Rooting for Pigfruit: Pig Feeding in Neolithic and Iron Age Britain Compared
Hamilton, Julie, Hedges, Robert E. M., Robinson, Mark, Antiquity
Rowley-Conwy (2004) contrasts two views of the establishment of Neolithic farming in Britain: (1) the gradual adoption of agriculture by local Mesolithic groups, implying a slow change in the economy with considerable input from (nomadic) hunting and gathering in the earlier Neolithic, versus (2) a rapid change to (settled) agriculture based on cereals and domestic cattle, sheep and pigs. He reviews evidence from Britain, Ireland and southern Scandinavia and comes down in favour of the second interpretation. Moffett et al. (1989) and Robinson (2000) likewise argue for a rapid transition from hunting wild animals to raising domestic stock, and widespread adoption of cereal cultivation from the start of the Neolithic. However, they suggest some of the animals were herded under partly wooded conditions and that woodland food plants, particularly hazelnuts, remained an important part of human diet throughout the Neolithic. Dairying was also important from the early Neolithic (Copley et al. 2005). A rapid change certainly accords with the isotopic evidence from humans of a sharp change in diet between Mesolithic and Neolithic (e.g. Richards et al. 2003).
If there was a change to (settled) agriculture, we might expect rapid ecological change as Neolithic farming populations expanded, clearing primary woodland to create habitats suitable for cereal cultivation and sheep and cattle grazing. Cycles of woodland clearing and regeneration would have created a diverse and more open landscape. Indeed, from the Middle Bronze Age, widespread evidence of settlement becomes common and there were also permanent land divisions (e.g. Yates 1999; Bruck 2000). By the Iron Age, the landscape was very different, with perhaps half of the primary forest ('wildwood') already cleared (Rackham 1986: 72).
Stable isotope values in fauna may reflect some of these ecological effects, particularly the significance of woodland. Noe-Nygaard et al. (2005) showed that on Sjaelland the [delta][sup.13]C values of aurochs collagen became more depleted through the Holocene. This is interpreted as reflecting a 'canopy effect' as woodland cover increased (but see Stevens et al. 2006). Domestic cattle were introduced to Sjaelland several centuries after aurochs became extinct there (so identification is secure), and consistently had less depleted [delta][sup.13]C values, something which is interpreted as reflecting a diet derived from more open habitats. Lynch et al. (2008) showed that, in England, aurochs consistently had more depleted [delta][sup.13]C than contemporary domestic cattle at the same sites, reflecting different habitat use (ecological niche), though they suggest that the difference reflects greater use by aurochs of wetland habitats. At Ascottunder-Wychwood, [delta][sup.13]C values of aurochs and domestic cattle from the pre-barrow phase overlap completely, while those of cattle from the later construction phase are significantly less depleted (Hedges et al. 2007). This would be consistent with a canopy effect reflecting a more wooded feeding environment for aurochs and the earliest Neolithic cattle than for the slightly later--at least 50 years (Benson & Whittle 2006: 329)--cattle contemporary with the mound construction.
Each of the common domestic species (cattle, sheep, pig) could be seen as occupying its particular ecological 'niche', reflecting its requirements and preferences in habitat and resources, and also its effects on other organisms within the occupied landscape (e.g. Sumsion & Pollock 2005: 3). We have no direct experience of, or analogue for, the ecosystems of the fourth millennium BC in Britain, and are all too apt to interpret plant and animal management in the light of familiar semi-natural and agricultural systems. We do know that both environment and agriculture have changed considerably since the earlier Neolithic. In this paper, we highlight a prehistoric shift in the position of pigs in the foodweb, indicated by a change in the pattern of stable carbon and nitrogen isotope values of domestic animals, which may reflect the major change in environment that resulted from taming the wildwood. …