Plan around a species
The free Trip Engine ranks all twenty-two files against your dates and shows which of these are actually in your window — with a month scrubber to preview the whole year.
JOURNEYS/REFERENCE / THE NATURE MATRIX
Three hundred and fifty-four British species and seasonal spectacles — birds, mammals, marine life, butterflies, fungi, flowers, fossils, dark skies and a full freshwater, fly and sea angling thread. Filter by month, rarity, group or expedition, tap to log a sighting, and the whole thing works offline.
01 / HOW THE INDEX WORKS
Every entry carries a rarity band, the months it is actually in season, a one-line field note and the expedition files that hunt it. COMMON you will probably see; LIKELY rewards a little looking; LUCKY needs the day to go your way; ★ RARE is never promised and never chased. Tap any card to log a sighting to this browser.
02 / THE INDEX
Combine filters freely — "May, rare, in the Highlands" or "fish, any month" for the angling thread. The region filter asks you where you are rather than tracking you: no location permission, no coordinates, nothing to consent to.
FIELD LAW: DISTANCE · PATIENCE · ENGINE OFF — THE CHECKLIST TICKS ITSELF; THE ARCHIVE NEVER CHASES.
03 / THE ANGLING THREAD
The archive tracks freshwater, fly and sea species alongside everything else, because a campervan and a rod belong together. Three honest rules travel with them: a rod licence is required for freshwater fishing in England and Wales (Scotland and Northern Ireland run their own permit systems); the coarse close season runs 15 March to 15 June on English rivers; and almost all water is owned or clubbed — a day ticket is the normal price of a cast. Sea fishing needs no licence, but size and bag limits do apply. Check locally, every time.
04 / TAKE IT WITH YOU
The free Trip Engine ranks all twenty-two files against your dates and shows which of these are actually in your window — with a month scrubber to preview the whole year.
Six species carry each expedition. Four earns bronze, all six turns the patch gold. Rank runs Passenger to Archivist of the Nebuchadnezzar.
Every expedition page prints an A6 spotting card — six species, tick boxes, no signal required. The best version of this runs on a picnic table.
Distance, patience, engine off. No nests, no leks, no baiting, no chasing. Nothing in this index is worth disturbing an animal for — the log records what found you.
05 / A–Z
The whole Matrix as a plain list — useful when you already know the name, and readable with images off, scripts off or on a very slow connection.
FOUND THIS USEFUL?
Everything in the free archive today - the expedition files, the Nature Matrix, the seven calculators and the Trip Engine - is free forever. In future, we may offer paid expansions for people who want more. They will add to the free archive, never take anything away from it.
But if a file saved you a wasted weekend, or the Matrix put a puffin in front of your children, you are very welcome to stand us a coffee. It goes on diesel, ferries and the next expedition — which comes back up here, free, for you.
Fuel for the Nebuchadnezzar£10 · ONE PAYMENT →Entirely optional. One payment, never a subscription — and you can set any number up to ten at the checkout if you are feeling especially kind. No perks, no supporter tier, and absolutely no hard feelings either way.
FACTS VERIFIED AUGUST 2026Spotted something out of date? Tell us →