For more than 150 years, many academic experts and gifted amateurs have visited Wicken and studied its wildlife. Over the years, a superb list of the variety of wildlife that has been found at Wicken Fen has been built up and it now totals over 8020 different species. The most diverse group is not the plants or bird, but the invertebrates and especially the insects. Three groups of insects each have over 1000 species, the flies (1891 species), the beetles (1516) and the moths (1082). These three groups alone make up over 56% of all the species found at Wicken so far.

Some species are regularly recorded but others have been found only when a special study by an expert has been carried out. Even with such a long species list, there are still new discoveries to be made. In 1998, 20 species new to the Fen were discovered and another 15 species were added in 2006.  Also, there are often re-discoveries of species that had not been seen for many decades, which is always good news.

Photo, right; toad.

Table of the major species groups at Wicken Fen nature reserve
(updated June 2008)

Other taxa for which there are species lists, but are not included above table include Collembola, Dermaptera, Neuroptera, Megaloptera, Mecoptera, Psocoptera, Siphonaptera, Rotifers, Triclads, Annelida.