Ben Rhydding Gravel Pit

Yesterday evening I attended my first event with the Bradford Botany Group, a joint meeting with the Wharfedale Naturalists Society at one of their managed sites, the local nature reserve at Ben Rhydding. This was a gravel extraction site but ceased production in the 1970s. Since then, the pits have filled with water to become lagoons, and a mosaic of different habitats exist on the 4.5 hectare reserve just outside Ilkley.

With a mixture of grassland, scrub and woodland there were a range of plants to look at, including the broad-leaved helleborine and other orchids.  It is a varied reserve, and I was able to collect grass samples for my MMU assignment whilst also learning some more about the site and its less usual species.

One of these is the sea holly, a plant normally only found in the very south of England. It must have been brought up to Yorkshire for some reason, but has since become naturalised, presumably because the gravelly soil and warm sheltered site provides ideal conditions for its growth. It is a very stunning but rather unusual looking plant.

The visit was well attended with over 18 members, and they all seemed very friendly and welcoming. I will try and attend more field visits this summer, as it is a good way to improve my botanical knowledge and field skills.

Advanced Pond Training

Yesterday I joined some other volunteers and our local PondNet coordinator Anne and we had a relaxed and informative training day on a site near Gateshead in the north east of England. Despite the early start and the long drive, the visit was worthwhile as it gave the opportunity to visit a new site which offered a range of biodiversity. Whilst I carry out amphibian surveys for the PondNet project, there are other strands to the project. Combined, these aim to get a view of the overall health of ponds. Volunteers can choose survey specialisms such as aquatic plants, pond invertebrates, and dragon/damselflies. This was a chance to see what was involved in those other survey strands, and record some useful data for the pond whilst we were being upskilled.

On arrival, the sun was out and we spent half an hour or so chasing butterflies, dragonflies and damselflies from plant to plant. Skipper butterflies were most abundant, and I was able to add azure and emerald damselflies to my seasonal tick list.

For the rest of the morning we had a slow walk around the pond and identified all of the plants either in the pond or around its margins. These included grasses (a good opportunity to practice from the weekend!), several different species of reed and other wetland plants including bur-reed and spearwort. From within the pond we also pulled out some ivy-leaved duckweed and crystalwort, a type of liverwort with an antler-like structure. The full plant list is as follows:

Water starwort species undt. (Callitriche sp.)
Waterweed, Canadian (Elodea Canadensis)
Crystalwort, Channelled (Riccia canallculata)
Duckweed, Common (Lemna minor)
Duckweed, Ivy leaved (Lemna trisulca)
Pondweed, Broad-leaved (Potamogeton natans)
Angelica, Wild (Angelica sylvestris)
Bent, Creeping (Agrostis stolonifera)
Bird’s-foot-trefoil, Greater (Lotus pedunculatus)
Bur-Reed, Branched (Sparganium erectum)
Cuckooflower (Cardamine pratensis)
Forget-me-not, Tufted (Myosotis lexa)
Foxtail, Marsh (Alopecurus geniculatus)
Iris, Yellow (Iris Pseudacorus)
Mint, Water (Mentha aquatic)
Rush, Jointed (Juncus articulates)
Rush, Soft (Juncus effuses)
Rush, Sharp-flowered (Juncus acutiflorus) 
Spearwort, Greater (Ranunculus ligua)
Spearwort, Lesser (Ranunculus flammula)
Stitchwort, Bog (Stellaria uliginosa)
Sweet-grass, Floating (Glyceria fluitans)
Willowherb species undt. (Epilobium sp.)

After lunch, we focused on invertebrates and carried out timed nettings around the margins of the pond, taking samples from different habitat types including open water and amongst the vegetation. We then discussed what we had found, and tried to identify them. For the purposes of the
PondNet invertebrate survey, identification is to family level.

One of the other volunteers had an amazing device - a lens that fitted to his i-phone and acted like a microscope. As well as seeing the insect at a high magnification, he could take photographs of the detail. I was slightly jealous! This would greatly help with identification, especially of the smaller species.

