Susie

Overview of Works

The works to repair and enhance the flood defences at Burnham Overy, and to repair the footpath through to Burnham Overy Staithe, were successfully completed in July 2011. The works were subject to delays as a result of the presence of natterjack toads and common lizards. A total of 338 lizards, 10 natterjack toads, 129 common toads, 10 common frogs and 6 smooth newts were translocated during the course of the project.

The natterjack toads and common lizard were moved into the dunes while the other amphibians were all released approximately 1km south of the start of the works area in the grazing marsh.

Before Works

View prior to work

The works at Burnham Overy were initially due to start in 2009, but were delayed as a result of a desk study that revealed the presence of natterjack toads on the site. It was too late in the 2009 season to survey for natterjack toads, and Natural England had also advised restrictions on the acceptable timing of the works in order to avoid disturbance to the wintering birds on the grazing marshes.  The project was necessarily delayed until the 2010, when it was anticipated that surveys would establish the level of presence by natterjack toads and mitigation to translocate reptiles and natterjack toads would commence.

In readiness for the start of works in 2010, reptile translocation from the bank was started (221 lizards were caught and translocated to the dunes) and a vegetation survey was conducted. The vegetation of the banks was cut short to reduce the habitat value for lizards and displace the majority of the population. The shrubby sea-blite and other potential refugia were removed from the bank and used to create an artificial reptile hibernacula at the back of the dunes.

The works to the bank were delayed, and did not start in 2010 Fortunately an agreement with Natural England was reached to remove the bird-related timing restrictions placed on the works so that these could be started in the spring of 2011. As the site is regularly disturbed by large numbers of walkers, dogs and cyclists, it was agreed that the increase in activity due to the works was unlikely to have a significant additional detrimental effect on nearby breeding birds.

Creating a reptile hibernacula

Dry weather reduces the activity of natterjack toads significantly, and owing to the extraordinarily dry spring in 2011, the natterjack toad surveys and mitigation was again delayed. However, work continued to translocate lizards and to maintain the vegetation cutting to deter them from the bank. A further 72 common lizards were translocated in 2011 prior to the works.

Once the weather was suitable, torchlight searches for natterjacks began, and animals located on or near the bank were removed to suitable foraging habitat in the dunes.

61 natterjack toads were seen during the searches, which covered the bank and dunes. Of these 9 were on or near the bank and needed to be translocated.

During Works

The plan was to divide the bank into four sections. As each section was cleared of natterjacks and lizards, it could be signed off and the topsoil stripping could begin.

Works started in April 2011 on the end of the bank farthest from the dunes. The top soil stripping was overseen at all times by a minimum of two ecologists. 45 lizards were caught and translocated during the top soil stripping of the bank. 1 natterjack toad was unearthed in the last 50m of bank, right at the base of the bank in a patch of sand that was checked before being tracked over.

As the works coincided with the breeding bird season a survey was completed by a qualified ornithologist along the haulage and works corridor. The survey covered the works corridor plus a 50m buffer either side. There were strong indicators that birds were holding territories along the haulage route and in the salt and grazing marshes adjacent to the works corridor.

Seth checks for water vole

Bearded tit juveniles were seen in the reeds next to the haulage route confirming successful nesting during the works, and lapwing alarm calls from the grazing marsh indicated that they likely had chicks. Redshank, meadow pipit and little grebe were also heard calling from the marshes indicating that they were likely to be holding territories. Sedge warbler, blackbird, goldfinch, skylark, wren and reed warbler were heard singing this is also a sign that they were holding territories. Oystercatchers, spoonbill, black-tail godwits, little egret, tufted duck and shelduck were all observed foraging within 50m of the works corridor.

Access for this and future works to the bank was improved where the haulage route crossed over a dyke separating the grazing marsh from the foot of the bank. Improvements to the dyke crossing were mitigated for potential water vole impacts by cutting short the vegetation along the dyke edges to displace any activity. The digging works commenced with an ecologist on-site to monitor the turf stripping and to check any potential water vole burrows revealed by the gradual removal of soil.  No occupied water vole burrows were found during the works to prepare the dyke crossing.

Re-profiled clay bank before dressing

The topsoil stripped from the floodbank was used to re-cover the front face of the repaired bank, while new topsoil was imported to dress the rear face. The rear face was seeded with a seed mix drawn up by the Environment Agency. The front face was not reseeded as the topsoil used to cover it originated from the bank and was presumed to have a viable seed bank. Some of the topsoil from the bank was also used to cover the artificial reptile hibernacula.

Post Works

In 2012, we have been back to the site to for natterjacks use along the works corridor and the surrounding area. Adult natterjacks were found within the dunes to the north of the works corridor. In the ponds closest to the works natterjack spawn was present along with 45 adult natterjacks. Males were heard calling from the ponds and grazing marshes. Adult toads were seen at the northern end, on the rear face, of the worked bank and around the hibernaculum.

