Urban Gull Surveys 2020 Project (Lot 3 off ES Framework)

Background

Gulls, particularly herring and lesser black-backed gulls, have expanded their breeding distribution into urban areas, and present a problem for survey and monitoring. The current seabird census, Seabirds Count, uses a 1 km sample square design to estimate nesting gull abundance and distribution within a representative sample of urban habitats. These 1 km squares are used to model and estimate abundance at wider spatial scales, based on habitat availability. In England, we have about 3,800 1 km urban squares across the country which require survey visits in 2020.

Additionally, we require 100 of these 1 km squares to also be surveyed within the same breeding season using digital aerial survey methods. The precise location of these squares is yet to be determined, but contractors may plan for them to be located in one or more 'clusters' to minimise aircraft travel distances and times. This is to build upon an existing Defra project awarded to BTO / HiDef Aerial Surveying designed to develop correction factors for ground-based urban gull surveys (Annex D).

Aims and objectives

The primary aim is to organise, manage and deliver coverage of these 3,800 1 km squares, and additionally cover 100 of them by digital aerial survey for comparison. In order to meet this aim, Natural England expects bidders to meet the following objectives: