Five of our ecologists contributed to a Nathusius’ pipistrelle (Pipistrellus nathusii) research project that featured on The One Show on BBC1 as part of the film Bats Without Borders by Icon Films! Our Senior Ecologist Matt Cook led the project for Nottinghamshire and Rutland Water and four of our other ecologists, Courtenay HoldenKatie Watson, Rich Hall and Kelly Clark have also been involved.

Background to the project

After a Nathusius’ pipistrelle was found to have migrated from Great Britain to the Dutch coast in 2013, scientists’ previously held assumption that British bats were unable to migrate across the North Sea was challenged. Bats Without Borders set out to find out whether some of the UK’s bats were migratory and if it was possible for a bat weighing only seven grams to cross the English Channel or the North Sea.

Bats Without Borders poster

Bats Without Borders poster

Several bat groups were involved in the Bat Conservation Trust and University of Exeter study, including Nottinghamshire Bat Group, for which Matt is project co-ordinator. Matt led the project for Nottinghamshire and Rutland Water, overseeing the catching of 46 Nathusius’ pipistrelles so far. These bats have all been adult males, with five recaptures from within Nottinghamshire and at Rutland Water, one of which has actually ‘migrated’ over 10km along the River Trent. The project group hope to catch a breeding female, which they hope to radio-track back to a roost. This would be an important piece of research, as there are currently no known active roosts on mainland Great Britain. Two to three more maternity roosts were discovered this summer, but none of any notable numbers.

About Nathusius’ pipistrelles

The Nathusius’ pipistrelles are associated with freshwater habitats, mainly large water bodies, and their diet largely consists of medium-sized flying insects such as aquatic flies, midges (particularly non-biting midges), mosquitoes and caddis flies. They feed by aerial hawking, meaning they pursue and catch their prey in flight. In comparison to other pipistrelles, they typically fly higher, faster and further, and have distinctive social and advertisement calls. They typically weigh between six and 13 grams.

Nathusius' pipistrelles. Photos by Jon Russ

Nathusius’ pipistrelles. Photos by Jon Russ

Distribution-wise, Nathusius’ pipistrelles occur across mainland Europe, generally migrating north-east to south-west in autumn. They were first recorded in the UK in the 1940s in Shetland and were considered only a migrant visitor to the UK until the 1990s, when a small number of mating and maternity colonies were found. Overall, they are considered widespread, although uncommon. Less than ten mainland Great Britain maternity roosts have been recorded and none have been found to be active since 2012 (the last roost was in Kent). This means there are no major hibernation sites.

There is still much that is unknown about Nathusius’ pipistrelles in the UK, including the nature of their movements in and out of the UK, their migration routes and origins, their population status and their distribution. We hope that the research Matt, Courtenay and Katie have been involved in provides an important stepping-stone to better understanding the behaviour of this fascinating species.

The full results from the stable isotope analysis of the discreet fur samples taken from the bats caught in 2014 are due very soon. However, the preliminary results suggest that most of the Nathusius’ pipistrelles are likely to have moved quite significant distances.

Our latest in-house training course, run by Senior Ecologist Matt Cook (BSc (Hons) MSc MCIEEM), covered advanced bat survey techniques including using harp traps and acoustic lures.

After an initial training session on advanced bat surveys including Natural England class licensing back at the office, our terrestrial colleagues set off into the wilds of Derbyshire (or Carsington Water, as it is popularly called) for some field training in the use of harp-traps and acoustic lures.

Harp trap by Simon Curtin

Harp trap by Simon Curtin

This latest in-house training was a very informative and hands-on session, with five different species of bat caught under licence: Daubenton’s bat, whiskered bat, Brandt’s bat, brown long-eared bat and soprano pipistrelle. This allowed for close examination of common bat identification features such as size, ears and tragus, and the presence or absence of a post-calcarial lobe. Being able to identify a bat in the hand is important for our ecologists working with these protected species.

