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!

Survey season ahoy!

It’s that time of year again when we start planning for the forthcoming survey season.

However, don’t think we have been twiddling out thumbs since November!  There have been Phase 1 surveys to carry out and arboricultural impact assessments to write – but now we’re coming up the busy season.

By planning ahead and taking account of various seasonal constraints posed by many protected species we can help project managers avoid potential delays in submitting planning applications or enabling construction works.  For example the breeding season for great crested newts typically starts in mid-March and continues until mid-June (subject to weather), which dictates the optimal window for surveying.


Survey calendar

 

Click on the image to view a calendar that identifies the seasonal constraints associated with ecological and protected species surveys.

 


In anticipation of the survey season we’ve been tidying up the equipment shed, ensuring we have all the kit needed for the months ahead:

  • The great crested newt bottle traps have been made making sure all the associated canes all have hazard tape on so we don’t lose any.
  • The bat detector batteries are all on charge and the pencils have been sharpened.
  • There have been trips to the DIY store and roofing felt cut to size for reptile surveys.
  • The life-jackets have been sent for a service ready for water based surveys and our wellies have all been cleaned.

We look forward to working with you during this survey season and throughout the year.  If you have any questions about surveys and when they can be undertaken please do let us know.

Which tree survey do I need ?

Sycamore canopy in spring bud

Clients are often asked by planners or others for a tree survey, but are not always sure what type is needed.   We have outlined the different types of tree surveys and the reasons they are needed.

A. Development survey = BS5837:2012 ‘Trees in relation to design, demolition and construction- Recommendations’

A Development Survey also called BS5837 survey is the one normally required by Local Planning Authorities (LPA) for development and planning permission.

A competent “arboriculturalist” [ = tree person ] must inspect the trees on and adjacent to the site. The trees on site are assessed in terms of their retention value which includes their health, longevity and amenity impact.

Trees that are marked for retention, as well as any adjacent trees not on site but affected by development need to be protected from any potential harm that may occur during the demolition and construction phases of the project. This involves both above and below ground precautions. Above ground, the crown spread and dimensions of the tree will need protecting, below ground the roots of the tree are a constraint governed by the Root Protection Area (RPA).

( The RPA is the area the tree’s roots occupy – this requires fencing and ground cover to protect it from above ground operations.) Information on protective measures for the trees on site will be provided as part of the BS5837 report.

B. Tree Hazard Surveys

Where you are concerned about your “duty of care” over a tree, then a Tree Hazard Survey is the one you require.

All tree owners have a legal responsibility as their “duty of care” to ensure others are not at risk from falling trees and branches. You need to assess the level of risk involved on your land. The risk is generally assessed based on :

  1. The level, extent and type of access that people have to the land on which the tree stands or where the branches could fall.
  2. The condition and health of the tree.

The factors underlying the condition and health of the tree will dictate how often the tree should be re-inspected for potential hazards. Advice on mitigating hazards by undertaking tree work can be suggested as part of the inspection, which you need to act upon.

C: Advice on Tree Works

Tree works on trees in Conservation Areas or on those with Tree Protection Orders on them need a “Tree Works” application.

When carrying out any tree work it is always advised that a competent arborist be consulted, whether it is a consultant or a tree surgeon. Work should be carried out in line with the British Standard, BS3998:2010 ‘Tree Work- Recommendations’. Trees should be inspected before the work is carried out too ensure the best management practices are employed.

Trees in Conservation Areas and with TPOs often have high amenity value and are well loved by their owners, so are felt to be worth the extra investment.

D: Surveys for underground utility installations

As stated in NJUG Guidelines for the Planning, Installation and Maintenance of Utility Apparatus in Proximity to Trees, there are generally low incidence of damage to underground apparatus by trees where these installed within hard surfaces ( e.g. pavements ). However trees can have variable growing patterns in term of root structure, especially if there are below ground obstructions to root growth. This can make any changes on site in the trees RPA potentially hazardous. Work on operational land for utilities often requires no LPA application, however it is considered good practice to follow BS3857 to implement tree protection methods where possible.

