Innovation in Bird Bioacoustics saves manpower and cuts costs for surveying target species

Earlier in the year Baker Consultants published a paper in the Elsevier Ecological Indicators journal on “Combining bioacoustics and occupancy modelling for improved monitoring of rare breeding bird populations”.

This innovative piece of research work has caused some excitement in ecology circles and is one that opens up new possibilities when it comes to species monitoring using technology and data analysis skills.  Funded by Natural England, the research was carried out by Baker Consultants’ Technical Director Carlos Abrahams, and published in a high quality peer reviewed journal.  Carlos’ expertise in sound recording and data analysis drove this piece of work, following his previous studies on capercaillie in Scotland. One of the key elements of the paper was the ability to combine the acoustic recordings of target species at a range of locations, with GIS and satellite remote sensing data of the habitats present at each site.  This allowed the environmental factors that determine species presence and detectability to be assessed.

We’re really excited by the outcomes of this research, as it makes acoustic survey methods much more viable for landowners, developers and estate managers.  Traditional surveying techniques ordinarily rely on huge manpower efforts to regularly visit sites to observe and record target species.  With the techniques developed by Carlos, we’re able to monitor the species by gathering larger data sets over longer time-frames, while reducing the manpower costs of data collection.  Survey by acoustic recording is also more effective at producing a robust and defensible dataset, as it can be subject to quality assurance processes and the raw data can be stored permanently.

We are continuing to carry out ecological consultancy during the Covid19 lockdown. If you have any surveying or monitoring needs during this period, then please  get in touch with us via our  contact form on the website, call us on +44 (0)1629 593958 or email us on

Baker Consultants’ Technical Director Carlos Abrahams is leading a webinar in association with the Institute of Acoustics and UK Acoustics Network on 13 May from 2pm.  The session will take delegates through the use of bioacoustics for field survey covering a wide range of species groups including birds, mammals, amphibians and invertebrates.

Baker Consultants’ Technical Director Carlos Abrahams is leading a webinar on the use of bioacoustics for field survey in association with the UK Acoustics Network on 13 May from 2pm.

If you would like to know more about how bioacoustic recording can provide a cost effective, highly robust method for gathering ecological data, register for this free session at the link below:

If you need advice on surveys for land management, planning or development, then please  get in touch with us via our contact form on the website, or you can call us on +44 (0)1629 593958 or email us on

Received today specialist bat access roof tiles for a client’s roof.

The tiles provide access to roof space for protected bat species, whilst blending in seamlessly to the slate roof.   They have a capped vent which allows access to roof felt (for roosting Pipistrelles) or roof space (for Serotine, Leisler’s, Daubenton’s and Barbastelle Bats).

As part of your bat mitigation measures consider designing in this facility to maintain the aesthetics of your estate buildings.  Contact us for a survey.

From once being the most common species of owl in the UK, barn owls (Tyto alba) have undergone a long-term decline in numbers. This has mirrored the increase in agricultural intensity and landscape development, which has led in turn to a loss of roost and nesting sites and a reduction in the numbers of small mammals they feed on. These factors, coupled with persecution, the increase in road traffic and other urban hazards, have led to the breeding numbers of barn owl falling from an estimated 12,000 pairs in 1933, to approximately 4,000 breeding pairs today.

The number of breeding barn owls appears to fluctuate year on year, but encouragingly, the overall trend in recent years is for their population decline to be levelling off. Despite the apparent halt in the steep decline in their numbers, their population remains vulnerable to the aforementioned threats. This highlights the importance of undertaking targeted barn owl surveys on potential development sites that hold favourable breeding, roosting or feeding habitat.


Barn owls are given protection against killing, injury or capture under the Wildlife and Countryside Act 1981 (as amended), with nests given further protection against disturbance under Schedule 1 of the same act. Developers therefore should be mindful of undertaking targeted barn owl surveys at sites holding favourable barn owl breeding/roosting habitat, to avoid potentially committing a legal offence.

Favoured Habitat

Barn owls use a variety of roost and nest locations in natural environments such as tree hollows, rock crevices and sea cliffs and man-made structures, such as those found in agricultural, industrial and domestic settings. They favour rough, tussocky grassland when hunting their preferred prey of small mammals.

Breeding Ecology

Barn owls have been known to breed in every month of the year but the usual breeding months are March to August, with peak breeding taking place between April and June.  One in ten pairs will then produce a second brood later in the summer. The four to six eggs usually hatch after a calendar month, with the young fledging between eight and ten weeks old.

Barn Owl Survey

Barn owl surveys are usually requested in relation to planning applications to convert or remove buildings located in rural surroundings. An ecologist has to hold a Class Survey Licence issued by Natural England, if they are to provide a thorough investigation of a site and fully establish the presence and status of barn owls.