Beyond this, there are other benefits that ‘advanced’ survey techniques can bring to our clients and their projects; for example:

  • These techniques can assess where key flight-lines and bat activity hotspots are on a site, ensuring that mitigation measures are evidence-based;
  • They can remove many of the limitations of bat detectors, especially for quiet and cryptic species, by allowing identification of species, sex and an assessment of breeding status;
  • They can often be more cost effective than ‘traditional’ alternatives, as they can reduce the amount of time needed in the field; and,
  • Overall, important information about bat assemblages on a site can be gathered to help maintain the Favourable Conservation Status of these European Protected Species.

Additionally, development of these skills sets us apart from other consultancies, as very few have the in-house expertise to conduct these types of surveys.

whiskered Brandt's bats in the hand, caught during training at Carsington by Ecologist Courtenay Holden

Whiskered and Brandt’s bats in the hand, caught during training at Carsington by Ecologist Courtenay Holden

About Baker Consultants

At Baker Consultants, we regularly run in-house training sessions to make sure our colleagues continue to develop throughout their careers, encouraging colleagues to share their specific expertise with others. This internal training helps to maintain the high professional standards expected by the Chartered Institute of Ecology and Environmental Management (CIEEM) and our clients.

We are experienced in the full range of bat surveys. For more information, visit our Bat Surveys page and read our Elvaston Castle case study.

About Matt Cook

Matt is an experienced bat ecologist, holding Class licenses 1 to 4, and with a range of survey and reporting experience. Matt’s passion for all things bat-related extends outside work, where he has been actively involved with local bat conservation groups since 2008. Matt has also been coordinating the Bat Conservation Trust National Nathusius’ Pipistrelle Project in the region for the last two years (read more about this here).

About bats

There are 17 resident breeding species of bat in the UK and all bats and their roosts are protected from harm and disturbance at all times by EU and UK law. Bats’ foraging habitats also receive some protection within the planning system. Bats can typically be surveyed between April and October using a variety of different survey methods. For more on bats, visit our Bat Surveys page.

A new method for translocating rare waxcap fungi developed by our Principal Ecologist Barry Wright could offer considerable cost savings for construction and development projects and has recently been featured in both British Wildlife and In Practice magazines.

Rather than moving whole turves in order to translocate the waxcap fungi affected by the construction of a link road, Barry used an ultra-low impact, low-cost method of spore translocation. This potentially represents a new, more efficient method of mitigating the impact of a range of developments on ecologically important grassland.

The translocation method developed by Barry had a significant cost saving over more traditional turf moving and achieved the client’s aim of attempting translocation while accommodating the landowner’s requirements.

Below is a summarised version of the full case study, versions of which featured in British Wildlife and In Practice.

Pink Waxcap (Hygrocybe calyptriformis)

Pink Waxcap (Hygrocybe calyptriformis)

The project

During the early stages of construction of the Heysham to M6 link road scheme near Lancaster by Lancashire County Council, the pink waxcap (Hygrocybe calyptriformis; listed, at the time, as a British Red Data List species (Ing 1992)) was discovered on site. To mitigate the issue, it was proposed to translocate all waxcap species impacted by the development to a nearby mitigation area acquired by management agreement. Our Principal Ecologist Barry Wright, consulting ecologist for the project developer ADAS at the time, was tasked with translocating the waxcaps.

Waxcaps

Grasslands that support fungi are under threat nationally and internationally from agricultural improvements. Waxcap fungi (the genus Hygrocybe) are a colourful group of grassland fungi that are very noticeable in grasslands in the autumn when they fruit. Waxcaps are largely confined to growing in grassland, generally in pasture where the turf is kept short by grazing or areas that are mown such as golf courses and church burial grounds. Some UK waxcap species are regarded as rare and listed as Species of Principal Importance (formerly UK Biodiversity Action Plan (or BAP) species).

Simplified waxcap lifecycle and fungal mycelia diagram by Anne Wright

Simplified waxcap lifecycle and fungal mycelia diagram by Anne Wright

Although the pink waxcap was later removed from the Red List, Lancashire County Council honoured the translocation attempt. During a public inquiry in 2007, it had been agreed that waxcap-rich meadows were biologically important and worth protecting or mitigating for potential adverse impacts.

