RAUK - Archived Forum - The rough guide to reptile mitigation....

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The rough guide to reptile mitigation....:

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herpetologic2
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Posted: 12 Jan 2009

Or would be be named the unofficial reptile mitigation guidelines....

Anyway carrying on from the reptile survey best practice/guidance we are now going to look at reptile mitigation.

This guidance is aimed at development related projects which affect the conservation status of reptiles. The guidance also relates to the widespread reptile species and not the rare species - sand lizard & smooth snake

1. Survey effort - A minimum of 10 survey visits should be made to a study site. Non consecutive survey visits need to be made following the guidance on reptile survey. Trapping out reptiles based on peak counts or density figures. Capture effort should be plotted on graphs to determine the decline in numbers. Only after 5 clear days of suitable weather habitat manipulation can commence. Once a significant number of animals have been rescued then the last phase of the trapping follows a 'destructive' search

2. Habitat assessment & current impacts identified on the site - the assessment should be aimed at conserving the reptile interests of the local area with two main aims as identified by Natural England

2(i) To avoid harm to any resident reptiles

2(ii) To prevent any net loss of local conservation status of any reptiles found within a site 

3. Species specific mitigation - lizards should be treated differently to the snakes. The general requirements of the different species are similar but it needs to be recognised that snakes operate within a wider range of habitat than the lizards. Slow-worms and lizards would exist in small habitat ranges than the snakes. Effectively the scale of habitat use is larger in snakes.

4. Look for alternative sites to develop, then accommodate the reptile interest within a development by a redesign of development scheme, then a relocation to an in situ receptor site and an absolute last resort translocation to external sites.

5. Ideally all the required survey work should be completed over at least a full reptile season. The reptile survey should follow the guidance on reptile survey and it should also look beyond the study site and into the wider countryside to look for suitable receptor sites and sites which can be improved for reptiles as compensation for development. Putting the study site in context with adjoining habitat and reptile populations is important to assess the likely impacts towards conservation of reptiles.

6. Habitat features should be mapped on site using survey information - for e.g. adders found within the early spring would be pretty close to their hibernation area - this should be incorporated withina development design. If the hibernacula will be lost then a replacement should be provided. Ideally more habitat should be created which is lost.

7. Trapping effort - if reptiles need to be moved away from any harmful activities then the closer to the original capture site the better. Reptiles should not be translocated any great distance unless it is absolutely necessary. Large distance translocations over 35km should be avoided.

8. Receptor sites - receptor sites should ideally be larger than the habitat being lost to development. Ideally an existing reptile population should be absent but it has connectivity to other adjoinign reptile populations. Habitat enhancements should be made to a receptor site in advance of moving animals. Using receptor sites year after year should be discouraged. Farmland reverted to rough grassland habitats would be the best option. Habitat management on neglected habitats or unsuitable reptile habitat (such as planted pine forests) can provide suitable areas to move reptiles to.

(i) Receptor site should be larger in area than the habitat being lost (no net conservation loss)

(ii) Receptor sites should be a similar habitat to the donor site

(iii) Secure for the long term through a management agreement planning conditions or section 106

(iv) Within 10km of the donor site and ideally within 2km - only when absolutely necessary further distances can be considered. Distances over 30km should not be considered.

(v) connected to further habitat and near other reptile colonies

(vi)  Enhancements should be prepared in advance of the movement of animals

9. Monitoring - provision of monitoring reptiles should be aimed towards the long term - beyond 10 to 25 years - depending on the size of the project. Funds should made available to an organisation to help fund surveys at least every other year to inform management activities over the winter. Short term monitoring cannot provide the information whether a population is self sustaining and it is suggested that more long term monitoring programmes are required.

10. Follow up management works - it is important to provide money for follow up management guided by monitoring surveys. Funds should be paid to managing organisation - volunteer effort or paid contractors for a set period of 20 to 25 years - dependent on size of project.

Any other comments and suggestions

 

Jon

herpetologic239825.717025463
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Vicar
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Posted: 13 Jan 2009
Hi Jon,

This is really useful, as I have to write something similar for LPA guidelines in Surrey. Clearly the better aligned they are to national guidelines the better!

One immediate thought - the term 'Ideally' could be subjectively interpreted. I'm hoping to generate levels of evidence required by the developed to demonstrate that on-site mitigation is not practicable. putting the onus on the developer to prove to a defined standard that first steps are not available - rather than 'we couldn't find a local site, but we did find a site 200 miles away' :P

There may also be a trade-off between locality and quality of reptile habitat (within reasonable ranges) - again would need definition.

