Large Carnivore Guild Research Articles

Scarcity in the prey community yields anti-predator benefits

The majority of individuals in a community belong to a small number of abundant species. Understanding why some species are rare and others are common has been a long-held goal for ecologists. Africa’s large carnivore guild preferentially preys on a small number of species within a limited weight range. Within this weight range however, some species that are expected to be significantly preferred as prey are not. I tested whether these species avoid preferential predation through their low densities. Records of over 40,000 kills from up to 48 different communities were used to test if non-preferred species within the expected prey weight ranges of each large predator avoid preferential predation and why. Species expected to be prey of Africa’s large predators based on their body mass, that are preferred are preyed upon significantly more frequently at low densities than non-preferred prey. This results in a negative relationship between relative abundance and preference for preferred prey, but a positive relationship for non-preferred prey. The non-preferred prey species that are within the expected prey weight ranges of Africa’s large predators are significantly less abundant within the prey community than significantly preferred prey. Rarity in African ungulates may convey an anti-predator benefit in that it was suboptimal for predators to evolve morphological or behavioral strategies to optimally forage on them or in that prey species can avoid predators by existing in habitats with low carrying capacity.

Morphological Disparity in Plio-Pleistocene Large Carnivore Guilds from Italian Peninsula

Communities of large mammals exhibit changes in morphological diversity through space and time; changes that are possibly correlated to distinct aspects of the physical environment. Here, I explore shape changes in the trophic apparatus of large carnivore guilds, comparing extant communities with Quaternary ones, from peninsular Italy. Mandibular shape is quantified through geometric morphometrics and its disparity is computed for each carnivore guild. Patterns of morphospace occupation through space and time reveal that extant carnivore guilds are negatively influenced by number of artiodactyls. Very productive ecosystems show low values of morphological disparity because species tend to occupy central regions of the morphospace rather than extreme areas. Disparity of mandibular corpus shape remains relatively stable throughout the Quaternary in the large carnivore communities of the Italian peninsula. They exhibit similar values to extant guilds because the trophic apparatus did not evolved important mo...

Evaluating a potentially strong trophic interaction: pumas and wild camelids in protected areas of Argentina

Predatory interactions involving large carnivores and their ungulate prey are increasingly recognized as important in structuring terrestrial communities, but such interactions have seldom been studied in the temperate Neotropics. Here, the large carnivore guild is limited to a single species, the puma Puma concolor, native prey populations have been drastically reduced and lagomorphs and ungulates have been introduced. We examined puma dietary patterns under varying abundances of native camelid prey – guanacos and vicu ˜ nas – in protected areas of northwestern Argentina. We collected puma feces from seven protected areas, and sampled each area for the relative abundance of camelids using on-foot strip and vehicle transects. In one area, where longitudinal studies have been conducted, we examined the remains of vicu ˜ nas and guanacos for evidence of puma predation in 2004–2006. We compared our results with a study conducted in 1978–1983, and contrasted the frequency of carcasses showing signs of puma predation with estimates of camelid abundance. Across sites, we observed a positive and significant relationship between camelid consumption by pumas and camelid abundance, with pumas about nine times more likely to consume camelids where the latter were most abundant. The temporal variation in predation rates on camelids differed by species. Guanacos, which did not change in abundance between periods, showed a slight decrease (1.5 times) in the relative frequencies of individuals killed by pumas. Conversely, vicu ˜ nas increased in abundance by a factor of � 7 between periods, coinciding with an c. 3.4 times increase in individuals showing evidence of puma predation. Some protected areas of northwestern Argentina are conserving the trophic interaction between pumas and native camelid prey. This interaction may be the basis of the far-reaching community effects described for analogous systems on other continents. It also has implications for the possible recovery of or reintroduction of camelids to areas with high puma densities, where predation losses can be expected to be high, and possibly prohibitive.

Inferring palaeoecology in extinct tremarctine bears (Carnivora, Ursidae) using geometric morphometrics

Figueirido, B. & Soibelzon, L.H. 2009: Inferring palaeoecology in extinct tremarctine bears (Carnivora, Ursidae) using geometric morphometrics. Lethaia, Vol. 43, pp. 209–222. In this study we explore the ecomorphological patterns of extinct tremarctine bears in South America during the Great American Biotic Interchange (GABI). These patterns are used to derive palaeoautoecological inferences in extinct tremarctines and their palaeosinecological relationships within Plio-Pleistocene ecosystems. We used geometric morphometrics of landmark data to recover the shape of the craniomandibular skeleton of bears. The results reveal different ecomorphological specializations in extinct tremarctines during the Plio-Pleistocene of South America. Indeed, these bears could have increased the percentage of plant matter in their diets according with the increased diversity of large carnivores in South America after the GABI. Omnivorous bears retain the ability to behave as carnivores or herbivores depending on resource availability. This fact strongly supports that bears are one of the most ecologically and morphologically adaptable members of the large carnivore guild. Moreover, their skull morphology could reflect ecological adaptations under different selection pressures with the required evolutionary time. □Evolution, GABI, geometric morphometrics, palaeoecology, Tremarctinae.

