Cattle – Britain’s ecological engineers Stephen Hall • Where did our cattle come from? • What were their wild ancestors like? • What effect have cattle had on the environment? • What is the future for cattle in conservation? Evolution of bovines • Cattle and their relatives (124 species including antelopes, sheep, goats) are grouped in the family Bovidae • These are part of the suborder Ruminantia, animals which chew the cud A and B are possible precursor forms, long extinct The ruminants radiated in step with the evolution of grasses The radiation of the aurochs • First aurochs remains are very recent – only 1.5 – 2 million years ago • This coincided with the Pleistocene period, in which the global climate alternated between warm and cool – and included the Ice Ages • Extensive dry grasslands appeared in many areas • Aurochs seems to have evolved in India and spread from there – Indian aurochs may be effectively a distinct species Probable peak distribution area of aurochs From van Vuure: “Retracing the aurochs” Cattle and humans Aurochs – ancestor of domesticated cattle • Aurochs was domesticated 10,000 years ago in near East / west Asia, India, China and (probably) north Africa • First farmers came to Britain 5000 years ago and brought cattle with them • These cattle were very small – through selective breeding • No evidence the aurochs was ever domesticated in Britain though wild aurochsen might possibly have mated with domesticated cattle Reasons for studying aurochs behaviour • May lead to better understanding of cattle behaviour and of human-cattle relationships • May (possibly) give clues as to how aurochs was domesticated • May help with planning “authentic” ecosystem conservation – what was role of aurochs in British ecosystem before farming began? Demise of the aurochs Aurochs European bison (wisent) • Extinct in Britain 1500 BC (about 1500 years after first farmers arrived) • Described by Julius Caesar in Aurochs finally died out AD Germany but he and others often 1627 in a forest reserve in confused it with European bison Poland (which still exists) What was the natural (pre-human) forest cover of Britain like? • Pre-Neolithic era, 7,000 years ago • The last glaciers had receded 10,000 years ago and Britain became an island 8,500 years ago. • The first farmers (Neolithic people) arrived 5,000 years ago • What was the scenery like in that rather brief pre-farming era? Was tree cover continuous? • Cotswolds rhyme: – A squirrel can hop from Swell to Stow – Without resting his foot or wetting his toe • And from Lancashire: – From Birchen Haye to Hilbre – A squirrel might hop from tree to tree From Fauna Britannica (S. Buczacki) The traditional idea • The general idea has formed that the dominant vegetation in Britain will be closed-canopy forest • Well expressed by Oliver Rackham 1976: “It is supposed that if Britain had been left alone by man the “natural” vegetation would nearly everywhere be oak- dominated forest.” • However this is not asserted by most botanists nowadays Frans Vera’s hypothesis (2000) Proposes that 7,000 years ago the landscape for central and western European lowlands was “half open”, and park-like (photo: Grimsthorpe) Large herbivores • Vera argues that large herbivores were an essential driving force while others say fire and windthrow would have been important • Is the aurochs a candidate as an ecological engineer? Ecological engineers – species that determine the form an environment takes (beavers a possible example) From A. Kitchener: “Beavers” Deducing the ecology of the aurochs • We have information on where in Britain aurochs lived – their archaeological remains have Ordnance Survey map references (called “find squares”) • The general form of the landscape nowadays is probably broadly similar to that of the landscape soon after the glaciers receded for the last time & the aurochs and other species recolonised • If we look at what the landscapes of these find squares are like today, that should tell us something about the habitat (and, from that, the ecology) of the aurochs An “experimental” approach • Our prehistoric species included beaver, elk, wolf, bear, red deer, roe deer , aurochs • By focussing on the find sites of the 6 species of prehistoric Britain that aren’t globally extinct, we can deduce their habitats – if these deductions make sense, then our deductions about the aurochs would carry credibility • Analyse Ordnance Survey 1 km map squares to characterise “find squares” of the seven species SJG Hall (2008) Ecography 31, 187 Aurochs • Current question – was it a woodland animal? • Julius Caesar said it was – but cattle undoubtedly need lots of grass, more than will grow in tree shade • Much more likely it lived on floodplains and meadows, but lack of direct evidence