Will get back to you when I've developed thoughts more.


Steve Langham - Chairman    
Surrey Amphibian & Reptile Group (SARG).
herpetologic2
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Posted: 13 Jan 2009

Hi Steve

It would be good to develop the LPA guidelines into an advice sheet from ARG UK. There is a planning advice sheet for ARG groups perhaps a similar advice sheet can be developed for LPA's?

At the South East Meeting last year we discussed the need for new guidance on best practice and we need to think about what is acceptable practice (suggested by Lee Brady) rather than determine what consultants should do in projects - we should expect things like no net loss of status, increases in reptile habitat, monitoring of projects and reporting survey results.

Regards

 

Jon


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sussexecology
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Posted: 30 Sep 2010

 

Hi Steve and Jon

Do you know, or anyone else know, if the updated reptile mitigation guidelines from Natural England, have been produced yet? I believe that Natural England were hoping to get these published in the spring 2010.

I'm an ecological consultant but find it frustrating there is no formal reptile mitigation advice (which is up to date).

I was interested to read your comments though Jon. Certainly regarding reptile surveys, the minimum seems to be 7 although I have often found silow worms on the 3rd visit.

Some informaiton on assessing the impacts of develpoment would be helpful and what the minimum required for mitigation is. Particularly interested in slow worm mitigation advice that this up to date in relation to receptor sites and habitat enhancement.

i believe that it is bad practice to move reptiles from a development site without planning permission. However, in some cases, I have been forced to begin mitigation because planning authorities are somewhat laid back and often cause delays.

Any comments would be welcome. 


Vicar
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Posted: 30 Sep 2010
I have seen the draft. NE are currently wrapping up the consultation process. Shouldn't be much longer. There were still some ambiguities in the draft I saw, such as the failure to define 'suitable conditions'.

7 visits is probably inadequate, or to put it another way, provides only a low confidence of probable absence. It depends on the species and to some degree the refugia density, but 7 visits would give a confidence of probable absence of roughly 40%. That's not opinion, its statistics. DICE should be publishing a paper on detectability soon.

For low tin density sites, for snake species, you would need about 40 visits 'in suitable conditions' for 95% confidence of probable absence, which is the confidence we use for conservation translocations (re-introductions). This uses a 'worst case' detectability of 6-8%. 40 visits is probably excessive, but 7 is probably too few.
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herpetologic2
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Posted: 30 Sep 2010
Hi there.

There has been two years of testing the NARRS survey protocols for reptile survey. This will give an idea of what the minimum requirement for volunteers to detect the presence of each UK reptile species.

From the initial results the slowworm was the most frequently detected species in the study. To me surveys should aim for as many visits as possible.

Natural England have two main aims for reptile mitigation in their guidance for developers or any organisation whose activities will impact on the welfare (aim one) and the local conservation status of each species (aim two).

We have limited evidence on how effective mitigation strategies are for reptiles. Slowworms and lizards have anecdotally beenshown to have benefited by mitigation while the standard reptile mitigation that we all know and see has no evidence whether it benefits the snake species.

The obsession with reptile fencing and translocation is probably more to do with money and profit rather then whether it actually works or effective.

I have translocated several populations of lizards and slowworms with some success but we have not got to the required time needed to determine this success (who will pay for it?)

If you are getting presence from three visits that is great you have more time to work out the relative population size in the next seven visits. Survey results vary over the season in population density, sex ratios, concentration of animals around foci (hibernation features and foraging sites etc).
Surveys for snakes are best carried out in the spring. There is no way the population status can be determined during surveys during the summer as snakes are in very low density during this time. Hibernation sites need to be identified in surveys so that they can be protected or recreated during mitigation work

To me habitat is much more important than miles of fencing external translocation and the other revenue generating habits we find hard to break

Jon



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Vicar
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Posted: 01 Oct 2010
[QUOTE=herpetologic2]
Surveys for snakes are best carried out in the spring. There is no way the population status can be determined during surveys during the summer as snakes are in very low density during this time. [/QUOTE]

What Jon says is completely in line with received knowledge. In my opinion, We need to move more toward evidenced-based deductions. The controlled survey data doesn't support the Spring hypothesis...but early days yet. As the years go, the data gets better.

I agree with all the other points!



You can see the stats for other species here.
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Caleb
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Posted: 01 Oct 2010
What happened to December?

