Bird Survey

Glade Ecology's experienced ecologists are experts in undertaking a broad range of ornithological surveys. Identifying the presence of target birds early, ensures that they are not inadvertently affected by site works, thereby enabling amendment of architectural layouts, modification of working practices, or rescheduling the timing of works, ultimately avoiding potentially costly and time-consuming delays.

​

Nesting bird check - Typically undertaken when any vegetation clearance or works to structures with suitability for supporting roof-nesting species commences during the bird nesting season (March-August inclusive). Relevant features will be subject to an inspection by a suitably experienced ecologist, within 48 hours prior to the proposed works start date. Where access permits, the inspection will encompass a 10m buffer outside of the works area. If any active nesting or nesting territories are recorded, these will be protected, along with an appropriate buffer zone of 10m, until the nesting is complete, and the young have fledged and become independent. 

​

Breeding bird survey - Undertaken in order to determine the number of nesting bird species, and the density and distribution of territories within the site, enabling the full extent of effects on nesting birds to be established, and appropriate avoidance, mitigation and, where necessary, compensation measures to be devised. The survey involves the mapping of territories across six visits between mid March-early July, each typically commencing within 30 minutes either side of sunrise, and concluding by mid morning.  Survey visits are spaced at least two weeks apart, ensuring that a broad range of the breeding season is sampled, capturing early-season residential breeders, and later migrants. Transect surveys may be supplemented by the deployment of static acoustic detectors, set to record for several consecutive days, within different priority habitats across the site.

 

Winter bird survey - Similarly to breeding bird surveys, a winter bird survey involves walking a series of transects across the site, recording all wintering or non-breeding birds, seeking to qualify the diversity and distribution of birds interacting with each distinct land parcel, in the context of their specific ecology and population status. A desk study will initially be undertaken, to determine the habitats present on site and the ecology of priority species likely to be encountered. The survey effort will typically encompass both the core winter months (November-February inclusive), and passage (September-October inclusive, and March). At least one survey per month will be undertaken. Whereas many species are primarily detectable through breeding and territorial call and song during the breeding season, audible detectability generally diminishes during the non-breeding season, with behavior shifting to foraging and resource acquisition. Surveyors must therefore typically rely on visual identification. Given that birds are typically more obvious for longer periods during this time, there are fewer restrictions on the timing of winter bird surveys, with optimal visibility conditions being the most significant factor in survey planning.

 

Vantage point survey - These surveys focus on identifying flight heights and paths of target species, such as wildfowl, waders, and raptors. They are typically undertaken for wind turbine developments, where determining the regular flight patterns of such species enables collision risk modelling, identifying threats to bird populations such as mortality, disturbance, displacement, exclusion, or loss and damage of habitat. For smaller developments, a single vantage point will be established, allowing optimal visibility of the proposed turbine location(s), the core area survey, and wider buffer zone. Several vantage points may be required for larger schemes. Surveyors at each vantage point record detailed data for each target species observed, as well as less specific data for secondary species. Though survey effort is always site specific, general methodology stipulates that a minimum of 36 hours of observation time is undertaken at each vantage point, each season (breeding, spring and autumn passage, and winter), broken down into six days of three two hour survey sessions (two hours at dawn, two at mid day, and two pre dusk).

 

Tailored species-specific presence/ likely absence and distribution surveys - For certain species, the standard breeding bird methodology may not be appropriate for determining presence/ likely absence, and/ or the number of territories. If as part of a preliminary desk study, it is deemed possible that any such species may be present on site, a tailored species-specific survey may be required, to ensure that the description of the ornithology baseline is complete, precise, and definitive. Such surveys cover a broad range of species, each with specific associated methodologies, from barn owl nest inspections, to evening nightjar territory transects, kingfisher surveys, or gull spot counts.

 

When

 

Bird surveys can be undertaken throughout the year, depending on the nature of the survey. The bird nesting season runs between March-August inclusive, though the majority of breeding activity occurs between mid March-early July. Nesting bird checks, breeding bird surveys, and many species-specific surveys should therefore ideally be spread between these dates. Depending on the nature of the site and the anticipated species assemblages, winter bird surveys typically encompass both core winter and passage months (September-March inclusive). Vantage point survey data my require acquisition throughout the entire year.