Wildlife and Conservation Review of 2001
An Invertebrate Group meeting at Bedfords Park suffered through drizzle, which suppressed
insectiferousness, but three colonies of the notable ant Lasius brunneus were found in dead wood,
together with the local Woodlouse of damp habitats in the south-east, Lygidium hypnorum. Stag
Beetles are a well-known feature of the Colchester area, though numbers fade out rapidly moving
to the north and cast. So it was quite a surprise when I was handed a specimen taken in a Dovercourt
garden. Much better known as dispersive/immigrant insects are various hoverflies, and during the
month there were repeated influxes, especially of Episyrphus balteatus. Particularly on 31st, strong
evidence for immigration came in the observation of huge swarms coming in off the sea in the
north of Essex.
Over the summer, Writtle College organised a countywide survey of Glow-worms, a beetle which
has long been considered to be very scarce and declining in Essex. The survey involved transect
counts (in July and August) and casual records, together with an overview of recent historical
reports. The results indicated a widespread but localised distribution in the county, and that it was
not as rare as previously supposed (as is so often the case when specific searches for any species
are carried out). The highest single transect count was at One Tree Hill on 11th July, when 76
were recorded (more than a third of all transect records). In addition to the Langdon Hills, there
were concentrations of records on the Danbury Ridge and around Creeksea, but it remained
unreported from several former locations, including Epping Forest. Recording of the habitat
preferences indicated that almost half of the records came from meadowland and scrubland, while
most of the rest were in woods or hedges; nearly 80% of all records came from sites with no
artificial lighting from houses, vehicles and streetlights. Whether this represents direct interference
with and exclusion of the glowing females, or external lighting makes them harder to discern during
a survey is not known. This year's records added to those from the past decade suggest that in
Essex Glow-worms may be present at around 43 sites, a figure which compares rather favourably
with some other counties such as Gloucestershire, with 58 colonies between 1980 and 1990, believed
to be one of the favoured British counties due to the presence of extensive tracts of calcareous
grassland. Not that we should be complacent, especially as the main site is continually under pressure
through the encroachment of development and its associated light spillage.
The discovery of a breeding aggregation of Odynerus simillimus at Alresford was reported in the
last Essex Naturalist. During 2001 Peter Harvey and David Scott carried out further searches, and
found only a few nests scattered along a kilometre of sea wall, but a healthy population of adult
wasps. They appeared to be collecting the larvae of a single weevil genus (Hypera sp.) as larval
food, but there are as yet few clues as to how this important population may be effectively conserved.
Single individual wasps were also located near Southend and at Minsmere, Suffolk, again suggesting
this 'rare' species may be somewhat overlooked.
A third example of 'seek and ye shall find' is the rare bracket fungus, the Oak Polypore. Its
inclusion in the UK BAP has increased awareness of the species, which made funding available for
survey, with the result that it was located in Epping Forest in July. Its habitat is certainly specialised
- shattered old oaks - so it is never likely to be a common species, but it may not be as rare as the
paucity of records suggests.
Breeding bird information was also coming in this month, with the observation of 31 young fledged
from a Little Egret colony in the south of the county. With such productivity, we can look forward
to continued increases in Essex. Presumably the same Wilson's Phalarope as was missed by many
at Old Hall earlier in the year reappeared, and a White Stork flew over Bradwell, and a Cory's
Shearwater past Wakering Stairs. July always sees the start of returning autumn migrants, which
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Essex Naturalist (New Series) 19 (2002)