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Wildlife introduction

Rare species
New species
Extinct species

Species information:
Monthly reports
Marsh Harrier
Migration dates
Ringing 2005
Ringing 2006
Ringing 2007
Ringing 2008
Ringing 2009
Ringing 2010
Ringing 2011
Ringing 2012


It is inevitable that some species will become extinct on a nature reserve. Species may not adapt to the changing environment and climate. Their populations may become so small that a run of bad weather during their breeding season may be enough to push them to extinction. The risk of species extinction also greater in a reserve that is at a distance from reserves of similar habitat types, because there is no chance of new immigrants arriving to bolster a failing population.

Species believed extinct at Wicken Fen (examples)

Birds - Montagu's Harrier, Spotted Crake, Marsh Warbler
Butterflies - Swallowtail, Large Copper, Marsh Fritillary,  Dark Green Fritillary
Moths - Reed Tussock, Marsh Dagger, The Many-lined, Gypsy Moth
Hymenoptera (Bees) - 8 species of Bombus bumblebee
Coleoptera - Dromius sigma, Pterostichus aterimus, Lixus paraplecticus
Dragonflies - Small red damselfly, Common Hawker, Keeled Skimmer, Black Darter, Norfolk Hawker (extinct in the Fens)
Crustacea - White-clawed Crayfish
Vascular plants - Wild Celery, Lesser Marshwort, Greater Water-parsnip, Bottle sedge, Bladder sedge, Common Cotton-grass, Black Bog-rush, Round-leaved Sundew, Water Soldier, Bulbous Rush, Heath Wood-rush, Greater Duckweed, Marsh Helleborine, Fen Orchid, Green-winged Orchid, Heath Grass, Golden Dock, Bog Pimpernel,  Marsh Lousewort, Vervain

Extinction of the Swallowtail Butterfly

One of the most famous extinction at Wicken Fen was that of the beautiful Swallowtail Butterfly (Papilio machaon britannicus). The Fen was famous for the Swallowtail and entomologists came from far and wide to see and collect the species. Swallowtail butterflies used to occur all over the fenlands, but by 1904 William Farren wrote “Swallowtail still exists in considerable numbers in Wicken Fen but no longer in the surrounding fens and north of Ely where it was plentiful 50 or 60 years ago”.

The Swallowtail caterpillars only feed on one food plant, the Milk Parsley (Peucedanum palustre). This is a rare plant which only thrives in wet fen habitats. At Wicken the fen was drying out, as the land around it was drained for agriculture. The Milk Parsley was becoming less abundant and the Swallowtail butterfly seems to need lots of strong growing food plant in order to thrive. Gradually, the Swallowtail numbers declined and by 1952 it could not be found. The National Trust and expert entomologists have tried three times to re-introduce Swallowtail butterflies to Wicken Fen (1955, 1975, 1993), and also spent a lot of time trying to increase the abundance of the food plant. However, each time the Swallowtail butterflies survived for a few years and then became extinct again. The conclusion was that the Fen was not wet enough for the Milk Parsley (which still survives) to be sufficiently vigorous and abundant for a viable Swallowtail population to survive.

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Wicken Fen, Lode Lane, Wicken, Ely, Cambridgeshire, CB7 5XP, UK
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