*** NEW SERVICE *** Tree consultancy

Bee on thorn flower

Bee on thorn flower

Norfolk Wildlife Services now offers an arborist service for trees alongside its existing wildlife services.  During development planning, arboriculture often requires consideration with ecology. Indeed with bats and trees the two often interact.

Furthermore in many of our urban and brownfield spaces, trees and woodland are frequently important features – sites on which we already offer ecology advice to clients. Specified properly in site management, trees and woodland can offer enhancement for the amenity, ecology and landscape of a site, as well as benefits for leisure and recreation.

With arboriculture being a natural synergy with our other wildlife services, we wanted to offer our customers a joined up service for all their trees requirements.  What we offer is :

  •  Tree surveys for development ( to BS5837 )
  •  Woodland management and planting advice
  •  Arboricultural Impact Assessment
  •  Planting plans for small sites
  •  Applications for tree works
  •  Liaison with planners, tree officers and statutory authorities

We are not tree surgeons, but can recommend or source you a reliable contractor should you request. Our ability to source the right contractor for your circumstances means you will have the contractor that fits your needs.

Not sure what type of tree survey you need – read our easy introduction to tree surveys

How many surveys for great crested newts ?

Great Crested Newt on handGreat crested newt captured by nettingGreat crested newt fence with bucket

We thought it helpful for clients to have set out what actual Natural England requirements are for licencing – how old your survey can be  – and how many surveys are necessary.

Natural England guidance

Natural England guidance on presently acceptable levels of survey effort is set out in their EPSL method statement form – which we present below – slightly tweaked.  This sets out both the type and age of data viewed as acceptable.  You can use the filters to find your project type.

This is our Excel table here : Great crested – survey effort and age

Deconstructing this gives some interesting insights about the age of data required, but also whether as to whether a full six surveys or repeat surveys are necessary.

Low impact licences and survey data

If we read through this table, you will find that low impact or temporary development can often use presence/absence data alone, which makes sense.  You may only need four instead of six visits ( or possibly only one if you find them first time ! ). Newt numbers decline rapidly away from ponds ( either the creatures are too unfit or simply due to dispersion effects ). The effect a long way from ponds can therefore be predicted as being low, based on their presence alone.  Far enough away and you can assume de minimus effects, and possibly avoid surveys all together.

The age of data is based on spring/summer survey seasons elapsed ( but see also later for a potential complexity here ):

Survey done Age of survey (before May[?] 2015)
March to May 2015 0 (before May 15)
2014 1
2013 2
2012 3
2011 4
2010 5
2009 6

So this year, data from the 2011 summer season is 4 years old, assuming you apply before end of May[?] 2015.  This also means that for some low impact schemes, older data will be helpful.  There are various caveats to this.

It is not 100% clear from the footnote on the NE guidance whether the age of the survey is the number of survey seasons missed, inclusive or exclusive of the present year.  It would seem more logical that 2015 data is 0 years old until March 2016, but in fact it appears to be 1 after May this year. However it would be impossible to survey, get planning and apply in the time period. We will take this point up with Natural England for clarity [ thanks to someone for pointing this out to me ].

What survey effort is most helpful ?

This raises for us an interesting question about proportionality and efficiency – what solution for survey effort allows most accurate information most efficiently ?

Given that most ponds are in the small or medium range and that large counts are generally from aggregation across ponds, should we focus more on the number of ponds involved and their functional nature ?

eDNA difficulties for presence/abscence

A difficulty of eDNA for results is that it shows us nothing of the pond’s function.

Four nocturnal visits will not only give a very good guide for impact assessment,  but also should generally reveal if the animals are breeding successfully and may turn up eggs or efts dependant on timing.