Challenges for waxcap translocation

The first challenge was to find a suitable translocation method for the landowners’ requirements, as the mitigation land was organically farmed and the owner reluctant to allow access to the potentially damaging machinery necessary for turve translocation. This led Barry to develop his unique translocation method using spores, which offered an ultra-low impact solution that satisfied both the council and the landowner.

The other challenge was that, to date, there was no proven track record of success even for the standard waxcap translocation method using turves containing waxcaps. As underground mycelia (the vegetative part of a fungus) can take over twenty years to reappear after disturbances (Griffith et al 2004) to the extent that they can once again produce fruiting bodies (i.e. waxcaps), proving success of translocation can be difficult.

Barry proposed the use of environmental DNA (eDNA) testing to analyse soil samples from the area that received the translocation of spores and look for the presence of waxcap DNA in order to determine success of translocation prior to the production of fruiting bodies.

The translocation

Previous surveys had identified locations within the management agreement mitigation area with similar vegetation to the waxcap-rich site that would be lost, but where there had been no evidence of fruiting waxcaps found since surveys began in 2003. It was believed that these vacant areas potentially did not contain waxcaps due to wind dispersal being restricted by waxcaps’ tendency to nestle in the grass. Therefore, artificially moving fertile caps into these vacant areas and allowing spores to be shed directly into the receptor areas could theoretically have a good probability of creating new waxcap colonies, particularly given vegetation similarities between the sites.

Waxcaps develop caps mainly during the autumn, so collections were made between 19 September (before the first caps emerged) and 4 December (when the number of caps was very low due to the cold weather). This was timed to ensure that early species and specimens were not missed. The candidate donor areas were walked in a zig-zag pattern with each leg approximately five metres from the previous and repeated weekly using a GPS track back function.

The location of each donor cap or caps (often small colonies of five to twenty caps were found close together) was recorded as a waypoint on a GPS device and the number of caps and their species recorded. All sporulating (meaning those producing spores) fruiting caps of any waxcap species visible were collected and separated into species groups to allow representative numbers of each species collected to be apportioned to each receptor location.

A typical mixed collection of caps in a trug

A typical mixed collection of caps in a trug

 

Translocation was carried out by moving sporulating waxcaps to receptor sites, where they were placed gill-side down to allow them to shed their spores naturally into the receptor turf. Only two caps of pink waxcap were found and both were translocated.

The future

This translocation was carried out in autumn 2014, so success cannot yet be determined. However, the site will be monitored for the next 20 years of the management plan and funding for future eDNA analysis is hoped for to enable assessment of whether soil in the receptor sites contains waxcap DNA. Waxcaps can form new colonies from spores and, as high concentrations of spores were deposited into comparable receptor areas, the probability of success is believed to be high.

Barry Wright says: “Going forwards our aim is to eDNA barcode the donor and receptor areas as well as the remaining vacant areas that did not receive the ripe caps to compare waxcap presence. We hope to answer questions such as: Are the vacant areas truly vacant or did they already contain the waxcap species that were translocated? Have the spores deposited from the donor site germinated in the receptor sites, in which case can they be detected yet?

“This analysis will allow us to detect success or failure in advance of any colonies becoming established enough to produce fruiting bodies. While it is still too early make conclusions regarding the future potential of this novel approach to waxcap translocation, it is hoped that this technique could become an accepted approach in the future.”

Read the full case study here.

Why Baker Consultants

Innovation in ecology survey methods is part of Baker Consultants’ DNA and we are experienced in mitigation and translocation methods for a wide range of species, including waxcaps, reptiles, marine mammals and butterflies. Contact a member of our team today to discuss your project or explore our website for more information. Read more about our expertise in eDNA here.

References

Ing, B. (1992). A provisional red data list of British Fungi. The Mycologist 6: 124-128.

Griffith, G. W., Bratton, J. H. and Easton, G. (2004). Charismatic megafungi – the conservation of waxcap grasslands. British Wildlife 16 (1), pp. 31-43. Rotherwick, Hampshire: British Wildlife Publishing.