Guidelines for the Selection of Biological Heritage Sites

Contents

7. Section 2: Species Guidelines

Application (all species guidelines)

In most cases, each species guideline is followed by a list of species to which that guideline applies in Lancashire. Such lists generally include only those species which are known or believed at the time of writing to be extant in the County. For some of the less well-recorded groups of plants and animals these lists include species which were last recorded in Lancashire some time ago, but which may still be present. In some cases, however, species which are likely to have become extinct in recent years are included too, as are a few species which are in the process of extending their established geographical ranges to include Lancashire. Records of species new to the County or of species previously considered extinct which are not included in the lists will also be eligible if they satisfy the terms of the guideline concerned. Hybrids have only been included within the lists where one or both parents are extinct or rare within the County. Wherever possible, English names have been given for the species listed in these guidelines, except for non-vascular plants, where very few species have modern English names. For the sake of clarity, scientific names are also given for each group, except for birds which are generally known by their English names.

For the purposes of these guidelines, a 'locality' is defined as an area not exceeding one square kilometre in extent comprising either a movable 1km x 1km square (not necessarily corresponding to a national grid square), a unit of corresponding area or a single continuous habitat. General guidance on the application of all species guidelines is also given in paragraphs 3.11 to 3.16 of the Introduction.

It is important to note that Biological Heritage Sites should normally be identified only on the basis of reliable field records made within a period of not more than five years prior to the time of first assessment. For the purposes of the first systematic identification of sites throughout Lancashire, records should be post-1987 (except where otherwise stated), but this date should be adjusted for future assessments (see paragraph 4.8 to 4.10). It should also be borne in mind that monitoring of sites for the presence of particular species can take place only as often as resources allow.

Use of the term 'regularly' in those guidelines relating to animal species means that the species should be recorded from the site concerned for a minimum of 3 separate years (not necessarily consecutive) since 1987, unless otherwise stated. In some cases, sites may be designated on the basis of less regular evidence, where there are reasonable grounds to assume that the species concerned is still present or continues to use the site in question (but see also paragraph 4.8 of Introduction).

The internationally accepted system for the preparation of "Red Data Books" has recently changed. Reference in these guidelines to species included in Red Data Books or Red Data Lists means, firstly, all relevant species included in those Red Data Books published for species groups before 1997 and, secondly, those species categorised as Critically Endangered, Endangered, Vulnerable, Near Threatened or Data Deficient in Red Data Books or Lists compiled according to the revised IUCN Red List system (World Conservation Union 1994), except where Data Deficient species are subsequently shown to occur in more than 15 10km squares in the UK.