It may not be obvious at first sight, but railway land is teeming with wildlife, ranging from plant communities, breeding birds, dormice and badgers to reptiles and amphibians. There are more than 30,000 hectares of line-side vegetation running in corridors in the towns and countryside of the UK. Land beside railway tracks is important to a whole variety of native species and provides a haven of natural habitat often surrounded by intensively farmed or built-up land.

Railway track runs through, or adjacent to, nearly 300 Sites of Special Scientific Interest (SSSI’s) in Britain as well as through locally important wildlife sites. Given this background, those who manage the railways have an important role to play in preserving the diversity of life there and ensuring it thrives and flourishes.

Specialist ecology consultancy, Thomson Ecology, is currently working closely with Network Rail and its partners providing strategic ecological advice and habitat mitigation measures for Phase 2 of the East West Rail project, which will run from Bedford to Bicester and Milton Keynes to Aylesbury. The company has also provided training on ecology and biodiversity issues for Network Rail project managers and is working with the Crossrail team providing habitat mitigation services during extensive nature reserve creation on Wallasea Island.

When rail projects require planning permission, or transport and works orders need to be approved, it is no longer enough to avoid, mitigate and compensate for the environmental or ecological impact of a scheme. Under Section 40 of the Natural Environment Research Council (NERC) act, there is now an obligation for any proposed development to enhance the biodiversity of the chosen site. That means that there is a need to do more than neutralise negative impacts. As ecologists, we make sure that good ecological management is built into project plans and ensure that they comply with local, regional and national planning policy and with existing legislation.

As specialists, we know the importance of timing and forward planning when dealing with wildlife. The breeding season is key to ecology and habitat surveys and we advise rail managers that it is important to think about ecology right at the start of any project so that surveys can be factored into long-term plans. This was our advice right from the start of the East West rail project.

The East West Rail Link, like others, passes through areas of habitat which can be full of native species. So far we have found three of the four common reptile species as well as many species of bat. Typically, bats roost under railway bridges; great crested newts find resting places in streams or rivers alongside rail tracks; and breeding birds nest in trees and shrubs along the line. It is important to understand the ecology of the land you are dealing with before you start work, so that planning issues can be avoided.

Called in at the earliest stages

Ideally we are called in at the very earliest stages of design and planning. At this point, we will carry out an assessment of the proposed site and advise the developer or project manager of possible ecological issues. For example, on projects like East West Rail Link we look at the site

Preserving biodiversity on Britain’s railways and advise where bats may be roosting, dormice may be hibernating or breeding birds may have built nests. If an ecological baseline survey isn’t undertaken, that can lead to more surveys being necessary than might otherwise have been the case; legal and licensing issues, more complex requirements for mitigation and compensation; more restrictions on working during development; higher adverse biodiversity impact and higher costs. By moving a site only slightly, it may be possible to avoid some or all these issues and make life considerably easier.

Most ecological impact assessment work takes place in the spring during the breeding season. When work is being planned, time needs to be allowed for surveys to take place and if this time is not factored in, significant delays can result. We may undertake desk survey work in the spring and, if there is evidence that great crested newts or breeding birds could be present, we would undertake field surveys during May and June when they are most active. However, if bats, water voles or badgers are potentially present, then our survey work would need to take place in September. It can be frustrating for project managers if work has to be delayed for several months until we can survey the development site during a later breeding season.

Adverse impacts avoided

A key part of the ecological assessment is accurately locating and mapping the habitats and species on site so adverse impacts on them can be successfully avoided or reduced. This happens at all stages during the project from receiving the site boundary and base mapping from Network Rail, through collating information for the desk study and onsite data collection, to drawing up the proposed mitigation and landscaping plans.

Thomson Ecology has an award-winning team who work with the project team to use the latest technology and in-field devices to achieve this. Our ecologists have mobile mappers which are pre-loaded with all available site information and can record data to sub-metre accuracy. This information can then be uploaded via the mobile phone network to our secure server to provide live updates which can be seen by the project team via our interactive mapping website. The immediacy of this solution has tremendous advantages, allowing decisions to be made quickly and efficiently making use of the most up-to-date information.

Planning consent

Once surveys have been undertaken, designs may need to be changed in order for the project to receive planning consent. If an ecologist finds protected species on a site, then special licences will need to be obtained in order to move them and we have to propose strategies for avoidance or mitigation of risks to those creatures or compensation for loss of their habitat.

In many developments, ecological surveys are completed and then the land is left for a long period of time before any works are started. During the intervening time, the vegetation on site changes and new wildlife moves in; this may mean that the whole ecological impact process will need to be repeated. The expression ‘nature abhors a vacuum’ may be a cliché, but it certainly applies here. Again, we can work with project managers to determine the risks and help them to control the budget and time implications.

Biodiversity impact is a crucial aspect to consider when planning track work on both small and large projects. Timing is critical and it is important to plan ecological consultancy into your timetable for the whole life of the project. Remember that, when ecology is factored into the project from the outset, it will be more straightforward to get the planning permissions you require and you will stay within the law.

David Prys-Jones is Thomson Ecology’s railway sector lead