Many ponds around a breeding pond have occasional newts, but are not of high enough quality for breeding – this issue was never tackled by HSI.  Vice versa large numbers of males lecking at a pond indicate one thing.  Knowledge about successful breeding at a pond seems to us essential in stating the effects on the population.

Conclusions

So to return to the question only four surveys with presence or possibly even eDNA to prove absence could be sufficient for your needs, or you may be able to rely on existing older data. However really your consultant needs to have some understanding of population ecology to advise you on mitigation and obtaining a licence. Following guidance verbatim is not a good solution and could waste your money – sorry that slipped out.

With this in mind we advise you not to rely on this article for formal advice, but let us discuss with you how it applies to your suituation – please contact us directly if you have a licencing query or you have some observations about the article.

There is more Natural England advice on their website : https://www.gov.uk/government/publications/great-crested-newts-apply-for-a-mitigation-licence

Getting stuck in the mud at Cley

With support from members, business and the Heritage Lottery Fund, Norfolk Wildlife Trust acquired 60 hectares of land at NWT Cley Marshes in 2014. Norfolk Wildlife Services carried out baseline studies of the plants and invertebrates with particular focus on the impacts of the January 2014 flooding on the site’s ecology.

We decided to get stuck into the project (literally) to survey the saline lagoons and freshwater dykes across the site for aquatic plants such as Phragmites australis, and aquatic invertebrates such as the water boatman Arctocorisa garmari.  Initial results showed that an increased proportion of the open water on the site was unsurprisingly either brackish or saline. The effect on invertebrate species was evident during surveying as several groups were under-represented such as dragonflies.

In early summer 2015, we will survey the terrestrial invertebrates when they are most active. Some of the terrestrial invertebrates sought for include the Red Data Book ground beetle Pogonus luridipennis, or more commonly found cross spider Araneus diadematus.  Invertebrates like these are key indicators of the habitat quality and conditions present.

NWS will be running a workshop in September next year, looking at how the invertebrate population at Cley supports birds such as bittern, avocet and godwit. Check our website for more details on this “Bittern’s Breakfast and Avocets Lunch” event.

Great Crested Newt Surveys

Why are great crested newt surveys needed?

Great crested newts have suffered serious declines in numbers over the last century. Where a development project might impact this species or habitat it uses, great crested newt surveys may be required to determine whether newts are present to assess if they will be affected by the project.

Who can do surveys ?

The great crested newt is protected both under national and European law.  An experienced great crested newt surveyor is required to complete the surveys and make this assessment.  Our staff have the necessary licences in place to do this and can work efficiently to do the surveys for you.

This great crested newt was found during pitfall trapping in 2014

This great crested newt was found during pitfall trapping in 2014

Smooth newt found during bottle trapping

Smooth newt found during pitfall trapping

 

 

 

 

 

 

 

Where are they found ?

Great crested newts are not only found in ponds, but spend much of their life on land in habitats such as grassland, woodland, hedgerows, and can even spend winter in building foundations. Because they can travel long distances and are found in a range of places, it is typical for all ponds within at least 250m of a proposed development site to be assessed.

This pond in South Norfolk was home to 120 great crested newts, 50 smooth newts and a number of frogs and toads

This pond in South Norfolk was home to 120 great crested newts, 50 smooth newts and a number of frogs and toads

The picture on the right shows a pond surveyed in 2014 that had the largest great crested newt population seen by NWS staff for a few years, with a total count of over 120 newts on one night!

 

 

 

How is a survey carried out?

The first stage of a great crested newt survey is normally to carry out a daytime assessment of ponds in the vicinity.  We would normally carry out a Habitat Suitability Index (HSI) assessment on these water bodies. This is a predictive tool which looks at the likelihood that great crested newts are present, and can be undertaken at any time of the year. Low HSI scores are sometimes sufficient to conclude the likely absence of newts, but for higher scores, further surveys will be needed.

