This simple approach often represents the most effective means of deterring birds. Unfortunately, birds keep unsocial hours as far as most humans are concerned, normally leaving their roost before first light and feeding most actively just after dawn. Therefore, unless someone is able to mount an early patrol or lives on or very close to the site to be protected, this option may be impractical. However, human presence over a reasonable period will enable you to obtain an accurate count of the numbers of birds affecting the fishery and thus better assess the extent of the problem. This is vital information when applying for a licence.