eDNA and the fight against invasive non-native species (INNS)
Invasive non-native species (INNS) are one of leading causes of biodiversity loss worldwide and there is a demand for more...
APEM Group - Case Study
Natural England contracted APEM Group to determine the spatial extent and breeding population size of the Lesser Black-backed Gull (Larus fuscus) in the Bowland Fells Site of Special Scientific Interest (SSSI) and Special Protection Area (SPA), situated on the border of Lancashire and Yorkshire. Having used foot and drone surveys in previous years, Natural England was keen to see if Digital Aerial Surveys (DAS) would give accurate results with less disturbance to bird colonies.
Due to population decline, all gull species in the UK are protected, with Lesser Black-backed Gulls (Larus fuscus) on the UK conservation Amber list. The UK is home to nearly half the population of Lesser Black-backed Gulls, which live at a handful of coastline and lowland sites.
Why Bowland Fells
As the Bowland Fells are one of the few breeding colonies of Lesser Black-backed Gulls in the UK, Natural England commissioned APEM Group to undertake digital aerial surveys that would give a robust breeding population estimate and a baseline against which future monitoring could be compared.
Previous colony counts of Lesser Black-backed Gulls had been conducted on foot. However, foot surveys were labour-intensive, on rough terrain and caused disturbance to gulls. An initial drone survey was trialled, but the limited range meant that ground access was limited and gulls were still disturbed. As digital aerial surveys offer incredible detail and data accuracy, Natural England was keen to try this surveying method.
Example imagery of lesser black-backed gulls, grazing sheep and marshy terrain
Close-up example of nesting gulls.
The Project
Surveys centred on colonies of Lesser Black-backed Gull within the Bowland Fells Site of Special Scientific Interest (SSSI)/Special Protection Area (SPA). Data on nesting bird numbers was needed, so surveys were time critical, needing to be undertaken in a two-week window during nesting season.
The advantages of using digital aerial surveys were a lack of disturbance to the birds and, with the right technology, no loss of detail compared with ground or drone surveys. Ultra-high resolution imagery to 1.5cm Ground Sampling Distance (where the distance between pixel centres is 1.5cm) captured details of Gull species, life-stage and behaviour. The images picked up the birds’ shadows to discern whether the bird was sitting or standing.
Outputs
The Environmental Data Solutions team at APEM Group created a 3D digital elevation model of the terrain and an orthomosaic of the survey area which the experts in the Image Analysis team tagged with bird identifications, ages and behavioural categories. Due to the experience and expertise of the Environmental Data Solutions team, coupled with high quality imagery, the number of birds recorded is likely to be an accurate and robust indication of true breeding numbers. The report included data on gull locations inside and outside the survey area and the locations of any possible disturbances such as ramblers or climbers.
‘‘
The Bowland Fells Lesser Black-backed Gull survey was the first time that this important seabird colony has been fully surveyed from the air. Using plane-based digital aerial techniques allowed us to count the birds without disturbance, and we hope our 3D terrain modelling maps will be invaluable for the future management and monitoring of the colony. APEM Group are continually working to refine our survey technologies, and analysis techniques to capture ever more useful data and insights to help protect and manage our wildlife and natural heritage.
– Alistair Davison, Managing Director, Marine Science and Development, APEM Group
’’
‘‘
Our coastlines and landscapes across Lancashire and Yorkshire are host to a diverse range of seabirds including internationally important populations of Lesser Black-backed Gulls. Natural England uses science and evidence, such as these surveys, to better understand the dynamics of these colonies, target our conservation efforts and undertake our statutory duties.
The successful aerial survey completed by APEM will make an important contribution to local nature recovery. It will ultimately help Natural England to make more evidence-based decisions in our work and will provide opportunities for further analysis of this population and its context within Bowland and the wider region. This means we can work more effectively to turn the tide for the better when it comes to the conservation status of our species and habitats, including the Lesser Black-backed Gull.
– Samantha Critchley, Natural England Senior Manager Cheshire to Lancashire Area Team
’’
The coverage also made it possible to accurately map the extent of each of colony, which will be key to providing adequate conservation and management measures where required. These data will prove valuable for future SSSI and possibly SPA designation, as well as adding confidence in decisions around the management of lesser black-backed gulls and the monitoring of other Gull species.
APEM Group undertake surveys across the marine, water and terrestrial environment to support projects for clients across the world. To speak to a member of the team about this or any other projects, contact us.
Related Case Studies
Case Study: Continuous Water Quality Monitoring (CWQM) for United Utilities
Continuous water quality monitoring (CWQM) is a requirement under the Environment Act (2021) and plays a key part of the...
Fish Rescue and Relocation Project in the River Rheidol
Statkraft, Europe’s largest generator of renewable energy, called upon APEM Group’s specialist team for a technically challenging fish rescue from...