either way • May have been chased into woods by farmers Available archaeological remains from Yalden (1999)* and pers. comms. Before last ice Last ice age and No age Totals age (Devensian) more recent assigned Aurochs 17 75 96 188 Beaver 7 61 0 68 Brown bear 18 68 10 96 Elk 2 7 18 27 Roe deer 0 28 18 46 Red deer 0 47 26 73 Wolf 25 68 8 101 *Yalden, D.W. (1999) The history of British mammals. Poyser, London Examples of find squares - 1 • Find square is to NE of symbol • SK 0954 (near Dove Dale, Derbyshire) • Species found - Brown bear & wolf Examples of find squares - 2 • Find square is to NE of symbol • TL 5467 (Cambs. fens) • Species found - Aurochs Examples of find squares - 3 • Find square is to NE of symbol • TA 1656 (S. of Bridlington) • Species found - Beaver & wolf Map features considered 1. Numerical features – height above sea level, number of contour lines and distance between highest & lowest contour lines (indicates flatness) 2. Landscape features – presence/absence of cliff, lake, woodland Results –how the species differed in the altitudes of the sites where their remains were found Height above Distance between highest sea level (m) & lowest contours (m) Beaver 29 10 Aurochs 30 10 Elk 50 20 Roe deer 50 20 Red deer 55 20 Wolf 61 40 Brown bear 76 46 Statistical test shows there are very probably (at least 95% chance) real effects of species on these variables Landscape features • For each species, how do find squares compare with other map squares in the vicinity? • For each species, compare each find square with a randomly chosen, nearby “control square”. Comparison is particularly clear for this find square: • Find square is to NE of symbol • Species found - Brown bear & wolf • Compared with any nearby control square, find square has steep slopes and caves Beaver 68 find Only 5/68 control A tendency for beaver squares – 13 squares have a finds to be in areas have a lake lake which today have a lake Brown 26/96 find Only 9/96 control A tendency for bear bear squares have squares have a finds to be in areas a cliff cliff which today have a cliff Wolf 18/101 find Only 4/101 A tendency for wolf finds squares have control squares to be in areas which a cliff have a cliff today have a cliff Roe & No differences between find and control squares red deer, elk Aurochs 84/188 find 107/188 control A tendency for aurochs squares have squares have finds to be in areas woodland woodland which today do not have woodland For all these comparisons there is at least a 95% chance these are real effects Conclusions – 1 – lakes, cliffs and woodland • Map squares with beaver finds are significantly more likely to have a lake today, than the control squares • Similar for brown bear and wolf, in relation to cliff These results are as would be predicted • Aurochs is significantly more likely to have been found in areas which lack woodland today • In Britain today, woodland tends to be on the more infertile ground Suggests aurochs was a creature of the more fertile areas Direct comparisons between find squares and control squares for aurochs Find square - Control Statistical median square - test median Height above sea level (m) 30 50 99% chance this is a real effect Distance between highest & 10 20 94% chance lowest contours (m) this is a real effect Implies aurochsen tended to live in the lower-lying, flatter parts of the landscape Conclusions – 2 – height above sea level of find squares Beaver 29 m • The rank order for the non-extinct species is Aurochs 30 m as would be predicted Elk 50 m from knowledge of present -day Roe deer 50 m populations Red deer 55 m • Suggests the aurochs was a creature of low- Wolf 61 m lying areas while the red deer was more Brown bear 76 m upland Conclusions – 3 – flatness of find squares Beaver 10 m • The rank order for the non- extinct species is as would Aurochs 10 m be predicted from Elk 20 m knowledge of present-day populations Roe deer 20 m • Suggests the aurochs was Red deer 20 m a creature of flat areas • Supported by the Wolf 40 m comparison of aurochs find and control squares Brown bear 46 m Ecological findings • Ecologies (at the landscape scale) of prehistoric animals, predicted from present-day landscape features, are consistent with what is observed today • Suggests overall approach is valid • Suggests aurochsen lived in flat, low-lying, highly fertile areas like floodplains – and that it was not a creature of the more upland woodland • The main herbivores of the more upland woodlands were probably red deer Implications • Regarding the Vera hypothesis – this suggests the aurochs may have shaped the low-lying floodplain environment, but probably not the more upland areas • However, a finding that the aurochs was a creature of highly fertile, open areas does have some implications