Pan Listing – Why looking at all species matters…

Epipogium aphyllum, Buckinghamshire August 1971

It has been a privilege, and a joy, that my professional life has allowed me to indulge fully a fascination with the incredible variety of life forms that live on our planet.

Having taught biology briefly, and developed a passion for Lepidoptera, I was appointed a student assistant at Leicester Museum at the beginning of my career. A biological curator in a regional museum is responsible for looking after study collections in all groups of organism. This gives the opportunity to work on that all important vocabulary that I believe is so necessary in evaluating and understand the ecology of our environment.

Leicester museum concentrated on collections of British specimens. These ranged from stuffed animals to the parasites that live in association with these animals. The museum had an active taxidermy department, and I well remember the disgust of a member of the public who had donated a dead hedgehog to the museum, when, in the museum’s acknowledgement of her presentation, it was described as a ‘fine collection of fleas and other parasites’ which had been added to a large spirit collection of small invertebrates all carefully labelled, preserved in alcohol  and stored in jars. The hedgehog itself was not required for the mammal collection. The specimens had to be identified accurately before they were catalogued. What a fantastic beginning this training was for the dedicated pan lister.



Another route into expertise as a field ecologist is through conservation either through organisations such as Natural England or local county naturalists’ trusts. Staff in these organisations spend large amounts of time in the field assessing the value and health of the countryside. They cannot fail to increase their knowledge and their species vocabulary.

Leucorrhinia dubia, Surrey June 1981

Many naturalists and professional ecologists are specialists, and to gain a respected expertise in any group requires a lifetime of study. Life is short, and with a potential of thousands of life forms to be learned, an advanced knowledge of all groups is clearly unobtainable. However, must be room, and an important place, for naturalists with broad based knowledge. This experience allows ecologists to see conservation problems across the board, and to come up with holistic solutions. It is understandable that specialists in conservation will be biased towards their group.

Having spent twenty years as a professional biological museum curator, in 1988 I went freelance as an ecologist. I had hoped that my broad approach would be an asset for site evaluation, but as I launched myself into this new world, it rapidly became apparent that a broad approach would get me nowhere. Slowly, and almost without realising it, I began to specialise, and my particular group is lichens.

Carex atrofusca, Perthshire July 1974

In spite of this, I have maintained my broad approach as a dedicated pan lister. I have kept lists all my life, first written by hand in notebooks and then typed and stored in ring files. As long as I can remember, I have kept lists at British and World levels in all groups, flitting in a less than disciplined fashion from group to group as my enthusiasms took me. I accept a species onto my list if I have seen it in the wild, or if it has recently been taken from the wild. I add a species to my list if I am shown it by an expert whom I trust. I do not necessarily have to arrive at the identification myself. Two groups that offer a particular challenge to the ethics of pan listing are lichens and Lepidoptera.

A lichen is an association between a fungus, or fungi and an alga, or algae. In fact, a lichen can consist of a fungus with a second species, either living parasitically or in harmony in the association. There are one or two lichen fungi that can live in association with more than one alga, and the associations can look very different. However, even though one association may be a dull brown and the other bright green, they can only be considered as ecotypes of the fungus. Lichens are all named on their fungal partner, which in almost every case cannot survive independently. I know of no lichenologist who actually makes a list of the alga in the lichen association. In my personal list of algae, I have just one species of blue green alga that forms lichen associations.

Eriocrania subpurpurella, Sharpthorne, Sussex April 2004

Lepidoptera create enormous ethical problems for the lister, and I probably take a more relaxed approach than many. Many listers like to list only those species they see genuinely in the wild.  Can a bird be counted if it has been caught in a mist net, if it has been taken into care or if it is recently dead? Many would not allow such birds onto their lists. Can a moth sitting on a piece of egg carton in a moth trap be considered natural? I believe most lepidopterists would have little problem with this, so long as they were running the trap. There are obvious grades of acceptability away from this. Is it right to travel to see species caught in other people’s traps? If so, must the moth still be sitting as it was originally on its piece of egg carton, or can it be stored in a pot in a fridge? I would support a lepidopterist who only listed species seen sitting naturally on tree trunks, flying or perhaps attracted to wall lights but if a purist approach is adopted, then I can see a big argument for not listing species trapped away from their wild habitat.

Crucibulus laeve, Abbot's Wood, Sussex September 1987

Putting my lists together is proving to be a most enjoyable, but highly time consuming exercise. My lists are stored on my computer using databases constructed from software called Filemaker Pro. These (designed by my wife) do exactly what I want, and are superb at sorting species under a series of headings. As I began to amalgamate my lists recently, I found that there are life lists made prior to 1991, the date I started using Filemaker Pro. These lists have proved to be a source of several species that would have been left off my lists. Even pan listers are human, and humans are liable to error. Species may be omitted when being added from one list to another. However, the goal is an up-to-date, comprehensive list using current taxonomy. How many will ever be able to achieve this goal? Approaching perfection will be such fun. In my case, I have the added attraction of listing all my world species as well.

Cryptothallus mirabilis, Hampshire February 1974

Pan listing has been a very private pastime until Mark Telfer began to get some of us together. We all come from a variety of positions in ecology and taxonomy, and have many motivations, ethical positions and goals. What we share is a holistic approach to the world in which we roam.

Please add comments to this blog, either about what you think of my position or how you see pan listing.  Or simply to say hello.