Hazardous tree inspection for TPO

NWS Aborist Jim Allitt recently advised on the management of a substantial oak tree subject to a Tree Preservation Order and within the Broads National Park.

Our client, Mr Coleman, had concerns over the extent of deadwood in the canopy, especially where it was close to his and a neighbouring property, but as also keen to retain it as a beautiful feature of his home.

Mr Coleman asked NWS to determine the condition of the tree and make future management recommendations. The tree was surveyed to look at issues such as weak unions or forks, cavities, and especially any defects hidden higher in the canopy.

Hazard tree feature – Branch failure

Sometimes hazards are obvious but subtler hazards may go unnoticed and mechanical failure may occur without specialist management.

Under the Occupiers’ Liability Act (1957 and 1984) the ‘occupier of the land’ where the tree is rooted has a duty of care to ‘take reasonable steps to prevent or minimise the risk of personal injury or damage to property’, both for visitors to the occupiers land (1057) and other persons (1984). The law is quite complicated.

To avoid or deal with risks while retaining the tree, a reasonable and balanced approach to future management requirements is needed, with a full understanding of calculated risk involved. In this case, NWS suggested a 2m, crown reduction and to clear larger deadwood from the canopy so that ‘sailing’ from the wind stressed the branch unions less.

Aerial tree inspection by Jim

Since the tree was protected, the works had to be agreed with the local planning authority, the Broads Authority. NWS’s successful application demonstrated that the works retained the screening the tree provided but were also necessary to reduce the risk the tree posed to the adjacent house and property.

2018 great crested newt eDNA “closes” 30 June

Some of our clients were not aware that you can carry out surveys for the presence of great crested newts using “environmental DNA” until the end of June. This may prevent you having a delay in the planning application for your development until spring 2019 – the next survey window – and is worth considering.

Confirming newts are absent at a development site confirms that a development does not have a significant impact.  Waiting until 2019 for “traditional” surveys may simply confirm absence, but a year later.

Presence from an eDNA survey may be sufficient for planning consent and/or obtaining a licence. This may therefore resolve your planning application in 2018 rather than mid-2019.

The survey technique is not always suitable. Whether to use it needs to consider your particular development and situation. We can advise you whether the technique meets for your needs based on our knowledge of regulations and our years of experience.

We can also assess the impact of your development on newts and say what to do next if they are present, guiding your through any necessary licencing process later and finding solutions for compensatory habitat on or off-site.

If you do want to proceed though, there is a limited window left to make the last Great Crested Newts “last survey date” on 30 June. As such we suggest that you contact us immediately.  We can book a laboratory analysis slot for you now.

If you have more questions about great crested newts, read through our in-depth article or ring us to find out more about survey and assessment options.

 

 

 

What to do if you find a stag beetle

During work, tree surgeons ( especially while removing decaying tree stump) sometime find large black beetles. They may be concerned that they are Greater Stag Beetle Lucanus cervus and want to know what action to take to protect them.

Greater Stag Beetles are protected against sale in the UK under the Wildlife and Countryside Act, 1981 and are also a Priority Species under the NERC Act and an Annex II European Species.  They do occur in Norfolk, but are much commoner futher south in Ipswich and Suffolk.

Often though they will be stag beetles but the easily confused Lesser Stag Beetle Dorcus parallelipipedus , which is more widely distributed.

Lesser stag beetle Lucanus cervus

Decaying wood is important to all mini-beasts, especially in the “tidier” urban areas like Norwich.  An easy approach if possible is to reduce any stump in large sections and re-sited somewhere safer (something the lesser stag beetle colony will appreciate).

If you do find any text a photograph to us and we are happy to identify for you and let you know what to do.

We are also happy to carry out full invertebrate surveys of sites and make recommendations for managing them for charismatic stag beetles.

Photo gallery for newts

Invertebrate survey successes for Cley Marshes

coastal lagoon

Ben Christie sampling lagoonal invertebrates

FOLLOW-UP SURVEY ON TRUST’S NEW COASTAL LAND REVEALS IMPORTANT INVERTEBRATES

Our follow-up survey on Norfolk Wildlife Trust’s new marsh at Cley has found five invertebrate species of conservation importance, including lagoon sand shrimp Gammarus insensibilis (legally protected) and mud snail Ecrobia ventrosa.

