A Special Field

Exton 'Goosefields' County Wildlife Site - survey by Malcolm Randle

The field is situated at grid reference SX 98142 86325, beside the River Exe estuary with only the railway line to Exmouth in between. It has been designated as a County Wildlife Site (CWS) by the Devon Biodiversity Records Centre which is operated by Devon Wildlife Trust. A CWS is a site of county importance as a particular wildlife habitat or for special wild plants or animals. It is an informative label and not a statutory one such as an SSSI. As a CWS is included in a Council’s local plans it will be taken into account before any development can take place there. There is no obligation on an owner to manage the site in a wildlife-friendly way but if they do then it may increase their eligibility for land management grants.

 

On 23rd July 2009, the field was the subject of a survey by a surveyor from the County Wildlife Sites office. It was determined that it was still of CWS status due to the presence of over 0.5 hectare of coastal saltmarsh and the existence of nine Devon notable species. The survey revealed a total of 81 plants, nine insects, five-birds and two mammals. These included species recorded in a previous survey in 1993. The owner of the field lives in a house opposite and allows public access. During the summer months paths are mown to allow people to walk around and also a complete cut is usually done in late June. A brook, known as “Gilbrook” flows alongside the field. This rises on Woodbury Common and runs down through Woodbury and across the fields to Exton before making its entry into the River Exe. 

Grasses and flowers near the field entrance in May

During 2017, between spring and autumn, I made a survey of the Woodbury section of the Gilbrook then in 2019 I did a similar survey of the Exton field over the same period.   I spent several hours each month noting and taking photos of all the various species of plant and insect that I found and comparing them with the survey list, always hoping to find some un-recorded species.

 

In the winter, particularly the most recent one, the field is water-logged with rainwater as well as tidal water, but the paths are just about negotiable. In May and June however, the field is an absolute delight with an abundance of wildflowers and grasses. These grow in a fairly wide band, mainly around the perimeter and include many grasses, hemlocks, hogweeds, cow parsley, ox-eye daisies, nettles and crosswort to name but a few.

Crosswort (Cruciata laevipes) growing amongst nettles

Along the edge of the Gilbrook large swathes of red campion grow and by late summer there are sizeable clumps of common fleabane to be found. These attract a variety of insects, in particular butterflies and hoverflies. Of course, many of these plants can also be found beside most verges and field boundaries. The centre part of the field is pretty marshy most of the year, particularly in winter and early spring when it’s not really negotiable. From late June it becomes a little more accessible and by August it becomes easily reachable, unless it has been a very wet summer.

Some of the Red Campion bordering the Gilbrook

For me it is the saltmarsh and maritime species which make the field so “special”. These include a variety of grasses such as:  marsh foxtail (Alopecurus geniculatus), common saltmarsh grass (Puccinellia maritima), annual sea-blight (Suaeda maritime), saltmarsh rush (Juncus gerardii), sea arrowgrass (Triglochin maritime), sea club rush (Bolboschoenus maritimus), sea couch grass (Agropyron pungens), sea plantain (Plantago maritima) and sea rush (Juncus maritimus). Whilst most of the grasses are similar to their country cousins, they appear sturdier and more resilient, which is not really surprising as they have to endure a harsher environment.

 

As well as the grasses there are a number of flower species that help to complete the special nature of the field.  One of these grows right beside the central path, that being sea aster (Aster tripolium) which is a miniature version of the flower we are more familiar with, namely the Michaelmas-daisy (Aster amelius). Other plants in the aster family that can be found are sea mayweed (Tripleurospermum mantimum) with a white daisy like flower, greater sea spurrey (Spergularia media) having a pretty little pinkish/white flower about one cm across, and lesser sea-spurrey (Spergularia marina) which has a similar but even smaller flower. They are all members of the pink family Caryophyllaceae. Also found is sea milkwort (Lysimachia maritima), which I will mention again in the following paragraph. Apart from the sea aster I have yet to find any of the others but will be looking hard for them this summer.

