Predator–Prey Relationships and the Role of Homo in Early Pleistocene Food Webs in Southern Europe

Palaeogeography, Palaeoclimatology, Palaeoecology 365–366 (2012) 99–114 Contents lists available at SciVerse ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo Predator–prey relationships and the role of Homo in Early Pleistocene food webs in Southern Europe Jesús Rodríguez a,⁎, Guillermo Rodríguez-Gómez a, Jesús Angel Martín-González b,1, Idoia Goikoetxea a, Ana Mateos a a Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Paseo Sierra de Atapuerca s/n 09002 Burgos, Spain b Dpt. Matemáticas y Computación, Universidad de Burgos, Burgos, Spain article info abstract Article history: Predator/prey relationships in Mediterranean Europe during the Early Pleistocene are analysed at the local Received 18 June 2012 and regional scales and compared to patterns observed in recent fauna from four regions worldwide (East Received in revised form 10 September 2012 Africa, South Africa, Southeast Asia and North America). Three subregions (South Eastern, Central and Accepted 18 September 2012 South Western Mediterranean) and three time periods (middle Villafranchian, late Villafranchian and Available online 25 September 2012 Galerian) are considered. Our approach focuses on large primary consumers and their potential predators; both are defined as mammals weighing over 10 kg. Early Pleistocene food webs are characterised by a unique Keywords: Predator/prey body size distribution of primary consumers and an extremely rich carnivore guild. These characteristics Food web likely affected ecosystem function in a way not observed in recent communities. The percentage of megafau- Megafauna na species was higher in the middle Villafranchian than in recent fauna, and it increased in the late Pleistocene Villafranchian and early Galerian. The number of predators able to kill megafauna species was high in the late Villafranchian but decreased to modern values in the early Galerian. Competition inside the carnivore guild was similar to recent values in the middle Villafranchian and early Galerian but higher in the late Villafranchian. Hominins likely entered Europe during the late Villafranchian, when survival opportunities for a hunter–gatherer were low and hominins were most likely relegated to a marginal role in the palaeocommunity. This scenario changed in the early Galerian with the extinction of several predators and relatively reduced intraguild competition. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Domínguez-Rodrigo et al., 2010) and Swartkrans (Pickering, 2001) evidencing that primary access to ungulate carcasses in search of Resource availability and competition with carnivores influenced meat, not only marrow, was a common practice and suggesting that survival opportunities for Early Pleistocene hominins and conditioned hunting activities were also important for those Early Pleistocene their ability to spread beyond Africa. Most recent hunter–gatherer human populations. Evidence of primary access to ungulate carcasses populations from temperate regions relied on animal resources as has also been found in Europe, at the lower levels of the Sima del their main energy source (Cordain et al., 2000), and a wide consensus Elefante site (Rodríguez et al., 2011). Moreover, several authors stress of researchers considers that large mammals were key resources for the importance of the carnivore guild composition and food web Palaeolithic foragers (e.g. Binford, 1981; 1985; Marean, 1989; structure, containing large herbivores that weighed over 20 kg and Moigne and Barsky, 1999; Gaudzinski and Roebroeks, 2000; their predators, in conditioning access opportunities for the earliest Roebroeks, 2001; Speth, 2010). The role played by large mammals European hominins to meat resources (Turner, 1992a; Arribas and as a key food resource for early Homo is, however, a more controver- Palmqvist, 1999; Croitor and Brugal, 2010; Palombo, 2010). sial topic. It was initially proposed that Early Pleistocene Homo Studies about food web structures and predator/prey relationships accessed large mammal carcasses mainly through scavenging and in have a long tradition in ecology (Cohen, 1977; Critchlow and Stearns, search of bone marrow (Binford, 1981; Blumenschine et al., 1994). 1982; Pimm et al., 1991; Pascual and Dunne, 2006; Owen-Smith and However, this interpretation has been challenged by several recent Mills, 2008). Several studies have also addressed predator/prey studies at Olduvai Gorge (Bunn, 2001; Bunn and Pickering, 2010; relationships in the Pleistocene both at the regional (Palombo and Mussi, 2006; Raia et al., 2007; Croitor and Brugal, 2010; Palombo, 2010) and local community scales (Stiner, 1992; Palmqvist et al., ⁎ Corresponding author at: CENIEH, Paseo Sierra de Atapuerca s/n 09002 Burgos, Spain. 