Bat Surveys and Mitigation

Wildscapes bat surveys

Bat Surveys and Mitigation

Bats inhabit a wide range of habitats including trees, caves, mines and man-made structures amongst others. If there is a potential that bats are present on the site of a proposed development, then a survey is required to identify the species and also how and when they are using the site. There are a variety of surveys that can be undertaken, depending on the type of project and time of year.

Preliminary Roost Assessment

A Preliminary Roost Assessment (PRA), sometimes referred to as a daytime bat survey or bat scoping, is designed to determine the suitability of the building to support roosting bats.

The survey involves an Internal and External Visual Inspection (IEVA) of the building or structure. Features such as small gaps in soffit and fascia boards, raised or missing ridge tiles and gaps at gable ends, which have potential as access points are visually assessed by our team. The interior of the building including roof voids (where possible) is visually assessed for evidence of bat activity and for their suitability to support roosting bats. 

Preliminary Roost Assessments can be undertaken at any time of year.  However, the level of visual evidence created by target species (bats and birds) may vary throughout the year due to weather conditions and human disturbance.

A Preliminary Roost Assessment will typically also include a data search with the local bat group or records centre as part of a desk study.

Tree Survey – Ground-Based and Aerial Risk Assessment

The Ground-based Risk Assessment of trees involves the assessment of a tree from the ground to search for Potential Roost Features (PRF). Wildscapes follow the standard guidance for preliminary ground level roost assessment of trees as listed within Bat Surveys for Professional Ecologists Good Practice Guidelines 3rd Edition (Collins.J. (ed.), 2016).

An endoscope will be used by a suitably licenced ecologist to view any cavities which are accessible from ground level. A torch and binoculars are also used to assess the canopy branches and upper canopy. Any signs of bat activity such as staining are recorded.

Each PRF will be classified into the following categories based upon its likelihood to support roosting bats, the number of bats the feature could support and types of roost likely to use the PRF; Negligible, Low, Moderate, High and Roost present. Each tree is then given an overall classification based upon the PRFs present.

Should any proposed works be likely to affect trees with bat roost potential, they can be assessed by our tree climbing team in an Aerial Risk Assessment.

Our climbing team are all City and Guilds NPTC certified in tree climbing and aerial rescue. A licensed ecologist will access the upper branches of the tree using a rope and harness to further assess any Potential Roost Features which have been identified from the ground. A torch and endoscope are used to determine if bats are present and to confirm the feature suitability.

Should any proposed works be likely to affect trees which have been assessed to have bat roost potential during the aerial assessment, they are then subject to nocturnal presence/absence surveys. 

Nocturnal Bat Survey – Trees and Buildings or Structure

Nocturnal bat surveys are intended to determine the presence or likely absence of a bat roost in a building, tree or other structure (bridges, tunnels etc…). These surveys take place at dusk and dawn and involve surveyors observing the building, tree or structure from vantage points. Any bats seen to be entering or leaving the features are recorded. In addition, surveyors record any other bat activity detectable from their survey position. Where possible, the time of recording, species, the number of bats, type of activity, and flight path of observed bats are recorded.  Bats entering or leaving a building or tree are considered evidence of bat roost presence within that entity.

Surveyors are equipped with the board-band bat detectors to allow calls to be recorded and analysed at a later date if required.

Our in house bat ecologists have over 15 years combined experience undertaken nocturnal surveys on a range of buildings and structure.

Surveys are typically undertaken from May to September in weather conducive to bat activity, i.e. little or no rain, low wind and temperatures above 10°C. Emergence (dusk) surveys commence 15-30 minutes prior to sunset and continue until 1.5 hours after sunset. Return (dawn) surveys commence 1.5 hours prior to sunrise and continue until 15-30 minutes after sunrise.

Bat Activity Surveys

To determine the value of a site for foraging and commuting bats, bat activity survey are undertaken. These involve a combined approach of installing static board-band detectors on site and undertaking transects surveys of the site and the surrounding area.

The data from these surveys are then statistically analysed in various computer packages and GIS to determine which species are using the site and which areas are valuable for foraging and commuting bats. 

Access creation and improvement

We offer a wide range of services to make sites easily accessible; from building and improving footpaths to adjoining land management and installing site furniture. We are qualified to use high quality machinery which speeds up the time of creating/improving access points where appropriate.

We provide clearance of public right of ways (PROW), and specialise in labour intensive work on sites where use of large machinery may be intrusive, inappropriate or inaccessible. We make sites more easily accessible whilst protecting wildlife. We are experienced at delivering PROW works within a wide range of habitats, be it extensive moorland habitats to urban woodlands.

Boundary work and Improvements

Wildscapes deliver boundary improvements to greenspace sites consisting of:

  • Post and wire fencing
  • Post and rail fencing
  • Vehicle barriers
  • Access points and entrance gates
  • Dry stone walling

We use locally sourced materials wherever possible, enabling you to support the local economy by working with us. Our materials are sustainably sourced, with all of our timber for our fencing being of Forest Stewardship Council (FSC) standard. This means you can be reassured that the work we deliver for you isn’t damaging to the environment.

Grounds Maintenance

Wildscapes provides competitive grounds maintenance services for a range of clients. We specialise in nature reserves, schools, neighbourhood parks and housing landscapes, bringing real quality to some of the most challenging urban locations. Our experience of involving users results in a safer and better-valued outdoor environment.

Conservation Management

We work with landowners who are required to manage their landholdings to Local Wildlife Sites, Areas of Outstanding Natural Beauty (AONB) or Sites of Special Scientific Interest (SSSI) standards, and with conservation organisations implementing enhancement or restoration works. Our experience includes woodland, wetland, meadows and heathland management, as well as maintenance for grazing infrastructure, firebreak creation and scrub clearance.

