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The rules

Please visit the new home of the Pan-species Listing rules.

Here are the rules from the old Pan-species Listing webpages, with comment chain, for historical interest.

Geography: The biogeographical unit of ‘the British Isles’, i.e. Britain, Ireland and the Isle of Man, including the seas around the isles (defined for the UK as the UK Economic Exclusion Zone of 200 nautical miles (370 kms) or midpoint between the UK and any neighbouring country). The Channel Islands also count, even if they are biogeographically part of France.

Taxonomy: All species in the animal, plant, fungus and protist Kingdoms, i.e. everything except Bacteria and viruses. Bacteria are excluded partly because they have not been traditionally covered by naturalists and partly because the very concept of a species is difficult to apply to Bacteria.

Taxonomic level: Only species count as ticks. But note that a ‘splinter faction’ has made a good case for ticking higher level taxa: see Malcolm Storey’s page.

Sensory: You must see the species, not just hear it. It doesn’t count if you see it only via television or digital camera.

Alive or Dead: Dead wildlife doesn’t count, except for invertebrates where you can count species that you have only seen in lethal trap samples (e.g. pitfall traps, malaise traps). Yes, it would be better if we had a consistent rule across all taxonomic groups but most entomologists count species that they have only seen dead, and neither Jonty nor Dave is able easily to submit a list total excluding species they have only seen in trap samples. Of course, trapping should only be carried out where the results are likely to justify the casualties, e.g. on a site that is scheduled for development.

Free or Captive: It is scraping the barrel to tick things in captivity but most moth-ers are happy to tick moths in pots in fridges. So pan-species listers can tick things that are being temporarily held captive, if they wish. Species in long-term captivity (e.g. zoo or farm animals) or culture (e.g. crops, garden plants) don’t count.

Developmental stage: All developmental stages count. For example, eggs, larvae, nymphs and pupae count just the same as adult insects, if they can be confidently identified. Likewise, plants that are not in flower can be counted (even though not everyone chooses to do so). Even seeds can be counted as long as they are alive, which raises the possibility of adding sea beans, nickar nuts and other marine drift seeds if you can find them and get them to germinate.

Aliens: I think this is the area, more than any other, where attempts to make a simple set of rules that can be applied consistently across all taxonomic groups, are doomed to failure! There is a spectrum from native species that have lived in Britain from before the time that humans started to make their mark on the planet, up to alien species that have just been intercepted on arrival at one of our ports. Although I value the true natives above all others, I find the whole spectrum fascinating. So I draw the ‘line in the sand’ to include the majority of aliens as long as they have established, or seem capable of establishing, without deliberate human assistance. I’d count any garden plant that has dispersed and established beyond the garden fence. I’d count any invertebrate that has established, even if only in highly man-modified environments (e.g. only in warehouses or heated greenhouses). But I wouldn’t count any of the invertebrates that you can occasionally find in your groceries but which are unlikely to be able to survive here unaided.

Hybrids: Ordinarily, interspecific hybrids are evolutionary dead-ends with little or no fertility: not countable. But amongst plants at least, there are numerous species which have a hybrid origin, usually formed by polyploid hybrid speciation. Pan-species listers won’t want to count a hybrid unless it can reproduce and persist in the absence of one or both parent species. The wording “one or both” is deliberately chosen: Edible Frogs and various Sorbus species are countable but have a hybrid origin and need reproductive contact with one of the parent species to be able to reproduce themselves. In practice, it’s not always easy to determine whether a hybrid plant is countable or not. Dave Gibbs suggests that as a rule of thumb, any hybrid that is normally known by its own name is a countable one (e.g. Viola x wittrockiana, Garden Pansy) whereas any that is normally known by the combination of both parents is not countable (e.g. Viola riviniana x V. reichenbachiana, the hybrid of Common and Early Dog-violets).

Be your own judge: Most pan-species listers have their own rigid standards about what they can and can’t count. I won’t count anything that’s in a pot. Dave won’t count plants unless he’s seen them in flower. Martin won’t count anything unless he’s found it for himself. We only need a set of rules if we’re competing against each other to get the biggest list. But pan-species listing is more about the personal challenge to get a grip on the immense biodiversity of these islands.


  1. Andrew Duff says:

    What about mollusc shells? Most snail and marine mollusc recording is done from empty shells found casually, but these are not from lethal trap samples. Similarly can you count a cuttlefish bone?

