“Wolves and wildcats: mammalian response abrupt climate change at the end of the last Ice Age”.
Prof Danielle Schreve spoke to a packed room about her research at Gully Cave in Ebbor Gorge, a NNR in Somerset. This previously unexcavated cave is formed in Carboniferous limestone, on a SW facing slope of the Mendips in a steep sided ravine, and was almost completely filled with sediment and overgrown.
To date, over 120 tons of sediment have been carefully excavated and passed through a half-millimetre sieve to extract all bone fragments. Large mammal finds and artefacts are surveyed in 3D and the cave has been laser-scanned so that a virtual reconstruction is possible.
Thousands of teeth and bones of small mammals have been identified, some of which are extant today but not currently found in Somerset e.g. mountain hare and common vole. Some were of cold climate tundra taxa including the narrow skulled vole, northern vole and various lemmings. The bones of larger mammals, including a complete articulated hind limb of aurochs, were also identified as well as bones of red deer and reindeer, including many broken leg bones with green bone and impact fractures. Does this indicate early humans were after the bone marrow? Some bones are brown which may be due to proximity to fire. Charcoal has been recovered in the cave but as yet no sign of a hearth.
Deeper down, the sediments are sterile and coarser with chunks of broken flowstone. These represent the Dimlington Stadial 26,000 to 13,000 years BP, the last ice advance of the Pleistocene. At 25,000BP, the cave was occupied by brown bears, including a very old individual, sub-adults and several cubs. The bones show signs of being gnawed by a spotted hyaena. Below were discovered numerous remains of reindeer, bison, horse and huge red deer, dating to the middle part of the last glaciation (40-50,000 years BP), as well as a struck flint flake, evidence of the presence of Neanderthals or Homo sapiens.
Prof. Schreve highlighted the importance of the cave for understanding how mammals responded to very abrupt climate change at the end of the last Ice Age and the position of the gorge as a potential, sheltered refugialarea for warm-adapted species during times of climatic deterioration.