FENCE ALERT

I first started to think seriously about the danger fences can present to wildlife during survey work some years ago on sites being made secure for various reasons – military sensitivity, deterring badgers, foxes and other predators, and site security/boundary delimitation generally. The fact is that people seldom walk all along fences, so the harm they can cause to wildlife is not noticed often enough. A quick search on the internet, though, reveals a multitude of depressing and gruesome photos of the problem – but I have preferred not to reproduce any here.

Fences of all kinds can be not only barriers to wildlife movement for access to foraging areas, shelter, territory, etc. and thus undermine biodiversity policy, but they can also cause injury and death. Most birds, for example, do not have the best forward vision as their eyes are on either side of their head, so they may not see wires across their flight path. Barbed wire is particularly dangerous, but they can also be snared in a plain wire fence. There is a very long list of bird species that have been found dead or injured because of fences.  And it is not just when they are in flight: many birds are terrestrially mobile, especially when they are young but cannot fly (pheasants, ducks, geese, swans, grouse, etc.) so fences can be significant barriers to their mobility. Fences that are poorly designed or not visible to low-flying birds result in collisions. Adult bird species commonly crashing into fences and similar obstacles include owls and other raptors, lapwing, partridge, pheasant, starling, swift and woodcock[1].

Mammals of many kinds have problems with fences, usually because they block access to foraging. Hedgehogs are a good example because they need to travel far and wide to find food and cannot pass through fencing that does not leave gaps for them (at least 13cm by 13cm without rough edges). Badgers and other mustelids, deer, foxes, rabbits, hares and even bats can all have problems with fences. Also, only too often I have had to remind people erecting impermeable fences that amphibians need access to their breeding ponds away from which they can travel long distances before they return to mate and reproduce.

Fence design and installation should therefore be expertly planned and implemented. Whilst of course some areas need to be fenced, it must be done so as to minimise harm to our wildlife which is disappearing at such an alarming rate. Fences must be made clearly visible, yielding if struck and not prone to snaring or blocking wildlife movement through the landscape and to foraging, breeding or sheltering habitat. Frankly, barbed wire should be universally banned.

Betts Ecology advise clients developing land or changing its use to be extra-careful about fence design and fitting.

 © Betts Ecology

[1] There is an interesting and useful article on this topic in the November 2024 issue of British Wildlife (Summers & Kempe, pp 109–117).