WATER VOLE AMERICAN MINK CONFERENCE Editor: Martin Ketcher, 2017-18 American Mink – predator Water Vole Conservation and Invasive Non-Native The main cause of the decline in water vole use in the last five years are shown on Species Officer populations is predation by the invasive the map (right). There may be others that Water vole newsle tter non-native American mink Neovison vison are still functioning but are not included so controlling mink numbers is paramount on the map. If you know of any please WATER VOLE, MINK AND NON-NATIVE INVASIVE SPECIES NEWS IN AND MIDDLESEX for water vole conservation. As with the get in touch. As you can see, there are water vole, the situation with mink seems large gaps and some rivers where there Thank you... to be similar to earlier years. are very few rafts. The conservation of water vole in shire and Middlesex is The positions of mink rafts within the At least 27 mink were caught in 2017. dependent on the efforts of volunteers, county that are known to have been in so whether you are a water vole All but one of these were caught on the surveyor or check a mink raft, thank Welcome... Lee or the Stort and many were on the Mink raft MINK CAPTURES locations you very much for everything you have ...to the 2018 Newsletter. side of the rivers. As before, most done. The list of those involved is

l This is the annual report on 2017 l YEAR TOTAL HERTS ESSEX i

of the mink caught in the lower Lee Valley H longer than ever so, as before, I have the situation within the Trust’s m i not attempted to list everyone this year. 2017 27 7 20 were as a result of the efforts of the T

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o area – the whole of Hertfordshire t

2016 23 14 9 rangers of LVRPA, coordinated by Dawn o Thanks are due to the Environment h

P and the boroughs of Barnet, 2015 33 14 19 Richardson, while the mink rafters on the is not down to the availability of water Agency and the Lee Valley Regional Park Authority for their continued funding Enfield, Harrow and Hillingdon. 2014 33 7 26 Stort are coordinated by Bob Reed. Both voles as prey! It does illustrate the the Lee and the Stort are important rivers importance of maintaining the mink for the Water Vole Conservation and 2013 40 20 20 for water voles so it is hoped that the control effort everywhere within the Water Vole, Mink and Invasive Non-native Invasive Species Officer post 2012 34 26 8 in 2017/18 at Herts and Middlesex increase in mink on these rivers in 2017 two counties. Species Conference Wildlife Trust. t r e b

b In 2017 the annual conference was a way for anyone to report evidence i

H If you would like a new raft or if once again kindly hosted by Affinity of pollution. m i T

you know someone who might be n

o : i o Water in Hatfield on Thursday 9th Jack Herriot , EA Geomorphology s

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able to take a raft, anywhere in the V o

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November. Technical Specialist, talked about the 2 P county, please get in touch. If you 0 2 / r

work that the EA has done with the e

need guidance on the use of the raft k a t t Tim Hill , HMWT Conservation Boxmoor Trust to improve the River i or on the safe dispatch of captured • h W

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Manager chaired the evening. Bulbourne in Hemel Hempstead. r mink please refer to the Mink r e T

Martin Ketcher , HMWT Water Vole Bob Thornton from the : • • o

Control booklet from the Wildlife t Water vole update o h

Trust or go to the website of the Conservation and Invasive Non-Native Restoration Association spoke about P Game and Wildlife Conservation Species Officer, gave a 2017 water vole, how the RBRA has been working with 85 sites were surveyed for water vole Distribution Trust www.gwct.org.uk mink and INNS summary. HMWT towards a possible water vole Registered address: Distribution • Dr Djami Djeddor , Senior Scientific re-introduction on the river. in 2017. Of the 85 surveyed sites, 37 The map (right) shows the distribution Herts and Middlesex had water voles, four had signs that of water Officer and project manager, a plant • Cath Patrick , LVRPA Senior Wildlife Trust, of water voles in Hertfordshire and pathologist working on the biological Conservation Officer, gave us her Grebe House, could have been water vole, three that down the River Colne into Middlesex. voles control of invasive weeds at the annual update on what the LVRPA have St Michael’s Street, had signs that were probably not from Overall the picture is similar to previous St Albans, AL3 4SN River Corridor Survey –the River Beane Centre for Agriculture and Bioscience been doing for water vole conservation. water voles, and 44 had no signs. years. While there is some evidence Ideally, to confirm the presence of of expansion in water vole populations The River Corridor Survey (RCS) is a way After training, a group of volunteers from surveyed part of the River Beane, International (CABI), gave us an update • Bob Reed , Living Rivers Champion for 01727 858901 inf [email protected] water voles it is necessary to find a in the two counties the situation could to assess a river in considerable detail. the River Beane Restoration Association contributing to the River Corridor on research towards finding biological the , wrapped up the evening www.hertswildlifetrust.org.uk latrine. It is more difficult to be certain be a lot healthier so it is important to RCS records such things as water depth (RBRA) have used a slimmed-down Survey assessment of the river and controls for INNS. with a talk about a small re-introduction Registered in : 816710 that feeding signs are from water maintain the conservation effort. and width, type and extent of vegetation version of the RCS to survey the Beane. now most of the river from Watton- • Rod Cutler from the Colne Valley of water voles on Sawbridgeworth Fisheries Consultative (CVFC) spoke Marsh to link up with the Thorley Wash Registered Charity: 239863 voles if no other signs are present cover within the river, and on the bank, RBRA member Bob Thornton organised at-Stone down to Hertford has been hence the ‘possible’ category. and produces much more detailed maps several volunteer sessions, such as the surveyed. The results will be digitised about the Consultative’s River Outfall population and hope-fully boost overall Key Site Surveys Monitoring Project (ROMP), essentially numbers on the upper Stort. There are some places across the area than are produced when mapping water one shown below, with RBRA member and analysed to see which areas have All maps... The table below shows the yearly vole surveys. Marcella Randall. The volunteers the best water vole habitat and what comparison of surveying results. The that are key sites for water voles. This could be done to improve the river for © Crown copyright and database rights 2017 proportion of positive sites remains is almost certainly because these sites water voles. Hopefully this will lead How Ordnance Survey 100048466. You are not are a complex of water bodies within n Train as a As a surveyor, if you come permitted to copy, sub-licence, distribute or similar to previous years indicating that ca • • a relatively small area. Unlike on a to a water vole re-introduction on the you water vole across a raft on a survey please sell any of this data to third parties in any water vole populations are broadly stable. river at some point in the future. LP surveyor. check it and let the Trust know form. YEAR ON YEAR WATER VOLE SURVEY RESULTS E what you find, including Training H ter 2017 2016 2015 2014 2013 2012 2011 wa • Become a evidence of water voles. In 2017 there were two survey les Number of sites surveyed 85 78 78 68 79 60 46 y o mink raft e v

