ESL has over 20 years experience of carrying out protected species surveys, and can provide objective, pragmatic advice on how to deal with any potential ecological constraints. We have considerable expertise in designing mitigation strategies, obtaining Natural England development licences, carrying out habitat creation work, writing habitat management plans, translocating protected species and monitoring.

ESL ecologists are licensed by Natural England to work with all protected species and whilst we regularly undertake small, quick turn-around jobs, we also have the capacity to carry out large-scale, complex projects requiring large teams of surveyors.

Our senior staff fully understand the importance of turning reports around quickly and safeguarding your programme and are always available to advise you.

Click on the tabs below to see a brief summary of the range of surveys that we undertake

  • Stage 1 – Initial site walk-over to determine badger presence and assess risk;
  • Stage 2 – Detailed survey to locate setts, record latrines and map pathways;
  • Stage 3 – Territory mapping surveys (bait-marking);
  • Advice on accommodating badgers into the project design and on protection measures through the works;
  • Liaison with Natural England and exclusion and sett closure under licence including the provision and installation of badger gates;
  • Design and creation of replacements setts;
  • Identifying suitable locations for underpasses and permanent fencing;
  • Monitoring of populations in accordance with planning conditions and S106 agreements; and
  • Advice on the creation of badger-friendly habitats.

ESL have extensive experience of badger surveys, mitigation, sett exclusion and monitoring. We know how to protect your development programme when badgers are present on a site.

Timing of surveys

Stages 1 and 2 surveys can be undertaken at any time of year, although October through to April is generally the optimum period since dense vegetation can obscure activity signs in late spring and summer. Stage 3 surveys are best undertaken between February and April when there is a paucity of natural food sources, a lack of dense vegetation and when badgers are actively marking their territorial boundaries.

  • Preliminary Roost Assessments of all types of buildings and trees;
  • ‘Bat and Bird’ surveys for planning applications;
  • Tree surveys including supervised felling;
  • Habitat surveys and assessments including wind farms;
  • Radio tracking
  • Natural England ‘mitigation’ licence applications;
  • Habitat design & creation including the provision & installation of bat boxes;
  • Discharge of planning conditions and monitoring;

ESL have extensive experience of bat surveys, mitigation and monitoring. We know how to protect your development programme when bats are present on a site.

Timing of surveys
Preliminary Roost Inspections of buildings and trees can be undertaken at any time of year. However, if follow up activity surveys are required , then these need to be undertaken in the active season, between May – September.

  • Transect, point count and territory mapping (eg Common Bird Census – CBC) surveys to determine the general breeding bird population and provide an estimate of numbers;
  • Specialist surveys for groups such as wildfowl, raptors, waders, nocturnal/crepuscular species (eg owls, woodcock, nightjar) and colonial species (eg seabirds, heron, terns, hirundines);
  • Nesting bird checks in advance of site clearance or demolition of buildings;
  • Habitat design and production of management plans for breeding bird habitat;
  • Provision and erection of bird nestboxes, including advice on siting;
  • Provision, erection and maintenance of barn owl boxes and checking for use by barn owls, under licence; and
  • Advice on protection of nesting Schedule 1 breeding species.
  • ESL also have personnel licensed to handle and ring birds, including barn owls.

ESL have extensive experience of bird surveys, mitigation and monitoring. We know how to protect your development programme when birds are present on a site.

Timing of surveys

In general terms the breeding season is taken to extend from the beginning of March to at least the end of July, although this will vary with latitude and species specific requirements. Surveys should therefore be designed to target the species likely to be present. There is also a small group of species, including barn owls, which are able to breed throughout the year, and active nests of these species can be found in most months. We can provide advice both on survey timing for all species, and on the need for nesting bird checks in any month, depending on the habitats available.

Botanical surveys underpin the initial stages of most site assessments and ESL have been undertaking these types of surveys since 1995. These include:

  • Phase 1 habitat/land use surveys
  • River corridor surveys
  • Hedgerow surveys

These would normally form part of an initial site assessment, but may be used alone, for example as part of a biodiversity audit; to monitor improvements to river corridor quality, following management; or to identify or monitor Section 41 (formerly BAP) habitats, respectively.

