Ivell’s sea anemone – Britain’s most recent extinction

Ivell’s sea anemone (Edwardsia ivelli) is the only know endemic animal to be known to have gone extinct (probably) in Britain in modern times. It has not been found since 1983 despite detailed searches at its only known site, Widewater Lagoon in West Sussex.

From Few and Far Between: On The Trail of Britain’s Rarest Animals by Charlie Elder. An excellent and amusing read,

“It was the summer of 1972, and Oxford zoology graduate Richard Ivell had risen early, eager to press on with his research. He stepped into his backyard to sort through several buckets of mud and brine collected the day before. These thick, stinking sections of sediment dug from Widewater Lagoon in West Sussex provided raw material for his master’s thesis on the ecology of brackish environments. Sandwiched between land and open sea, lagoons are vulnerable and yet hostile habitats, where fluctuating temperature and salinity test life forms to the limit. Landlocked Widewater, a shallow stretch of water running for nearly a mile next to the A259 near Worthing, provided the perfect place to study. Bordered by the back gardens of houses to the north and beach huts to the south, the narrow basin is kept topped up by rainfall and by the sea that percolates through its shingle banks during high tides. Various kinds of prawns and cockles live within its confines, and some of these creatures would have been scooped up in the samples Richard had collected just a couple of metres out from the seaward edge. The mud had settled overnight within the buckets, each surface a dark brown disc submerged under a lens of clear salt water. In the quiet, life had stirred.

Forty years later, the memory is still vivid, as Professor Ivell told me on the phone from the animal biology institute in Germany where he now works. Peering over the rim of one of the containers, he couldn’t believe what he saw. ‘In the stillness, small anemones had emerged and their lightly banded tentacles were spread out flat against the sediment. The thing I remember is how beautiful they were, and how fragile, like tiny flowers in a desert. It was quite amazing to see.’Unable to identify the small burrowing species, he showed a colleague at Oxford University, Richard Manuel. If the catchphrase among Anthozoa taxonomists is ‘know thine anemone’, then Dick was the person to ask. An expert in such marine life, he realised that these specimens, no more than a couple of centimetres long, buff coloured with twelve transparent tentacles, the outer nine marked with cream bands, were new to science.”

Pioneering wildlife photographer

Bittern_-_Emma_Turner

In 1905, Emma Turner built a houseboat on Hickling Broad, still today the largest reed-bed in England, in Norfolk to photograph the wildlife, while lying in the marshes her lens poking out from the reeds, Six years later she managed to photograph a young Bittern in the nest proving that Bitterns were breeding again in Norfolk having been driven to extinction in Britain in the late 1800s. This BBC Radio 4 programme tells the remarkable story of Emma Turner a pioneer of bird photography (1866-1940); who spent some 20 years on her boat, she nicknamed ‘Water Rail’ (after the first photograph she took in the Broadlands).

Darwin at Glen Roy

Parallel Roads

Darwin studied the unique geology of Glen Roy when he returned from the Beagle voyage. The valley is noted for the geological puzzle of the three roads (“Parallel Roads”) – lake terraces that formed along the shorelines of an ancient ice-dammed lake. The lake existed during a brief period (some 900-1,100 years in duration) of climatic deterioration, during a much longer period of deglaciation, subsequent to the last main ice age (The Devensian). From a distance they resemble man-made roads running along the side of the Glen, hence the name.

Darwin made his “Gigantic Blunder” on his visit in June 1838 by drawing on his recent findings in South America during the Beagle expedition and believing that the shorelines were of marine origin. This was contradicted by Louis Agassiz’s Glacial theory of 1840 which postulated that the shorelines had been cut by freeze-thaw processes of lake ice during the maximum extent of glacial ice in the climatic reversal known as the Younger Dryas / Greenland Stadial 1 or locally the Loch Lomond Readvance. Four decades after his 1839 paper and shortly before his death, Darwin conceded that he was incorrect. Wikipedia writing ‘I do believe every word in my Glen Roy paper is false’.

It is now known that the feature is the remains of ancient shorelines formed at the end of the last ice age when an advancing glacier pushed up the water level of a lake that filled the valley.

Fraser Darling’s deer studies

herd of red deer fraser

Fraser Darling’s study of the red deer population of Dundonnell, in Wester Ross between 1935 and 1959, gave a detailed picture of the reproduction, social behaviour and habitat of deer. His book “A Herd of Red Deer” transformed modern ethology and revolutionised the way that British wildlife was studied.

Describing the role of barefoot walking in Darling’s deer research, Robert Macfarlane writes in “The Old Ways”:

Darling’s unconventional methods: instead of considering the deer as reflex creatures, displaying learnt but versatile reactions to their environment, he proposed a dynamic model of the herd in which each deer’s sensed experience of its landscape shiftingly informed their way of living. Darling’s contention, in short, was that deer ‘were capable of insight’, and his insight into their insight emerged from his decision to go sympathetically barefoot.