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Volunteers have been busy helping input data into the KRAG db this year. We had a large number of paper records from various events and these have now all been added to the system. Many thanks to everyone who has helped with this task. One or two very interesting records have cropped up and I've started contacting callout volunteers to ask for assistance in following up leads. Here's what the combined spring and autumn 2010 Kent Garden Show records look like plotted in Google Earth.
This year's Kent Garden Show was a great success and Jo was able to use a combination of paper forms and the group's shiny new iPad to collect nearly 500 records! Below are the Spring 2011 records plotted in Google Earth.
Many thanks to Jo and her team for doing such a great job at this year's events!
No-one knows exactly how many snakes Harry caught, or whether and how often he was bitten, but it’s likely he caught around:
- 30,000 grass snakes
- 4,000 adders
What are National Park Heros? From the website:
National Parks are inspiring places. They give people space to breath, space to think, space to create.
These National Park heros have been inspired to do all kinds of things; Catch snakes in the New Forest, set sail to explore the world, fight for their country and create beautiful music, art, poems and stories.
Nice words. But surely we don't want National Parks to inspire people to murder the wildlife do we? I realise we live in a more enlightened age, but the tens of thousands of snakes that ended up being boiled or sold to London Zoo as food for the inmates would have been much better off if Brusher Mills had never worked there.
Although I don't consider Brusher Mills a hero, he was certainly a character.
You may have noticed that there has been virtually no activity from Sussex ARG for quite a considerable time. This is due to a number of reasons , but mainly down to changes in commitments of many of the existing committee members. Sussex ARG was the first ARG to be established in the UK and now, more than ever our native species are under ever increasing risk - so now is a good time to re-establish the group. This is your chance to shape Sussex ARG into a new and effective conservation group. As with all conservation groups, key roles need to be filled and new initiatives brought in.
As a starting point we now have a new presence on the web:
In a very short space of time the website has received hundreds of hits but it needs to provide much more comprehensive information and updated items. To see what other ARG's are doing go to the Surrey ARG site:
or the Kent Reptile & Amphibian site:
If you would like to help re-launch SxARG, we are setting up informal meetings in East and West Sussex during December. The dates are 6th December @ 19:30 at Sussex Wildlife Trusts HQ at Woods Mill in Henfield and13th December @ 19:30 at the Linkleter Pavillion in Lewes.
If you are interested in attending either of these meetings, or can not attend but would like to be involved in Sussex ARG please contact Barry Kemp via email.
Directions to venues:
Many thanks,
Barry Kemp (Acting Chair, SxARG)
Another focus for this year's list is Madagascar and its reptiles. The report found that 40% of terrestrial reptiles are threatened. But it also says that new areas have been designated for conservation.
That will help protect endangered species including Tarzan's chameleon (Calumma tarzan) and the limbless skink (Paracontias fasika).
via www.bbc.co.uk
More information on IUCN and the red list can be found on the organisation's website.
The latest update of The IUCN Red List of Threatened Species™ illustrates the efforts undertaken by IUCN (International Union for Conservation of Nature) and its partners to expand the number and diversity of species assessed, improving the quality of information in order to obtain a better picture of the state of biodiversity. With now more than 61,900 species reviewed, another big step forward has been made toward developing the IUCN Red List into a true ‘Barometer of Life,’ as called for by leading experts in the magazine Science in 2010.
I've had a query about the risk assessment categories that are used in database search requests. I therefore thought it was time to provide a little detail.
The db risk assessment tool is based on two separate analyses.
Range Assessments
I've already written about range assessments and more information is available here. The Range Assessment Score classifies species presence using nearest neighbour analyses, with predictions summarised using the following categories:
outside of known range
maximum expected range
predicted range
core range
For example, the range map for adder looks like this (updated from the earlier linked blog post).
Knowing the distance from a target site to the closest available record for any given species is very useful. Previously, the risk assessment report presented this information only for great crested newt and the closest reptile record. I have now updated the output, so that distance to closest record is reported for all species (regardless of whether they are present within the defined search area). The relevant section of the report now looks like this:
Habitat Assessments
Species range assessments are influenced by survey effort. High distance values in areas with limited survey effort may simply be due to a lack of recording activity. In an attempt to better control for differences in effort the Range Assessment Score is modified by an assessment of the quality of available habitat (1 km square resolution) to generate a Likelihood of Presence Score.
Habitat quality includes several factors (e.g. broadleaf woodland cover) and for each species a landscape level Habitat Suitability Index is calculated. The detailed methodology for this will be a topic for a future blog post.
The Kent HSI for adder is illustrated below. The more opaque areas represent 1 km squares that are more likely to support adder based on the quality of available habitat.
Since we know the range of adder, we can exclude those areas where adder are not believed to occur.
Likelihood of Presence
The risk of a species being present at any particular location will be primarily dependent on the proximity of the target site to an available species record. However, in areas of high or low quality habitat, the Likelihood of Presence Score may be modified (up or down respectively). Rather than using terms based on range, Likelihood of Presence Scores are described using the following catergories:
unlikely
Possible
Likely
High
For example, in an area with limited survey effort the db may consider a target site to be within the 'maximum expected range' of adder. This could be considered to represent a 'possible' risk of presence. However, if the habitat HSI is favourable the Likelihood of Presence Score may increase from 'Possible' to 'Likely'. Conversely, an area located within the predicted range of the adder that displays low quality habitat may have a Likelihood of Presence Score decrease from 'Likely' to 'Possible'.
In an area of very high quality habitat that is outside of a species range, the db will still report Likelihood of Presence as 'unlikely'.
Since the habitat assessment is calculated at only a 1 km square resolution, it is important to note that a site with excellent habitat may be located in an area that is considered to display a low landscape level HSI. For adder this could be a small urban nature reserve. Adders generally avoid urban areas, but isolated populations do occur (e.g. Chatham). The db therefore weights the Likelihood of Presence Score. A target site located within the core range of a species would have to display a very low habitat score before the Likelihood of Presence Score dropped from 'High' to 'Likely' or 'Possible'.
Interpretation
Users should interpret the Likelihood of Presence Scores in the following manner. For reptiles, survey work should always include methodology and effort targetted at species with Likelihood of Presence Scores of 'High' or 'Likely'. For species with a score of 'Possible', the species should only be discounted if local habitat conditions are unsuitable. For sites that are outside of the known range of a species (score = 'unlikely'), consideration should still be given to undertaking appropriate survey work if local habitat conditions are deemed suitable. It is important to remember that a db is only as good as the information it contains and false negatives are possible.
If we consider the Landscape Level HSI for adder in areas outside of its known range, it is apparent that there are some areas that appear to offer suitable habitat. Future survey work should target such areas to determine whether the species really is absent.
For amphibians things are a little different. The Likelihood of Presence Scores apply in the same way as for reptiles. However, determining presence of amphibians is much easier at breeding ponds. Determining the presence of amphians away from breeding ponds can be challenging. It is therefore important to remember that sites without ponds may still offer amphibians opportunities for sheltering, foraging and dispersal, even if it is not practical to undertake terrestrial survey work. Ponds created within such sites may well be colonised by amphibians.