Beetles (Order Coleoptera)
  Dytiscidae (Noteridae): Diving Beetle
  Hydrophilidae (Hydraenidae): Scavenger Beetle

Water Bugs (Order Hemiptera, Suborder Heteroptera)
  Corixidae: Lesser Water Boatman
  Gerridae: Pond Skater
  Naucoridae: Saucer Bug
  Nepidae: Water Scorpion
  Notonectidae: Water Boatman
  Pleidae: Saucer Bug

Caddisflies (Order Trichoptera)
  Limnephilidae

Damselflies (Order Odonata, Suborder Zygoptera)
  Coenagrionidae: Red & Blue Damselflies

Dragonflies (Order Odonata, Suborder Anisoptera)
  Libellulidae: Skimmers, chasers, darters

Flatworm (Order Turbellaria)
  Planariidae (Dugesiidae)

Mayflies (Order Ephemeroptera)
  Baetidae: Olives

Water Slater (Isopoda)
  Asellidae: Water Hog-Louse

White Clawed Crayfish

This week I attended a one day introductory workshop, organised via CIEEM, on the native white-clawed crayfish (Austropotamobius pallipes). It was held at an outdoor centre near the upper reaches of the River Kent near Windermere and run by Paul Bradley who runs his own consulting firm.

After a classroom session in the morning looking at the ecology of the species, the rest of the day was spent outdoors.

First, we walked up to the local reservoir. En route, we carried out a visual search of the river bank and saw claws discarded by feeding otters, so could confirm presence without even touching the water. At the reservoir, we raised some lobster pot type traps set the night before, and got three adult males out of eight traps.  We had a chance to have a look at the finer points of their physiology in the flesh, had a first go at handling them, and learnt how to measure the carapace length with dial callipers.

After a picnic lunch in the sun, we walked down to the stream and learned how to do a refuge search. The first crayfish caught by the tutor was a female still carrying young! We then had 15 minutes in the water in wellies trying to find crayfish. I found eight, but they are extremely fast and agile and difficult to catch. I did manage to catch two, and we got some more practise handling them as we filled in survey forms detailing their gender and size. 

Later in the afternoon we drove up to another reservoir, even further up the valley, and had a discussion about habitat management, species conservation, and how best to deal with invasive species. Our native white clawed crayfish are very vulnerable, due to predation and displacement by the larger more aggressive American signal crayfish, but also due to diseases being spread and carried by them and other introduced species. The importance of biosecurity was stressed throughout the day, though unfortunately the outlook seems bleak for our native population, which is continually dwindling with remnant populations becomes increasingly isolated and vulnerable.

It was a useful course and great to get close to these fascinating little creatures, and I'm pleased to have picked up some useful new survey skills.

eDNA Testing for Great Crested Newts

This week I answered a plea for help and stepped in to carry out some e-DNA testing of five ponds at Tintwistle near Glossop in the Peak District, as part of the PondNet project.

Environmental DNA (e-DNA) testing is a relatively new procedure and the technology is still being trialled to a certain extent. It aims to offer another way of surveying for Great Crested Newts. Traditional surveys have to be carried out at night, and at least four visits should be completed between April and June to demonstrate whether newts are present or absent. This is time-consuming and has it's issues, such as the health and safety of wandering in dark woodlands near water at night, the cost of paying for consultants, working unsociable hours, cleaning bottle traps, etc.

One advantage of e-DNA is that only one visit is needed to collect the water samples, and this can be done in the daytime, making it ideal for remote sites. DNA is 'lost' by newts through skin, faeces etc and can persist in the pond's water for up to three weeks. The e-DNA samples therefore need to be taken within the normal window for newt surveying ... My survey was therefore a little late in the season, due to another volunteer being unable to do the sampling, but it could still pick up some DNA.

It was an easy hour's drive down the M1 and across the Pennine moors via the Woodhead Pass.  Parking up at the side of an angling club, it was then an pleasant twenty minute walk around the reservoir and into the nature reserve at Swallow's Wood. Armed with a map, I managed to find the ponds without too much trouble, and after ignoring a 'closed footpath' sign and battling my way through the woodland undergrowth, I reached the site.

The first three ponds I surveyed were really pools in a stream separated by weirs. As well as recording environmental data and noting any amphibians seen, I collected e-DNA samples following a strict protocol.  This took around 30 minutes per pond and the process is described below.

One kit is provided for each pond and contains everything you need to carry out the water sampling. This is all disposable. The first stage is to put on a pair of nitrile gloves. This is to minimise contamination from other ponds/water that have been touched. 

Twenty water samples are taken from around the pond, trying to space these out as evenly as possible and make sure that some are from open water and other around vegetation.

Without standing in the pond (again to avoid cross-contamination), reach into the pond with the test-tube ladle and fill it with water. You should swirl the water around a little to mix the water column, but avoid disturbing the sediment on the bottom of the pond as DNA can persist here for a long time and may give a false result.

