Potential Bat Roost?

[benedmonds]

We have a beech with a big cavity, to come out. Obviously there is huge bat potential although there is no staining etc..

It has been a long time since my bats in Arboriculture course, what is best practice now days? 

It is complicated by the fact that there is a building going up in a month that will mean no crane access and it will be a very different job without a crane.

 

I have jus t ordered:

Bat Roosts in Trees A Guide to Identification and Assessment for Tree-Care and Ecology Professionals

 

Edited January 6, 2022 by benedmonds

[Mark J]

Ideally you want to find someone trained in secondary roost surveys -  including endoscope use. They will be able to determine if it is indeed a roost.  

 

[benedmonds]

18 minutes ago, Mark J said:

Ideally you want to find someone trained in secondary roost surveys -  including endoscope use. They will be able to determine if it is indeed a roost.  

 

But what can we do if it is a roost?

We would presumably need an EPS licence?

Then what?  If we have a crane we could soft fell/lower the roost to the ground.

Then what are the options.

Relocate the roost? 

Give them the option to fly off themselves? I don't see that as an option at this time of year.

 

Edited January 6, 2022 by benedmonds

[benedmonds]

Scoping surveys for Arborists - online - Events - Bat Conservation Trust

WWW.BATS.ORG.UK

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The Bat Conservation Trust was formed in 1990 as an umbrella organisation for the rapidly growing network of bat...

 Anyone done this training?

 

 

[Mark J]

2 hours ago, benedmonds said:

But what can we do if it is a roost?

We would presumably need an EPS licence?

Then what?  If we have a crane we could soft fell/lower the roost to the ground.

Then what are the options.

Relocate the roost? 

Give them the option to fly off themselves? I don't see that as an option at this time of year.

 

Yes, if determined that it is a roost then a Level 2 bat licensed person/ecologist will have to be involved with mitigation. 

I did the online course you linked to and then followed it up with the secondary roost surveys course, which was a one day thing at Wollaton Hall.

It might be worth getting in touch with your local bat group.

First step though is to determine if it is a roost.

This is a useful book: 

Bat Roosts in Trees

PELAGICPUBLISHING.COM

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This is a guide to finding tree-roosts. It is the result of the collaborative efforts of professional surveyors and amateur...

 

Edited January 6, 2022 by Mark J

[Bob_z_l]

2 hours ago, benedmonds said:

We have a beech with a big cavity, to come out. Obviously there is huge bat potential although there is no staining etc..

It has been a long time since my bats in Arboriculture course, what is best practice now days? 

It is complicated by the fact that there is a building going up in a month that will mean no crane access and it will be a very different job without a crane.

 

I have jus t ordered:

Bat Roosts in Trees A Guide to Identification and Assessment for Tree-Care and Ecology Professionals

 

 

That bottom right entrance/exit looks so similar to the  wild bee colony I have in a cedar.  That waxy look on the bottom lip.

 

I hope you get a safe result that works either way

[benedmonds]

Do bats and squirrels ever share roosts?

I know squirrels will predate birds nests do they do the same to bats?

 

[daltontrees]

Ben your best bet is initially to use the microguide that accompanied BS 8596. It is aimed at arbs in your situation. It will guide you as to whether someone like you can reasonably rule out roosts. If you can't, then you probably need to refere it to a specialist. Then wait for 3 months while they do dawn and dusk emergence surveys. In my expereince a lot of bat people overdo it, really disproportionate survey effort. Including such madness as emergence surveys at trees that have no potential roost features. A client once got charged £12,500 for this, I signed the tree removals off with a short but pertinent report for £75.00.

 

There's a fundamental difficulty in makign decisions about roosts. In brief, if it has ever been used just once for a day by a solitary bat that got caught out far from home as it got light one morning, it is officially a roost. The legislation creates 2 offence types, disturbing (or worse) bats or destroying bat roosts. Obviously it's possible to do both, and if a bat is present then it is a de-facto roost. I think this is why roost features are more important initially than bat presence, becuase they can be seen during the day. And of course, no roost, no bats.

 

A realistic approach is needed. Think in terms of the test being whether the assessment gives a robust defence against prosecution.  Much like tree risk assessments, there are several components. Quality of roost x size of roost x evidence of use. Big upward pointing dry features with staining or actual live bat signs are highest, but a shitty wee downward pointing knothole a foot off the ground might theoretically be used by a bat (the equivalent of sleeping in a bus shelter when you miss the last bus home) but even if it is then removal is of low low impact on bat populations and ecology.

 

Try the guide I mentioned. If you can't find it, let me know.

[nepia]

That's an incredibly helpful post as recognised by someone who has two roosts in the cladding of his house and wants to do building work.  Fortunately we've at least delayed such work on grounds of cost - we've actually withdrawn the planning application - but if we wanted to go ahead we wouldn't be able to do anything until the 3rd and 4th surveys were done late next summer.

 

I suppose the general advice has to be the same as ever; become knowledgeable, be careful and cover your ass whatever you decide to do

[benedmonds]

When doing the bats in Arb awareness course back in 2006 I remember coming away thinking, "that was pointless, anything can be a roost."  

 

BSI pricing makes purchasing the BS8596 rather unaffordable..

The Micro guide can be downloaded:

https://cdn.bats.org.uk/uploads/pdf/BSI-Bat-Microguide-UK-EN.pdf?v=1549304693