scholarly journals Naturally-occurring tooth wear, tooth fracture, and cranial injuries in large carnivores from Zambia

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11313
Author(s):  
Blaire Van Valkenburgh ◽  
Paula A. White
Keyword(s):  
Prey Species ◽  
Prey Type ◽  
Tooth Wear ◽  
Spotted Hyena ◽  
Fracture Rate ◽  
Large Prey ◽  
Ecological Data ◽  
Tooth Fracture ◽  
Spotted Hyenas ◽  
Prey Handling

Determining the incidence and causes of craniodental damage in wild carnivores is often constrained by limited access to specimens with associated ecological data, such as prey type and abundance. We assessed dental condition and cranial injuries in lion, leopard, and spotted hyena in relation to prey and predator populations in Zambia’s Luangwa Valley, where large prey are more abundant and lion and leopard more numerous, and the Greater Kafue Ecosystem, where smaller prey species are more prevalent and lion and leopard less common. In Luangwa, lions had significantly higher rates of tooth fracture, and blunt trauma injuries attributable to prey-handling, compared to Kafue lions. In contrast, leopards in both regions had similar rates of tooth wear and breakage. Overall, lions showed a significantly higher tooth fracture rate than leopards on a per tooth basis. Spotted hyenas had the highest rates of tooth wear and fracture among all three carnivores, and greatly exceeded previously recorded rates based on historical samples. Despite larger numbers of lion and leopard in Luangwa, there was no difference in incidence of intraspecific injuries between regions. These results are consistent with a greater abundance of large prey species, especially buffalo, in the diets of Luangwa lions, and previous work showing a reliance on smaller prey species in Kafue throughout the large carnivore guild.

Taphonomic and zooarchaeological implications of spotted hyena (Crocuta crocuta) bone accumulations in Kenya: a modern behavioral ecological approach

Paleobiology ◽  
2009 ◽  
Vol 35 (2) ◽  
pp. 289-309 ◽  
Author(s):  
Sarah W. Lansing ◽  
Susan M. Cooper ◽  
Erin E. Boydston ◽  
Kay E. Holekamp
Keyword(s):  
Behavioral Ecology ◽  
Prey Species ◽  
Species Abundance ◽  
Crocuta Crocuta ◽  
Site Formation ◽  
Behavioral Variability ◽  
Spotted Hyena ◽  
Site Formation Processes ◽  
Spotted Hyenas ◽  
Bone Accumulation

The significant impact of extant carnivores, particularly spotted hyenas, on the depositional history and physical characteristics of archaeofaunal and paleontological assemblages is well recognized. We focus on the behavioral ecology of extant spotted hyenas (Crocuta crocuta) in relation to bone accumulations produced by one East African clan at communal dens. Limbs and skulls of prey animals more frequently appear at dens than do other carcass portions. These items reflect the relative abundance of prey species near dens; carnivore remains are poorly represented. Comparative analysis reveals that bones are deposited far more slowly (<7 carcass portions per month) and accumulations tend to be smaller at Crocuta dens than at dens of either brown (Parahyaena brunnea) or striped (Hyaena hyaena) hyenas. We propose that extant Crocuta bone accumulation rates and sizes are likely affected by prey species abundance, clan size, social interactions within the clan, and the type and availability of den sites. We also suggest that the potential for intraspecific behavioral variability in bone accumulation patterns is important when comparisons are made among spotted hyena populations and across hyena species. For example, accumulation patterns may be dramatically influenced by the temporal span, potentially ranging from days to hundreds or thousands of years, in which bones are collected, depending on the species-specific history of occupation at a given site. Understanding the behavioral and ecological variability likely to influence bone accumulation patterns at dens used by different hyaenids will allow taphonomists and zooarchaeologists to refine their knowledge of mechanisms underlying site formation processes and potential causes of variability in deeper-time den assemblages.

scholarly journals Feeding Ecology of Short-Toed Snake-Eagle (Circaetus gallicus [Gmelin, 1788]) in the Montados of Iberian Peninsula

2020 ◽  
Vol 28 (2) ◽  
pp. 155-179
Author(s):  
Nuno Onofre ◽  
Luís Sampaio
Keyword(s):  
Relative Abundance ◽  
Diet Composition ◽  
Prey Species ◽  
Prey Selection ◽  
Prey Type ◽  
Generalist Predator ◽  
Important Prey ◽  
Psammodromus Algirus ◽  
Circaetus Gallicus ◽  
Water Snakes