  2. Steve Gale says:

    Not allowed to count the Channel Islands but you can count Eire? Surely some mistake! All botanical recording carried out by the BSBI includes the Channel Islands and always has done. Can you please rethink on this one Mark?

  3. Steve Gale says:

    PS – all UK botanical lists include the Channel islands, including the legendary Wild Flower Society league tables. And yes, I’ll admit it, I’ve got a few flower species that I’ve only seen on Jersey!!! It is all a bit haphazard when looking at other groups and what they allow as part of their recording areas. The BOU don’t recognise Eire as part of their recording unit, but the lepidopterists and botanists do, with trips to the Burren part of the circuit. I propose that we shouldn’t treat the Channel Islands as off limits.

  4. markgtelfer says:

    Andrew, a pan-species lister will always want to see an animal alive. All credit to those who record empty shells, tideline corpses, road casualties, feeding signs, fossils, etc. But I don’t think they should count. Mark

  5. markgtelfer says:

    Steve, There’s nothing to prevent you starting a West Pal Pan-species List. But I agree we should include the Channel Islands. Even if they are biogeographically part of France, they have always been covered by British naturalists and ignored by the French. Mark

  6. James H-M says:

    I have recently discovered ‘official’ pan-listing, after doing it myself for the past year or so.

    However, with shore species being one of my main specialities, I would plead for the acceptance of deceased specimens – most of my deeper water species were found dead on the shore.

    I’ll have to get my species total totted up and submitted, but I would expect to be in the lowest position – for now.

  7. markgtelfer says:

    James, welcome aboard. A pan-species lister will naturally be interested in empty shells, tideline corpses, road casualties, feeding signs, fossils, etc. But they will not be satisfied until they have seen the organism alive. So I don’t think dead should count. We’ll just have to club together to hire a submarine! Mark

  8. Dave Green says:

    Hi Mark,
    Now, I know that everyone has their own rules for pan-species listing, but what are your thoughts on plant galls?
    For many of the galls you can be sure of the identity of the organism that has caused the gall, but even if the gall is still occupied you can’t necessarily see the agent that caused it.
    I would err towards counting it as it is a direct expression of the species genes. What do you reckon?

    All the best.


  9. markgtelfer says:

    I like having one rule to cover all groups, so I have to see the living gall-causing organism. I either break open a gall, or rear out the gall-causer. I see your point but wouldn’t it be the same as ticking, say, a Harvest Mouse nest without having seen the mouse that built it? Mark

  10. Simon Horsnall says:

    What are people’s thoughts on “wire hoppers” or potential “wire hoppers”? I’m disinclined to count them as they don’t make it onto my bird list but can we ever be sure about things like ducks? We have a nearby Red-tailed Hawk. Can I count it now, when it has produced hybrid young with a Common Buzzard or never?

  11. Owen Martin says:

    Does a garage window count as a lethal trap? I’ve found Odes, various hemiptera, beetles, fishflies, dozens of moths, six species of Chrysops, Tabanidae, lacewings, harvestmen, etc. on the windowsill. I live in the US, so I can’t really do official listing, but I’m curious about what actually entails a lethal trap. Do you have to set it with the intention of catching specimens? Or can you take advantage of an existant structure?

  12. markgtelfer says:

    Simon, I think your Red-tailed Hawk would have to establish a breeding population (with others of its own kind) to become tickable. Will be interesting to see if the hybrid offspring are fertile.

  13. markgtelfer says:


    Another interesting query about listing rules. I would still stick to my guns and say that whether the organism has been killed accidentally or deliberately, you can’t tick dead things. But why do I feel this way? After all, there is a great deal to be learnt about biodiversity by studying tidelines, fossil beds, road casualties and other sources of deceased specimens as well as by pitfall trapping, malaise trapping and other lethal sampling techniques.

    But while the collectors of old might have been happy to find a dead specimen and add it to their cabinet, I think pan-species listers should aim to experience wildlife alive. Nothing really compares to seeing a bird/mammal/insect/whatever alive, in its habitat, doing its thing, foraging, displaying, mating, fighting.

    I am also wary of a set of rules which might encourage people to catch and kill wildlife simply to add to their lists.

  14. Stuart Warrington says:

    How about adding Francis Rose to the list – his notebook data are on the NBN & show 3640 species.


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