Prey deposits and den sites of the Upper Pleistocene hyena Crocuta crocuta spelaea (Goldfuss, 1823) in horizontal and vertical caves of the Bohemian Karst (Czech Republic)

Abstract

Middle and Upper Pleistocene bone accumulations in caves of the Bohemian Karst, Czech Republic, are newly classified as several types of hyena dens or hyena bone deposits, and cave bear dens. This new taphonomical and paleoecological interpretation of localities that have been known for decades is based on revision of available bone collections, additional field observations at existing localities, and on comparisons with recent spotted hyenas. The thousands of bones from this region, including about seven hundred Pleistocene hyena remains, are strongly fragmented by having been cracked and chewed, consistent with typical hyena activities. The localities can be subdivided chronologically as Middle and Upper Pleistocene, or taphonomically as horizontal and vertical caves and karst depressions. Horizontal and vertical caves show contrasting types of bone accumulations. Several vertical cavities were filled in the Middle Pleistocene and contain the remains of Pachycrocuta brevirostris and its prey. This is the case of the areas of Srbsko-Chlum and Koněprusy-Zlatý Kůň Hill. In the Upper Pleistocene, at least eight caves in the Bohemian Karst were used by hyenas of Crocuta crocuta spelaea as dens and prey storage, some of which were also used by cave bears for hibernating. Upper Pleistocene cave bears were scavenged postmortally by Ice Age spotted hyenas at four cave sites, where they left cracked and chewed Ursus spelaeus bones. Hyenas also stored the remains of their prey in the caves. These remains also include rests of other hyenas, which indicates cannibalism. Fecal pellets were used for marking the den sites. The Nad Kačákem Cave near Hostim is shown to have been a frequented hyena den based on the presence of many "nibbling sticks" and the remains of juvenile hyena bones. Many hyena skeletons of C. c. spelaea, including juveniles and adults, their coprolites, and the partly cracked bones of their stored prey, were found in vertical caves such as Srbsko-Chlum-Komín. The most spectacular finds are a nearly complete skeleton of the female steppe lion Panthera leo spelaea and an embryo of the Przewalski horse Equus ferus przewalskii. A nearly complete hyena skeleton in the Koněprusy Caves-Prošek Dome is another remarkable find. The most bone-rich localities at Koněprusy-Zlatý Kůň Hill and Srbsko-Chlum Hill are located on, or close to, exposed hill tops, where hyenas had an overview of the surrounding landscape. Statistical analysis of the remains shows that the main animals preyed upon by Upper Pleistocene hyenas were Equus ferus przewalskii and Coelodonta antiquitatis. Additionally, the hyenas fed on Bison priscus, Rangifer tarandus, Cervus elaphus, Megaloceros giganteus, Equus hydruntinus, the Bohemian alpine fauna including Rupricapra rupricapra and Capra ibex, and even the carnivores Ursus spelaeus, Panthera leo spelaea, Canis lupus and possibly Gulo gulo. The very few remains of the mammoth Mammuthus primigenius seem to indicate its scarcity in the hilly Bohemian Karst. Sediments in the horizontal caves show that, after being used by cave bears or hyenas, they were inhabited by foxes or marmots, and more recently by humans, especially during the Magdalenian period and later in the Holocene.