4.1. Landscape Reconstruction and Freshwater Ecosystems at Borsodivánka
We provide the first zooarchaeological data for a better understanding of the freshwater ecosystem and surrounding landscape of Borsodivánka based on fish and microvertebrates. Here, we combined data from micromammals, reptiles, amphibians, and fish as an essential tool for landscape reconstruction around the site during the Bronze Age. At Borsodivánka, a mosaic landscape is evidenced by the coexistence of a well-developed forest, open areas, and a mature freshwater inland ecosystem.
The micromammals present in the Borsodivánka assemblage support the presence of this varied and patchy landscape. The wood mouse (
A. sylvaticus) inhabits forests, grasslands, and cultivated fields, tending to seek out more wooded areas in winter. The European mole (
T. europaea) is typical in temperate habitats with soils deep enough to allow tunneling. These include arable fields, deciduous woodland, and permanent pasture. The voles of the group
M. arvalis/agrestis are found in a range of habitats, including meadows, field borders, plantations, woodland verges, clearings, upland heaths, dunes, marshes, bogs, and river banks, and tend to prefer wet areas [
18]. In addition, one species of snake present in Borsodivánka, the Aesculapian ratsnake (
Z. longissimus), prefers forested, warm but not hot, moderately humid but not wet, hilly or rocky habitats with proper insolation and varied but, not sparse vegetation that provides sufficient variation in local microclimates, helping the reptile with thermoregulation. Most of their range is typically characterized by relatively intact or fairly cultivated warmer temperate broadleaf forests, including the more humid variety, such as along river valleys and riverbeds (but not marshes) and forest steppes [
45].
In conclusion, the microvertebrate assemblage in Borsodivánka presents several species indicating a well-developed forest, shrubland, and grassland. According to the archaeobotanical data, land for farming must have been available due to the occurrence of cereals in Borsodivánka (
T. spelta,
T. monococcum,
H. vulgare vulgare, and
T. dicoccon) [
14]. The presence of the mouse (
M. musculus), as well as ruderals (such as
Sambucus ebulus and
Hyoscyamus niger) and the presence of cattle dung with reed (cows could have been kept close to the tell), would indicate anthropogenic areas around the tell.
Based on our research, the presence of a mature freshwater inland ecosystem in Borsodivánka is evident. Reptiles such as the grass snake (N. cf. natrix) and the European pond turtle (E. orbicularis); amphibians such as toads (Bufo/Bufotes sp.) and frogs (Rana sp.); and micromammals such as the European water vole (A. amphibius) support the reconstruction of this landscape. However, the fish assemblage provided the most information about this freshwater ecosystem in Borsodivánka.
Cyprinidae species are the most common in the assemblage, such as the roach (
R. rutilus), the common carp (
C. carpio), the common chub (
S. cephalus), and the common nase (
C. nasus). The common carp (
C. carpio) and the other cyprinids are typical of stagnant, muddy waters of relatively high temperatures and concomitant low rates of dissolved oxygen [
24,
46].
The second-most frequent family is Esocidae, with just one species, the northern pike (
E. lucius). Pikes like cool water but have a wide range of environmental tolerances concerning water temperature and clarity, as well as varying concentrations of dissolved oxygen [
24,
46]. Percidae is less present with two species, the European perch (
P. fluviatilis) and the pikeperch (
S. lucioperca). The European perch lives in slow-flowing rivers, deep lakes, and ponds. It tends to avoid cold or fast-flowing waters, but some specimens penetrate waters of these types, although they do not breed in this habitat. The pikeperch is characteristic of clear waters with hard substrate oxygen [
24]. Across the assemblage, only one specimen corresponds to the Siluridae family and belongs to the Wels catfish (
S. glanis). Catfish mostly prefer deep and warm waters with rich aquatic vegetation oxygen [
23].
Similar taxa are present in other Bronze Age Hungarian sites such as Százhalombatta [
6]. Our study of Borsodivánka is in agreement since cyprinids and pike represent the majority of the assemblage. Other species, such as pikeperch and catfish, are generally less frequent [
7]. However, we recovered remains of common nase, common chub, and European perch for the first time, updating the list of known taxa in Hungary during the Bronze Age. Finally, the Salmonidae family is present in the assemblage with one element, excluding that this fish association fits into the Trout Zone of the river [
47,
48]. This association with mostly nase, European perch, common carp, pike, and Wels catfish characterizes a mature river system with deep and slow-flowing waters. It indicates that Borsodivánka was located close to the downstream (Nase and Bream zones) with a maximum water temperature of 20–25 °C [
47,
48].
