Cat diets in Qalhât and Siraf
As a consequence of their peculiar ecological and behavioral options, cats may be each autonomous predators in addition to depending on meals provisioning by humans23,76. Looking of untamed prey is extra important in rural areas, the place anthropogenic meals is scarcer13. Cats which can be impartial on meals availability by people and their actions, have been proven to exhibit low δ13C and δ15N values and slim worth ranges, which mirror a specialised trophic area of interest that’s primarily based on small wild animals17,23. Cats from city contexts, nevertheless, are anticipated to exhibit a large δ13C worth vary that displays entry to quite a lot of meals sources via people, in addition to excessive δ15N values, particularly if marine sources are available17.
The cats included within the current research come from city contexts. In Siraf, cat stays have been found within the business coronary heart of the city, the realm of the Nice Mosque, which was surrounded by shops36,47, whereas in Qalhât, they have been present in numerous buildings throughout the medieval town43. Thus, it’s anticipated that, both by direct feeding and/or scavenging on human meals scraps, the Siraf and Qalhât cats consumed meals that they’d not be capable of entry in any other case, for instance, meat from massive mammals, similar to sheep and cattle, in addition to fish.
In Qalhât, cats have a 0.4‰ decrease imply δ13C worth, however a 2.8‰ greater imply δ15N worth than the marine fish, which signifies that marine protein contributed considerably to the weight-reduction plan of the cats from this website. The truth that cats have the same imply δ13C worth to the finless porpoise and the small delphinid, however a 1.5–2.0‰ greater imply δ15N worth, helps this interpretation and additional signifies that cats consumed protein of upper trophic stage than these two marine mammals, which generally feed on small fish, crustaceans, cephalopods and different molluscs. Furthermore, though cats and pink foxes goal the identical prey groups77, the pink fox from Qalhât has a 7.0‰ decrease δ15N worth than the imply δ15N worth of the cats, reflecting the consumption of small prey that was of lesser dietary significance for the home cats. Seabirds in addition to rats feeding on each fish and seabirds may have additionally been a part of the weight-reduction plan of the Qalhât cats78,79,80,81. In keeping with our FRUITS mannequin, rats and birds (together with seabirds) could have constituted, respectively, ~ 16% and ~ 21% of the dietary protein consumed by these cats.
Though the imply δ13C worth of the Siraf cats is barely 0.3‰ decrease than the imply δ13C worth of the cats from Qalhât, the 4.8‰ imply δ15N worth distinction between the cats from the 2 websites, suggests the consumption of decrease trophic stage meals by the Siraf cats. This imply worth distinction in nitrogen is statistically important (p < 0.001). Having a 3.1‰ lower mean δ13C value and a 0.6‰ higher mean δ15N value compared to the analyzed fish, cats from Siraf were less dependent on marine protein than the cats from Qalhât. This is further supported by the results of the mixing model (Supplementary Table S6), which suggest that ~ 41% of the protein consumed by the cats from Qalhât derived from marine resources, compared to only ~ 34% for the cats from Siraf, with herbivorous mammals comprising their highest dietary contribution (~ 37%). Therefore, the high mean δ13C value of the cats from Siraf most likely indicates their dietary dependence on animals who fed on C 4 plants, with a small contribution of protein from marine sources for those with higher δ15N values. Different cat diets and local baselines Although both Siraf and Qalhât are coastal sites (Fig. 1) and were major harbors during the investigated periods42,47, cats from the two sites seem to have had different diets. For urban cats, anthropogenic food comprises an important part of their diet13. Hence, the different diets observed in the cats from the two sites may be related to the composition of waste resulting from human food preparation and consumption on the one hand and its accessibility and corresponding feeding opportunities offered in the cats’ respective home ranges on the other. Although it was not possible to analyze human bone samples from either site, archaeological and historical evidence provide information on the availability of food sources in Siraf and Qalhât during the studied periods. Historical information and archaeobotanical evidence indicate that fruit (especially dates), cereals (including wheat, rice, sorghum and millet) and vegetables (e.g., garlic and eggplant) were either cultivated and/or imported in pre-Islamic and Islamic Oman72,74,75,82, including medieval Qalhât73,83. The three rat specimens with lower δ15N values that were primarily feeding on crops, corroborate the presence of such plants at the site and likely their importance in human diets. Archaeological evidence of plant remains, such as dates84, grapes85, millet and wheat86,87, is also present in prehistoric Iran. Crops, such as wheat and barley, were paid as taxes during the medievalperiod88, when water mills close to Siraf were likely used for grinding cereals47. According to the zooarchaeological record, subsistence in Qalhât and Siraf was based on marine fish and domestic animals (Table 1). Hunting of wild mammals and birds was rarely practiced and occasionally larger marine vertebrates (turtles and delphinoids) were