The Trust commissioned a specialist baseline study on their new land at Cley Marshes when they purchased it in 2014. This was surveying the plants and invertebrates in the site’s ditches, dykes and scrapes.

Since then, the Trust has carried out extensive work on the marsh to convert it from wildfowling ponds to a nature reserve and wanted to repeat the surveys. The plan was to compare with the 2014 baseline and identify any changes resulting from the work.

Twelve sample ditches and lagoons sites from the 2014 survey were re-surveyed for aquatic invertebrates, following the same methodology. For each, we took two dip-net samples to collect a crosssection of the aquatic invertebrates in the water: one in underwater vegetation near the shore; and one reaching out into the depths of the open water.

Ben Christie, our invert specialist said: “By first grouping inverts into taxonomic orders and then using specialist microscope keys for identification, we were able to efficiently identify the specialist communities for every sample site. This allowed both a direct comparison of communities in 2014 and 17, but also showed distributions for five invertebrate species of conservation importance.

“Norfolk Wildlife Trust can now fully assess the benefits of their management on invertebrates as well as the birds and other wildlife who are dependent on them in the food chain.”

 

 

Students Go Batty For Work Experience

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An unusually warm autumn has meant more bats out in the evenings later in the year than normal. This provided students from East Coast College with a chance to gain bat survey experience on two different dusk surveys.

Ben Moore, Assistant Ecologist at NWS, said: “Our first site was along a stretch of the upper reaches of the river Bure surrounded by wet grassland and woodland edge. We had great views of noctules, one of our largest bats, as they foraged high in the twilight over the open grassland”.

students

East Coast College students gain experience by helping with bat surveys

“The students heard the characteristically slow slapping calls of the noctule, which distinguished it from most other species. Once it had become darker, we saw bats over the water, their white underbellies still visible. Coupled with distinctive rapid ‘machine gun’ like calls, this identified Daubenton’s bats using the river to feed on mosquitoes and other tasty morsels of the flying insect variety.”

“The second survey site was along a stretch of the Marriott’s way, a well-sheltered commuting and foraging route for bats with its tree-lined embankments. Here we observed common pipistrelle and soprano pipistrelle and used a handheld frequency detector to tell them apart as they zipped up and down the disused railway.””

 

Urban wildlife : using IR cameras for badger surveys

It can be difficult to prove the presence or absence of badgers, as they are shy when near their setts. Badgers also have an extremely good sense of smell and can detect the scent of humans easily. To stand a better chance of recording them a camera can be used to reduce human scent near the sett.

We recently used our night vision trail camera to assist a client on the outskirts of Norwich who is seeking planning permission for a new build. We had identified a badger set in close proximity, which may have been home to not only badgers, but also other burrowing animals who often co-habit or move in, if the burrow has been abandoned.

The camera works on an infrared motion trigger, capturing pictures or videos of animals moving nearby. In this case there was a family of foxes and some hedgehogs, but we were able to prove there were no badgers present at the sett.

Camera catching a passing fox

camera shy squirrel

Can eDNA detect great crested newts later in year?

Natural England [1] only accept “negative” eDNA results for newt licencing where efficacy has been proven ( e.g. between the above dates and by trained personnel ) . “Positive” results clearly have no such limitation.

The pilot work [2] on using eDNA for detecting newts relied on comparing conventional field survey techniques to eDNA and comparative results were therefore only available during their sampling period i.e. mid-April and late June. Detection rates for sites where newts were known to be present were 99.3% using professionals and 91.2% using volunteers.

The report [ 2 ] states that “Overall, collecting eDNA appears to be a highly effective method for determining whether Great Crested Newts are present or absent during the breeding season. We do not know how effective the method is outside this period.”

Natural England indicates the peak season for surveying for larvae is August, so in theory these should be detected by later eDNA tests.

eDNA declined rapidly once great crested newts were removed from experimental ponds [3] – to undetectable levels over 1-2 weeks. Ponds could therefore have been utilised by adults earlier in the season e.g. for foraging, but the absence of larvae would point towards absence of successful breeding.