Habitat creation and restoration

We are extremely passionate about creating new habitats to be enjoyed by both people and wildlife. To add to our passion we have a proven track record in the successful delivery and creation of new habitats through our Land Management service.

We pride ourselves in constructing, managing and maintaining all types of outdoor spaces; ensuring that the clients and end-users are at the heart of service. Our team are all trained in practical land management with the relevant technical accreditations and practical conservation knowledge. Together this provides our clients the assurance that our service is safe, efficient, of the highest quality and practical to fit to the needs of users both during and on completion of projects.

Whether our clients are required to re-instate lost habitat via the planning process or are investing in local green infrastructure for employees or communities, Wildscapes has extensive experience of creating a range of natural habitats such as ponds, wetlands, flower-rich grassland, woodlands or artificial habitat such as otter holts, badger setts or water vole ditches.

Invasive Species Control

If you’re having difficulties with invasive species our land management team can help you save time and expense and also prevent you from breaking the law.

Professional support when dealing with invasive species can save time, expense and diminish health risks. Wildscapes can advise on appropriate management and differing control techniques for these problem species, and is licensed to undertake practical removal and control work on site.   Our team are experienced and trained to eradicate species such as Japanese Knot weed, giant hogweed and Himalayan balsam, which can course serious and ongoing problems for both existing and new development.

Japanese knotweed can compromise the structural integrity of buildings and pavements and if left untreated will reduce both the amenity value of a site and its commercial value. The Wildlife and Countryside Act 1981 requires that landowner or land tenants take all reasonable steps to control Japanese knotweed from infringing into adjoining land. Penalties for causing an infestation can be as serious as two years imprisonment and/or a large fine. The Environmental Protection Act 1990, Duty of Care Regulations 1991, states that cut knotweed materials and soil containing rhizomes must be disposed of as controlled waste if they are to be removed from their site origin.

The Weeds Act 1959 requires that the following plants are controlled:

  • Creeping thistle (Cirsium arvense)
  • Spear thistle (Cirsium vulgare)
  • Broad-leaved dock (Rumex obtusifolius)
  • Curled dock (Rumex crispus)
  • Common ragwort (Senecio jacobaea)

These plants do have some ecological value so action should only be taken to prevent them from spreading in large quantities to other areas or, in the case of common ragwort, to prevent them from adversely affecting livestock.

Tree planting

Our Team are experienced in the art of tree planting; whether it be habitat restoration via woodland creation in remote moorland cloughs; tree planting as part of schools or volunteer day events or planting of native hedgerow or native trees as part of landscaping schemes. We have worked for a variety of clients from large scale conservation organisations such as RSPB and National Trust, to councils, including Sheffield City Council and Rotherham MBC, and private individuals.

Moorland Conservation

Our land management team have an exceptional local knowledge and as a result have helped restore some of the most damaged areas of moorland in the UK. With expert heathland and moorland restoration skills, we work on a number of projects throughout the winter months to help stabilise bare peat. This is achieved through a combination of methods including the spreading of heather cuttings (brash) to prevent any further deterioration of the bare peat, and the planting of sphagnum and other native moorland plants to create a healthy blanket bog. We specialise in delivering moorland restoration works to remote areas, using working methods that protect the surrounding ecological and archaeological valuable habitats and features.

Wildflower ID Workshop

This course provides a day’s introduction to the identification of wildflowers with an emphasis on the most common plant families and basic flower structure.

We will spend the morning in the classroom before heading out to a local nature reserve in the afternoon.  Following the course, attendees should be able to;

– Recognise the key diagnostic features used to identify wildflowers

– Recognise members of the 9 most common families of wildflowers

– Learn to identify a number of common species

– Become familiar with the use of keys to identify species

The course is aimed at anyone with a general interest in botany, no previous knowledge is required.

Winter Tree ID Workshop

Do you know your ash from your alder?

If you do, you’ll know that ash trees have distinctive black buds, whilst the buds of the common alder often have a striking purple tinge. 

If you’re still in the dark, you can learn the secrets of tree identification in winter with this day-long course run by our Wildscapes ecologists. We will spend the morning in the classroom looking at winter identification features before heading out to a local park to practice identifying trees, and end the day with a fun quiz to test your knowledge.

The course is aimed at anybody with a general interest in tree identification, no previous knowledge is required.

An Introduction to Phase 1 Habitat Surveys

This one day course provides the detail on how to conduct a Phase 1 Habitat Survey – an essential skill for quickly surveying and mapping habitat types.

The course covers understanding how to plan, conduct and write up a Phase 1 survey. There will be a classroom-based introduction in the morning, followed by the opportunity to try out techniques in the field in a local park.

Following the course, attendees should be equipped with the skills to; 

– Understand the methodology of a Phase 1 Habitat Survey

– Be able to use mapping techniques, target notes and create a species list

– Understand the key indicator species to identify habitats

– Understand the basic report format

– Understand the options for mapping

– Understand how Phase 1 surveys are used and their role within extended surveys and PEAs

An Introduction to Bat Surveys

This one day course is aimed at people entering or working in the ecology sector who want to get an introduction to bat surveying before the start of the survey season. The course covers:

– An introduction to the biology and ecology of bats

– An introduction to the identification of British bats

– An introduction to bat legislation

– How to plan and conduct a Preliminary Roost Assessment on buildings, identifying potential for bat roosts

– How to plan and conduct ground based tree assessments, identifying potential for bat roosts

– An introduction to aerial survey techniques with a demonstration of tree climbing and use of endoscopes

– An introduction to nocturnal activity surveys

– Bat walk in a local park, practicing using bat detectors