  • Phase-2 plant community surveys
  • National Vegetation Classification (NVC) surveys

These two are closely linked, and either may follow an initial Phase-1 survey to provide more information on the plant community and thus assess their biodiversity value, either to identify potential Local Wildlife Sites, or as part of an ecological baseline assessment.

  • Aquatic macrophyte surveys
  • Fixed quadrat monitoring

These are just two examples of a number of forms of botanical monitoring, normally undertaken to demonstrate the (potential) effects of changes due to management, mitigation measures, natural succession, etc.

  • Invasive plant surveys and advice on treatment
  • Japanese knotweed control by spraying with herbicide

Timing of surveys

A highly experienced ecologist can carry out an initial site assessment at almost any time of year, since they will be trained to recognise vegetative grasses and basal leaves of perennials and to identify woody species by their bark and winter buds. This will allow most plant communities to be recognised, and recommendation for further survey to be provided where necessary. The ability to do this can save considerable time and money and prevent delays.

However, the more detailed surveys need to be carried out during the growing period of the target species. This may be spring (March-May) for winter annuals (eg on heathland) or late summer (July-September) for aquatics, although most species can be recorded during May-September at least. For a small number of species timing can be more sensitive, and senior staff can advise on this.

  • Desk study to identify any known existing populations;
  • Habitat and landscape assessments for dormice to establish potential for presence;
  • Surveys, including placing and checking dormouse tubes and searching for nuts opened by dormice;
  • Advice on accommodating dormice by design and on protection measures through the works; and
  • Advice on mitigation, including creation of suitable new habitat.

ESL have extensive experience of dormouse surveys, mitigation and monitoring. We know how to protect your development programme when dormice are present on a site

Timing of surveys

Habitat and landscape assessments can be carried out at any time of the year; searching for and identifying opened nuts is most successful between autumn and spring, though nuts may be found at other seasons. Dormice hibernate from October through to late spring, and surveys for nests, feeding signs and the animals themselves can only be carried out between May and September. Tubes or boxes need to be placed at least 2-3 weeks before surveys commence, and should then be checked at least four times, at intervals, through the active season.

  • Daytime assessment of ponds including Habitat Suitability Index (HSI);
  • Presence/absence surveys;
  • Provision of reports to accompany planning applications;
  • Mitigation strategy design;
  • Natural England European Protected Species licence applications;
  • Habitat creations, including ponds and hibernacula;
  • Installation of temporary amphibian fencing;
  • Translocation of animals under EPS licence;
  • Ecological Clerk of Works; and,
  • Population Monitoring.

ESL have extensive experience of amphibian surveys, mitigation and monitoring. We know how to protect your development programme when great crested newts are present on a site.

Timing of surveys
Aquatic presence/absence surveys can only be undertaken between mid-March to mid-June. and are very prescriptive. In order to protect the project timeline, it is crucial that surveys are undertaken in the Spring survey window. If there are ponds on or near your site, contact ESL as soon as possible to discuss the potential implications.

  • Desk study to identify any known existing populations;
  • Habitat and landscape assessments for otters to establish the potential for their presence;
  • Surveys of the bank top, sides, foot and structures for signs of presence or activity, on foot and boat-based as required;
  • Nocturnal/crepuscular surveys to confirm presence where necessary;
  • Advice on accommodating otters by design and on protection measures through the works; and
  • Habitat design and creation including holt creation.

ESL have an Avon inflatable with outboard motor and 8 staff members who are qualified boat-handlers, holding the RYA National Powerboat Certificate Level 2 and a relevant first aid qualification.

ESL have extensive experience of otter surveys, mitigation and monitoring. We know how to protect your development programme when otters are present on a site.

Timing of surveys

Otter surveys can be carried out at any time of the year.

  • Desk study and data searches to establish if reptiles are recorded in the area.
  • Habitat assessment to determine the potential for each species to be present;
  • Surveys including laying and checking Artificial Cover Objects (ACOs) – ‘tinning’;
  • Advice on best practice to safeguard the reptiles whilst protecting the build programme;
  • Exclusion of reptiles from development areas using temporary fencing;
  • Locating existing alternative habitat where possible;
  • Design and creation of new reptile habitat;
  • Translocation of reptiles to alternative habitats;
  • Monitoring of populations in accordance with planning conditions or S106 agreements.

