UES were appointed to undertake ecological surveys to support a planning application for a residential housing development on a site in Colchester, Essex. A Preliminary Ecological Survey (PEA) was carried out to advise on the habitats present on the site, and the potential for the site to support legally protected species. PEAs are produced to a recognised standard and format to enable a full assessment of the site to be made, and to identify the need for any further surveys. The PEA identified that the proposed works may impact on foraging, commuting and roosting bats, and therefore further survey work was recommended.

Bat activity surveys were undertaken by UES in 2014 and 2015 to determine the species of bats, and the level and type of bat activity on site. Transects were walked around site by two suitably experienced and licenced bat surveyors using sophisticated bat detection equipment. The equipment picks up and records the ultrasound echolocation calls of the bats making species identification possible. The recorded calls can also be analysed at a later date in more detail.

UES were also commissioned to undertake an aerial tree inspection of any semi-mature / mature trees to be removed as bats often use cracks and holes in trees to roost. Climbing the trees to get a closer view of any potentially suitable roosting features can enable the surveyor to discount features which may have seemed suitable from the ground, or to confirm the presence of bat droppings or feeding remains. Aerial inspections can also confirm or discount the use of trees by nesting birds, or use by protected species such as Barn owls.
The surveys recorded low levels of commuting and foraging bats on site. No roosting bats were recorded on site, and therefore no further survey or mitigation works were required.