4.2. Borsodivánka Environment in the Carpathians Context during the Bronze Age
Traditionally, studies based on landscape reconstructions argued that, in general terms, the dry and warm climate of the Late Neolithic and Copper Age gradually became wet and cool during the Bronze Age, promoting a well-developed forest in this Carpathian region [
9].
However, recent studies in Hungary indicate a more complex climate evolution scheme in the Carpathians. Palynological studies confirm the persistence of wooded steppe in the Great Hungarian Plain during the Holocene [
2]. The authors also described the presence of typical temperate summergreen tree taxa from floodplain forests, such as
Corylus,
Fraxinus,
Quercus, and
Ulmus, which we also assume for Borsodivánka. The occurrence of the genus
Alnus indicates the vicinity of a water source, such as a lake or river. However, the presence of the common reed (
P. australis) indicates nearby water sources, since this species is an aquatic grass [
5]. The authors also observed an increase in herbaceous taxa, principally Graminae, characteristic of steppe and meadow communities, suggesting that human impact may have been a major factor in the decrease in tree cover [
2].
In the Eastern Carpathians, other research indicates rapid climatic changes during the Middle to Late Holocene transition, noting a temperature decrease that agrees with other Northern Hemisphere records. Abrupt temperature declines occurred at 6.2, 5.4, 5.0, 4.7, and 4.2 cal ka BP in this region, featuring a prominent decrease from 5.4 to 4.2 cal ka BP [
3].
The occurrence of plants related to human land use and the increase in emergent wetland plants is recorded after a well-expressed 4.2 cal ka BP cold event. During the Middle Bronze Age (around 1600 BC), some researchers postulate a link between the landscape and societal changes in Hungary during the Bronze Age [
3], indicating a period characterized by fluctuating humidity but a relatively warm climate between 4 and 3.5 cal ka BP. These climatic conditions were appropriate for agriculture and demographic growth. One prominent feature that characterizes the Middle Bronze Age is the formation of the named tells or stratified settlement mounds [
1,
4]. Between 3.55 and 3.45 cal ka BP (Koszider period), a short-lived environmental deterioration and a decrease in soil activity occurred, contributing to the demographic increase inferred for this period. The authors conclude that environmental variations were associated with societal changes during the Middle Bronze Age, indicating that settlement pattern changes reflect climate conditions.
On a regional scale, this climate evolution scheme is also complex. Studies based on isotope analysis indicate periods of dry/warm and humid/cold conditions between 3.2 and 3.9 cal ka BP at Trió Cave and Ordacsehi-Bugaszeg (Southern Hungary) [
5]. The period between 3.9 and 3.7 cal ka BP begins with a peak representing a period of high humidity. However, a dry period is recorded around 3.8 ka that ends with an abrupt change to very humid conditions at 3.7 ka. Between 3.65 and 3.5 cal ka BP, the authors indicate a short-term increase in dry conditions related to an environmental deterioration event. Short-term dry periods occur around 3.5 and 3.3 cal ka BP. However, a humidity peak with cooler conditions is present between 3.5 to 3.4 cal ka BP. Finally, warmer and drier conditions follow this humidity peak of around 3.35 and 3.2 cal ka BP. Around 3.2 cal ka BP, drier and warmer conditions are present, but settlements were still lower [
4,
45].
Locally, based on the relatively short period of occupation at Borsodivánka ((3665 +/− 35 BP to 3359 +/− 27 BP), the presence of a well-developed forest and a mature freshwater ecosystem around the site indicates a relatively humid period during the Middle Bronze Age occupations. It coincides, regionally, with fluctuating humidity levels but a relatively warm climate between 4 and 3.5 cal ka BP in the Carpathians [
3]. This coalesced with a humidity peak with cooler conditions between 3.5 to 3.4 cal ka BP in southern Hungary, although short-term dry periods occur around 3.5 and 3.3 cal Ka BP in this area [
4]. At Borsodivánka, the forest coexists with shrubland, grassland, pastures, and land for agricultural purposes in the broader area.
