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DuoNat
Open DuoNat

Getting more out of it

How to use DuoNat

The game is one screen: two photos, two names. Underneath it there is a good deal more — drill a single taxon, narrow to one country, hand someone a set as a link. Here is what to do, depending on what you're after.

Start here

Four gestures cover almost everything.

Match the names

Drag each name onto the photo you think it belongs to. Get the same taxon right three times in a row and it counts as learned.

Swipe left, swipe right

Left brings the next pair. Right goes back to the one before, when you want another look at it.

Swipe up

Opens the pairs you've already seen, newest first. Tap one to jump straight back to it.

Swipe down

Opens the filter sets you've played and how far you got in each. Tap one to pick up where you left off.

A DuoNat round: two toucan photographs, one above the other, with the names “Keel-billed toucan” and “Toco toucan” between them waiting to be matched.

Starter kits

Not sure where to begin? Each of these opens DuoNat with the filters already set. Change or clear them whenever you like — nothing here is permanent.

Two of them show what else the filters can do: you can narrow to a single country or continent, and you can play at the level of families rather than species. How that works.

Birds, gently

The biggest collection in DuoNat, easiest level, species against species. A good first hour.

Plants & wildflowers

The things you actually walk past. Harder than it sounds.

Mammals, by family

Families rather than species — voles against squirrels, not one vole against another. A different way to see the group.

Butterflies of Ecuador

One country, one group. Swap Ecuador for anywhere you're going — this is what the country filter is for.

Fungi, for experts

Hardest level only, species against species. Small, and not gentle.

Straight to the deep end

Everything DuoNat has, hardest level only. Pairs that look alike on purpose.

Six ways to use it

The same game underneath, and very different sessions on top. Take whichever one matches what you came for.

“I keep mixing these two up”

Good for: One stubborn confusion

  1. Press and hold the pinning knob between the two name tiles, about half a second. On a laptop, double-click it instead.
  2. Search for the taxon you keep getting wrong, and pick it.
  3. Every pair from now on contains that taxon against a different partner — which is the practice that actually separates it from its look-alikes.
  4. Unpin when you're done, and the filters you had before come back.
The two green name tiles, “Keel-billed toucan” and “Toco toucan”, with a small round pin button sitting between them.
The pinning knob, between the two name tiles.

The pinning knob also works directly on what is already on screen: flick it toward one of the two names to pin that taxon, and flick it back to the middle to let go. That is a different move, though — it keeps your current filters and varies the partner inside them, where searching from the knob clears the filters to draw partners from everything DuoNat has.

The top of DuoNat's filter dialog: buttons for Diversity, All Levels and Rank on one row, a world map button and Clear Filters on the next.
The top of the filter dialog, where most of what follows starts. The world map is the location filter.

“What lives where I’m going?”

Good for: A trip, or your own backyard

  1. Tap the chili-pepper icon in the top left to open the filters.
  2. Tap the world map, then choose Other Location.
  3. Type a country into the search field — or any other place, a city or a national park — and pick it from the results.
  4. Play. Only taxa actually recorded there will come up.

A country resolves instantly and keeps working once you are offline. Anywhere smaller is looked up on iNaturalist when you pick it, so give it a few seconds.

By default a pair only appears if both of its taxa occur where you picked. If that turns out to be too strict, Settings → Filter can relax it to either one. (Settings appears in the menu once you sign in.)

“I want to learn the warblers”

Good for: One branch of the tree, properly

  1. Open the filters (the chili-pepper icon, top left) and tap Diversity.
  2. Browse the tree of life as an outline, or search for the group by name.
  3. Tap Filter clade to play only what lives inside it.
  4. Add Rank if it helps — it decides whether you're learning to tell families apart or species apart.

The number beside each row is how many taxa DuoNat has in that branch, so you can see the size of the job before you commit to it.

DuoNat's phylogeny browser, listing the families inside the woodpeckers-and-barbets order with the number of taxa in each.

“Make it harder”

Good for: When everything feels too easy

  1. Open the filters (the chili-pepper icon, top left) and change the level: Easy, Medium, Hard.
  2. Level means visual similarity, not obscurity — Hard is two things that genuinely look alike, not two names you have never heard.
  3. Tap the leaf counter at the top to see the set’s progress. Each taxon climbs green, silver, gold — how progress works has the detail.
  4. Once the set is gold throughout, widen the filters by one step and start the climb again.