The diet of Short-toed Snake-eagle (Circaetus gallicus) during the breeding season in an area dominated by cork and holm oak parkland forests (Montados) was analyzed in this study. As expected, results showed that snakes are the dominant prey in the diet of this eagle, comprising up to 92.5% of the identified items, if potential secondary prey species were excluded. The Montpellier Snake (Malpolon monspessulanus) was the most consumed one (42.2%), followed by the Ladder Snake (Zamenis scalaris) (28.0%), and the water snakes (Natrix spp.) (14.2%). According to the same criteria, lizards (mainly Psammodromus algirus) and mammals represent between 4.8 and 2.2%, respectively. Other animals such as pond turtle and amphibians are irregular prey (<1%), and no bird remains were found at all. Short-toed Snake-eagle is usually referred as a stenophagic predator where snakes are by far its most important prey type, and where within this taxonomic group it behaves as a generalist predator. In this study this premise was then tested comparing the relative abundance of the snake species with their proportion in the diet composition of the eagle in order to know whether or not prey selection exists with regard to the species of snakes in this region. Results point to a quite plausible "preference" for the Ladder Snake and an "avoidance" for the smooth snakes group (Macroprotodon brevis/Coronella girondica), and possibly for the Horseshoe Whip (Hemorrhois hippocrepis). The avoidance to the Horseshoe Whip must be indirect and habitat related, while in relation to the two smooth snakes it may be due in large extend to its small size, in particular.

scholarly journals Lion and spotted hyena distributions within a buffer area of the Serengeti-Mara ecosystem

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stanslaus B. Mwampeta ◽  
Clay M. Wilton ◽  
Imani J. Mkasanga ◽  
Lusato M. Masinde ◽  
Peter S. Ranke ◽  
...  
Keyword(s):  
Anthropogenic Activities ◽  
Spotted Hyena ◽  
The South ◽  
Large Carnivore ◽  
Serengeti Ecosystem ◽  
Northern Tanzania ◽  
Spotted Hyenas ◽  
Western Border ◽  
Eastern Border ◽  
June July

AbstractMost large carnivore populations are declining due to anthropogenic activities including direct persecution, prey depletion, habitat loss and degradation. protected areas (PAs) can help maintain viable large carnivore populations; however, anthropogenic activities occurring near and within PA borders or edges can reduce their effectiveness. We investigated the influence of edge effects on abundance of lions (Panthera leo) and spotted hyenas (Crocuta crocuta) in Maswa Game Reserve (MGR), a part of the Serengeti ecosystem in northern Tanzania. We conducted repeated call-ins to attract and enumerate lions and hyenas at 20 stations in MGR during June–July 2017. We used N-mixture models to estimate hyena and lion abundance in relation to land cover and distance from the south-western MGR borders which are adjacent to villages. We found lowest lion and hyena abundances by the south-western border, with abundance of both species increasing toward the eastern border adjacent to Serengeti National Park. Lions were uniformly distributed among land covers whereas hyenas were more abundant in woodlands. We suggest that reduced lion and hyena abundance near human settlements was in response to depleted prey, due to human actions. We recommend ecologically compatible land uses and effective border patrols to mitigate these adverse effects.

scholarly journals Evolution in interacting species alters predator life-history traits, behaviour and morphology in experimental microbial communities

2020 ◽  
Vol 287 (1928) ◽  
pp. 20200652
Author(s):  
Johannes Cairns ◽  
Felix Moerman ◽  
Emanuel A. Fronhofer ◽  
Florian Altermatt ◽  
Teppo Hiltunen
Keyword(s):  
Life History ◽  
Prey Species ◽  
Rapid Evolution ◽  
Prey Type ◽  
Automated Image Analysis ◽  
Foraging Efficiency ◽  
Predator Prey ◽  
Evolving Systems ◽  
Interacting Species ◽  
Evolutionary Response

