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calumma
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Posted: 29 Jul 2004 Topic: Travelling Reptiles



The number of times I have surveyed a site for the first time and asked local people (landowners/managers, walkers, dog walkers etc), what reptiles they have seen - only to receive a blank expression and assurances that no such animals will be found... On many occasions I have then found lizards and slow-worms literally within a few minutes of arriving at the site.

Many, many people look but do not see...

Understanding reptile distribution can sometimes appear to be a black art. In Kent I can usually predict exactly what species will occur on a site (we only have 4 to choose from!). However, the criteria that I use to predict species occupancy in Kent would be useless in Manchester where I grew up. As an enthusiastic young Mancunian herpetologist I was constantly frustrated in my attempts to find reptiles.

Species can be found on sites where we so-called experts would perhaps not expect them. At other times the species can be seemingly absent from sites where local conditions suggest that they should appear. What is important to remember is the barriers that restrict species distribution may be invisible to us, yet very important for reptiles.

While out on site yesterday I tried to explain this to a chap who is writing a management plan for a SSSI where reptiles occur. The issue was the lack of reliable survey data and potential disturbance to areas where reptiles (specifically adder) may be hibernating. Hibernacula are crucial to species such as adder, yet such features may be invisible to the untrained eye. On sites with breeding amphibians, land managers are generally aware of the need to protect ponds (or other waterbodies) where amphibians breed - because these structures are obvious features in the landscape. The structures that reptiles use can be more subtle and consequently are more likely to be overlooked (and thus disturbed).

I have surveyed several large sites where slow-worm are very patchy in their distribution. There are no obvious habitat factors that explain this patchiness. Multiply this up at the landscape level and you can see how there are likely to be problems in predicting species distribution.

Lee


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 06 Aug 2003 Topic: Great-crested newts and fish



As county recorder for reptiles and amphibians in Kent, I look at an awful lot of crested newt ponds...

Yes there is a negative relationship between presence of fish and breeding crested newt. However, as others as stated the relationship is not as simple as many believe and is often species dependent.

One of the best crested ponds that I have surveyed in Kent is in a public open space and has had goldfish introduced. I often find that goldfish and cresteds coexist. Others have stated that one of the fish species most likely to predate crested larvae is stickleback. Yet I know of several ponds where crested newt and stickleback co-exist. Work in Europe has shown that crested newts can detect the presence of sticklebacks in a pond, even before the newts enter the water. Where several ponds occur in an area, cresteds may avoid fish ponds and preferentially breed in fish free ponds (I have also seen common frog exhibit the same avoidance behaviour when cresteds are present in ponds...). However, where available breeding ponds are more limited such a strategy may not be possible.

Earlier this year I led a kent Field Club meeting. Whilst netting one pond I actually caught a female crested that was in the act of swallowing an adult stickleback!

My own observations suggest that major fisheries that include species such as perch, roach, rudd, pike or trout rarely support breeding crested newts. Ponds with carp and sticklebacks sometimes support cresteds depending upon size of fishery and other local conditions.

Lee Brady

KRAG Recording Officercalumma37845.8834606481


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 10 Aug 2003 Topic: Adder bite at Swanwick



I agree that few people would consider the current weather conditions as good for reptile surveys. Imagine my shock when I took a colleague to one of my study sites on Friday (8/8/03) in Kent and found three adder basking under separate tins (along with a grass snake and nine slow-worm). I know what you are thinking, what time of day was it? The answer? Noon and 31 degrees C! We had only gone out so I could show him where the site was...

I have data loggers recording temperature under my tins and given local conditions on the day, temperature under tins is likely to be over 40 degrees C.


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 10 Aug 2003 Topic: Monitoring the Common Lizard



If you are recording animals in Kent, I hope all records will be passed on the the relevant local recorder


Lee Brady
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calumma
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Posted: 10 Aug 2003 Topic: "Tins"



Be aware that different materials will generate different survey results. Lots of consultants rely on roofing felt, but are their results representative of the area under study?

I am currently engaged in a pilot study that involves a pairwise comparison of felt v tin on a 4 species site in Kent (although grass snake are rare on the site). Results are interesting and will be previewed at this year's HGBI SE Regional meeting (hosted by KRAG in Sevenoaks).

SE Regional meeting

Dave's preference for tin is well deserved, particularly if you are surveying for adder... calumma37858.5194560185


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Joined: 27 Jun 2003
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Posted: 11 Aug 2003 Topic: "Tins"



A list of refs that deal with cover boards would be useful for all surveyors. Another quick ref to add to Dave's list:

Tofts, R. and Craine, R. (2000) The effectiveness of ætinningÆ in the translocation of slow-worms (Anguis fragilis) populations. Practice, No. 27.

Gemma, my own surveys suggest that roofing felt is very effective for viviparous lizard (I refuse to call them common) and slow-worm. Carpet tiles can be good on some sites, particularly early in the season.

Placement of refugia is critical as is re-positioning between years (and even within a year). However, results can often be very specific to individual sites and (as Dave has said elsewhere in the forum), describing a standardised method for surveying reptiles is fraught with difficulties. My own preference is to use a combination of different refugia material.

