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Winter bird survey

William Girling Reservoir - Winter Bird Survey

There are approximately 250 bird species that breed in the UK.  Many of these are resident all year round, but some are summer migrants and others migrate to the UK in winter to escape colder climes.  Given the wide variety of birds found in the UK and the range of nesting sites birds can utilise, almost all development sites have the potential to support nesting birds.

We employ ornithologists with extensive expertise in conducting breeding and wintering bird surveys in terrestrial, wetland and marine environments, as well as being trained and experienced in flight line and collision risk survey and assessment.  One of our ornithologists is also trained in completing European Sea Bird at Sea (ESAS) surveys to assess the impact of off-shore windfarm developments.


We undertake flight line and collision risk assessment to inform windfarm development


Conservation status

A large number of bird species in the UK have declining populations. Some populations have already declined to a fraction of their former size. Birds of Conservation Concern’ – a report by many bird conservation organisations – identifies 52 “red list” bird species in the UK of high conservation priority.


The Wildlife and Countryside Act (1981) (as amended) gives blanket protection to all wild birds, making it an offence (with certain exceptions) to:

  • kill injure or take any wild bird species; and
  • take, damage or destroy its nest or eggs.
Golden eagle (Aquila chrysaetos)

Golden eagle (Aquila chrysaetos)

Some species, listed in Schedule 1 of WCA 1981, have additional protection, which makes it an offence to intentionally or recklessly disturb them at the nest.

Click HERE for a list of  Schedule 1 species.

The NERC Act (2006) inserts a new schedule into the Wildlife and Countryside Act (1981) to protect the nests of some species that regularly re-use their nests, even when the nests are not in use.

Currently this protection applies to golden eagle (pictured left), white-tailed eagle and osprey.


A licence may be required to survey birds on Schedule 1, such as Barn Owl, and we hold the necessary licences to survey a number of Schedule 1 species.


Slavonian grebe

Slavonian grebe (Podiceps auritus)

Bird survey would normally include an initial desk based and/or walkover survey of a site to establish the presence of habitats that are potentially suitable for breeding and wintering birds and determine the likelihood of birds being impacted by a proposed development based on known local bird records and professional judgement.

Where a site has the potential to support significant bird interest, a follow-up survey may be required (depending upon the nature of the development) to assess its importance to birds as a breeding and wintering location.

To evaluate the importance of a site for breeding birds, the survey should coincide with the time that birds are making nests, laying eggs and rearing young which is typically March-July across the UK.  In enclosed habitats with fine grained habitat structure such as woodland and scrub, we would typically employ territory mapping survey methods based on the British Trust for Ornithology (BTO) Common Bird Census, to map individual bird species territories, and enable the abundance and breeding distribution of individual birds to be assessed.  In more open habitats such as farmland and moorland, a line transect type survey would be a better way to calculate bird density and diversity, with a survey route pre-determined to enable all habitat areas within the site (or a representative selection) to be covered.

In some situations, for example where the presence of an individual species of high conservation importance needs to be assessed, targeted survey approaches may be required e.g. a search for potential barn owl nest sites involving winter and summer visits, and dusk and pre-dawn surveys for other crepuscular species such as nightjar.

Black redstart and peregrine falcon survey Battersea Power Station


Mitigation & Compensation:

Black redstart (Phoenicurus ochruros)

Black redstart (Phoenicurus ochruros)

Nests, eggs and nestlings are vulnerable to disturbance and it is advisable to complete site clearance activity outside the breeding season (March-July).  If this is not possible, then the site may need to be checked for the presence of nesting birds and their dependent young if it has recognised bird nesting potential, and clearance delayed as necessary to avoid disturbing birds.

Alternative habitats can be created as compensation for the loss of bird habitat, and a number of measures can be employed to increase birdlife on site, from planting ‘wild’ areas to putting up nest boxes and green roofs. These must be properly maintained to ensure that they continue to provide a habitat for birds.

See Survey Calendar for survey timings.

Return to ‘Animal Species Surveys’