Great crested newt captured by netting

Great crested newt captured by netting

Because great crested newts are nocturnal and can be spread across a large area, surveys  take place at night between mid-March to mid-June when they gather in ponds to breed. Four visits are required to determine presence or likely absence, and two of these must take place between mid-April to mid-May during peak breeding activity. If great crested newts are found during these surveys, an additional two visits are needed to estimate the population size more accurately.  The survey will involve looking for eggs, searching for adults with a bright torch and netting for adults and larvae.  Where there is poor visibility or the site is unsafe to enter at night, then bottle trapping can be used.  This technique is more risky as it can potentially drown animals if the traps are not set correctly.

An alternative and new technique to work out if newts are present is to collect water samples from the pond and have them analysed for great crested newt eDNA. This technique can quickly rule out a number of ponds and avoids unnecessary night surveys. However, if the results come back positive, six nocturnal visits will still be required to determine the population size. Water samples can only be collected between mid-April to end-June and must be collected using a strict methodology.  We have used this technique in 2014 and can advise you if it is suitable for you.

How is the information used by planners?

The Local Planning Authority responsible for considering a planning application need to know if great crested newts are present, and in what numbers, so they can make sure that the development will not impact the species long-term. Where an impact is likely, a European Protected Species Mitigation (EPSM) licence from Natural England will be required, which will detail how and when the work can take place. This will usually be conditioned on to any planning decision, but will need to be demonstrated as deliverable prior the planning stage.

 

 

 

 

 

 

 

 

Alex’s Work Placement Blog

At Hellesdon High School, we need to do a work placement in Year 11, so I have been completing work experience in the NWS consultancy office on Monday 14th and Tuesday 15th July 2014. I learned about what the consultancy does to preserve protected species and how developers have to take precautions if they want to develop areas which have been found to contain any protected species  in them ( such as bats or great crested newts ).

I also helped during my placement on evening surveys with my dad, which was probably a bit more interesting to get out and about.

The first survey was a night time newt survey at three different ponds with torches and bottle traps. My dad and I enjoyed this so much we went back there in the morning to come and see the results of the bottle trapping.  We had caught a great-crested newt and I got to handle it [supervised !] before it was released, which I had never done before and found very exciting.  The most enjoyable thing was finding out about how to prove the existence of great-crested newts – they are not very easy to find except by night.

The second survey for the placement was a bat survey on a thatched house at Hickling.  In this we counted the numbers of bats coming out of a gap in the thatch. We counted 98 bats from the same place, which means a big roost inside the roof somewhere. This was fantastic to see – so many bats in one night – the person on the other side didn’t see any all night so I was lucky ! I enjoyed learning about bat species – I hadn’t realised before that there were many different species of bat and not just one.

Finally we found a kitten on the riverside on our lunch break, so I also got to look after the rescue kitten for a bit, although I am not sure he was that happy about it. All in a day’s work at NWS !

Rescued cat with Alex

Kitten with good acting skills as Great Crested Newt in training exercise

Picture of Alex with the cat

Alex on placement at the NWS office with bemused kitten

When are reptiles active ?

Reptiles, such as adders, grass snakes, common lizards and slow worms, rely on the heat from the sun to warm their bodies in order to become active, but if it becomes too hot will overheat and seek shelter from the midday sun.

Therefore, these creatures are only active during the warmer months, typically from March to October, but are easiest to spot when the weather is not above about 18 degrees C [ so June and July are often too hot once the sun is fully up]. During suitable times, they can sometimes be seen basking in the sun on south-facing banks, or rocks, or underneath hotspots, such as discarded corrugated iron sheets. They hibernate throughout the colder, winter months, during which time they seek refuge underground or, for example, in log or rubble piles, so called “hibernaculum”.

NWS can undertake reptile surveys on sites, that are proposed to be developed. Where they are discovered on a site, we can advise clients on any mitigation required, for example reptile translocations or habitat creation.