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s training sessions – one in March at u checker. Let the Trust know if Printed by N2 Visual Communications on Xerox Colour Number with voles 37 24 31 27 24 19 12

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e t Thorley Wash for volunteers from Impressions Silk, an FSC certified stock made from t you see water vole or mink o % with voles 44 31 40 40 30 32 26 l r a minimum of 50% recycled fibre, at a mill that has been a the River Beane Restoration h If you have a mink anywhere in the county, or single-channel river, it will be difficult C awarded the ISO140001 certificate for environmental Number with possible signs 4584710 : •

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t Association (RBRA) and a second

o raft that isn't checked as often as if you come across either species management. for mink to find and eliminate all water

h % with possible signs 5610 6920

P V in April at Tewinbury, with a total voles. These sites are usually nature RBRA member Marcella Randall surveying part of it should be, let us know and we killed on the road or in some of 21 people trained. Designed by Wildcat Design ([email protected]) Number with no water vole signs 44 49 39 37 48 40 34 the River Beane, November 2017 Water vole survey on can organise others to check it. other way. reserves so knowing which parts of the the River Beane % with no water vole signs 52 63 50 54 61 66 74 site are used by continued overleaf ª

Protecting wildlife for the future Protecting wildlife for the future INVASIVE INVASIVE WATER VOLES NON-NATIVE PLANTS NON-NATIVE PLANTS ª continued from previous page park’s survey areas include three KEY SITE SURVEY – Panshanger 2017 Water Vole update sections of the , four Spring Autumn sections of lakeside from three lakes, Annual Survey – results Section Latrine Feeding Latrine Feeding sign sign two parts of the Broadwater and three ditch sections. With a small team of 116n.s. n.s. surveyors all twelve sections can be 2814 00 surveyed in a morning. Ideally the site is 3337 09 surveyed twice a year, once in the spring 4 n.s n.s. n.s. n.s. and once in the autumn. The results in 5326 00 the table (left) are from Panshanger 6 0211 Park in 2017. P h

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Sections three and five are both edges P 805n.s. n.s. a u

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dry in the spring but had water in the t o

12 01612 h water voles can inform the management autumn illustrating the importance of P Total 26 215 20 54 water to water voles! This sort of of the reserve. At these sites 10 or 12 spread 100m strips of bank are surveyed instead detailed site information would not be st consistently wide alayan balsam - the mo of surveying a standard 500m of one Panshanger Park is one example of such obtained by surveying one 500m section Him recent surveys the invasive species in ditch or river. a site surveyed with this method. The once a year. of 2017 distribution of Himalayan balsam

The details of the survey results of Invasive in 10% of all the sites where INNS were Non-Native Species (INNS) are shown recorded. in the tables below. Floating pennywort Hydrocotyle Biodiversity Action Plan Himalayan balsam Impatiens glandulifera ranunculoides is a huge problem on the

remains the most widespread and lower Colne and the Fray’s River (around s n i k

frequent of all the invasive species. Denham) – see photo opposite . It is p o H

The map (above) shows where Himalayan also a problem on the Stort and the reason b