References

[1] https://www.gov.uk/guidance/great-crested-newts-surveys-and-mitigation-for-development-projects

[2] Biggs, J., Ewald, N., Valentini, A., Gaboriaud, C., Griffiths, R.A., Foster, J., Wilkinson, J., Arnett, A., Williams, P. and Dunn, F., 2014. Analytical and methodological development for improved surveillance of the Great Crested Newt. Defra Project WC1067. Freshwater Habitats Trust: Oxford. http://randd.defra.gov.uk/Default.aspx?Menu=Menu&Module=More&Location=None&ProjectID=18650&FromSearch=Y&Publisher=1&SearchText=wc1067&SortString=ProjectCode&SortOrder=Asc&Paging=10#Description

http://randd.defra.gov.uk/Default.aspx?Menu=Menu&Module=More&Location=None&ProjectID=18650&FromSearch=Y&Publisher=1&SearchText=wc1067&SortString=ProjectCode&SortOrder=Asc&Paging=10#Description

[3] Thomsen, P., Kielgast, J.O.S., Iversen, L.L., Wiuf, C., Rasmussen, M., Gilbert, M.T.P., Orlando, L. and Willerslev, E., 2012. Monitoring endangered freshwater biodiversity using environmental DNA. Molecular ecology, 21(11), pp.2565-2573.

https://s3.amazonaws.com/academia.edu.documents/34355462/Thomsen_Kielgast_et_al._2012_Monitoring_endangered_freshwater_biodiversity_using_environmental_DNA.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1502361592&Signature=Mjs46Dii13qt4xOQn90M6w5u72M%3D&response-content-disposition=inline%3B%20filename%3Dpapers.pdf

Spring Newsletter 2017

All our latest wildlife news in our Norfolk Wildlife Services’ Spring Newsletter 2017.

In this issue we bring you :

Or click to download a pdf copy

Blackthorn flowers and hedgerow assessments

March marks the meteorological start of spring and it’s also the time to start looking out for the first blackthorn [Prunus spinosa] flowers.

blackthorn flower

Photo © Ian Calderwood

Blackthorn flowers are easy to spot because they appear before any of the hedgerow leaves.
As soon as you spot the first flowers you’ll suddenly begin to notice whole swathes of them.  At this time of year of you might be forgiven for thinking all hedgerows are predominantly blackthorn, but our hedgerow assessments can offer an insight into the diversity of hedgerows.

 

Why are hedgerow assessments important?

Hedgerows are protected under the Hedgerows Regulations Act 1997 and these are part of planning regulations. The Regulation was brought into effect due to the changes in agricultural practices which saw a rapid removal of hedgerows from the countryside.

“Hedgerows have their part to play in helping us to respond and adapt to climate change, providing conduits through which wildlife may move, and protecting soil, livestock and property against extreme weather events. They even help to lock up carbon and provide a sustainable source of fuel. ” Hedgerow survey Handbook (2007)

This protection covers hedgerows over 30 years old and over 20 metres long (or if shorter, connected to other hedgerows at both ends or part of a longer hedgerow).

Hedgerow removal is a tricky subject and a landowner who wishes to remove a hedgerow must serve a Hedgerow Removal Notice in writing on their local planning authority. The authority then has to determine whether or not the hedgerow is ‘important’ and whether or not to issue a Hedgerow Retention Notice.

What makes a hedgerow important?

This is where hedgerow assessments come into their own.

hedgerow

Photo – Emily Nobbs

We need to assess how many woody species are within the hedgerow, how old it is and whether the hedgerow is associated with any archaeological sites of interest.

There are lots of different combinations of features that make a hedgerow important, such as being at least 30 years old and have a minimum of 6 woody species and a supporting bank and/or ditch running along its length.

Woody species include alder, wild cherry, dogwood, black-poplar, hawthorn and of course blackthorn.

The NWS Arboriculturist can help

Jim Allitt is our resident Arborculturist and can help with any questions you have regarding hedgerows and what you can and can’t do.  Having a hedgerow assessment early on in any proposed development will allow you to understand more about the hedgerows you are working with and help you to plan any mitigation.

So the next time you see a hedgerow full of blackthorn flower don’t dismiss it, you may be looking at a very important hedge!