Lee




Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 17 Aug 2003 Topic: Reptiles in gardens news release



Gemma,

If you are looking for a historical Kent population ask the county recorder!

You may be interested to know that KRAG will be launching a new project 'Adders in Decline' at this years SE Regional HGBI Conference. I have spent the last several weeks chasing up many of the old records and I now have a reasonable idea of where most of the Kent sub-populations are located.

I am just about to post details about the conference...



Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 17 Aug 2003 Topic: SE Regional HGBI Conference



Announcement of forthcoming meeting:

South-East Regional Meeting of the Herpetofauna Groups of Britain and Ireland

"Applying Ecology to Conservation"

Sunday, 9th November

The Plaza Suite, Stag Theatre
London Road, Sevenoaks, Kent

The SE Regional conference will be hosted by KRAG this year and will focus on how we can use information about amphibian and reptile ecology to enhance their conservation in all situations. The increasing development in the South East means that now, more than ever, everyone concerned in the protection of herpetofauna needs to work together.

Talks by those involved in herpetofauna conservation, research, surveying, recording, habitat management & local planning will be followed by an open discussion on how best to compensate for development.

A full programme will be posted in due course.

Location:
The Plaza Suite is situated behind the Stag Theatre in London Road. Access to the car park is via South Park.

The cost for the day will be ú6.00, including tea and coffee (lunch not included, but many venues nearby). Please enclose a cheque payable to the Kent Amphibian & Reptile Group with your name, address, email and telephone number (and organisation if relevant), and return to:

Dr. Sue Young, Krag Treasurer
Flat 1, 14 Mount Harry Rd, Sevenoaks, Kent, TN13 3JH

(If you require confirmation of your booking, or a receipt, please enclose a sae)

If you would like more details about the event please email either Sue or Lee directly (or post here). administrator37850.8102083333


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 16 Sep 2004 Topic: Sand Lizard Reintroduced into Kent



If you follow the BBC link you will say that it states:

"Fifty rare reptiles have been released back into their native habitat in Kent after an absence of over a century."

The last 'official' record for sand lizard in Kent is from 1969, and Keith C reckons they were present in Sandgate in the mid-1970's.

Don't you just love journalists...


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Joined: 27 Jun 2003
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Posted: 17 Sep 2004 Topic: Slow-worm densities



I have data available and slow-worm numbers can easily exceed 1000 animals per ha. I have a site that supports a closed population of slow-worm. The site is about 2 ha in size that has had over 1000 animals removed from it. Not all areas within the site offered suitable habitat and the work remains uncompleted (only ~60% of the site has been cleared to date). Obviously delays in progressing the works cause problems when attempting to calculate density/abundance in schemes such as this, since recruitment into the population may occur. No reptile fence is perfect and animals do breed!



Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 17 Sep 2004 Topic: Quite a Day!



Today I showed a colleague around one of the Adders in Decline study sites in Kent. Very pleased indeed with the results. In total we had:

1 adult grass snake

4 adult + 4 juvenile adders

10 adult + 38 juvenile viv lizards

24 adult + 22 juvenile slow-worms

One of the female adders was basking on top of a tin. Unfortunately she disappeared before I could get a shot. However, knowing she would slip under the tin, I waited a little while before lifting it. And here she is!




Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Joined: 27 Jun 2003
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Posted: 17 Sep 2004 Topic: reasons to explain adders absence



Never exclude random chance!


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 17 Sep 2004 Topic: Quite a Day!



Danial,

The adder project is going very well indeed. We have a fair few sites that are being monitored by a good number of enthusiastic volunteers. Regular updates of survey work and other news are posted to my blog.

We are surveying at least two sites that are within the London boundary (formally part of west Kent). These sites are being surveyed as part of both the Kent project and a London wide survey of adder sites (organised by English Nature). If you know of any London adder sites and would like to email me privately I will pass your records on to the appropriate people. Historical records of London adders would also be helpful.




Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 23 Sep 2004 Topic: reasons to explain adders absence



Mike,

You seem quite sure that there are no adders at Kenfig. Could it be that there are simply not yet detected? My own survey work has shown that adder can be difficult to confirm from some sites. It has taken just over a year of fairly intense effort to confirm adder from one site where we know that they are present! Remember it is easy to confirm presence, but nigh on impossible to *confirm* absence - only predict it. Even if animals are absent from a site one year, who's to say that they won't recolonise it in a year or so? In Kent, we have just reconfirmed adder from 2 sites where that have not been recorded since the late 1960's!

Given Tony's observations above, I would recommend that you review your survey strategy at the site.


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 04 Nov 2004 Topic: Natrix - the longest!



It may be the bottom of KRAG's list, but it's never too late to send me a record...!


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 11 Nov 2004 Topic: GCN Survey Project 2004 - Results Summary



I've written this up on my blog already, but thought that it might be of wider interest.

This survey project was run in conjunction with KRAG and BTCV Pond Wardens. Most of the data is now in and I have prepared some preliminary analyses that are very revealing.


Some of these numbers can appear a little mind bending at first so stick with me!

