Autumn Migration of Diurnal Raptors Across Kenting National Park, Taiwan, Along the East-Asian Oceanic Flyway

ABSTRACT Diurnal raptors were counted during their southward migration in autumn of 2019 at Kenting National Park, southern Taiwan, an important hawkwatch site along the East-Asian Oceanic Flyway. Observations were conducted from 1 September to 31 October 2019 in the morning hours, but the observation period was extended to 1400 H whenever large numbers of raptors passed the site before noon. A total of 329,559 individuals of 14 migratory raptor species was recorded. The Chinese Sparrowhawk (Accipiter soloensis) and Gray-faced Buzzard (Butastur indicus) made up 78.3% (257,971 birds) and 21.6% (71,045 birds) of the total, respectively. The number of Chinese Sparrowhawks increased significantly when we extended the survey duration from 1200 H to 1400 H (paired t-test, t = 2.44, P = 0.04), but the number of Gray-faced Buzzards did not (t = 1.94, P = 0.09). Thus, Chinese Sparrowhawks may continue passing the site en route to the Philippine Islands in the afternoon hours, whereas Gray-faced Buzzards usually stop migrating in early afternoon, at least under certain conditions. How prevailing wind conditions along the East-Asian Oceanic Flyway in autumn shape the different migratory strategies of these two hawk species requires further study.

Traces of the Dahaean and Sarmatian Cultural Legacy in Ancient Turan and Old Rus

This study examines the migrations of the Dahae and Sarmatians—the two related early nomadic peoples of Middle Asia and Eastern Europe—directed to the south and west of their homeland. Archaeological, written, and folkloric sources make it possible to trace the migrations of the Dahae and Sarmatians over several centuries preceding the spread of Islam in Central Asia and of Christianity in Old Rus. The study focuses on mortuary monuments, temples, and sanctuaries, cross-shaped in plan view, of migrants and their descendants. A detailed analysis of the major southward migration of Dahae from the Lower Syr-Darya in the late 3rd to early 2nd BC is presented. This migration had a considerable effect on ethnic and cultural processes in Middle Asia. The migration aimed at conquering the lands of Alexander the Great’s descendants, who were rapidly losing control over them. Features of Dahaean culture are noticed in town planning, architecture, mortuary rites, armor, etc. over the entire territory they had captured. Southward migration of the descendants of the Dahae—people of the Kaunchi and Otrar cultures—from the Syr-Darya, led by the Huns, was part of the Great Migration. The Kaunchi people headed toward the oases of Samarkand and Kesh, the Otrar people toward the oasis of Bukhara, and those associated with the Dzhetyasar culture toward the Qarshi oasis. It is demonstrated that while the cross-shaped plan view of religious structures turned into the eight-petaled rosette, the fu neral rite did not change, remains of burials and charcoal are observed everywhere. Relics of the ScythoSarmatian legacy are seen in the culture of Old Rus. For instance, remains of the sanctuaries of Perun are walls and ditches arranged in a cruciform or eight-petaled fashion, fi lled with charcoal and bones of sacrifi ced animals, with a statue of the supreme Slavic deity, in the center. Early sanctuaries of Perun in Kiev and Khodosovichi were cruciate in plan view, while later ones on the banks of the Zbruch and the Volkhov rivers had octopetalous plans. Apparently they were infl uenced by the architectural traditions of Dahae and Sarmatians, who took part in the ethnogenetic processes in both Old Rus and Turan.

Dietary Shifts and Risks of Artifact Ingestion for Argentine Shortfin Squid Illex argentinus in the Southwest Atlantic

Cephalopods play an important role in both ecology and fisheries. Variations in the dietary compositions of squids with large populations further promote interactions between different trophic levels in marine ecosystems. Moreover, due to marine pollution, squids are also at risks of artifact ingestion, and there is limited understanding about the influence of artifacts on the feeding behavior of squids. We examined 296 stomachs of the Argentine shortfin squid Illex argentinus collected through commercial catches across the Southwest Atlantic from February to April of 2018 and 2019 to establish the monthly dietary compositions and risks of artifact ingestion. The results supported typical observations that the Argentine shortfin squids switched from a diet dominated by crustaceans at small sizes to consuming larger prey, predominantly fishes and/or cephalopods, at large sizes during their growth and southward migration. Significantly higher consumption of fishes was observed in recent years compared with that observed in other studies since 1992. The ingested artifacts examined were composed of plastic and non-plastic materials. Artifacts were observed in 19.9% of the total number of stomachs, with 20.5% of the empty stomachs containing artifact remains. The results indicate that although the main dietary compositions of the Argentine shortfin squid maintain the taxonomic groups of prey compositions, the dietary structure, i.e., composition percentage, is varying. The detection of artifacts suggests that environmental monitoring is needed in this region in order to manage and conserve the squid and safeguard aquatic food safety.