captured, probably as a bycatch of fishing activities. The proportion of the domestic animal bones is higher in Siraf, suggesting that fish contributed less to the human diet in this site compared to Qalhât. Historical sources nevertheless support a high consumption of fish both in Oman35 as well as in the coast of the Arabian Gulf34. In Oman, both small fish, such as sardines and anchovies, as well as larger fish, such as sharks and sailfish, were consumed likely after being sun-dried or salted35. Thick layers of fish bones discovered in the domestic building B94, where some of the cat remains analyzed in the present study were also found, may indicate the use of the building for fish processing activities89. Such activities, however, may have also taken place on the beach, providing subsistence opportunities to animals, such as seabirds, rats and cats35. In Qalhât, pelagic fishing seems to have been more important than coastal, inshore fishing (Table 1). The 18 pelagic and four coastal fish from this site have a lower mean δ13C value (− 11.3 ± 1.1‰ and − 12.1 ± 1.1‰, respectively) compared to the four pelagic (− 9.6 ± 0.9‰) and 16 coastal (− 8.9 ± 1.0‰) fish from Siraf (Fig. 2, Supplementary Table S3). In the Arabian Gulf, high temperatures and high evaporation rates lead to hypersaline conditions90,91, which result in the underdevelopment of the mangrove tree populations92,93. A benthic trophic pathway in microphytobenthos sites, which are 13C-enriched compared to mangrove sites94,95, may, thus, account for the higher δ13C values of the fish from Siraf. Moreover, fish from Qalhât, both coastal and pelagic (Fig. 2), have higher δ15N values compared to fish from Siraf (Fig. 3), which indicates perhaps a longer trophic chain in the Oman Gulf (although the δ15N value differences between fish from the two Gulfs could be also attributed to baseline δ15N variations96). The high trophic level of the fish available in Qalhât is seen in the high δ15N values of the cats that probably consumed fish, such as longtail tuna and requiem shark, which are the most represented fish categories from the site37, and/or seabirds and rats that fed on fish78,80,81. The zooarchaeological evidence from both sites indicates also that among the domestic species, sheep and goats were the most important, with a representation in the skeletal assemblage of > 90% (Desk 1). In Qalhât, the vast worth ranges (δ13C: 1.7‰ and δ15N: 2.9‰) for sheep and goats counsel a weight-reduction plan with numerous quantities of C 4 protein (maybe partially at coastal areas and salty grounds) in addition to doubtlessly a dietary contribution of marine protein (particularly for one sheep with a δ15N worth of > 15.0‰). Related isotopic signatures have been noticed within the ovicaprines from the Islamic website of Qalʿat al-Baḥrayn in Bahrain97. The follow of utilizing small fish, particularly sardines, as fodder has been reported for Oman by late thirteenth and fourteenth century CE sources34,35. Though barely extra current in Siraf (3.0%) than in Qalhât (0.6%), cattle have been uncommon, in all probability because of the animal’s measurement that requires bigger portions of water to be sustained in comparison with sheep and goats98,99. Cattle are additionally much less tolerant to consuming saline water100,101. Coastal Iran and Oman have an arid local weather, with low annual precipitation, resulting in freshwater shortages and elevated salinity, whereas nearly all of the freshwater used originates from groundwater resources102,103. Of the 5 cattle from Siraf, three have isotope values that point out a excessive dependence on C 4 vegetation. There’s a excessive variety of untamed C 4 vegetation within the region104,105,106, whereas archaeobotanical proof of millet proves that it has been cultivated within the space for hundreds of years earlier than the studied period86,87. Though, at first look, cattle couldn’t have contributed considerably to the weight-reduction plan of the cats given their low total illustration to the faunal assemblage, it was famous that the Siraf cat stays have been collected within the particles deposited close to the Nice Mosque, extra exactly within the business coronary heart of the city middle characterised by outlets, the place butchers seemingly practiced their craft as nicely. Cattle butchers particularly not solely want massive markets with good gross sales alternatives, but in addition produce a number of offal per capita. Due to this fact, the comparatively massive variety of cats within the excavation space in query in addition to their isotopic signatures may probably relate to the presence of such a guild. Moreover, contemplating that the location has been partially excavated47 and solely 10% of the recovered faunal stays has been analyzed36, it’s seemingly that giant accumulations of cattle bones related to butchery actions, similar to these reported for early Byzantine Sagalassos in Turkey107, weren’t found. An alternate supply of C 4 protein for the cats from Siraf may have been small prey that ate up C 4 vegetation. But, the 2 rats analyzed have decrease δ13C and comparable or greater δ15N values than the cats, whereas the consumption of primarily wild prey would seemingly lead to decrease δ15N values, equally to the pink fox from Qalhât. This brings us again to the earlier level that financial actions within the metropolis middle opened up alternatives for Siraf cats to pay money for meals with a excessive C 4 content material.