A total of 125 ponds were assessed during the project (there may be a few additional ponds to add, but the total is unlikely to change too much). Pond wardens and members of KRAG undertook much of the survey work. A large number of ponds were also assessed by David Sewell who is currently studying crested newts as part of his PhD at DICE.

Many ponds were assessed in a single visit and the likely presence of crested newts determined through the collection of various habitat variables. Rob Oldham and colleagues at De Montfort University have used these habitat variables to calculate a Habitat Suitability Index (HSI) for crested newt. The higher the calculated value the greater the number of crested newts that are likely to be found in the pond. I use this technique in my work all of the time and find it to be a very useful tool for predicting likely presence of crested newt. However, note that the calculation of a HSI does NOT replace decent survey work!!

I have adapted the published HSI slightly to make the results more accessible to my clients (and survey volunteers). Basically, calculated results are grouped into the following categories:

Poor Potential
Below Average Potential
Average Potential
Good Potential
Excellent Potential

Unsuprisingly, crested newts are most likely to be encountered in ponds with a HSI potential of 'good' or 'excellent', although they may also be found in ~50% of the 'average' ponds. Crested newt are rarely encountered in 'below average' ponds and I have never confirmed crested newt from 'poor' ponds.

The suitability of ponds for supporting crested newt during the 2004 project was found to be:

Poor: 26%
Below Average: 18%
Average: 22% (but remember that crested newt are only likely to be found in half)
Good: 25%
Excellent: 9%

During this year's project, survey work sufficiently detailed enough to reliably determine the likely presence of crested newt was undertaken in 57 of the 125 ponds. Of the 57 ponds surveyed, we predicted that crested newt would be encountered in 45% of the ponds (9+25+11). To save your brain, 45% of 57 is 26 ponds.

So how did we do?!

Survey work in 2004 actually confirmed crested newt present in 27 of the 57 surveyed ponds (47%)! This is a little better than expected and I think that everybody involved in this project deserves a very large pat on the back!

Hopefully we can run this project again in 2005. If you would like to participate please let me know.

I have also identified those areas in Kent where survey work is most needed. For more details follow the link for my blog.

Lee


Lee Brady
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calumma
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Posted: 12 Nov 2004 Topic: GCN Survey Project 2004 - Results Summary



Rob Oldham's original paper uses the HSI to do just that. Basically the higher the calculated score, the higher the gcn population is likely to be. My own work corroborates this to some degree. However, I prefer to use the technique in two ways:

1) A tool for volunteers to guide survey work. Volunteers can quickly calculate HSIs for a relatively large number of ponds. Based on their results the volunteer surveyors can then focus effort on those ponds where gcn are most likely to be found. We will be testing this next year. The ponds where gcn were expected this year, but for what-ever reason did not show, will be revisited again next year.

2) A tool for myself (working as a consultant) to help justify to a client/LA etc, why a surveyed pond displays a good/poor gcn count. Survey work that fails to confirm gcn in a pond that scores excellent on the HSI may need resurveying.

A side effect of the HSI is that it is a very useful teaching tool on training courses. When calculating HSI scores for themselves, volunteers quickly grasp how the different habitat variables can affect gcn occupancy.

For those not familiar with the technique, HSI calculations rely on the collection of 10 variables:

1. Location (in Britain)
2. Pond Area
3. Desiccation Rate (years out of 10 that pond dries)
4. Water Quality (subjective assessment)
5. % Shade
6. No. Fowl
7. Fish Population (subjective assessment)
8. No Ponds Within 1km
9. Terrestrial Habitat Quality (I have modified this slightly...)
10. % Macrophyte Cover

Reference for Oldham et al:

Oldham, R. S., Keeble, J., Swan, M. J. S. and Jeffcote, M. (2001) Evaluating the suitability of habitat for the great crested newt (Triturus cristatus). Herpetological Journal, 10, 143-155.calumma38303.4007291667


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 12 Nov 2004 Topic: GCN Survey Project 2004 - Results Summary



Nope, none.

But my experience with volunteers is that this would be something that is too difficult for them to collect.

I record depth as a variable anyway - but usually only as a subjective assessment. I agree that it is important and could write for hours on how it probably affects results...

I should also add that I am attempting to develop a similar technique for reptiles. I have some preliminary data, but probably not enough for even preliminary statistics. I will post something about this once I have looked at the data some more.


Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 16 Jun 2005 Topic: Re: Epping Forest adder survey



I have been contacted by some folks undertaking survey work at Epping Forest who were keen on participating in the 'Make the Adder Count' project. I recommend that you go along to the meeting and find out what is happening.

It seems to me that there are a few projects underway at Epping, with little or no coordination between them. This may be a good opportunity to build some bridges.

John is currently on holiday.



Lee Brady
Kent Herpetofauna Recorder | Independent Ecological Consultant

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calumma
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Posted: 17 Jun 2005 Topic: Re: Epping Forest adder survey



I'm not actually involved in any of the survey work - other than promoting the make the adder count project. I will therefore not be attending the meeting (too much stuff to keep on top of in Kent!).


Lee Brady
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