After an initial desk study to obtain records of barn owls for the surrounding area, a site visit is undertaken to identify any signs that barn owl are using (or have previously used) the site for roosting or nesting. Signs of barn owl presence on a site include pellets, feathers and droppings, as well as nest debris, eggs and carcasses (of owls or prey).


If a barn owl nest and/or roost site has to be disturbed or destroyed, alternative nesting or roosting provision must be provided, ideally within the structure being renovated, or if the current structure is to be demolished, within a replacement structure. If this is not possible, specially designed artificial nest/roost boxes should be positioned alongside and facing suitable rough grassland habitats, away from hazards such as busy roads and tall structures.

Artificial boxes should ideally be positioned outside the usual nesting months over the autumn/winter period.

Baker Consultants Barn Owl Surveys

Baker Consultants has two ecologists that hold the Class Licence for barn owls, following intensive training by the Barn Owl Trust and demonstrating their competence  in undertaking barn owl surveys.

Andrew Baker has been invited to speak about the legal position of European Protected Species (EPS) at a Planning and Design Group (P&DG) breakfast seminar on Thursday 14th July.
Read more

In response to the upcoming referendum on the UK’s membership of the EU, the Chartered Institute of Ecology and Environmental Management (CIEEM) surveyed its members on their views on what Brexit would mean for the UK’s natural environment.

Baker Consultants has made clear why we are concerned about Brexit, publishing several pieces on our views on why the EU is important for nature legislation and the negative implications of Brexit for the ecology and construction sectors and the environment. (See our pieces titled: ‘Brexit could worsen the construction sector’s skills shortage‘; ‘UK’s potential exit from the EU threatens economic and regulatory uncertainty‘; British exit from EU would be bad for UK renewable energy business‘; and ‘The EU is good for business and the environment‘).

Snapshot of our Scottish Energy News piece

Snapshot of our Scottish Energy News piece

CIEEM’s survey

Given this, we welcomed CIEEM’s survey and our Managing Director, Andrew Baker, and other colleagues made up several of the 841 respondents.

Today, CIEEM has publicised the results of the survey, showing that an overwhelming majority of ecology professionals (nearly 87% of respondents) are concerned about Brexit having a detrimental impact on the ecology and environmental management sector as a profession. Only 1% said Brexit would be beneficial.

CIEEM members are concerned about Brexit and its potentially negative impact on our efforts to safeguard our environmental quality and its effects on our health, well-being and prosperity.  Other concerns include less effective and integrated action on climate change, invasive species and plant and animal diseases, as well as negative impacts on protected areas and environmental schemes on farmland.

Cover image from CIEEM's EU referendum survey

Cover image from CIEEM’s EU referendum survey

Here we pull out some of the key statistics from CIEEM’s survey:

  • 67% indicated that Brexit would have a negative impact on their company or organisation
  • Over 93% believed that EU environmental legislation has been beneficial to the UK’s natural environment
  • If the UK were to leave the EU, respondents felt that there would be significant negative impacts on:
    • Protection of certain wildlife species (90%)
    • Protection of the natural environment for its environmental benefits (89%)
    • Benefits to migratory species (e.g. birds and cetaceans) (87%)
    • Improved water quality and the recovery of freshwater fish populations (77%)
    • Reduction of nitrates in the environment (74%)
    • Recovery of marine fisheries (74%)
    • Improvements in air quality (70%)
  • 85% do not believe current UK environmental policies would have been delivered to the standard that they are now if we had remained outside the EU
  • 93% say EU environmental directives have had positive additional benefits on UK habitats and species
  • 73% believed that UK nature conservation policy and legislation delivery is dependent, at least to some degree, on EU funding mechanisms
  • Nearly 84% of respondents thought that the UK had achieved more for nature conservation as an EU member than it would have done if it had relied only on international nature conservation agreements.

Furthermore, the timing of the UK’s proposed exit from the EU could have implications for large infrastructure projects such as HS2.

As CIEEM President, Dr Stephanie Wray, says: A change in regulatory regime, or worse, a policy vacuum, would be disastrous at a time of high construction output, both for the environment, and for the contractors attempting to deliver major projects without a clear legislative framework.”

In summary, CIEEM CEO, Sally Hayns said:

It is clear that leaving the EU would have far-reaching effects for those employed in ecology and management of the natural environment. Not only would there be an impact on jobs and livelihoods, with over 50% of our members expressing concern about their own job security, but the industry would be severely damaged. The skills that are playing such a significant role in delivering improvements in environmental quality could be lost, and there would be significant repercussions for the UK’s natural environment.”

Read the full results here.

The Mammal Society has just published new water vole mitigation guidelines for development and construction projects. Here we provide an overview of the background to the guidelines as well as the key recommendations within them. The full guideline PDF can be viewed here.