Lee Valley Regional Park o R

balsam was recorded in 2017 and the for the apparent decrease from 18% to 8% : o t o

different colours indicate the abundance of sites from 2016 to 2017 was that less Floating pennywort h P recorded in Lee Valley Park. This total (related to the DAFORN scale). There are, of the Stort was surveyed in 2017 The water vole is an important species This vision will be met through certain includes over 300 species of bird, 33 however, examples of it being brought following the blitz in 2016. in the Lee Valley, here Cath Patrick, key objectives: under control.

species of mammal and over 900 t

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Conservation Manager at Lee Valley i Floating pennywort

species of flowering plant. There are With little chance of total eradication of r – in search of a solution

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Regional Park Authority (LVRPA), • To create, restore and link character - also records of over 2,400 species of In 2016, orange balsam seemed to be floating pennywort hope is pinned on a o

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looks at the process of updating the istic ecological, hydrological and increasing so was included as an invasive n

invertebrate. Within this diversity many weevil as Djami Djeddour’s piece (next w Floating pennywort is a strong contender for the title of worst aquatic weed in the UK. o Bio diversity Action Plan (BAP) for the landscape features to form a fully r species to record in 2017 and was found C

individual species or assemblages page) details.

: o Lee Valley that will include protecting integrated river floodplain corridor. t Djami Djeddour, Senior Scientific Officer and Project Manager at the Centre for Agiculture

are significant from local up to o h water voles. international level. INVASIVE NON-NATIVE SPECIES (INNS) – Sites Surveyed P To realise the full ecological potential and Bioscience International (CABI), tells us about the search for a natural solution. • 2017 2016 2015 2014 2013 Giant hogweed The first Lee Valley Biodiversity Action of the Lee Valley Regional Park by The Species Action Plans in the Originating from South America, floating With the invasion going beyond any biocontrol licencing authorities for review Plan was launched in 2000 and although maintaining and enhancing the present revised plan include all those from Total Number of Sites 67 84 66 70 75 pennywort arrived in the UK in the late containment and eradication stage, longer- and feedback was received. Further there has been a national policy shift range of species, habitats and landscape the initial BAP; this includes water vole, Sites Surveyed 59 65 53 66 60 1980s as an oxygenating ornamental plant term solutions, such as classical biological research is now being undertaken to fill in away from BAPs, the LVRPA still sees features combined with extensive for which the Lee Valley is still an Sites Not Surveyed 8 19 13 4 15 for the aquatic trade. It now over-runs control (the use of highly co-evolved, host knowledge gaps and further consolidate the merit in the system as it provides re-creation and expansion of key important area, as well as some new clear targets for delivery of biodiversity habitat types. water bodies and is threatening the specific natural enemies from the country the data on safety before the review additions including invasive non-native PERCENTAGE OF INNS IN SURVEYED SITES action and partnership working to species which are closely linked to habitats and native biodiversity they support of origin of the target weed), are being process is resumed.This year, the final achieve those targets. • To achieve a sustainable use of the water vole conservation and to the 2017 2016 2015 2014 2013 in the UK and across northern Europe. investigated in the UK. From a large suite of application to release the weevil into the natural resource. quality of a range of habitats across Himalayan balsam 47 35 40 33 47 herbivores and pathogens associated with wild in the UK will be comprehensively This year consultation opened on the new Able to grow up to 20cm per day, floating the plant in its native range in Argentina, reviewed by government licencing the Regional Park. Japanese knotweed 22232 draft with the final document due to be • To achieve awareness and under - pennywort is capable of forming dense a weevil (Listronotus elongatus) has been teams as well as going through external adopted following this consultation. standing of the biodiversity of the Lee Giant hogweed 36688 mats which reduce light, restrict growth prioritised and causes considerable damage scientific and public consultation before

d Floating pennywort 8 18 894 l

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Valley Regional Park and to encourage r of submerged aquatic plants and to the plant. a decision is made.

If you would like further information a

H The overarching vision for the LVRP BAP participation in its conservation. Water weeds 05222 outcompete native plants in an affected on the plan please contact Cath Patrick, a d

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is to work with partners and communities Water fern 05222 e area. Floating pennywort is an economically Under the Defra-funded project initiated This weevil could be the fourth in a series Conservation Manager at Lee Valley r

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to create, restore and enhance the A species review carried out by Herts : Parrot’s feather 00020 o important weed; costs linked to flood and in 2011 and through comprehensive of recent biocontrol agent releases in Regional Park Authority on t

o habitats of the Regional Park, providing Environmental Records Centre identified h physical management and the impact on specificity testing in CABI’s UK quarantine the UK – a sign that long term solutions [email protected] New Zealand pigmyweed 20000 P access to and appreciation of this area. that over 4,700 species have been Japane Orange balsam 10 0.5 0.5 0.5 0.5 se knotweed tourism and recreational activities across facilities, the weevil’s safety and impact has are being sought to help mitigate the Europe and Great Britain is estimated to been largely assessed. In early 2017, a Pest impacts of our most intractable invasive exceed £25 million per year. Risk Analysis was submitted to the UK weed problems.

Protecting wildlife for the future