Further detailed studies based on absolute dating and paleoclimatic reconstructions are required to provide better evidence of the coalescence between regional scale palaeoenvironmental conditions in the Carpathians and a more local landscape reconstruction at Borsodivánka and the other Tisza floodplain sites to study the settlement patterns in the context of ‘tell societies’ during the Middle Bronze Age.
4.3. Fishing at Borsodivánka (Tisza Region) and Hungary during the Bronze Age
The role of fishing at Borsodivánka must have been significant, given the choice of settlement location, fish processing, and the number of fish bones in the assemblage. Also, the selection of exploited fish species indicates a preference for two taxa: the northern pike (E. lucius, NISP = 1259, 22.08%) and cyprinids (NISP = 1332, 23.36%) (unidentified Cyprinidae, NISP = 1234, 21.64%; common carp (C. carpio, NISP = 34, 0.60%), common chub (S. cephalus, NISP = 16, 0.28%), roach (R. rutilus, NISP = 47, 0.82%) and common nase (C. nasus, NISP = 1, 0.02%).
The downstream fish association in Borsodivánka indicates organized fishing in this river section. However, incursions into more distant fishing grounds cannot be excluded. The species identified in the corpus, particularly cyprinids, northern pike, and common perch, generally prefer waters with moderate currents. These species are, therefore, mainly found on the main channel banks or in secondary arms.
Although it is complex to reconstruct past fishing methods, several authors argue that different techniques and tools can be useful [
44,
49,
50]. Traps (or nets) designed to capture small individuals are the most likely fishing technique to explain the observed common perch and small cyprinid species such as roach, common chub, and common nase at Borsodivánka. We cannot rule out that the pikeperch, slightly larger but more elongated than cyprinids, could have been caught in these same traps [
44]. Such traps could have been set in moderately deep water in diverse environments [
51]. However, catching larger fish, such as the northern pike, common carp, and catfish, must have required some form of active fishing, possibly in relatively deep waters, with harpoons, bows, arrows, or even by hand, which only targets specific individuals [
44,
50].
Researchers indicate that spawning is vital to human communities because it is a predictable time when many fish species move close to the back and can be easily targeted [
9]. The fish species recovered in Borsodivánka show different spawning periods. Pike spawn between February and March; the common carp, the perch, the nase, the pikeperch, and the roach spawn between April and May; and the Wels catfish spawn between May and June. [
7,
8,
24,
36,
50]. Based on the more relevant presence of cyprinids and northern perch, we can conclude that, at Borsodivánka, if the inhabitants followed the spawning periods of those taxa, two probable periods of fishing periods were present: February–March and April–May.
Our burning analysis concludes that most fish remains show no visible burning (97.46%). It could indicate fish were not directly roasted over the fire. The recovered fish remains from Borsodivánka are characterized by postcranial elements such as vertebrae, spines, branchial spines, scales, and ribs (70.6%), and the cranial bones are underrepresented (10.4%). This shows that the fish in Borsodivánka were beheaded before their consumption (researchers mostly recovered the fish remains from the secondary position waste layer S7). The head constitutes 10–20% of the total fish weight and is cut off as an inedible part. The absence of cutmarks on cranial elements is usually because freshwater fish can be beheaded manually [
52]. The beheading process would indicate that the fish were gutted and then processed for long-term consumption with their skin intact, as is the practice in present-day populations across the world. The most common long-term (several months) preservation processes are salting, sun-drying, and smoking [
53,
54,
55,
56,
57,
58]. However, we cannot exclude the cooking process, since this process occurs under 700 °C with no visible evidence of burning [
58].
In the Carpathian region during the Bronze Age, “obvious” fishing apparatuses such as hooks are scarce [
7,
59]. In northern-eastern Hungary, the presence of seven huge bronze hooks indicates active fishing in the fortified Late Bronze Age settlement of Telkibánya-Cser-hegy [
59]. The hooks present a barb, whose function is to keep the point embedded in the fish’s mouth, and a terminal hook for attaching the line. The author indicates that, in modern Hungarian fishing culture, similar fish hooks are used when fishing for catfish (
S. glanis) along rivers. Researchers also describe the presence of small boat-like vessels in Rakamaz (northeast Hungary) [
60] and argued that those vessels were the miniaturse of real objects. Such representations would indicate an important aspect of the everyday life of the Bronze Age populations, such as transport or active fishing [
61,
62].