My own personal contribution was the discovery, on 30th July last year, of a tiny little flower which, at first sight, looked like a mossy growth along the middle of the main path. On closer inspection I could see that it consisted of numerous tiny pink flowers in a mat of fleshy leaves (see photo). Initially, it was thought it might be sea milkwort, a species in the family Primulaceae which does appear in the 2009 survey list but, when compared, the flowers were not similar. Eventually, after showing the photo to some local botanists, it was finally identified as sea heath (Frankenia laevis) in the family Frankeniaceae. It did not appear in the 2009 survey list but maybe the surveyor just missed it, or it has arrived there since. It is classed as relatively rare in Britain.

Sea heath (Frankenia laevis) (close up inset)

I did also find some other plants which were not in the list, namely crosswort (Cruciata laevipes) (see photo and also (9) below) and common mouse-ear (Cerastium fontanum) (13 below) but they are not maritime specific, and the date of the survey (9th July) was outside their flowering period.

Wild or dog rose (Rosa canina)

I have to say that it was the insect life that first attracted me to the field due to their abundance. Particularly prolific were hoverflies and butterflies but, of course, these can be found in most places where there are flowers, and none were specific to maritime locations. However, an insect that was particularly prolific was the lesser marsh grasshopper (Chorthippus albomarginatus) (see 8) below. It is similar in appearance to the meadow grasshopper i.e. straw brown or light green, but less brightly coloured. In August and September, the field was absolutely hopping with them!  Its habitat is described as “the landward side of sand dunes, also saltmarshes and shingle banks, low lying pastures and on the grassy slopes of dykes”. 

 

An insect which I hadn’t previously seen was the sixteen-spot ladybird (Tytthaspis sedecimpunctata) (see 10 below). They were to be found in good numbers, mostly on the fleabane. Coloured creamy yellow the spots were distributed fairly evenly on the wing cases (elytra) and the thorax with what looked like three joined together along the outer edge of the wing case, which is counted as one spot. This little beetle is said to be an inhabitant of the grass layer occurring on dunes, inland dunes and sandy shores. Apart from their colour the other most significant feature (or perhaps insignificant) was their size as they are only two to three millimetres long. It does not appear in the 2009 survey list of insects but then not many insects are mentioned at all.  I suspect the surveyor was not really looking at insects much.  There were also several day flying micro moths to be seen none of which appeared in the survey. One of these was particularly attractive and was usually found on the fleabane (see (3) below).  I eventually managed to identify it as Apodia bifractella whose food plants are common fleabane and sea aster. The moth has a wingspan of 9-12 mm and flies between July and early September. It overwinters in the larval stage, the larvae being active from October to April. They feed within the seed heads of their host plant and pupation takes place within the seed head.

Most of the hoverflies I saw were in the fairly widespread Eristalus species but there was one attractive little hoverfly which was usually to be seen whenever I visited, namely Sphaerophoria scripta, known as the ‘long hoverfly’ (see 4 below).  It mainly feeds on nectar and pollen of various species of the Asteraceae family which, of course, includes fleabane and sea aster.  The larvae, as with many hoverflies, feed on aphids.   Needless to say, there was also a number of bee species to be seen.

  1. Sea aster (Aster tripolium)

  2. Common blue butterfly (Polyommatus icarus)

  3. Micro moth (Apodia bifractella)

  4. Long hoverfly (Sphaerophoria scripta)

  5. Hoverfly (Eristalus tenax)

  6. Brown argus butterfly (Aricia agestis)

  7. Beetle (Neocrepidodera transversa)

  8. Lesser Marsh Grasshopper (Chorthippus albomarginatus)

  9. Crosswort (Cruciata laevipes)

  10. Sixteen Spot Ladybird (Tytthaspis sedecimpunctata)

  11. Common vetch (Vicia sativa)

  12. White dead nettle (Lamium album)

  13. Common mouse-ear (Cerastium fontanum)

  14. Lady's smock or Cuckoo flower (Cardamine pratensis)

  15. Sea heath (Frankenia laevis)

Malcolm Randle