The temperature graph for 'all species' is somewhat bizarre, with those massive zigzags- is that really correct?

Do you include zero-per-hour records in those data? If not, I guess that 3-per-hour peak at 6C could be based on one observation.

Sorry, lots of questions...
herpetologic2
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Posted: 01 Oct 2010
Hi Steve

Thats a great tool. maybe I should clarify a few things
on what I am looking for to assess an adder population.

I tend to use the 'adult counts' to determine a rough
idea of the relative population size of a population of
adders. These counts normally only consist of male adders
- you could argue that the sex ratio should be nearer to
1:1 so you could double the population estimate based on
adult male adder counts.

Often it is a sub population within a larger
metapopulation that we find when surveying sites.

If you use the surrey tool and put in Adult, male and all
sightings you will see that it is more efficient to
survey in the spring (one of the most optimal times of
year according to NE).

I tend to use visual surveys to detect the adult animals
coming out of hibernation - thus finding an important
habitat feature and where part of the population is
centred during the winter and spring.

I have several sites which I have surveyed using visual
and refugia and it would be good to number crunch these
sites as well.

Jon











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sussexecology
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Posted: 01 Oct 2010

Thanks for your comments.

I agree that more than 7 visits are required as well as the density of refugia. In fact I feel that the  more visits you can do, the better - providing the weather conditions are suitable.

Regarding the number of refugia - Froglife recommend using 5-6 per ha but I have found that using a density of 50+ is far better. It depends on the site conditions and available habitats as well as the materials that you have available. I have found that roofing felt and corrugated iron works well for slow worms.

I think more research is required to determine if translocation programmes are successful for reptiles - esp slow worms. I would normally recommend that surveys are undertaken for at least 5 years following the translocation, although obviously this depends on time constraints, weather conditions and funding.

Re the mitigation for slow worms - i have found that strimming areas of grass where slow worms are known to be present and leaving patches of grass uncut makes it easier to catch them. Obviiously this needs to be controlled and done gradually but it works!

Thanks again.

 


herpetologic2
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Posted: 02 Oct 2010
The froglife guidance is not intended or wasn't intended
to be used for consultancy work - it is a problem as
consultancy work often far exceeds the required effort as
indicated in the froglife advice sheet - 5 to 10 aco's
per hectare - the key reptile site criteria cannot be
used to assess reptile populations using consultancy data
as it is based on much more detailed surveys.

An example
My local churchyard has 30 Aco's laid out in approx
0.07Ha - the level of survey effort is therefore 428 Acos
pre hectare!

The peak counts for the site have been 109 last year and
151 this year - an exceptional population based on the
criteria in the froglife advice sheet -

If I wanted to put the density of 10 Aco's per hectare,
as indicated by Froglife, I would have to have put 0.7
Aco's out on the site! clearly the froglife advice is out
of date and needs to be updated even for volunteer
surveys.

The NARRS survey protocols is using just 30 ACO's at a
standard size of 0.5m2 - At the churchyard I used 0.25m2
ACO's starting with 30 but recording how many were
checked on each survey - as this is a variable which is
being tested along with weather, site conditions,
location, site size, numbers of surveyors and their
experience etc.

Hopefully the survey standards will be adopted as part of   
standard reptile survey protocols - DICE have just got
funding for workshops on this matter over 2011 and 2012 -
so I think we will have more robust guidance to which
survey effort can be assessed

Jon









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Vicar
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Posted: 02 Oct 2010
[QUOTE=Caleb]What happened to December?

The temperature graph for 'all species' is somewhat bizarre, with those massive zigzags- is that really correct?

Do you include zero-per-hour records in those data? If not, I guess that 3-per-hour peak at 6C could be based on one observation.

Sorry, lots of questions...[/QUOTE]

All excellent questions!

  • December - we've not conducted controlled surveys in December, so we have no December data...yet.
  • The zig-zag should not be interpreted as a zig-zag. This is because the 'bin-range' on temperatures is set to too fine a resolution (1?C). Initially this was very 'zig-zagged' but as we build up survey data, all the lines smooth out more. I'l will change the temperature bin-range. So far (500? surveys) we haven't had a survey for each 1?C step, or at least not enough to get a good mean. If you see a spike at 15?C, you can assume that 1?C either side won't make much of a difference.
  • Yes all negative results are recorded and are a function within the statistics. Recording time spent surveying and negative results are key to determining these stats, and eliminating some of the biases.
Using the evidence has changed my opinion on some aspects. The human brain isn't very good at sorting data trends by itself...If I have a great day in Spring...that lodges in my memory, forgetting all the poor surveys. Recording everything and running the stats can be illuminating !

