A recent survey undertaken by the Royal Society for the Protection of Birds, (RSPB) and the British Trust for Ornithology (BTO), has indicated that one of the factors associated with the fall in certain species of woodland birds is the reduction in active woodland management. The declining species included summer migrants such as the Pied Flycatcher which rely on breeding areas such as welsh deciduous woodlands.

Based on the information available, changes in woodland structure were thought to be the most likely driver for many of the bird declines. Potential causes of these changes include the increases in the woodland age, reduction in active management, and possibly increased deer browsing.

The aim of woodland management is to increase the production of wood products through such silvicultural practices as selective thinning. This allows the remaining, desirable trees to increase in size and for the woodland as a whole to have a more even range of young, juvenile and mature specimens so that good quality timber is continually produced. A well managed wood can provide valuable, locally produced materials such as construction timber and firewood. This has the additional environmental benefits of reducing carbon emissions created by the transportation of foreign timber imports and the consumption of fossil fuels for heating. 

What this recent survey has shown is that this type of management, rather than being detrimental to bird populations actually improves their habitat. When small areas of woodland are opened up, a rich and diverse under-story of new vegetation is allowed to develop as light reaches the woodland floor. It is this ground vegetation where most of the woods biodiversity is found.

Birds are often used as indicator species for assessing how healthy an area is in environmental terms so that this study could support woodland management as a means to wider environmental stewardship. This is important because wild bird populations are one of the Government’s 15 headline indicators of sustainable development.

Report co-author Ken Smith of the RSPB added:
"These findings are very valuable in helping to narrow down the possible causes of woodland bird changes but further discussion and research will be needed to explore the real factors at work here. As always with natural populations, one problem we have is that habitat changes can lead to a huge boost in numbers of some species, but those same changes could be making life harder for others. The challenge that lies ahead for us now is to take forward the most appropriate actions to help those species in dangerous decline, to make sure they are around for future generations to see in our woodlands and across our countryside."

Woodland plots were surveyed in 2003 and 2004, repeating the surveys first carried out in the same plots mainly in the 1980’s. A total of 406 woodland sites were surveyed, all of which were broadleaved or mixed woodland. The survey not only considered bird species but also the condition of the woodland and other factors such as evidence of deer browsing, density of grey squirrel dreys and the possible effects of climate change. Nine out of a total of 34 bird species included in the final analysis showed national declines. These were the garden warbler, lesser redpoll, lesser spotted woodpecker, spotted flycatcher, tree pipit, willow tit, willow warbler and wood warbler as well as a large decline in hawfinch.

What's Happening to our Woodland Birds? - Executive Summary (Link)

What's Happening to our Woodland Birds? - Full Report (Link)