A collection of wildlife photographs

Friday, 27 December 2013

Fieldnotes from a walk

In July of this year, I took a walk along a diverse marshland on the Hawestwater RSPB reserve in Cumbria. The marshy grassland was a Site of Special Scientific Interest. The intention behind the walk was to see a Small Pearl Bordered Fritillary, Boloria selene butterfly, a Species of Principal Importance under the Natural Environment and Rural Communities (NERC) Act (2006).

As I walked along the path ran next to a small stream, I noticed several Alder, Alnus glutinosa trees. The picture above shows one of their broad, oval leaves. Being located on the bank of the stream corresponds well with their water-loving nature. They also grow best in neutral soils.

Secondly, I spotted multiple Tormentil, Potentilla erecta plants, on the other side of the path, one of which is shown below. They have 4 yellow petals, and leaves which appear to be 5 lobed, because stipules (paired appendages that in this species resemble leaflets) are present at the leaf base. Its leaves are deeply lobed, and leaflets and stipules can be up to 2cm in length. Tormentil is common on acid grasslands, but is not limited to such acidic soil, and can also grow on neutral and calcareous soils. 

Further along the path, as it diverged from the stream, I  recorded a cluster of Red Clover, Trifolium pratense individualsThis looks a little like Zigzag clover, but the three leaves growing directly beneath the flower head are not present in Zigzag Clover. The Red Clover also has a hairy calyx tube (the tubes that support the floral leaves- shown in the photograph), whereas the Zigzag Clover has hairless calyx tubes. 

A few strides further, I stumbled upon a Cuckoo-flower, Cardamine pratensis- a type of Bittercress from the Cabbage family (shown in the image below). Its 4 pale-pink petals with obvious venation, are comparatively much larger than other Bittercress species. Cuckoo-flower has high water requirements  and also grows well on neutral soil.

Additionally, an abundance of Creeping Buttercup, Ranunculus repens individuals were found (shown in the background of the photograph above). This species is aptly named after its creeping overground stems, which enable it to rapidly establish clones through asexual vegetative propagation. However, Creeping Buttercup can also produce sexually through seeds. Most species from the Buttercup family have flowers with 5-petals.

The damp conditions also enabled Soft Rush, Juncus effusus to comprise a large proportion of this assemblage. Soft Rush are characterized by smooth green stems. Its stems are 'side-flowering', with a single inflorescence growing from their side.

Following the path further, I finally arrived at the marsh. Looking out over the marsh, which was waterlogged in parts, I could see a diverse botanical assemblage.
Accompanying the dense stands of Soft Rush, Juncus effusus, I could see multiple Marsh thistle, Cirsium palustre individuals, with their characteristic spiked stems, distinguishing them from Creeping thistle, Cirsium arvense. Marsh Thistle's particularly square flower are also a distinguishing feature, compared with other thistles. As its name suggests the Marsh Thistle grows well in damp soil.

Then finally, I clamped eyes on the species I had set out to find! Two Small Pearl Bordered Fritillaries were flying between rush and thistle. Occasionally the two males spiralled around each other, in graceful, yet furious competition for territories. In the photograph to the right, one of them rests on the stem of a Soft Rush. Although not shown here, they are characterized by 7 'pearls' bordering their underwing, framed by black chevrons, as opposed to red chevrons found on the underside of the Pearl Bordered Fritillary, Boloria euphrosyne. 

The Small Pearl Bordered Fritillary species can occur in this habitat, because it is supported by the diverse flora. The butterfly's food plants include Marsh Thistle, and many species of Violet. The foodplants of the Small Pearl Bordered Fritillary caterpillars are Marsh Violet and Common Dog Violet. 

Walking a little further into the marsh, I recorded several Early Marsh Orchid, Dactylorhiza incarnata plants. Both photographs below illustrate Early Marsh Orchid individuals, highlighting that this species has the most variable colour of its flowers, of any UK orchid species. Although the flowers look similar to the Common Spotted Orchid, Dactylorhiza fuchsii, which could feasibly occur in such a damp habitat, the Early Marsh Orchid lacks the spots on its leaves, that Common Spotted, Heath Spotted and Early Purple Orchids have.

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