2008; Perez-Claros and Palmqvist, 2008; Feranec et al., 2010). How- Tel.: +34 947040800; fax: +34 947040810. E-mail address: [email protected] (J. Rodríguez). ever, predator/prey relationships at regional fauna scale are generally 1 Temporarily assigned to CENIEH. described using crude predator/prey species ratios, or even carnivore/ 0031-0182/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.palaeo.2012.09.017 100 J. Rodríguez et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 365–366 (2012) 99–114 non-carnivore proportions, considering neither the predators' prefer- Mediterranean region of Europe below 45° N was separated from ences and killing abilities nor the potential prey's characteristics. the rest of Europe by a bio-geographic and climatic frontier of varying Exceptions to these general rules include the description of carnivore intensity throughout the Early Pleistocene (Rodríguez et al., 2011). intra-guild completion in Java during the Pleistocene by Hertler and We here analyse the changes in European food web structures Volmer (2008), based on estimations of carnivore species' prey size below the 45° N parallel throughout the Early Pleistocene to detect preferences, the study of European felids and their prey by Hemmer changes in resource availability for the first human colonisers. As (2004) and the analysis of the effect of predator pressure on prey Kostopoukus et al. (Kostopoulus et al., 2007) discussed, the three abundance in Plio-Pleistocene Italy by Meloro et al. (2007). Works southern peninsulas included in this region have been separated by focusing on local assemblages are usually more refined in their ecological and geographical barriers since the Caenozoic, though approach and provide accurate information on predator preferences connections between Italy and the Balkans occurred during glacial (García et al., 2009; Feranec et al., 2010) and food web function periods allowing some species to migrate from one peninsula to the (Palmqvist et al., 2003; Palmqvist et al., 2008). Nevertheless, studying other (Michaux et al., 2005) We have thus subdivided Mediterranean changes in predator/prey relationships through evolutionary time Europe into three subregions, coinciding with the three peninsulas. and detecting generalised food web patterns are not possible when a study focuses on a single assemblage. We present a new perspective that studies food web patterns and 2. Methods predator prey relationships in Early Pleistocene Southern Europe both at the regional and local scales using a macroecological approach The study area includes southern Europe below latitude 45 °N. This (Brown, 1995). We combine information from studies on local assem- area has been divided into three subregions (Fig. 1), South West (lon- blages, morphofunctional analyses and behavioural information on gitude from −10.00 to 4.00 degrees), Central (longitude from 4.00 to living relatives to assess the prey preferences of Early Pleistocene 18.00 degrees) and South East (longitude from 18.00 to 40.00), basical- large carnivores. This information is eventually used to evaluate ly coinciding with the three southern peninsulas. A dataset of Early predator/prey relationships at the local and regional scales, consider- Pleistocene Local Faunas from this area has been compiled from pub- ing predator preferences and the ecological characteristics of the lished sources (Table 1). Three time periods, corresponding to the mid- potential prey species. Furthermore, the Pleistocene food web dle Villafranchian (2.6–1.8 Ma), late Villafranchian (1.8–1.2 Ma) and characteristics are interpreted using the patterns observed in several early Galerian (1.2–0.78 Ma) (Palombo, 2010) or Epi-Villafranchian selected recent faunas. (Kahlke et al., 2011) were distinguished, and local faunas were Homo likely arrived in Europe during the late Villafranchian, al- assigned to one according to biostratigraphic correlations and numeri- though human populations were unable to cross parallel 45°N until cal ages provided by the original sources. Numerical ages were always 1.2 Ma at the beginning of the Galerian (Rodríguez et al., 2011). The preferred to biostratigraphic correlations for assigning a site to a time Fig. 1. The study area has been divided into three sub-regions: South Western (SW), South Central (C) and South East (SE) Europe. Middle Villafranchian sites are marked with black dots, late Villafranchian sites are marked with black triangles and early Galerian sites with white dots. J. Rodríguez et al. / Palaeogeography, Palaeoclimatology, Palaeoecology 365–366 (2012) 99–114 101 Table 1 South Mediterranean early Pleistocene Local Faunas used in the present

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