Predicting the patterns, perceptions and causes of human–carnivore conflict in and around Machiara National Park, Pakistan

Human–carnivore conflict is considered to be a major conservation and rural livelihood issue because many carnivore species have been heavily persecuted due to elevated conflict levels with communities. To mitigate such conflicts requires a firm understanding of their underlying patterns. This situation is epitomized in Pakistan, where carnivore populations have been greatly reduced, but where no research has investigated the conflict patterns of large carnivore guilds with humans. Focusing in and around Machiara National Park (MNP), Azad Jammu and Kashmir region, we conducted the first such scientific study in Pakistan. From January 2004 to May 2007, 148 people lost their livestock to four carnivore species. Leopard was responsible for the majority (90.6%) of the 363 livestock killed, mainly goats (57.3%) and sheep (27.8%). Information-theoretic evaluation of a candidate set of regression models found that leopard kills inside villages were significantly higher for areas without electricity, while leopard kills outside villages were higher for pastoralists with larger herds that were further from MNP, with no effect from several guarding strategies used. Temporal leopard attacks were significantly and positively related to temperature, but not to rainfall, for goat kills, but not for other livestock kills. While leopard kills caused the greatest overall financial loss (19.8%) amongst carnivores, which negatively affected local tolerance towards leopard, disease caused greater livestock losses (72.7%). To improve both large carnivore and local livelihood prospects around MNP and across rural Pakistan, conservation and development projects should install village electricity supplies and vaccinate livestock, while the cost-effectiveness of different conflict mitigation strategies should be trialed.

Taphonomic perspectives on hominid site use and foraging strategies during Bed II times at Olduvai Gorge, Tanzania

The faunal assemblages excavated by Mary Leakey in Bed II of Olduvai Gorge, Tanzania, have, like the more well-known Bed I assemblages, traditionally been interpreted as the result of hominid butchering activities in the lake margin and riverine settings of the paleo-Olduvai Basin. A reexamination of all of Leakey's Bed I sites has shown that hominids played little or no role in the formation of all but one of those faunal assemblages, a finding that prompted the reanalysis of the Bed II sites presented here. We expand upon a previous taphonomic study that provided systematic data for HWK East Levels 1–2, MNK Main, and BK. In addition to these assemblages, we provide data on HWK East Levels 3–5, FC West, TK, and SHK. Our data contradict previous interpretations of MNK Main as a hominid accumulation but uphold the contention that BK represents a primarily hominid accumulation reflecting early access to carcasses. The small and poorly preserved assemblages from FC West and TK are difficult to link unambiguously to either hominids or carnivores. Site MNK Main and HWK East Levels 3–5 appear to be death arenas where carcasses accumulated via natural deaths and/or serial predation. Site SHK is severely biased by selective retention and therefore little can be said of its formational history. Nevertheless, no hominid modifications were documented in this assemblage. Comparisons with other Olduvai sites indicate a more conspicuous hyena taphonomic signal during Bed II times than Bed I times, which appears to mirror the changing configuration of the large carnivore guild. These findings also beg the question of what activities were being carried out by hominids with the stone tools discarded at these sites. Although it seems clear that hominids were utilizing stone tools to carry out subsistence activities unrelated to carcass butchery, more excavation and techniques such as phytolith analysis should be employed to explore alternative explanations.

The potential for large carnivores to act as biodiversity surrogates in southern Africa

Biodiversity in southern Africa is globally extraordinary but threatened by human activities. Although there are considerable biodiversity conservation initiatives within the region, no one has yet assessed the potential use of large carnivores in such actions. Surrogate approaches have often been suggested as one such way of capitalizing on large carnivores. Here we review the suitability of the large carnivore guild (i.e., brown hyaena Hyaena hyaena, spotted hyaena Crocuta crocutta, cheetah Acinonyx jubatus, leopard Panthera pardus, lion Panthea leo and African wild dog Lycaon pictus) to act as surrogate species for biodiversity conservation in southern Africa. We suggest that the guild must be complete for the large carnivores to fully provide their role as ecological keystones. The potential for large carnivores to act as umbrella and indicator species seems limited. However, self-sustaining populations of large carnivores may be useful indicators of unfragmented landscapes. Moreover, diversity within the large carnivore guild may reflect overall biodiversity. Although the global appeal of the large African carnivores makes them important international flagships, we stress that international conservation funding must be linked to local communities for them to be important also locally. In summary, we suggest that the flagship value of these large carnivores should be used to promote biodiversity conservation in the region, and that the suggested relationship between large carnivore diversity and overall biodiversity is empirically tested. Finally we suggest that direct conservation activities should focus on enhancing the keystone values of large carnivores through complete guild conservation and restoration.

The giant hyaena, Pachycrocuta brevirostris (Mammalia, Carnivora, Hyaenidae)

The giant hyaena, Pachycrocuta brevirostris, is known from deposits in Africa and Eurasia between ca. 3.0 and 0.5 Ma. It is the largest of the true hyaenas, but that size is not reflected in overall shoulder height since the distal limb segments are relatively shorter than those of living taxa. Its bodily proportions therefore appear to be suited to power and strength rather than speed. Its eventual extinction is part of the overall evolution in large carnivore guilds throughout the world and may have been closely linked to the extinction of machairodont cats.