Following references have been used for bird posts:
- ‘Birds | The Wildlife Trusts’. https://www.wildlifetrusts.org/wildlife-explorer/birds.
- ‘Birds A- Z | Bird Guides’. The RSPB. https://www.rspb.org.uk/birds-and-wildlife/wildlife-guides/bird-a-z/.
- Collins Wild Guide Birds. n.d. Collins.
- Holden, Peter, and Tim Cleeves. n.d. RSPB Handbook of British Birds. A&C Black Ltd.
- Holden, Peter, J T R Sharrock, and Hilary Burn. n.d. The RSPB Guide to British Birds. Macmillam.
- Hume, Rob, Robert Still, Andy Swash, Hugh Harrop, and David Tipling. n.d. Britain’s Birds. WildGuides. Prnceton.
- Sample, Geoff. n.d. Collins Field Guide Bird Songs and Calls of Britain and Northern Europe. Collins.
- Thomas, Adrian. n.d. RSPB Guide to Birdsong. Bloomsbury.
- Vinivombe, Keith, Alan Harris, and Laurel Tucker. n.d. Helm Guide to Bird Identification. Bloomsbury.
- ‘Wikipedia’. 2020. Wikipedia, the Free Encyclopedia.