Not all the gains have been aggressive aliens, we have also had new arrivals of native species and in some cases re-colonisations of species which have not been seen in the County for hundreds of years. The Military Orchid was first discovered in Suffolk in 1955 and the Early Spider Orchid, which reappeared in 1992, had not been seen since 1793. More recently we have added two nationally scarce species, Yarrow Broomrape and Sea Hog's Fennel.

Several of the new birds are introduced wildfowl but there are interesting species such as Cetti's Warbler which have expanded their range and Siskin which has benefited from the large conifer plantations.

ARRIVALS (first records) 1847-onwards

Over the past 150 years we have lost 5% of our native plants, 10% of dragonflies, 15% of breeding birds and 40% of butterflies. Some of these species were naturally scarce due to lack of suitable habitat, others have declined and disappeared as a result of the changes man has made to the countryside. Most of the plant extinctions have been either from wetland habitats which have suffered greatly from drainage, or from agricultural land where changes in seed processing and the use of herbicides has eliminated them. Many of the Bird and Dragonfly losses have also been due to wetland habitat destruction. The butterfly losses have been more varied with climatic factors playing a part in some species but the major factor has been habitat changes.

DEPARTURES 1847-onwards

Plants

* Has since become re-established as a breeding species.

~ Has since become re-established as a breeding species following re-introduction attempts.

# Sporadic breeding attempts have since been noted.

The countryside is a dynamic place with all sorts of changes happening to habitats and the species in them. Some of these changes are due to man's influence and others are the result of natural processes such as climatic variation. The loss of some species which are widespread in other parts of Britain or on the Continent may not be as important as the loss of internationally rare species or those which are very localised in Britain. Some losses may be early indicators of major changes such as global warming whilst others may be simply due to random fluctuations in population levels.

By the time a species is on the verge of extinction it may be too late for effective conservation measures to save it. We can do more to prevent such losses by looking at rates of change. Where it can be shown that a species has declined by 50% over the last 25 years we can act to reverse that decline before numbers are so low that recovery is not possible. Records of all sorts of species, both rare and common, are collated at the Suffolk Biological Records Centre in order to monitor the population levels and distribution of wildlife in the County.