Predator–prey interactions heavily influence the dynamics of many ecosystems. An increasing body of evidence suggests that rapid evolution and coevolution can alter these interactions, with important ecological implications, by acting on traits determining fitness, including reproduction, anti-predatory defence and foraging efficiency. However, most studies to date have focused only on evolution in the prey species, and the predator traits in (co)evolving systems remain poorly understood. Here, we investigated changes in predator traits after approximately 600 generations in a predator–prey (ciliate–bacteria) evolutionary experiment. Predators independently evolved on seven different prey species, allowing generalization of the predator's evolutionary response. We used highly resolved automated image analysis to quantify changes in predator life history, morphology and behaviour. Consistent with previous studies, we found that prey evolution impaired growth of the predator, although the effect depended on the prey species. By contrast, predator evolution did not cause a clear increase in predator growth when feeding on ancestral prey. However, predator evolution affected morphology and behaviour, increasing size, speed and directionality of movement, which have all been linked to higher prey search efficiency. These results show that in (co)evolving systems, predator adaptation can occur in traits relevant to foraging efficiency without translating into an increased ability of the predator to grow on the ancestral prey type.

Variation in the diet of the Lataste's viper Vipera latastei in the Iberian Peninsula: seasonal, sexual and size-related effects

2007 ◽  
Vol 57 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Juan Pleguezuelos ◽  
José Brito ◽  
Soumia Fahd ◽  
Xavier Santos ◽  
Gustavo Llorente ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Conservation Management ◽  
Prey Availability ◽  
Feeding Activity ◽  
Prey Type ◽  
Ontogenetic Shift ◽  
Ecological Data ◽  
Opposite Pattern ◽  
Iberian Range ◽  
Ambush Predation

AbstractSeveral life-history traits may increase vulnerability of species to extinction. Among snakes, ambush predation and dietary specialisation are factors that increase this vulnerability. European viper species, genus Vipera, display such traits and are categorised as endangered in several parts of its range. For their conservation management, a deeper knowledge of their ecology and habitat use is highly relevant. One of the species with less ecological data is the Lataste's viper Vipera latastei, a species which lives in the Iberian Peninsula and northwestern Africa. Here, we describe its diet based on the analysis of gut content of 435 museum specimens plus nine bibliographic data from the entire Iberian range. The species showed seasonal and ontogenetic shift in diet but no sexual variations. Feeding activity (percentage of vipers with prey) was low in accordance with its ambush predation tactics, being lower in spring than in summer and autumn. Prey spectrum included two main (reptiles and small mammals), and three sporadic, types of prey (arthropods, amphibians and birds). The consumption of reptiles and mammals was seasonal; the former decreased in occurrence from spring to autumn, whereas the latter showed an opposite pattern. There was an ontogenetic shift in the diet: juveniles fed mainly on reptiles and arthropods, whereas adult vipers progressively substitute this prey with insectivores, and the largest vipers primarily foraged on rodents and birds. Our results suggest that the seasonal variation in prey type was related to prey availability, whereas the ontogenetic shift was linked to gape limitation. The apparently wide prey spectrum of V. latastei must therefore be examined, taking into account that there are seasonal and ontogenetic dietary variations as well as geographic differences, the latter probably driven by climatic contrasts into the Iberian Peninsula. This new data of the endangered Iberian V. latastei can aid the effective conservation management of this species.

Is headfirst ingestion essential in gape-limited predators? Prey-handling behavior of the anurophagous snake Rhabdophis tigrinus (Colubridae)

2006 ◽  
Vol 84 (7) ◽  
pp. 954-963 ◽  
Author(s):  
Akira Mori
Keyword(s):  
Simple Model ◽  
Laboratory Experiments ◽  
Buccal Cavity ◽  
Stomach Contents ◽  
Large Prey ◽  
Behavioral Trait ◽  
Hind Limbs ◽  
Rhabdophis Tigrinus ◽  
Prey Handling ◽  
Physical Resistance

Headfirst ingestion of prey is a common adaptive behavioral trait in gape-limited predators that swallow large prey whole. To ascertain this tendency during anurophagy, prey handling and direction of prey ingestion were investigated in Rhabdophis tigrinus (Boie, 1826), a snake that feeds mainly on anurans. Examinations of stomach contents of wild R. tigrinus revealed that this snake does not show a tendency for headfirst ingestion of large prey, unlike most other snake species. In the laboratory, direction of ingestion depended largely on initial bite position, and when R. tigrinus swallowed a frog rump-first, the snake grasped both hind limbs of the frog and aligned them side by side so that both were swallowed together simultaneously from their tips. A simple model test suggested that physical resistance in the buccal cavity incurred during transportation of frogs may not differ between headfirst and hind-first ingestion if the hind limbs of frogs are aligned and swallowed simultaneously. Laboratory experiments also demonstrated that ingestively naive hatchlings of R. tigrinus are able to perform the unique manipulation required to swallow frogs hind-first. It is suggested that this unique ingestion mode is an adaptation for anurophagy, and several possible functional advantages are discussed.

