Photograph of a dog burian in Can Roqueta.
Sample of the morphological variability of dogs in Can Roqueta since late Bronze Age.
Experts from the Prehistoric Studies and Research Seminar (SERP) of the University of Barcelona led a study based on the analysis of the remains of thirty-six dogs from the Bronze Age and the First Iron Age found in the site of Can Roqueta (Sabadell). The study, published in Journal World Prehistory, concludes that the food intake of these animals 3,500 years ago was conditioned by human activities, as it happens nowadays. In the Neolithic, human communities in the northwest of the Iberian Peninsula modified the nutrition of these carnivorous animals by introducing cereals and legumes in their diet. This practice remained the same in dogs from the Bronze Age and the First Iron Age in Can Roqueta, but with innovations such as the presence of new cereals, particularly millet.
In ancient times, dogs fed from and bred due to their skills in protecting places and herds, as well as in hunting. Most of the dogs found in Can Roqueta were fed by the human community in a mixed manner: the diet was based on cereals with gluten and legumes that were probably transformed into flour, when mixed with water and were combined with animal-origin proteins. The great difference regarding what researchers observed in previous stages is the introduction of a gluten-free cereal in the diet: millet. This new cereal, introduced around the middle of Bronze Age in the northwest of the Iberian Peninsula, was an important change in the economy of the villages, since it allowed an intense agricultural exploitation over the year and resulted in a source of food that was more digestive than traditionally-grown cereals with gluten.
Researchers have also seen differences between the dogs in Can Roqueta, some had a carnivorous diet and others a strictly vegetarian one, which indicates a diversification of the function of the dog after the Iron Age. There is also a morphological diversification: there are big dogs registered, probably resulting from hybridization with wolves, and other smaller and graceful dogs. The general increase in the number of sheep and goats in herds in the transition period between the Bronze Age and the Iron Age could cause the appearance of other kinds of dogs that were used for other works. This class differentiation in dogs coincides with a growing social complexity and an increase in human mobility.
About eight-one canines were buried in Can Roqueta since the beginning of the Bronze Age, a period when animal burials multiplied as a result from their close relationship with humans. Sometimes, dogs were sacrificed and placed inside human graves. Researchers note that "dogs became our ancestors' friends to the point that they integrated in the symbolic and emotional world of human communities".
The published study analyses the values of carbon (δ13C) and nitrogen stable isotopes (δ15N) that were left in dog bones in Can Roqueta in order to know about their diet. The study completes two previous studies on the function of dogs in the northwest of the Iberian Peninsula, one on dogs from the Neolithic and another on dogs from the early Bronze Age. The current study has been carried out within the framework of the project of the University of Barcelona "Families, neighbours, and foreigners in recent prehistory in the Catalan pre-littoral", funded by the Spanish Ministry of Economy, Industry and Competitiveness. The study was led by Silvia Albizuri and F. Javier López Cachero, from the Prehistoric Studies and Research Seminar of the UB, led by Josep Maria Fullola, and Aurora Grandal, from the Isidor Parga Pondal University Institute of Geology of the University of La Coruña.
Article reference:
Silvia Albizuri, Aurora Grandal d'Anglade, Julià Maroto, Mònica Oliva, Alba Rodríguez, Noemí Terrats, Antoni Palomo, F. Javier López Cachero. "Dogs that ate plants: changes in the canine diet during the late Bronze Age and the first Iron Age in the northeast Iberian Peninsula", Journal World Prehistory, March, 2021. DOI: https://doi.org/10.1007/s10963-021-09153-9