The zooarchaeological proof from Siraf appears to counsel a lesser dependence on marine protein by people within the space in comparison with Qalhât. That is additional supported by the isotope values of animals similar to canine and chickens, which have beforehand been thought-about as proxies for human diets97,108,109 (nevertheless, see additionally Refs.110,111) and which have imply δ13C values indicative of a terrestrial weight-reduction plan. The upper δ13C values of the cats in comparison with these two animals (imply worth distinction of about 6.0‰) means that, though the marine dietary sign within the cats from Siraf shouldn’t be as clear as for the cats from Qalhât, cats from each websites appear to characterize a stronger proxy for the marine sources obtainable within the two areas. This has additionally been steered for the Islamic website of Qalʿat al-Baḥrayn, the place isotopic evaluation of each people and fauna revealed that regardless of the big numbers of fish bones on the website, people and rooster (seemingly consuming human meals scraps) have isotope values that point out a primarily terrestrial weight-reduction plan, whereas one cat has a better δ13C worth that signifies a better dietary dependence on marine protein97.
The next dependence on marine protein for cats, in comparison with animals that have been maybe primarily feeding on the waste of human meals preparation and consumption, seemingly signifies that these felids have been roaming freely, scavenging each on human meals scraps in addition to on refuse associated to on-site processing of fish. The clearer isotopic sign of a marine weight-reduction plan for the cats from Qalhât in all probability pertains to extra prolonged fishing actions on this website, which additional included massive pelagic species. Lastly, cats (and animals generally) are considered favorably in Islamic culture112,113, nevertheless, the excessive mortality of juvenile cats in Qalhât together with the presence of skeletal pathologies (together with traumatic lesions) noticed in a minimum of two cats43,45, could also be partially indicative of occasional human violence in the direction of cats. An total decrease human tolerance of cats on this city may have restricted them to the harbor, the place massive fish have been in all probability gutted previous to additional processing. Conversely, the cats that roamed the town middle of Siraf could have frequented primarily the rapid environment of the market place with its outlets, the place the processing and sale of fish could have been one exercise amongst many.
Cat diets at seaport websites
A marine dietary sign has additionally been reported for cats from medieval port cities in Europe. In a latest research, Krajcarz et al.17 analysed cat stays from numerous websites, each coastal and inland, in Poland, Germany and Belgium and reported greater δ13C and δ15N values for the cats from the coastal websites. Krajcarz et al.17 additional reported δ13C and δ15N variations between cats from port websites positioned within the Baltic Sea area (Puck, Gdańsk and Kołobrzeg in Poland) and people discovered within the North Sea area (Bremen in Germany and Nieuwpoort in Belgium), analogous to isotopic worth variations reported for fish by Barrett et al.114, i.e., each δ13C and δ15N values being decrease for the Baltic Sea, the place there’s a bigger freshwater enter. Though cats from Qalhât and Siraf have greater δ13C and δ15N values than the Polish, German and Belgian cats reported by Krajcarz et al.17 (Fig. 4, Supplementary Desk S4), these variations are most probably associated to native isotopic baselines. What stays evident, nevertheless, from each research, is that cats are opportunistic animals that regulate their diets primarily based on the supply of native sources.