This year has been pretty full on so far, with Wild Frontier Ecology being involved in a really interesting variety of projects all over the country. We have also been busy improving our work space, making the second office into a pleasant and convivial meeting place.

Workwise, much of the early season was devoted to reptile and amphibian works, with a lot of staff time devoted to the Broadland Flood Alleviation Project, and two mitigation schemes, one in West Norfolk and the other along a popular stretch of the Norfolk Coast at Burnham Overy.

Taking lizards to the Dunes at Burnham Overy

The latter was a rare chance to work with natterjack toads, a European protected species of restricted range. This slow, warty creeper of the dunes loves to burrow into soft sand, so we had to make sure that areas disturbed by essential sea wall maintenance were natterjack free. An interesting by-catch was a large number of common lizards, removed to the safety of the dunes to prevent killing and injury.

Breeding bird surveys also run in the April to June period, and we were assigned a number of wind farm proposal sites to survey. These proposals are often in intensive farmland, so the yield of interesting bird species can be quite low, although sometimes we are lucky enough to encounter a few goodies. Over the years this kind of survey has picked up stone curlew, crane, woodlark, quail and red-backed shrike, as well as good fistfuls of red and amber-listed farmland birds. This kind of survey is highly skilled, with the surveyor needing to know songs and calls of a large number of species.

Typical BREEAM site

This year has seen a definite upturn in the number of BREEAM and Code for Sustainable Homes assessments we have been involved with. These are often brownfield sites, and as the BREEAM credit system is based on the number of plant species present, it is usually to the developer’s benefit that the existing site is not very diverse. However, we do find that most of our clients are very keen to create a positive biodiversity benefit, even on the most urban of sites.

Pipistrelle Roost, Norfolk Barn

Our Norfolk bat surveys, as well as those in Suffolk and Cambridgeshire, have been turning up a good number and variety of bat species this year. Typically barn conversions or demolition/ rebuilds, the most frequent species are the two pipistrelle species and long-eared bat. The enigmatic barbastelle appears from time to time, although often as a single specimen. Bat surveys on wind farm sites are also rolling on, and we now have an impressive silent army of static detectors for this purpose. Transect surveys with handheld Duet bat detectors are also a regular feature of the wind farm investigations.

Finally, we have also been busy attending the small wind conference in March, giving presentations on small wind developments and ecological risk, contributing to research into Norfolk barbastelles, showing reptiles to members of the public and conducting bat walks.

Looking forward, the autumn is likely to bring a lot more bat surveys, and often a rush of small development projects as they look to get planning permission before the winter sets in. There is often another peak of reptile work in August/ September, while bird vantage point surveys continue, and reports and assessments become more of a priority.

Rob

I’ve always been fascinated by the daily movements of gulls across the part of north Norfolk that I know so well. Ever since I can remember, looking up to the skies on a winter’s afternoon, I would see numbers of gulls in straggling V formations heading northwards towards the coast. In my razor sharp teens I would set up my telescope out of my bedroom window to watch and count the considerable formations of black-headed, common, herring, greater and lesser black-backed gulls steadily moving coastwards.

Gulls in flight

Of course, I wanted to know where these birds were heading, where they had been and what they were doing during the day. I still haven’t really got all the answers, but gradually a few observations have helped me to have some understanding of this daily commute as predictable as the sunrise and sunset.

The general pattern seems to be that of a night-time gull roost at the coast, probably Wells Harbour, but maybe other places too. Then, as I have now seen many times, a dawn or pre-dawn southward movement and dispersal. This is very noticeable at my house in Foulsham, where each morning flocks of common and black-headed gulls come in low across the fields from the north-west, often settling for a short time before moving on.

During the daytime, the gulls often display a more random movement, presumably roaming in search of good food sources. Then, early or mid-afternoon, the familiar V shaped formations start appearing with a steady northward bearing, back to the coast. There is at least one regular en-route stop-off, the lake at Holkham Park where gulls will pause for a brief wash before flying down the length of the serpentine lake towards the tidal sands of Wells.

Although the five species mentioned above are the most usual, other gulls will inevitably get caught up in these daily movements. Viewed from my stupendous back garden one early morning a few years ago in March were two perfect summer plumaged adult Mediterranean gulls, mixed in with the commons and black-heads. I am sure that keen gull-watchers would find yellow-legged, Caspian and maybe glaucous and Iceland gulls every now and then.

Some mysteries remain. Presumably in other areas, the gulls perform the same commuting movements to and from other roosts. It would be interesting to map the hinterland from each roost; how far is a gull prepared to fly for its scavenged lunch?; what observations have been made at the north Norfolk roost (numbers? What happens when it’s high tide?; And are there well-used flight lines overland, or is it just a random spread of flocks across a broad front (I think there are flight lines).

For me, a wintry Norfolk sunset is not complete without a gull or two.

Rob

Robert Yaxley

Rob Yaxley is Wild Frontier’s director and chief gull lover. His hobbies include obsessive pursuits such as counting the freckles on his children’s faces, adding up the numbers on number plates and collecting wooden rhinoceri under 10cm in length.