Small Mammals at Ledston Luck

In September 2014 I helped survey Ledston Luck nature reserve with the Yorkshire Mammal Group - in fact it was my first event with them and on the site. On a single overnight session, five species were caught in the Longworth traps: wood mouse, field vole, bank vole, common shrew and water shrew. After being gently examined and carefully recorded, all were released unharmed back into the wild.

YWT has lots of improvements planned for the site, including cattle grazing to help manage the grassland. With lots of work and management going on, reserves manager Kate is keen to engage the local people by getting them involved and showing what's on the site. With this in mind, I agreed to help her run another small mammal session.

We decided to survey a different part of the site, and focused on three different habitats at the southern end of the reserve. These were:

1. Tall grass and hawthorn scrub near centre of limestone plateau
2. Semi-mature woodland with grass and bramble ground flora
3. Meadow area of knee-height grass and wild flowers close to the boundary with the industrial units and alongside a damp ditch

On Friday evening several volunteers from YWT and the University of Leeds MSc group helped to set up the traps, and learned a bit about survey protocols. They were shown how to construct and set the traps which were baited with a mix of bird seed, oats, raisins, peanuts, apple and blowfly pupae. A ball of hay was added for insulative bedding. The traps were placed on site along transects, and clearly marked with biodegradable tape so that we could find them again in the morning.

Early on Saturday morning we returned to check the traps. Just three of the traps had sprung, with a wood mouse and two common shrews caught. There were no signs of small mammals at site 1. Those traps were moved to the other side of the plateau near a reed bed, to try and increase our chance of catching something the next day. The traps were locked open during the day, with a visit planned that evening to re-bait and set the traps. However, heavy rainstorms flooded local roads and we were unable to reach the site to reset the traps.

Plan B saw Kate and myself on site early on Sunday morning to set and bait the traps. The previous days storms were a distant memory, and it was a lovely warm and sunny day. None of the local villagers unfortunately showed up, but keen members from the LAV volunteers met up at lunchtime to check the traps and collect them in. Site 1 again yielded no results, though bank voles and common shrews were found in the other two areas. Everyone got the chance to practice emptying the traps, handling the mammals, weighing them, and trying to identify their gender.

There was some excitement in the woodland when we thought we had caught a pygmy shrew, which would have been a new site record. However when weighed it was 8.5 grams, which although it seems very light is still heavy for a pygmy shrew as these are normally 6 grams at the most. Given the colour of the fur, on reflection it was more likely to be a juvenile common shrew. (Photo credit: Wilf Greenman).

The overall trap rate was just 17%, which is low compared to the 56% achieved in 2014. This may have been down to the appalling weather overnight and the relatively short time that traps were set on the second day. 

But although there were fewer animals caught than we had hoped, at least we did get to see some small mammals up close. It was good to meet up with some of the students on my upcoming MSc course, and the volunteers learned how to set the traps, handle animals safely and learnt a bit more about the species that can be found on site.

Canalside Aquatic Plants

This morning I attended a CIEEM regional field meeting looking at plants alongside (and in) the Stainforth & Kearby Canal at Thorne, South Yorkshire.

It was a relaxed morning, and it was good to see some familiar faces and have a chat. We had a very leisurely stroll down a 600 meter stretch of the canal, sharing knowledge and experience to identify as many plants as we could. Grappling hooks were used to scoop out some of the submerged aquatic vegetation from the canal itself. We also had a look at the coir rolls that were installed and planted up last year to support the bank.

Here are some of the plants found, along with my brief notes on their identifying features:

Submerged Aquatic Plants

- Curly water-thyme (Lagarosiphan major) - leaves curl backwards and are densely spiralled up the stem
- Flowering rush (Butomus umbellatus) - triangular, twisted stem that when snapped apart leaves fibrous strands [photo 1]
- Water-milfoil (Myriophyllum sp.) - slender with feathery leaves
- Yellow water lily (Nuphar lutea) - more obvious venation on leaf
- White water lily (Nymphaea alba) - leaf rounder, flower larger
- Fennel pondweed (Potamogeton pectinatus) - thin grass-like leaves with irregular branching
- Celery-leaved crowfoot (Ranunculus scleratus) - thick stem, shiny three-lobed leaf, yellow flower
- Curled pondweed (Potamogeton crispus) - leaves look crimped rather than curly
- Nuttall's waterweed (Elodea nuttallii) - leaves slightly recurved and taper to a point

Emergent Aquatic Plants

- Arrowhead (Sagittaria sagittifolia) - triangular stem, leaves in three's in a 'wind turbine' shape, flowers and fruit in clusters of three: flowers white with purple centre; fruit spiky like a bur [photo 2]
- Water plantain (Alisma plantago-aquatica) - large, wide, erect leaf with a cordate base
- Narrow leaved water plantain (Alisma lanceolatum) - large, narrow, erect leaf that tapers to the base [photo 3]
- Amphibious bistort (Polygonum amphibium) - creeping habit, pink flowers in a compact spike, floating hairless leaves, rooting from nodes