scholarly journals Post-weaning maternal effects and the evolution of female dominance in the spotted hyena

2009 ◽  
Vol 276 (1665) ◽  
pp. 2291-2298 ◽  
Author(s):  
Heather E. Watts ◽  
Jaime B. Tanner ◽  
Barbara L. Lundrigan ◽  
Kay E. Holekamp
Keyword(s):  
Crocuta Crocuta ◽  
Female Dominance ◽  
Spotted Hyena ◽  
Compensatory Mechanism ◽  
Feeding Apparatus ◽  
Skull Development ◽  
Spotted Hyenas ◽  
Selection For ◽  
Maternal Presence ◽  
New Hypothesis

Mammalian societies in which females dominate males are rare, and the factors favouring the evolution of female dominance have yet to be clearly identified. We propose a new hypothesis for the evolution of female dominance and test its predictions with empirical data from the spotted hyena ( Crocuta crocuta ), a well-studied species characterized by female dominance. We suggest that constraints imposed by the development of a feeding apparatus specialized for bone cracking, in combination with the intensive feeding competition characteristic of spotted hyenas, led to the evolution of female dominance. Specifically, we propose that protracted development of the feeding apparatus in young hyenas led to selection for increased aggressiveness in females as a compensatory mechanism for mothers to secure food access for their young after weaning. Our analyses yielded results consistent with this hypothesis. Morphological and behavioural measurements indicate that skull development is indeed protracted in this species; spotted hyenas do not achieve adult skull size or feeding performance capabilities until after sexual maturity. The period between weaning and completed skull development is particularly challenging, as indicated by high mortality. Finally, maternal presence between weaning and full skull maturity, as well as the relative ability of females to aggressively displace conspecifics from food, are important determinants of offspring survival.

scholarly journals Humans disrupt access to prey for large African carnivores

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Kirby L Mills ◽  
Nyeema C Harris
Keyword(s):  
Prey Species ◽  
Prey Selection ◽  
Diel Activity ◽  
Spotted Hyena ◽  
Nocturnal Activity ◽  
Ecological Processes ◽  
Predator Prey ◽  
Human Presence ◽  
Prey Resources ◽  
Trophic Responses

Wildlife respond to human presence by adjusting their temporal niche, possibly modifying encounter rates among species and trophic dynamics that structure communities. We assessed wildlife diel activity responses to human presence and consequential changes in predator-prey overlap using 11,111 detections of 3 large carnivores and 11 ungulates across 21,430 camera trap-nights in West Africa. Over two-thirds of species exhibited diel responses to mainly diurnal human presence, with ungulate nocturnal activity increasing by 7.1%. Rather than traditional pairwise predator-prey diel comparisons, we considered spatiotemporally explicit predator access to several prey resources to evaluate community-level trophic responses to human presence. Although leopard prey access was not affected by humans, lion and spotted hyena access to three prey species significantly increased when prey increased their nocturnal activity to avoid humans. Human presence considerably influenced the composition of available prey, with implications for prey selection, demonstrating how humans perturb ecological processes via behavioral modifications.

Spline Wear-Effects of Design and Lubrication

1975 ◽  
Vol 97 (4) ◽  
pp. 1257-1263 ◽  
Author(s):  
P. M. Ku ◽  
M. L. Valtierra
Keyword(s):  
Design Process ◽  
Low Cost ◽  
Tooth Wear ◽  
Light Weight ◽  
Angular Misalignment ◽  
Transmit Power ◽  
Tooth Fracture ◽  
Minimum Price

Spline couplings are widely used to transmit power or drive accessories, or to operate components within accessories. Their principal advantages are mechanical simplicity, compactness and light weight, and low cost. Although spline couplings have a reputation of being able to accommodate some angular misalignment, the dangers of tooth fracture, fatigue, and wear that may result should be recognized. Unfortunately, it is exceedingly difficult to achieve perfect alignment in practice; thus, the design process should prudently allow for some minimum misalignment attainable and accept a reasonable penalty. This paper is concerned with the wear of the spline teeth, which is the minimum price that must be paid if misalignment is present. Those design- and lubrication-related parameters that may be employed to minimize tooth wear are discussed.

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