé Ferrari, France 2026, CC BY 4.0.

Long-eared owl: longeared-hoot-01 from XC1107817 by Sonothèque ADVL, France 2026, CC0 1.0; longeared-hoot-02 from XC1103088 by Robert Petersen, Sweden 2026, CC BY-SA 4.0.

Redwing: redwing-tseep-01 from XC842620 by Jochem verweij, the Netherlands 2023, CC BY-SA 4.0; redwing-tseep-02 from XC707307 by Sonothèque ADVL, France 2021, CC0 1.0; redwing-tseep-03 from XC1062625 by Lionel Triboulin, France 2025, CC0 1.0; redwing-tseep-04 from XC1056587 by Philippe_Grange, France 2025, CC0 1.0.

Woodcock: woodcock-croak-01 from XC803891 by Grégoire Chauvot, Sweden 2023, CC0 1.0; woodcock-croak-02 from XC1005085 by Christian Kahle, Germany 2025, CC0 1.0; woodcock-tsiwick-01 from XC803891 by Grégoire Chauvot, Sweden 2023, CC0 1.0.

Nightjar: nightjar-churr-01 from XC432929 by Joost van Bruggen, the Netherlands 2018, CC BY-SA 4.0; nightjar-churr-02 from XC732172 by Sonothèque ADVL, France 2022, CC0 1.0; nightjar-churr-03 from XC1143454 by Tanguy Loïs, France 2026, CC BY-SA 4.0.

Corncrake: corncrake-crex-01 from XC1083485 by Robert Petersen, Sweden 2025, CC BY-SA 4.0; corncrake-crex-02 from XC735898 by Max Karlsson, Sweden 2022, CC BY-SA 4.0; corncrake-crex-03 from XC1138956 by Petr Holecek, Czech Republic 2026, CC0 1.0.

Nightingale: nightingale-song-01 from XC895646 by Eamon Gorman, England 2024, CC0 1.0; nightingale-song-02 from XC818342 by Sonothèque ADVL, France 2023, CC0 1.0; nightingale-song-03 from XC138451 by Sander Pieterse, the Netherlands 2013, CC BY-SA 4.0.

Moorhen: moorhen-call-01 from XC1080589 by Lionel Triboulin, France 2026, CC0 1.0; moorhen-call-02 from XC919286 by Sonothèque ADVL, France 2024, CC0 1.0; moorhen-call-03 from XC432930 by Joost van Bruggen, the Netherlands 2018, CC BY-SA 4.0.

Curlew: curlew-call-01 from XC543951 by Dan Whitley, England 2020, CC BY-SA 4.0; curlew-call-02 from XC776631 by Sonothèque ADVL, France 2022, CC0 1.0.

Bird sound identification

Powered by BirdNET. Sound scans are analysed on the Burbz server; the recogniser is selected at start-up.

BirdNET+ V3.0 by the K. Lisa Yang Center for Conservation Bioacoustics (Cornell Lab of Ornithology) and Chemnitz University of Technology powers Burbz's bird-sound suggestions. The model weights are licensed under CC BY-SA 4.0 and the source is MIT licensed. Burbz runs the published V3.0 preview 3.1 Global 11K weights unmodified for inference; species are narrowed by BirdNET Geomodel V3.0.2, also CC BY-SA 4.0. Burbz is a distinct application and is not endorsed by the BirdNET project. Cite: Kahl et al., 2021, BirdNET: A deep learning solution for avian diversity monitoring, Ecological Informatics 61:101236.

Perch 2.0 by Google Research — an alternative recogniser, model and weights licensed under the Apache License 2.0. ONNX conversion via the Kitzes Lab bioacoustics-model-zoo (MIT).

Earlier BirdNET models (V1.1–V2.4) are licensed CC BY-NC-SA 4.0 — NonCommercial — and are not used in this build.

No project endorses Burbz.