New research from a team at the University of Nottingham has found that high populations of deer in UK woodlands are having a negative impact on woodland birds.
Dr Markus Eichhorn studied the factors behind the decline in species such as nightingale, marsh tit, willow tit and lesser-spotted woodpecker.
Breeding populations of these birds have suffered severe declines over the last 25 years, whilst the number of deer has doubled. The absence of large predators, such as wolf, lynx and bear, and reduction in hunting, are some of the reasons for deer population expansion.
Although deer do play a part in the health of woodland ecosystems, over-browsing can also have a negative effect. The researchers used laser technology to build 3D maps of woodlands. Comparing 40 woodland areas in England, the team found in areas of dense deer populations there was 68% less foliage near the ground compared with areas with fewer deer.
Dr Eichhorn suggests that if we want to encourage more woodland birds, then we need to take action to restore the woodland structures that they require. Replacing farmed venison with wild meat is one way that deer populations could be controlled.
Citation: Eichhorn, M. P., Ryding, J., Smith, M. J., Gill, R. M. A., Siriwardena, G. M. and Fuller, R. J. (2017), Effects of deer on woodland structure revealed through terrestrial laser scanning. J Appl Ecol. doi:10.1111/1365-2664.12902