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Aerial Bat Inspections 

Aerial Bat Inspections

The Bat Survey Process 

The process of establishing and characterising a tree roost is guided by the Bat Conservation Trust Guidelines (2016) and ordinarily starts with a ground-level assessment of the tree. This is followed by emergence/re-entry surveys which involve a team of ecologist's standing at the base of the tree watching for bats either at dusk or dawn. These surveys are seasonally constrained to between May and September when bats are most active. The seasonal limitation can cause considerable delays to projects if they are not planned early enough. Bats can vary considerably in their emergence/re-entry times depending on a number of factors (prevailing weather, light levels, disturbance) which can limit the effectiveness of the survey.   


The Aerial Inspection

An alternative method of determining a roost (supported by BCT) can be to use a team of bat licensed  and qualified climbers to carry out an aerial inspection. This involves a team of two and a daytime visit to access the tree via a rope and harness system during which an endoscope is used to carefully probe potential roost features. In contrast to the seasonally-restricted emergence/re-entry surveys, aerial inspections can be done at any time of year (though they are most efficient when foliage is down) and can be more precise (In Practice, 2010). Aerial inspections can therefore be a much more cost-effective and efficient means to ascertain whether or not bats are roosting in trees. 

Hybrid Ecology are qualified in Tree Climbing and Aerial Rescue and hold a level 2 bat licence; enabling the team to carry out aerial inspections on any site where there is a suspicion bats may be present. 

We can also provide a HYBRID service alongside tree works - see our other pages for details. 


Legislation and Planning Policy

All bat species are legally protected from killing, injury, roost destruction, disturbance and roost obstruction. Bats roost in locations sheltered from prevailing weather and can be found in any tree feature offering these conditions, including but not limited to; cavities, hazard beams, splits, frost cracks and woodpecker holes. Of the 17 species we have in the UK, 13 are known to use trees at some point in their life cycle. 

If you have a tree with any of the above features and works or removal are unavoidable, bats may be present/affected and an offence may be committed in the absence of appropriate advice and mitigation.  

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