Tuesday 17 July 2018

Micromammals from Byzantine agricultural sites in the Negev Desert.

The Negav Desert, in fact a mixture of desert and semi-desert terrains, covers an area of about 13 000 km² in southern Israel. The area has an agricultural economy today, reliant on extensive irrigation projects and modern industrial farming methods, but for most the history of Human settlement in the area has been considered to arid for extensive farming. However, during the Byzantine Period, roughly 300-700 AD, an extensive system of terraced farming, and accompanying irrigation systems was present in the area, probably associated with a slightly wetter climate. Such an agricultural system is likely to have had a profound effect on local landscapes and ecosystems, though relatively little is understood about this.

In a paper published in the journal Royal Society Open Science on 10 January 2018, Tal Fried, Lior Weissbrod, Yotam Tepper and Guy Bar-Oz of the Zinman Institute of Archaeology at the University of Haifa describe the results of a series of excavations at dovecotes at Byzantine settlements in the Negev, in which sediments were sifted for micromammal remains, in order to understand the nature of small Mammal communities in the area during this period.

Dovecotes are a common feature in Byzantine settlements in the Negev, and are thought to have been used to produce not just Pigeon, Columba livia, meat and eggs, but also fertiliser for fields in areas where the soil was often very poor. The structures excavated were identified as dovecotes by the large amounts of both Pigeon bones and dung present, and were from two separate settlements, Shivta and Sa’adon.

Fried et al. found the micromammal communities of the Byzantine Period in the Negev Desert were dominated by Gerbils, Gerbillus spp., and Jirds, Meriones spp , (together Gerbilids), with a variety of other species present, including Lesser Egyptian Jerboa, Jaculus jaculus, House Mouse, Mus musculus domesticus, Asian Garden Dormouse, Eliomys melanurus, Black Rat, Rattus rattus, Mole Rat, Spalax ehrenbergi, Sand Rat, Psammomys obesus, White Toothed Shrew, Crocidura sp., and Etruscan Shrew, Suncus etruscus. All of these bones were from juvenile or young adult individuals, and many showed signs of acid digestion, consistent with having spent time in the stomach of an Owl of other Bird of Prey, suggesting that they had not actually been living in the Dovecotes but in the surrounding area.

Typical digestion marks on skeletal remains of micromammals from the structure A dovecote in Sa’adon on elements of the femur (a,b,d,e), mandible (c) and tibia (f ). Fried et al. (2018).

All of these species are present in the Negev today, but with rather different distributions. Modem micromammal communities around agricultural settlements are dominated by Mice and Rats, whereas both Gerbils and Jirds are found in more arid areas away from Human settlements, with Gerbils favouring sandy soils and Jirds favouring loess soils. 

Fried et al.'s data seems to suggest that Byzantine agriculture provided a more suitable environment for Gerbilids than modern farms (probably suggesting that they were on the whole drier than the modern farms). However the population size of Rats and Mice does appear to have been slightly larger than that in the same area both before and after the settlements were present, indicating the presence of these farms did make the desert more suitable for these species than it was in its untamed state.

See also...

https://sciencythoughts.blogspot.com/2017/12/understanding-dispersal-of-rockwood-and.htmlhttps://sciencythoughts.blogspot.com/2017/08/petaurista-leucogenys-how-japanese.html
https://sciencythoughts.blogspot.com/2015/08/evidence-of-cereal-cultivation-by-sea.htmlhttps://sciencythoughts.blogspot.com/2015/05/flying-squirrels-from-late-miocene-of.html
https://sciencythoughts.blogspot.com/2015/05/philistine-and-hellenistic-remains-from.htmlhttps://sciencythoughts.blogspot.com/2014/12/two-new-species-of-pinworms-from.html
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