Wetland/Riverbank Plants

- Marsh woundwort (Stachys palustris) - square stem, leaves short stalked; pink-purple flowers encircling the stem [photo 4]
- Gypsywort (Lycopus europaeus) - square stem; leaves short stalked; many very small white flowers (with purple dots) clustered above leaf axil [photo 5]
- Orange balsam (Impatiens capensis) - oval toothed leaves; orange flower with red-brown spots and a spur that narrows and curves back on itself [photo 6]
- Skullcap (Scutellaria galericulata) - blue-violet flowers with a long calyx tube [photo 7]
- Woody nightshade (Solanum dulcamara) - distinctive purple and yellow flowers; red berries
- Water figwort (Scrophularia auriculata/aquatica) - square stem with wings; leaves oval, opposite and blunt with blunt teeth
- Purple loosestrife (Lythrum salicaria) - tall with red-purple flower spike [photo 8]
- Great willowherb (Epilobium hirsutum) large, downy willowherb with deep pink-purple flowers
- Marsh willowherb (Epilobium palustre) - dainty willowherb with pale pink flowers
- Lesser pond sedge - (Carex acutiformis) - blue-green appearance with rough leaves
- Hemlock water-dropwort (Oenanthe crocata) - poisonous umbellifer
- Horsetail (Equisetum sp.) - distinctive plant - a sample was taken away to try and identify this to species level (either water E. fluviatile or marsh E. palustre)
- Tansy (Tanacetum vulgare) - identified by its distinctive smell, as the plant we found was rather stunted and trodden on, unlike the tall, clumpy yellow-flowered plants I have seen before

It was also good to practice my grasses, with reed canary-grass (Phalaris arundinacea) being identified by it's membranous ligule. (Common reed is larger with a ring of hairs as a ligule). 

Many thanks to Phillippa from the Canal and River Trust for organising the event.

Ledston Luck Nature Reserve

Today I helped out on one of the regular practical task days for the Yorkshire Wildlife Trust Lower Aire Valley volunteers.  This was held at Ledston Luck nature reserve, a small site a few miles north of Castleford.

Over the coming months, improvements are being made to the site. To help manage the grassland, it is hoped to implement a grazing regime with a small number of cattle. To facilitate this, fencing and gates need to be installed and some of the footpaths improved or re-routed slightly.

Our task for today was to finish installing a foot-bridge over a drainage channel, and to cut back some of the scrub and widen the pathway to allow access for contractors to install the fencing.

The day started off with a spot of rain, and this got more persistent, and heavier, as the day went on. However, we plodded on undeterred and managed to complete the tasks early.

Using loppers and hand saws, we managed to remove a swathe of around two meters of saplings and scrub from the path leading up to the plateau (top photo), opening up the path.

After fitting a strut under the bridge, we were able to lay the planks across and screw them in. The cross-rails/hand rail were then measured, cut and fixed onto the uprights.

Despite it being August, I was well and truly wet through and starting to get chilly by the end of the session.  I was pleased to get home by mid-afternoon for a cup of tea and a steaming hot bath.

Tansy Beetles

Earlier in August I attended a tansy beetle workshop organised by Buglife.

Tansy beetles (Chrysolina graminis) are small, green beetles that feed predominantly on the tansy plant.  They are a conservation priority species, and are found only in Norfolk and along a stretch of the River Ouse in York.

Many enthusiastic staff and volunteers are involved in trying to save this enigmatic little beetle, and help by managing the riverside habitat, growing tansy plants, and even breeding the beetles in captivity so that they can be released into the wild.

In the morning we had a session learning about the ecology and lifecycle of the tansy beetle. We had the chance to look at specimens at each stage of their life including eggs and larvae.

The eggs are just a few millimetres in size and are a pale yellow/cream colour. They are laid in April/May in small clusters on the tansy leaf, and stand upright.

The eggs hatch in May/June and feed on the tansy leaf. The larvae are small, 'slug-like' creatures with a black head. They go through four 'instar' stages before burrowing underground in July and going through a pupal stage.

The young adults emerge from the ground in August and spend the next few months feeding on the tansy to prepare themselves for their winter hibernation.  From September, they burrow underground and remain in these retreats during the cold winter months.

The adults re-emerge in April, when they mate and lay eggs ... and the cycle starts again.

Tansy beetles live along river banks. Whilst the adults can tolerate flooding, eggs and larvae are vulnerable at this stage. The larvae are also liable to be predated.

Another threat against the beetle is its reliance on tansy as a food plant - any reduction in the amount of tansy has a direct impact on the beetles. Tansy (Tanacetum vulgare) is a perennial plant. As agriculture expands and field margins disappear, tansy is at risk.

Another concern is tansy's close resemblance to ragwort (Jacobaea vulgaris). The leaves are very similar, and though tansy has a more compact flower-head, when ragwort's petals are closed they are hard to tell apart. Ragwort is believed to be toxic if eaten by horses and livestock. It is often removed from fields and meadows as a weed - and tansy is being pulled up by mistake.

Threats to habitat are bad enough, but the situation is exacerbated by the beetles reluctance to fly. Although adults possess wings, they do not use them. Beetles therefore have to walk from plant to plant, and their range is only about 200 meters. Thus, habitat fragmentation can have a large impact by isolating populations of tansy beetles making them even more vulnerable to local stochastic events.

In the afternoon, we had a stroll around Rawcliffe Meadows to search for tansy beetles.  Although it was a little early in the season, some adults had emerged from underground and could be seen on the tansy. 

Other invertebrates were also found in the area. As well as numerous frisky soldier beetles, I saw my first comma butterfly of the season. (The bottom photo shows the butterfly resting on ragwort - compare the flower to the tansy above).

It was a very enjoyable day, and I even came away with my own tansy plant to rear and re-plant in future!