Wildlife and conservation review 2003
these, especially feeding at Ivy, most years since 1992, but always in small numbers until this year.
In 2003, up to 7 individuals were seen at any one time, between 15th August and 17th September.
Marking revealed that at least 55 individual flies were involved, with the maximum recorded
longevity of males being 2 days and females 16 days. Furthermore the sex ratio was highly skewed,
as only 4 males was recorded as opposed to 51 females. It is hoped that more details of this marking
experiment will be published in Dipterists' Digest in due course. While it is believed that our
population is established locally, the good number of other records, especially in north-east Essex,
may have resulted in part from new immigration.
Other invertebrate news came from south Essex, where the Minotaur Beetle Typhaeus typhoeus
was reported from Two Tree Island (there are few other records from this sector of the county), and
the Cellar Spider Nesticus cellulanus was found in the fissures of the Southend Cliffs landslip.
Only its second Essex record, this spider is more usually found in other damp, dark habitats such as
mines, caves, cellars and hollow trees.
Pam and Peter Wilson continued their borrowdyke survey work, this year focusing upon the
Crouch and Roach. They located several very important stretches, which held good populations of
Lagoon Sand-shrimp Gammarus insensibilis, plus new sites for Lagoon Sea-slug Tenellia adspersa
(the eighth time they have found this in the survey, doubling its number of known UK sites) and
Starlet Sea-anemone Nematostella vectensis (all three being specially protected species). In
addition, other rare species located included the beetle Berosus spinosus (RDB3) and the soldier-
fly Stratiomys longicornis (RDB2), both at several sites.
A rather worrying feature of the late summer was an apparent resurgence of Elm die-back, due to
Dutch Elm Disease. This may well be related to the dry conditions, as the fungal hyphae block the
water-conducting vessels within the trees; another factor though could be the recent arrival of the
Lesser Elm Bark-beetle Scolytus multistriatus in Essex. As a smaller species than the usual culprit
S. scolytus, it can invade and infect trunks of a much smaller diameter.
September birds typically included a number of scarce migrants, including 4 Wrynecks across the
county, Barred, Icterine and Yellow-browed Warblers at the Naze (the latter being our only
contribution this month to a substantial early arrival in Britain), Red-backcd Shrike at Cudmore
Grove, and perhaps as many as 4 Ortolan Buntings at Sewardstone. A record-breaking movement
of Pectoral Sandpipers through Britain included 5 in Essex (3 at Abberton alone), and Red-
necked Phalaropes were seen at three sites. Rainham Marsh supported up to 45 Yellow-legged
Gulls, a typical post-breeding build-up, and a single Raven was seen flying over. And a White-
headed Duck appeared again at Abberton amongst the Ruddies, part of a small influx (or mass
escape bid) in East Anglia and the south-east.
But probably the most bizarre wildlife record of the month was the discovery in Colchester of a
paedomorphic Smooth Newt. This condition, formerly referred to as neoteny, involves the retention
of juvenile characters in the adult; it is of rather rare occurrence, and the individual concerned
proceeded to Star on Anglia TV and in the local press.
No doubt in response to the preceding summer weather, talk of global climate change and its
impacts was everywhere in the media. A few examples cited included:
• The soaring Badger population (from 270 to 350 thousand in 10 years nationally), as a
result of wilder, wetter autumns producing more earthworms
Essex Naturalist (New Series) 21 (2004)
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