ESL have extensive experience of reptile surveys, mitigation and monitoring. We know how to protect your development programme when reptiles are present on a site.

Timing of surveys

Reptile surveys must be carried out in suitable weather conditions during the active season, which typically runs between mid-March to early October, with April, May and September the optimal months.

  • Desk study to identify any known existing populations;
  • Habitat suitability assessments;
  • Detailed survey to record signs of presence by wading and by boat if necessary;
  • Displacement under class licence (max 50m during 15th Feb – 15 April only)
  • Advice on mitigation, including creation of suitable new habitat;
  • Translocation of water voles by trapping under licence;
  • Post-works monitoring to comply with licences, planning conditions or S106 agreements.

For watercourses where boat-based survey is required ESL have an Avon inflatable with outboard motor and 8 staff members who are qualified boat-handlers, holding the RYA National Powerboat Certificate Level 2 and a relevant first aid qualification.

ESL have extensive experience of water vole surveys, mitigation and monitoring. We know how to protect your development programme when water voles are present on a site.

Timing of surveys

Habitat assessments can be carried out at any time of year, but accurate surveys are best undertaken from mid-April to the end of June and from July to September. Surveys outside of these windows can often reveal the presence of water voles, but are often not sufficiently robust to inform appropriate mitigation or support a licence application should one be required.

  • Desk study to identify any known existing populations;
  • Habitat suitability assessments;
  • Detailed surveys to record signs of presence by manual searching, netting, night torching or trapping;
  • Translocation under licence;
  • Post-works monitoring to comply with licences, planning conditions or S106 agreements.

ESL have extensive experience of white-clawed crayfish surveys, mitigation and monitoring. We know how to protect your development programme when this species are present on a site.

Timing of surveys
Surveys for white-clawed crayfish are best carried out after the breeding season (mid-July to mid-September). The late May and June period is best avoided as females may be carrying newly hatched young unless the animals are to be moved.

  • Initial site walk-over to assess all habitats for potential use by invertebrate target groups;
  • Terrestrial macroinvertebrate surveys using a range of methods including sweep-netting, pan-trapping, pitfall-trapping, MV light-trapping, malaise-trapping, suction sampling and beating bushes and trees;
  • Calculation of indices to assess site value for biodiversity;
  • Aquatic invertebrate surveys, including water quality assessment (BMDP, ASPT);
  • Habitat design and creation for invertebrate target groups;

Timing of surveys

For terrestrial macroinvertebrates surveys should be carried out through at least one full year, since different groups and species have different activity periods. These surveys are also very weather dependent on several scales, since poor (cold and/or wet) weather will affect both timing of emergence for particular species and the likelihood of flight on a particular day. Surveys for aquatic invertebrates are less sensitive to season.

  • Initial site walk-over to assess all habitats for potential use by invertebrate target groups;
  • Desk studies and consultations to establish the extent of currently available data;
  • Scoping studies to discuss and agree the surveys and methods required to complete the baseline information;
  • High- and low-water counts of passage and wintering waterfowl on estuaries or coastal sites, including ‘through-the-tide’ counts and mapping of feeding and roosting areas;
  • Counts of passage and wintering wildfowl on significant inland waters;
  • Walkover surveys to map and count wintering populations within a study area;
  • Vantage Point (VP) watches through winter and passage periods, recording time and height of birds within a risk area;
  • Calculation of Collision Risk using VP watch data; and
    Advice on avoidance, reduction and mitigation of potential impacts on wintering bird populations during development works.

ESL have a team of staff ecologists with considerable experience of planning and carrying out wintering surveys.

Timing of surveys

In general terms ‘autumn’ passage surveys take place during all or part of the period August-November, ‘winter’ surveys cover October-March and ‘spring’ passage surveys will include all or part of March-May, with the exact period in all cases depending on the agreed target species. Surveys are normally required monthly as a minimum, but more frequent surveys may be necessary where the passage duration of a particular target species is known to be short.

Coastal or estuarine surveys are normally required to cover all or particular tide states, which will dictate actual timing. VP surveys are normally required to cover dawn, daylight and dusk periods, but may also be related to the tidal cycle for locations near the coast.