Bird PlacesMethodology
Where our data comes from
Bird Places combines three kinds of information: occurrence records showing which birds are recorded where, mapped locations of hides, and practical visiting details checked by hand against each site's own published pages.
Occurrence records
Species and seasonality come from GBIF, which aggregates records from eBird, BTO BirdTrack, the NBN Atlas and other surveys.
These counts measure how often a bird is recorded, not how many are present. The distinction matters more than it sounds. Bitterns are in the reedbeds all year, but males boom in spring and are silent the rest of the time, so spring records run several times higher than winter ones. That is a change in detectability, not in the number of birds. Where our charts say a month is the peak, they mean it is the month people log most sightings.
Recording effort is also uneven. A reserve near a city with a car park and a café generates far more records than an equally good site up a track, so comparing raw totals between sites is unreliable in a way that comparing months at one site is not.
Hides
Hide names and positions come from OpenStreetMap © OpenStreetMap contributors, available under the Open Database Licence. Around 1,700 bird hides are mapped across the UK, though only some carry names.
Most operators do not publish a list of their hides at all, so this is often the only structured source. Where a site claims a number of hides but we cannot name them, we say the count is not published rather than guess.
Access, fees and opening times
These are checked by hand against the operator's own page — the RSPB, a Wildlife Trust, a council or a local society — and dated when checked. They are the fields most likely to go stale: prices change annually and opening times change with the season.
Of 78 sites currently listed, 54 have accessibility verified against a published source and 49 have a confirmed entry price. Where a field is missing, the page says so rather than filling the gap. An unchecked accessibility claim is worse than no claim, because someone may plan a trip around it.
What we get wrong
Links rot, operators reorganise their websites, and prices move. We re-check official links weekly and flag records that have not been verified within six months. If something here is wrong, the reserve's own page is the authority — and we would rather hear about it.