Legislation to protect wildlife is designed for the benefit of the species, not to frustrate developers, and it is important to recognise that the law does make provision for lawful developments to be carried out provided that they do not have an adverse affect on the species concerned. For this reason it is very important to find out at an early stage whether protected species are present and if so which ones so that plans to mitigate for any adverse effects can be incorporated at an early stage.

It isn't always easy to find and protect species which may be very shy and retiring and not leave many traces of their presence. For dormice in particular, it may take several months of field work (though rarely more than a day a month) to determine whether they are present or not. A good quality 'Phase 1 habitat survey' carried out by a competent general ecologist should be adequate to determine whether or not badgers are present and to provide guidance on whether specialist mammal surveys are needed for this or for other species.

It is a good policy to ensure that ecological surveys are carried out as soon as possible, some are seasonal, some take a long time but in all cases the sooner the work is complete the easier it is to plan around the ecological constraints. The aim of ecological consultants is to enable their clients to carry out their proposals within the law without detriment to wildlife and the earlier they can give their advice the better.

Water Voles
Other species


The otter population of Britain underwent a dramatic decline in the middle of the last century until, by the 1970s, otters were almost extinct in England and scarce in Wales. With declining use of the toxic chemicals which caused the decline the population has recovered, and now they are found more or less throughout Wales and in many areas of England where they were formerly absent.

Otters are protected and for any proposals which adjoin, cross or affect a waterway there will be a need to carry out appropriate surveys and consider their needs.

Particular attention will be paid to the possibility of resting sites being present since it is an offence to damage or disturb these. It is often assumed that otter dens (known as holts) will always be found as a tunnel under the roots of trees at the water's edge. This is sometimes the case but otters are adaptable creatures and have also been known to rest in hollow trees under piles of boulders, old building and other, quite unlikely, places.
Otter breeding sites are rarely affected by small scale developments but impacts on large areas of otherwise undisturbed habitat will require an assessment of their potential for otters to breed.

Any proposal which involves a road crossing a river, stream or ditch will need to consider the risks to otters if they are forced onto the carriageway. There are well established methods for mitigating this risk but the fact that the population is recovering means that such risks need to be addressed even in areas where otters are not yet present. They will be in due course as the population re-colonises the area.

Although I have applied for dozens of licences to disturb badgers and many to disturb dormice, I have only once had to disturb an otter's den - and that was near the city centre in York! For the most part, the needs of otters can easily be accommodated into a development, provided they are considered at an early stage.

Photo: Nick Lawes

The badger is protected not because it is scarce, it is one of the most common carnivores in Britain, but because it has been persecuted in the past. As with other species, protection extends to its dens (setts) and the most common reason for needing to obtain a licence to disturb badges is because a sett is in 'the wrong place'.

Badgers live in clans of several adult animals plus their young and usually have a number of setts within their home range, one of which is used throughout the year, and for breeding - the main sett. As a result of this, it is usually fairly easy to obtain a licence to exclude badgers from the other setts (subsidiary or outlying) by installing one way gates for a period of a few weeks during the summer or early autumn.

Main setts are particularly important to badgers and it is not usually possible to exclude badgers from them unless alternative provision can be made for them, nearby, in the form of an artificial sett.

Natural England provide online guidance about badgers for developers but strongly recommend that a suitably qualified ecologist is employed to make the licence application and supervise the associated work.

I am more frequently asked to apply for licences to disturb badgers than any other species, a reflection of the abundance of this animal, but exclusion is a routine procedure and provided surveys are carried out at an early stage, one which can readily be scheduled into the development of a site.


Dormice are very small, very inconspicuous, and often overlooked. This can cause problems when a survey is commissioned late in the planning process and delays ensue. The problem is made worse because although these attractive animals are very scarce they are quite widespread in southern Britain and are capable of living in a wider range of habitats that many non-specialists think.

If there are significant areas of trees, shrubs, hedges or scrub on a site in the southern half of Britain, consideration should certainly be given to carrying out a dormouse survey. Ideally these are carried out over the period from March to November using inexpensive plastic nest tubes which are visited every month or two.

If dormice are present, and any of their habitat is to be damaged or destroyed, a licence to disturb them will be needed. There are only a few months in the year when it is safe to disturb dormice so it pays to know as soon as possible whether or not they are there. Generally my advice is, if in doubt, do a survey since it is better to know as soon as possible.

Mitigation for dormice will probably involve replacing any lost habitat with an area of equivalent size and quality and it is also important to ensure that the connections between dormouse habitat, along hedgerows or roadside plantings for example, is maintained or enhanced.

Photo: A Laurence

Water Voles

Once a common and widespread animal the water vole, probably the model for 'Ratty' in Wind in the Willows, has undergone a dramatic decline over the past few decades. Caught between deteriorating habitat and the jaws of an alien predator, the mink, water vole populations have undergone the most serious decline of any mammal since the crash in the otter population in the 1950s and 60s. Probably extinct in some counties in Wales, the north and the southwest, water voles are now found in small scattered populations which are very vulnerable to further losses.

That being so, the risk of water voles being present on a particular site are much lower than they once were. Not surprisingly any remnant populations now need as much protection as they can get. A complicating factor is that it is normal for water vole populations in anyone place to build up and decline to extinction, and then be replenished from other populations nearby. Even now, a site may have no signs of water voles being present one year but be recolonised the next.

If your site has a watercourse through it with a reasonable amount of bankside herbaceous vegetation it is a good idea to have a survey done to find out whether they are there or not.

Where voles are present, it is important to ensure that the habitat is retained, preferably enhanced, and any action which will have an impact on the banks of the stream or its vegetation will need to take the needs of water voles into account.


Other species

These four animals are the ones I work with most frequently but I have also carried out surveys for bats, water shrews, harvest mice, red squirrels and pine marten and done some work on deer and foxes. I have a wide knowledge of mammal ecology and if there is a species I don't feel able deal with myself I almost certainly know someone who can.
Bats are very much a specialist subject, for a start there are about 17 different species (a new one has just been discovered!) with their own particular habits and needs. While I have done quite a lot of bat surveying, and some radio-tracking, I would normally recommend a colleague who specialises in this group for surveys of large or complex sites.

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© Paul Chanin 2010