Steve Langham - Chairman    
Surrey Amphibian & Reptile Group (SARG).
herpetologic2
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Posted: 02 Oct 2010
Hi Steve

I think that the tool is excellent. I have looked at the
data for adult female and male adders - using the three
different combinations of all sightings, refugia
sightings and open sightings some interesting results can
be seen.

I have taken screen shots but I cannot get them
to upload on this post grrrrrr!






herpetologic240453.6388773148
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sussexecology
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Posted: 03 Oct 2010

 

Thanks Jon for your comments. I would be, and I know others would be too, of any further training on assessing population status of widespread reptiles.

By the way, I wasn't indicating that consultants should go by the Froglife's advice as it is obvious from reading this that it is intended for volunteer surveys. I was only stating that consultant surveys would naturally need to be detailed, due to the reasons whuconsultants undertake these surveys.

.


Vicar
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Posted: 03 Oct 2010
Actually...I could do with advice about how consultants use relative population estimates.

Presence/absence must of course be determined, hence initial survey and desk study.

If you have a 'high' population, then I guess this may affect the material considerations of the planning application.

Is the population size assessment done to assist mitigation planning assumptions? (How large a receptor size has to be, hours to capture etc?) - and is it really used to do this ?

As far as I can see, there are four ways to estimate the size of a population:
  • Peak counts
  • Detectability over a number of surveys (animals seen per hour)
  • Using an agreed carrying capacity and multiplying by area (for suitable habitat areas)
  • Mark/recapture
None of these, in my opinion, would be a practicable means for accurate determination of population size. Relative population estimate is about the best we could achieve, which points squarely at options 1 & 2 (3 being too generic, and 4 being too difficult and time consuming, due to proven low recapture rates for all reptile studies).

Interestingly, we capture detectability and peak count data for all our surveys, and the two do not correlate. I.e. a high detectability does not necessarily mean a high peak count, and vice versa.

What is the best means of determining relative population estimates?...and more importantly....why is it the best method??


Steve Langham - Chairman    
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Posted: 04 Oct 2010
[QUOTE=Vicar] All excellent questions![/QUOTE]

Thanks for the answers, makes a lot more sense now. The 2000+ sample size implies that the data should be pretty robust, but I guess the samples are very biased towards certain parts of the range. I suppose confidence bars would show this, but would clutter the graphs somewhat.

You just need to motivate people to get out on cold days in December to collect those negative results...
herpetologic2
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Posted: 04 Oct 2010
Hi Steve

I tend to use the peak adult count within a reptile
survey of at least 7 non consecutive survey visits over
the active reptile season. I would normally use visual
encounter surveys combined with artificial/natural
refugia surveys.

Using the adult counts you can make an estimate of a
likely number of animals - with the survey data - peak
counts this is assumed to be approx 5 to 10% of the
population. For a series of surveys I have been involved
in the peak counts within a survey does land between 5
and 10% of the captured population within a mitigation
project.

We had a peak count of 8 lizards from a small rough
grassland site one year - we went on to capture 96
lizards for translocation - peak count indicated 8.6% of
the population

On another site we had a peak count of 48 lizards - mixed
ages - we translocated 747 lizards - survey indicated 6%
of the captured population

On another site known to me in Essex the following
results were recorded (off the top of my head)
Peak counts - lizard - 30+, Slowworms - 35 grass snakes -
2
Captured populations - lizards - 350, Slowworms - 750 and
grass snakes - 32

This is where survey information combined with the
subsequent capture number would be most useful as
consultants tend to be the people who collect this data - unfortunately it is rarely reported.

Another option for the relative population size would be
the numbers of animals per ACO or on transects the
numbers of animals seen per unit of time - sightings per
minute or per hour.

My local churchyard has an exceptional population of
slow-worms according to the survey results - do you work
out detectability by the number of ACO with slowworms
under them?

if you have slowworms under each one would that be 100%
detectability? whereas the visual surveys would have 0%
detectability?

The main thing for a survey is to detect presence,
relative abundance, distribution, habitat features of
importance - so that can all be used to determine the
impact of a proposed land use change - this should work
for habitat management as well as development plans

The 96 lizards which were translocated in the previous
example went into a golf course release site - monitoring
surveys in 2005 found 60 lizards within a peak count
using artificial refugia - density 1.2 lizards per ACO
The adult peak count was 25 0r 0.5 per ACO

The receptor site was almost double the size of the area
which was lost - did we manage to compensate for the lost
of 0.7 Hectare of old rough grassland?

