Gloucestershire Moth Distribution Maps

New version: see text in blue below for changes

See also the Gloucestershire Moth Species Lists

If the map display does not appear, try the version using "object" instead of "applet" HTML tags. This version should also prompt you for a Java download if Java is not already installed.

If you have moth records which are not shown on these maps, please send them to Roger Gaunt. A few copies of Roger's 2006 publication "Gloucestershire Moths - A Second Account" are still available from him. This mentions many unmappable records (mostly old ones), including those for the many species with blank maps. A comment box on a map usually indicates reports in this publication of species with no mappable records in the database, or none until 2009 or later. Roger can be contacted by email at roger.gaunt@btinternet.com

To select a species, choose Scientific or Common names, then key in at least 3 characters of the name in the top box and press the [Enter] key. Nomenclature follows the Bradley 2000 checklist except for a small number of subsequent changes and additions. If there is a unique match for the partial name, the appropriate map is displayed. If there are more matches, select one of the matching names from the list which appears. Any part of the name can be used, so for example "tig" gives a list of the Tiger moths.

You can use the species scrollbar beside the map to move forwards and backwards through mapped species in numerical Bradley number order (not the scientific order in the Bradley checklist). Click on either end of the bar to move forwards or backwards by one species. Alternatively you can use the mouse wheel to scroll between matching named species when the cursor is over the matching name box, or use it to scroll through the full set of species when the cursor is elsewhere over the applet except over the period selection choice box.

The initial map shows the numbers of species recorded for each tetrad as one of 8 ranges. This map precedes the first species map when using the scrollbar or mouse wheel. To see the total number of moth species mapped for a tetrad, move the cursor over that tetrad on the map. With the cursor positioned over a tetrad on the map, you can use left and right mouse clicks to move backwards and forwards through the maps of species recorded from that tetrad.

The year chart shows relative numbers of records in 3 periods per month (1st - 10th, 11th - 20th, and 21st - end). Solid black bars indicate records of adults or unspecified stage, open grey bars indicate non-adult records: eggs, larvae, pupae, larval or pupal cases, distinctive feeding signs such as leaf mines etc. With the mouse pointer over a period in the chart, you can use mouse clicks to change species ordered by number of records for the period. Use [Ctrl] or [Shift] click to go to the most-recorded species for the period. (N.B. For some regularly-recorded sites Roger's database might only include one record of each common species from each year, usually the record with the highest specimen count).

Red and black dots across the top edge grid line on the map indicate years for which records are held in the database (including those not mappable to tetrad), starting from 1950. For example, a dot immediately to the right of the vertical 00 grid line represents the year 2000, and one just to the left of the 10 grid line represents 2009. These dots alternate in colour with red for even years, black for odd years.

A solid dot on a map indicates that the species was recorded in that tetrad (2Km x 2Km square) since 2000. The solid blue dots show records from 2010, and red dots show the records from last year, 2011. A hollow black dot indicates that the most recent record held for the tetrad is pre-2000. You can choose to display the distribution for all years, all except last year, pre-2010 or just pre-2000. To change this you can use the drop-down list in the period selection choice box, you can also use the mouse wheel when the cursor is over this box, or you can click on the appropriate column of tetrad counts (the counts for the current selection are highlit). The year chart is based on all records whichever distribution is displayed. For the species density map there are three more options: displaying maps for 2000-2009 records only, for 2010, and for 2011.

If you want to compare maps for two species (or more), you could right click on this link and open another window positioned at the applet, then select the next species to display on that window. Alternatively use the 4 preset buttons: a modified (e.g. Shift) click sets the button to the current map, an unmodified click displays the map indicated by the button. For simultaneous display you can use the copy button to make a small new window containing only a copy of the current map.

The map shows the recording area: the counties of Gloucestershire and South Gloucestershire, together with those parts of Watsonian vice-counties VC33 (East Glos.) and VC34 (West Glos.) which are outside the present administrative counties. The VC boundaries are shown in green, and where different the Glos. and South Glos. boundaries are coloured cyan. Rivers and coastlines are shown in blue, and within the recording area land over 175 metres in altitude is shaded. Ordnance Survey 10Km grid lines and 100Km square letters are shown.

Complete accuracy of the data can not be guaranteed - with more than 170,000 records some errors and omissions are inevitable. Records supplied to the Gloucestershire (VC33 & VC34) moth recorder Roger Gaunt have been shown, together with VC34 records supplied to the Bristol Regional Environmental Records Centre. Some unconfirmed records and those with insufficient information for mapping purposes have been omitted. For tetrad dots on the area boundary, some records might have come from just outside the intended recording area. For pairs or groups of species not separable with certainty from wing markings, only those records identified to species have been shown but some of these could be erroneous. Records of species forms originally given separate Bradley numbers have been included with the main species entry.

This page contains a Java applet which your browser's security settings might prevent from running automatically, prompting you for permission to run it. You might first also need to install the appropriate Java plug-in for your browser, if this is not already on your system. The applet downloads into its own memory a map image and a file of moth names and distribution data from the website, then constructs and displays the distribution map for each species that you select without any further interaction with the website (so that maps can be displayed very quickly).