Climate Change along the Silk Road and Its Influence on Scythian Cultural Expansion and Rise of the Mongol Empire

Climate change and cultural exchange both influenced cultural development along the continental Silk Road during the late Holocene, but climate change and its influence on nomadic civilizations during that time has yet to be systematically assessed. In this study, we analyzed records of climate change along the Silk Road covering key periods in the late Holocene, based on multiproxies from various archives including lake sediments, shorelines/beach ridges, peatlands, ice cores, tree rings, aeolian sediments, moraines, and historical documents. Combined with archaeological data, we assessed the influence of climate on development and expansion of representative pastoral nomadism. Our results show that the most notable climate changes in Central Asia were characterized by decreasing temperature, expanding glaciers, increasing precipitation, and increasing humidity during transitions from the Sub-Boreal to Sub-Atlantic Period (ca. 9–8th century BC) and from the Medieval Warm Period to the Little Ice Age (ca. 13–14th century AD). The two periods coincided with Scythian Cultural expansion across the steppe landscape of Central Asia and rise of the Mongol Empire, respectively. These temporal coincidences are interpreted as causally related, where temperature fall and glacial advance may have forced the pastoral nomadism to southward migration. Coeval wetness and southward migration of steppe landscape in Central Asia were beneficial for these cultural expansions, which spanned the Eurasian arid and semi-arid zone westward. Therefore, during the historical period when productivity was underdeveloped, although expansions of pastoral nomadism were closely related to internal social structures, climate change was possibly the most critical controlling factor for sustainability development and collapse.

Active deformation and Plio-Pleistocene fluvial reorganization of the western Kura fold–thrust belt, Georgia: implications for the evolution of the Greater Caucasus Mountains

Since Plio-Pleistocene time, southward migration of shortening in the eastern part of the Greater Caucasus into the Kura foreland basin has progressively formed the Kura fold–thrust belt and Alazani piggyback basin, which separates the Kura fold–thrust belt from the Greater Caucasus. Previous work argued for an eastward propagation of the Kura fold–thrust belt, but this hypothesis was based on coarse geological maps and speculative ages for units within the Kura fold–thrust belt. Here we investigate the initiation of deformation within the Gombori range in the western Kura fold–thrust belt and evaluate this eastward propagation hypothesis. Sediments exposed in the Gombori range have a Greater Caucasus source, despite the modern drainage network in the NE Gombori range, which is dominated by NE-flowing rivers. Palaeocurrent analyses of the oldest and youngest syntectonic units indicate a switch happened between ~2.7 Ma and 1 Ma from dominantly SW-directed flow to palaeocurrents more similar to the modern drainage network. A single successful 26Al–10Be burial date indicates the youngest syntectonic sediments are 1.0 ± 1.0 Ma, which, while not a precise age, is consistent with original mapping suggesting these sediments are of Akchagylian–Apsheronian (2.7–0.88 Ma) age. These results, along with recent updated dating of thrust initiation in the eastern Kura fold–thrust belt, suggest that deformation within the Kura fold–thrust belt initiated synchronously or nearly synchronously along-strike. We additionally use topographic analyses to show that the Gombori range continues to be a zone of active deformation.

China's historical record when searching for tropical cyclones corresponding to Intertropical Convergence Zone (ITCZ) shifts over the past 2 kyr

The northwestern Pacific Ocean and South China Sea are where tropical cyclones occur most frequently. Many climatologists also study the formation of Pacific Ocean warm pools and typhoons in this region. This study collected data of paleotyphoons found in China's official historical records over the past 2000 years that contained known typhoon activity reports. The collected data are then subjected to statistical analyses focusing on typhoon activity in coastal regions of southeastern China to garner a better understanding of the long-term evolution of moving paths and occurrence frequency, especially regarding those typhoons making landfall in mainland China. We analyzed the data with the year and month of each typhoon event, as well as the number of events in a 10-year period. The result shows that (1) north–southward migration of typhoon paths corresponds to the north–southward migration of the Intertropical Convergence Zone (ITCZ) during the Medieval Warm Period (MWP) and Little Ice Age (LIA) and (2) paleotyphoons made landfall in mainland China 1 month earlier during the MWP than during the LIA. This implies a northward shift in ITCZ during the MWP. Typhoons tend to make landfall in Japan during El Niño-like periods and strike the southern coastal regions of China during La Niña-like stages. According to paleotyphoon records over the last 2000 years, typhoons made landfall in southeastern China frequently around 490–510, 700–850, and after 1500 CE The number of typhoons striking Guangdong Province peaked during the coldest period in 1660–1680 CE; however, after 1700 CE, landfall has migrated farther north. The track of tropical cyclones (TCs) in the northwestern Pacific Ocean is affected by the North Atlantic Oscillation (NAO) and the Pacific Decadal Oscillation (PDO), which shows a nearly 30-year and a 60-year cycle during the LIA.