J












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Posted: 09 Oct 2010
Steve, we use relative population estimate to figure out capture effort required. The approximate percentages given by Jon turn out pretty accurate in my experience. Seeing the last week onsite results of zero captures is something I'm actually pretty proud of. To be honest though in terms of capture effort it would boil down to 'lots' 'quite a lot', 'not that many' in real terms and what I really want to know is do I need to snow the site with refugia and how many people do I need out there, as well of course that the receptor site(s) are more than adequate.

I've resisted the '10' survey visits approach in the past, OK I knew full well I would collect all the data I needed in 7 visits and at the density of ACO I survey with completely blow-away the 'high' count from the Froglife advice sheets for the target species. So why go on further repeating the same data collection on 3 more visits? In general though I agree 10 is better than 7. Still not enough for NN and Vb though.

I worry though that be it 7, 10 or 40 visits it all becomes a 'tick box' exercise if the people involved lack the field craft needed.

I strongly feel all the data from consultancy work must be fed to the right people  before things will really change. There are a few that can walk on a site and probably within minutes judge what they are dealing with on the first survey visit. Unfortunately I hear all too often about mitigation where animals far exceed what was expected, receptor sites over-flow and the developer is going bonkers because of the delays. It should really be self-selecting as to those who know what they are doing and those who do not, but that isn't the way it currently works out and it is really the developers own fault because they don't want the data going to a central source. (or should I say a central source where the data is actually used )

I think it is time they themselves realised that consultants should be working on a performance basis rather than the one who gives the cheapest quote... one way to do this would be to convince developers that survey and subsequent mitigation results being made available would show the consultant's abilities. The developers are only hurting themselves and leaving the door open to 'tick box' consultancy and cowboys the way things are. So consultancy 'A' carries out a poor survey and hugely underestimates the population of reptiles they are dealing with, whilst consultancy 'B' carries out good initial surveys.. the trouble is that consultancy 'B; knows what they are dealing with and is always going to have a higher quote so is not offered the contract! Wouldn't it be much better if consultancy 'B' was chosen because of their recorded past history of getting it 'right' based on their initial survey work???

Just one more point. Quality or quantity needs to be looked into regarding receptor sites. It certainly isn't all about hectares. We often get sites where reptiles are known to exist improved and use the improved areas as 'soft release' spots. For example a known 4 species site which was becoming shaded provided an ideal 'soft release' for common lizards once the area was opened up a little. Though I totally agree with overal conservation aims, there is also a duty of care issue that the animals are put in an environment where they have every chance of survival. I would much rather extend an existing habitat with good connectivity to large populations than create an isolate.

It's pretty obvious to me also for common lizards that a good log pile can sustain a whole sub-population, far better than some release sites I've seen used.

In all then, guidelines are great, unfortunately many will see the 'minimum' as the hoop to jump through (or box to tick) rather than the base line... revealing the actual performance of consultants in the field would clean up the whole show in a much shorter time...
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Posted: 09 Oct 2010
Couldn't agree more. But, there is always the argument of setting guidelines for the lowest common denominator.

We have a site in Surrey that was surveyed this year, in support of a planning application where the survey, on the face of it seemed fine. High number of refugia, appropriate number of surveys at an appropriate time of year in appropriate conditions that returned zero reptile presence.

I'm sure the developer was delighted.

Subsequent survey has show it to be a four-reptile species site.

If I was the developer, provided I don't get caught and prosecuted for killing reptiles (and what are the chances of that?) I've just increased my profit margin by reducing risk. Even if I am prosecuted, I'd have a professional survey to support my case.

Then we have cases where the development is sponsored by the same district council who are the line managers of the local planning authority. Conflict of interest ?

With the results of the comprehensive spending review due out in a couple of weeks, I'm expecting NE staff levels to be slashed, so any teeth NE had, will likely be diluted due to staff availability?

I can't see any pressure on developers at all, unless some prosecutions are brought to bear that actually make a difference to profit margins (or public reputation). Or am I being Captain Cynical ?

Steve

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will
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Posted: 09 Oct 2010
re Steve's last point, I've heard that NE in London are likely to suffer job losses, and that Phase 2 of the NE project funding adder habitat management in Greater London has been binned..

Will

- The rough guide to reptile mitigation....

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