The objective of a Preliminary Ground Level Roost Assessment of trees is to assess a trees potential to support roosting bats. The survey comprises a surveyor making an external assessment of the tree whilst stood on the ground, noting potential bat entry/exit points, potential roosting features (PRFs), and any evidence of bats seen. The trees are graded for their potential to support roosting bats (negligible, low, moderate or high), which will inform the need for further survey effort if required such as a Potential Roost Feature (PRF) Inspection.
The objective of a PRF Inspection survey is to confirm the presence/likely absence of roosting bats in trees and/or to characterise a roost. The survey comprises a surveyor using rope and harness climbing equipment to access the tree, at which point PRFs can be physically searched aided by an endoscope where required for the presence of bats or evidence that bats may leave behind. The seasonal timing of PRF Inspection should coincide with the period in which bats are most likely to use the PRF type present.
Elton Ecology PRF Inspection surveys are carried out by surveyors holding the relevant training certificates (such as City & Guilds NPTC Level 2 Awards in Tree Climbing and Rescue, and First Aid at Work) and a Natural England bat licence holder.
Where a Preliminary Ground Level Roost Assessment has identified PRFs that require further survey, and the tree is not safe to climb, nocturnal survey may be required to establish the presence/ likely absence of roosting bats.