view of moors YMG How to Record Species





The first comprehensive distribution maps of mammals in the historical County of Yorkshire were published by Howes (1983) together with a brief review of previous mammal recording in the region. These maps were based on records gathered between 1971 and 1981. Updated versions of the maps were subsequently used as a key element in Yorkshire Mammals (Delany, 1985).

Since that publication there has been no concerted attempt to re-map the mammalian fauna of Yorkshire, although significant changes in the national distributions of some species are known to have occurred, for example, water voles (Woodroffe, 1994; Strachan et al., 2000), otters (Lenton et al. 1980; Strachan et al. 1990; Strachan & Jefferies, 1996; Crawford, 2003; 2010;) and a number of deer (Ward, 2005).

In 1996 the Yorkshire Mammal Group (YMG) decided to collect mammal records more systematically, and appointed a Mammal Recorder. This post was for many years held by Dr Michael Thompson, then by James Mortimer and latterly by John Ray. The aim was to publish a revised atlas of Yorkshire mammals in 2006 after a decade of recording and approximately twenty years on from Delany (1985). As the end of the designated period approached it became clear that we had relatively few records from areas other than North Yorkshire and that even here they were, on the whole, more a function of the distributions of recorders than of mammal species. A decision was made, therefore, to (a) concentrate the mapping effort on the county of North Yorkshire, (b) make a concerted effort to recruit more mammal recorders, especially in woefully under-recorded parts of the county, and (c), extend the recording period to the end of 2010 so that the final species distribution maps were robust, and their interpretations meaningful.

A preliminary atlas was published in 2007 (Oxford et al. 2007) with the aim of drawing attention to the areas of North Yorkshire that still required enhanced survey effort, and to encourage naturalists in those regions to make, and submit, their records.

Survey Area and Scale of Recording

Previous atlases of Yorkshire mammals (Howes, 1983; Delany, 1985) were based on the pre-1974 county boundary, enclosing five Watsonian vice-counties (South-east Yorkshire VC 61, North-east Yorkshire VC 62, South-west Yorkshire VC 63, Mid-west Yorkshire VC 64 and North-west Yorkshire VC 65).

The current maps use the boundary of post-1974 North Yorkshire, comprising seven local government districts (Craven, Hambleton, Harrogate, Richmondshire, Ryedale, Scarborough and Selby) and York, a unitary authority (Fig. 1). The three unitary authorities of Redcar and Cleveland, Middlesbrough and the area of Stockton-on-Tees south of the Tees, which are also formerly part of the county of North Yorkshire created in the Local Government Act 1972, are not included. In terms of Watsonian vice-counties, the mapped area includes the vast majority of VCs 62, 64 and 65.

The total area of the county of North Yorkshire is 8654 km2, and that of the area mapped 8312 km2. North Yorkshire is by far the largest modern English county, with the area used for mapping still over 1500 km2 greater than that of the next largest county (Cumbria, 6768 km2). To produce high density recording of the mammals of such a large area is a major challenge. As the boundary of North Yorkshire includes only a short stretch of coastline, we restrict our mapping to terrestrial mammals.

Although many of the records gathered by the YMG are associated with at least a four-figure map reference (i.e. located to within a 1 km x 1 km grid square), some are held at two-figure (hectad) references. The latter records currently dictate the coarse resolution shown on the maps. Reasons of conservation concern, commercial value or to protect private land owners, also mean that some species' distributions should be shown at tetrad or hectad scales.

How to Use

Select a mammal from the Species List. The Atlas web page for the selected mammal gives information related to its occurrence within North Yorkshire.

Also from the Atlas web page for the selected mammal, a wealth of detail about it, not specific to North Yorkshire, can be found by clicking on the ArKive button.

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