The Forestry Commission has published new guidance on estimating the numbers of deer in woodlands, in Bulletin 128: Estimating deer abundance in woodlands: the combination plot technique. There are six species of deer living wild in Britain today: the native red and roe, and the introduced fallow, sika, muntjac and Chinese water deer. One or more species can be found in most woods and forests, and at low densities deer browsing rarely impairs tree growth and can enhance the biodiversity value of woodlands. At higher densities, however, deer can affect the success of woodland establishment and damage biodiversity.
It is often necessary to control deer populations by culling to limit these effects, but land managers need a means of measuring the numbers of deer on their land to help them set appropriate culling targets and discover how effective their control measures have been. In woodland, where tree cover usually makes visual counting impossible, faecal pellet group counts are often used to estimate deer numbers.
This new bulletin describes the ‘combination plot technique’, a variation of the faecal pellet group count method. The technique has been developed and refined using data from more than 10 years of monitoring and research. It employs aspects of both of the main faecal pellet group count methods usually used: the ‘accumulation rate’ method and the ‘ standing crop’ method. In justifying their choice of each element of the technique, the bulletin authors also provide one of the most comprehensive overviews of dung counting methods available.
The bulletin was written by Graeme Swanson and Douglas Campbell from the ecological consultancy Strath Caulaidh Ltd, and Helen Armstrong from Forest Research, the research and technical development agency of the Forestry Commission. The guidance will be useful to deer managers and deer researchers as well as being of interest to those considering using a dung-counting method to monitor the density of other herbivore species.
Forestry Commission Bulletin 128 is priced ?17.50 and can be ordered from Forestry Commission Publications, PO Box 25, Wetherby, West Yorkshire, LS23 7EW ; tel: 0870 121 4180 ; quoting stock code FCBU128