“Make a set for someone else”

Good for: Teachers, guides, parents

  1. Set up the filters you want — a clade, a country, a difficulty, or a single pinned taxon.
  2. Tap the share button, or press S. On a narrow screen it moves into the menu behind the ☰ button.
  3. Choose which parts travel with the link: the pair, the level, the region, the clade, the pinned taxon.
  4. Hand over the link or the QR code. It opens exactly your set — no account, no install.

A shared link replaces whatever filters the recipient had, rather than narrowing what they were already playing. What you set up is what they see.

“I just want to look around”

Good for: Reading, not being quizzed

  1. Open the filters (the chili-pepper icon, top left) and tap View collection to page through every pair and every taxon in your current set, with photos.
  2. Tap the ⓘ on any photo for that taxon’s names, its range, and a few facts — each one linked to the source it came from.
  3. Press A during a round to see how the two taxa are related — where their branch of the tree splits, and what sits on either side of the split.
  4. None of this scores you. Wander as long as you like.
A taxon info panel for the Keel-billed toucan, listing three facts about how it sleeps and feeds, each with a link to its source.

How progress works

The leaf counter at the top of the screen is not a score. It measures one thing: how much of the set you are currently playing you actually know. Each taxon climbs three rungs, and each rung has its own color.

DuoNat's top bar: a chili-pepper icon, a green leaf beside the count 13 of 59, then buttons for ancestry, the daily streak, help and the menu.
The top bar. The leaf and the count are the set’s progress; the chili pepper on the left opens the filters.
Learned
Identify it correctly three times in a row. A green leaf appears beside its name. Get it wrong before that and the count starts again — but once it is learned, it stays learned.
Confirmed
Meet it again in a different pair and get it right. The leaf turns silver. It has to be a new partner: knowing a taxon against one look-alike is not the same as knowing the taxon.
Mastered
And once more, against a third. Gold. At that point you can tell it apart from several different things it resembles, which is what identifying in the field actually asks of you.

Tap the counter to see the set broken down, how many taxa are left, and whether you are looking at your current filter or your whole history. Finish every taxon in a set and it is complete — which is the moment to widen it.

Getting somewhere with it

A set with an end is a set you can finish, and finishing is the part that makes the next one worth starting. Four things that help:

Start smaller than feels ambitious

One family, one country, one difficulty. A few dozen taxa is a set you can finish in a handful of sessions — where all of life is a number that never visibly moves.

Widen by one step, not ten

When a set goes gold, change one thing and only one: the family next door, the next level up, a different country. Most of what you already learned still counts, so the new set starts part-finished rather than from nothing.

Pin the one you keep getting wrong

A wrong answer sends a taxon’s three-in-a-row back to zero, so one blind spot can sit on the bottom rung while everything around it goes gold. Pin it rather than waiting for it to come round again: five minutes against a different partner each time usually settles it.

Keep a few sets running

Swipe down for the last twelve sets you have played, each with its own progress. A hard one for when you are sharp and an easy one for a bus ride is a better arrangement than one set you only sometimes feel like.

One thing about widening: the filters hold a single clade and a single location, so moving on is a swap, not an addition — you can play the family next door, but not it and the one you just finished together. Working through a superfamily means walking its families one at a time. The other direction is up: take the rank above, and if that turns out to be too much, drop back down into a branch you have not played yet.

Every gesture, in one place

Most of what DuoNat can do sits behind a gesture rather than a button, so this is worth a skim even if you have been playing a while.

Drag a name
Onto the photo you think it belongs to. That is the answer.
Swipe left / right
The next pair, or the one before it.
Swipe up
The pairs you've already seen. Tap one to return to it.
Swipe down
The filter sets you've played, with your progress in each.
Pinch a photo
Zoom and pan. Zooming out past the crop shows the whole original photograph.
Press and hold a photo
A magnifier lands on that spot; keep your finger down to move it around.
Press and hold the ⓘ
Goes straight to that taxon on iNaturalist, skipping the dialog.
Tap the little map
Hides the range maps — they can give the answer away. A globe button brings them back.
Tap the badge on a photo
Other versions of the same pair, where they exist: female, male, adult, young.
Flick the pinning knob
Toward a name pins that taxon; back to the middle releases it.
Press and hold the pinning knob
Opens the search, to pin any taxon rather than one on screen. This one clears your filters; flicking does not.

On a keyboard

N / P
Next pair, previous pair
C
Open the filters
A
How the two taxa are related
I / O
Info for the top photo, info for the bottom one
S
Share what you are playing
G
The pairs you've seen
K
Every shortcut
?
Help

Anything else

The FAQ covers where the photos come from, whether you need an account, and what it costs. If something on this page does not work the way it says, that is worth knowing about — email us or drop into the Discord.