Water vole by Diana Clark, Senior Ecologist

Water vole by Diana Clark, Senior Ecologist

Water voles

Water voles (Arvicola amphibius) are one of the UK’s fastest declining wild mammals and listed as a species of principal importance for the conservation of biodiversity in England, Scotland and Wales. As such, they are protected under UK wildlife conservation legislation, making them of material consideration in the determining of planning applications.

New water vole mitigation guidelines

The Mammal Society’s new publication aims to promote best practice amongst ecological consultants in undertaking surveys and designing and implementing water vole mitigation measures. It also aims to enable decision makers to ensure the appropriateness of survey information provided and mitigation measures proposed.

The guidance relates to development projects and other construction activities, including those requiring other environmental permits, such as flood defence consent. It supersedes the Water Vole Conservation Handbook in all aspects relating to development.

The below flow chart shows the different elements involved in considering water voles as part of a planning application.

Flow chart for considering water voles as part of a planning application. From The Water Vole Mitigation Handbook

Flow chart for considering water voles as part of a planning application. From The Water Vole Mitigation Handbook

Key recommendations

  1. Licensing for displacement: Activities aimed at displacing water voles in the context of a development project require a licence and are not covered by the ‘incidental result’ defence. Different types of licence are required for England, Wales and Scotland (see the full guidelines for details). In both England and Wales, the projects must deliver a net benefit for water voles.
  2. Relocation of water voles (trapping versus displacement): Although further research is needed on the effectiveness of displacement, displacement is currently considered a potentially useful technique, particularly for small-scale works where trapping would be disproportionately expensive and could impact other animals due to individuals moving into vacant territories. As a rule, displacement is recommended where the working area is a maximum of 50m long, where works are carried out between 15th Feb and 15th April and where sufficient available alternative habitat exists. In England, displacement that meets these criteria can be conducted under a Class Licence by a registered person, whereas displacement under other circumstances requires a site-specific licence. In Scotland and Wales, a site-specific licence is always required.
  3. Appropriate timing for trapping and relocation operations: Water voles should ideally be trapped during early spring (1st March – 15th April). As a last resort, water voles can also be trapped during autumn (15th September – 30th November). Trapping should be timed to avoid periods of heavy rain or snow, fluctuating water levels and periods when overnight temperatures fall below freezing. Some seasonal variation in appropriate dates for trapping is acceptable in certain parts of the UK.
  4. Water vole surveys that support planning applications and other construction activities: There are specific suggested protocols for field surveys that will support planning applications or other construction activities. Typically, the baseline information used to inform an assessment of the effects of a development on water voles should be based on a combination of desk study, habitat assessment and field sign survey. Field sign surveys should ideally include searches for field signs undertaken over at least two separate visits, conducted at least two months apart to account for variations in habitat suitability across the season. One survey should be in the first half of the season (mid-April – June) and one in the second (July – September). However, there are some circumstances in which only a single visit is likely to be necessary (see page 15 of the guidelines).

Find out more

Contact us today to discuss any aspect of these guidelines or any upcoming projects for which you may need water vole surveys or advice

Read the full guidelines here.


At the UK National Bat Conference last week, Wildlife Acoustics
announced a new hand-held bat detector and recorder. As you would expect
there was great excitement in the Baker Consultants office and Paul
couldn’t wait to get his hands on one.

Paul said: “It’s a unique piece of kit, finally we have access to
something that not only captures and records bat calls, but also shows
the calls in real-time as they come in on the screen.”

Here’s an extract from the press release and a link to the Wildlife Acoustics site to learn more. We are expecting products to be widely available sometime in the new year.

“Bringing unparalleled features, ease of use and low cost to the active bat monitoring market the Echo Meter EM3 is easy to hold, lightweight (weighing less than .35 kg), and fully self-contained, requiring no additional hardware to actively monitor and record bats. The EM3 ships with built-in rechargeable batteries plus an SDHC memory card so customers can start monitoring bats upon product arrival.

Users monitor bat calls with headphones or the built-in speaker. Bat passes are recorded while the user simultaneously listens to bat calls in the method of choice: Heterodyne, Frequency Division, or Wildlife Acoustics”s patent pending Real Time Expansion mode.

As the most flexible heterodyne detector on the market, the EM3’s Auto-Het feature automatically tunes the detector based on the echolocation frequency. Users program up to four frequency presents to rapidly tune into a bat call in heterodyne and then fine tune any frequency settings with the easy to use button navigation.

The EM3 also captures voice notes along with the bat passes in the same trigger for easy direct correlation. Users may categorise or tag a bat call in real-time in one of four categories to facilitate post processing.”

Are you a planner? Do you fully understand your legal obligations regarding protected species legislation?

You are invited to attend a half-day training seminar on Wednesday 18th May in Sheffield, run by Environmental lawyer Penny Simpson.