Ground Level Tree Assessment and Bat Surveys - Wokingham
(July 2019 – present)
Aven Ecology carried out a ground level tree assessment of 85 trees along the wayleave of a proposed road scheme.
Further surveys were recommended for 20 of the trees. A team of eight surveyors was used to carry out the emergence/re-entry surveys of the trees, aided by two thermal imaging cameras. A total of 18 tree roosts of two bat species were identified and, using R for statistical analysis, it was found likely that at least another three species were roosting in the vicinity. Anna produced and is the Named Ecologist on the bat mitigation licence, and Kevin has acted as the Ecological Clerk of Works/Accredited Agent during tree removal.
As part of the mitigation for habitat fragmentation impacts resulting from road schemes, a green bridge was built over a new road near Wokingham, along the route of a footpath. The bridge was close to the location of a hedgerow, identified as a bat commuting and foraging route during the emergence/re-entry surveys of trees along the road alignment. Baseline information was collected prior to the commencement of works, followed by monitoring surveys during and post development.
Monitoring of the bat boxes is on-going.
Bat Inspection, Surveys and Licence - Salisbury
(June 2021 – Present)
Two semi-detached dilapidated cottages were to be demolished to enable two new houses to be built on the Site.
An internal inspection of the roof void of the cottages revealed hundreds of brown long-eared bat droppings. Emergence and re-entry surveys using thermal imaging cameras revealed up to 16 bats emerging from the roost and returning at dawn. Data loggers and trail cameras placed within the void were used to monitor the temperature conditions and capture footage of the bats utilising the space and their different roosting locations. Six common pipistrelle roosts were also identified in the eaves and under roof tiles of the building.
Mitigation was designed to incorporate a roof void the same size as the existing to enable the bats to continue using a void in the new houses. Once planning had been achieved, a Bat Mitigation Licence was applied for and granted in December 2021. Aven Ecology provided the Named Ecologist and acted as the Ecological Clerk of Works during the demolition of the cottages.
Monitoring surveys are on-going.
Preliminary Ecological Appraisal, Bat Surveys, BREEAM Assessment, Urban Greening Factor and Biodiversity Net Gain Assessment – London
(March 2022 to October 2023)
A large office and commercial building complex in central London was undergoing major refurbishment.
Aven Ecology provided specialist Ecological input to the Planning Application, including the Preliminary Ecological Appraisal and Protected Species surveys, as well as BREEAM Land-use and Ecology, and Urban Greening Factor assessments. Working closely with the Design Team, Aven Ecology helped with the delivery and quantification of Biodiversity Net Gain, and attainment of Urban Greening Factor targets.
Aven Ecology also facilitated the smooth progress of pre-planning enabling works by providing on-site support to advise on and to document measures for compliance with UK wildlife legislation.
Bat Inspections, Emergence/Re-entry Surveys, Static Monitoring, Hibernation Surveys, Ground Level Tree Assessment – Ashford
(March 2022 – March 2024)
Anna and Kevin undertook Ground Level Tree Assessments on over 300 trees and building inspections on over 40 buildings for a large housing development near Ashford, Kent.
Bat emergence/re-entry surveys, aided by thermal and infra-red technology, identified roosts in 13 buildings of common pipistrelle, soprano pipistrelle and brown long-eared bats. Hibernation surveys of five buildings found roosts in two. To establish bat crossing points over the road dividing the Site, static bat detectors were installed monthly in four places over a three-month period; the calls were analysed using BatExplorer.
Great Crested Newt, Reptile, Dormouse & Bat Surveys – Hertford
(May – November 2019)
Aven Ecology undertook habitat suitability assessments for a series of 12 ponds for a potential housing development near Hertford.
eDNA samples were taken for all ponds considered suitable. Reptile and dormouse surveys were set up around and adjacent to the Site; slow worms and grass snakes were found around the edges of the Site whereas dormice were found to be likely absent from the area.
Bat activity and emergence/re-entry surveys, aided by thermal imaging, were undertaken, identifying bat roosts under the hanging tiles on the cottages on Site.
Bat Inspection, Surveys and Bat Mitigation Class Licence - Amersham
During the Preliminary Roost Assessment, a bat roost was identified within a private house in Amersham, which needed re-roofing.
Emergence/re-entry surveys, assisted by thermal imaging and infra-red cameras, revealed common and soprano pipistrelles roosting within the eaves and a brown long-eared bat using the garage porch as a feeding perch.
A Bat Mitigation Class Licence was obtained, enabling the works to proceed quickly under ecological supervision.
Somerset Pipeline
GCN Surveys
& Habitat Suitability Index (HSI)
Aven Ecology provided support to the Environment Team of a major multi-disciplinary consultancy, undertaking a suite of HSI, standard presence/absence, and eDNA surveys for great crested newts (GCN) covering over 40 ponds across Somerset.
These were required to inform proposals for a new water pipeline. Aven Ecology also assisted in a suite of bat activity surveys for the same project, leading a series of activity transect surveys.
Housing Development, Kent
Hibernation Surveys
A series of buildings to be demolished to make way for a large housing development were assessed as being suitable to support hibernating bats, following a Preliminary Roost Assessment and further emergence/re-entry bat surveys.
A static bat detector, accompanied by a data logger to record temperature and humidity, was placed in each building for a period of two weeks each month over the winter period. Hibernation roosts of brown long-eared bats and common pipistrelles were found within the buildings.
Dormice, GCN, Badger and Bat Surveys – Clacton-on-Sea
(March – October 2023)
Anna and Kevin carried out a ground level tree inspection for over 100 trees at a Site in Clacton-on-Sea. Between April and October, a dormouse survey was undertaken within the hedgerows and woodland within and adjacent to the Site, and static bat detectors were set out to monitor bat activity.
eDNA samples were taken from eight ponds within the vicinity of the Site.
Bat Inspection and Emergence Survey, Barn Owl Survey – Maldon
(September 2023)
Aven Ecology visited a barn in Maldon to carry out a bat inspection, coupled with a barn owl inspection. Barn owl presence was established and a bat tree roost identified. An emergence/re-entry survey identified further roosts in the barn itself.
Ground Level Tree Assessment, Bat Surveys & Licence, Bat Survey Monitoring– Arborfield
(June 2018 – January 2024)
Following the ground level tree assessment of ca. 300 trees Aven Ecology undertook a series of emergence/re-entry surveys on over 40 trees, which were scheduled for removal along the wayleave of a proposed road scheme. Thermal imaging and infra-red cameras were used to assist the surveyors in pin-pointing roost locations. Fourteen bat roosts of common and soprano pipistrelle bats were identified.
Aven Ecology produced the bat report, using R for statistical analysis, identifying likely roosting locations as well as the actual roosts found during the surveys. We produced and held the bat mitigation licence for the project, and provided the Ecological Clerk of Works during the felling of all the necessary trees.
Monitoring surveys have found 12 bat boxes, installed as mitigation, that showed signs of occupation by bats.
Bat and Great Crested Newt Monitoring, and Reptile Surveys – Chelmsford
(2015 – present)
Aven Ecology have provided assistance and undertaken a variety of surveys and mitigation/monitoring works at a Site in Chelmsford for over ten years (including before Aven Ecology was formed).
Aven Ecology assisted with pre-development surveys in respect of bats, great crested newts and reptiles, and provided field teams to undertake mitigation works, including translocation of reptiles and GCN to facilitate site clearance works.
As the development progresses apace, Aven Ecology has also supported ecological monitoring works, including bat activity transects throughout the year. Great crested newt surveys have been undertaken on the mitigation ponds every second year, and proven the mitigation successful.