Pour the ladle full of water into the 'whirl-pak' bag provided. This should stand up on its own, but take care not to knock it over. When all twenty samples are placed in the bag, close the bag and shake it for ten seconds to mix the water.

For each pond, six test tubes are provided. Each contains an alcohol-based fluid that will preserve any DNA until it can be tested.

Putting on a new pair of gloves, decant some of the collected water from the whirl-pak bag into test tubes using a plastic pipette. I found the pipettes, being disposable, were not very robust and I had to take several pipettes worth to make up the sample. Each test tube is filled up to the 50 ml mark. Replace the screw cap firmly, and shake the bottle for ten seconds. This is to mix up the water sample and the preserving fluid.

The water in the whirl-pak bag should then be shaken up again, as the DNA constantly sinks to the bottom, and the next sample taken. In total, six test tubes are filled, forming replicates of the test.

Each of the six test tubes are labelled with a bar code which is repeated on the box that they come in. It's really important to make sure that the test tubes all go back into the same box they came out of, and that this is clearly labelled.  As well as writing the pond name/code on the box, the DNA test code needs to be recorded on the paperwork so that the results and the pond can be married up together afterwards.

It was a really useful experience to carry out this testing and see what was involved. The results should be available in September, and it will be interesting to see if Great Crested Newts are present on the site.

Whilst carrying out the tests, I also spotted some good examples of woodland and pond plants (Sweet Flag, Betony, Wood Vetch), several species of butterfly (Speckled Wood, Red Admiral) and added Large Red damselfly to my list. It is a lovely site to have a wander around if you are ever in the area.

Dragonfly Day

On Sunday morning I joined other members of the Lower Aire Valley (LAV) volunteers, and some members of the public, in an educational walk around Letchmire Pastures to look for and learn about dragonflies and damselflies. During amphibian and invertebrate surveys on the site, we came across many dragonfly and damselfly larvae in the water, and this was a chance to see what they were changing into. The weather was kind to us and we saw a number of different species, though these were definitely more active when the wind dropped and the sun came out.

Dragonflies are generally larger, with wider bodies and large bulbous eyes that touch in the middle. At rest, their wings are held at right angles to the body, resembling a crucifix, and in flight they are fast and powerful.  In contrast, damselflies are usually smaller and more dainty. They have a thin body, and the head is slightly squarer with separate eyes on either side of the head. Flight is brief and weak, and at rest the wings are normally held together down the back.

As well as learning about their life-cycle, I learned how vulnerable the adults are when they first emerge from the larval case (exuvia). These teneral adults have faded colours and their case is soft. They need to rest for several hours, during which their wings and case harden and they are then able to fly.  During this time they are easily damaged, so it's important not to try and catch or disturb them, for example by getting too close to take photographs, as this can injure them and cause deformities as the tissues harden. They are also very prone to predation by birds during this stage. The top photograph shows a Common Darter (Sympetrum striolatum) freshly emerged for it's exuvia (taken on a zoom lens so I didn't get too close!).

One of the most impressive dragonflies seen was at the end of the session. We saw several Emperor dragonflies (Anax imperator), the largest in the UK, protecting territory over one of the ponds. When other Emperors came too close, they would get chased off, with the dragonflies reaching amazing speeds and changing direction in the blink of an eye. When they fought, you could also hear their wings as they clashed - quite an amazing sound.

Many damselflies were seen.  One group were the Blue Tailed Damselflies (Ischnura elegans), which has a predominantly black tail but with a bright blue tip, as on the middle photograph.  There are different forms of this species, identified by the different thorax (body) colours. This one is the typical which has a blue/green thorax.

The other main group of damselflies are the 'blues'.  There are half a dozen or so species that have a series of blue and black bands on their tail and they all look very similar in flight. To identify them, they either need to be caught or photographed so that the banding patterns can be examined in closer detail. One way of telling them apart is by looking at the first black mark below the thorax/at the top of the tail, as highlighted in red in the bottom photograph. The shape of this is distinctive. Here, it resembles a mushroom which identifies this species as the Common Blue Damselfly (Enallagma cyathigerum). Others are shaped line a wine glass, a U-shape, etc.

Four species of dragonfly and damselfly were seen:

• Emperor
• Red Darter
• Four Spotted Chaser
• Common Darter
• Red Eyed Damselfly
• Banded Demoiselle
• Common Blue Damselfly
• Blue Tailed Damselfly (Typica)

In addition, skipper butterflies were abundant and cinnabar moth caterpillars were also seen grazing on ragwort. It was a very enjoyable morning.