Role-Reversed Nepotism Among Cubs and Sires in the Spotted Hyena (Crocuta crocuta)

Nepotism is widespread among parents and offspring, and is typically associated with fundamental asymmetries; parents can usually do more to help their offspring than vice versa, and the cost of a given nepotistic behavior is usually less for parents than for offspring. This may not be so among spotted hyenas (Crocuta crocuta); sires never achieve social rank equal to that of their cubs, to whom they provide no obvious paternal care. Nepotism by sires towards their cubs is thus socially constrained. However, the higher social status of cubs might offset cubs’ developmental disadvantages and permit nepotistic treatment of sires by offspring. We therefore sought to determine whether the interactions among spotted hyena cubs and adult males were influenced by kinship, using long‐term observations from one clan of spotted hyenas. Sires exhibited no overt nepotism towards their cubs in most behaviors, but they did associate more closely with their daughters than with unrelated control females. Sires also associated more closely with their daughters than with their sons, with whom they associated no more closely than they did with unrelated control males. Cubs favored their sires by directing less intense aggression towards them than towards unrelated control males. Cubs of both sexes also associated more closely with their sires than with control males after the cubs were independent of the clan's communal den. Although sires evidently recognize their offspring, paternal nepotism by sires towards their cubs is weaker than filial nepotism by cubs towards their sires. The small size and immaturity of cubs thus appear to be weaker constraints on nepotism than is the low social status of their sires.     

Upper Pleistocene Panthera leo spelaea (Goldfuss, 1810) remains from the Bilstein Caves (Sauerland Karst) and contribution to the steppe lion taphonomy,palaeobiology and sexual dimorphism

Remains of the steppe lion Panthera leo spelaea (Goldfuss) from historical digs in the Bilstein Caves of Warstein (Sauerland, NW Germany) are described. Their age seems to be from the Early Weichselian periods (Upper Pleistocene). Whereas the Bilstein cave was inhabited by cave bears at that time only a few hyena prey remains, were most likely imported into the cave entrance by hyenas. Bite and crush marks on a few bones of Bison priscus, Bos primigenius, Cervus elaphus, a rhinoceros Coelodonta antiquitatis vertebra and even several chewed cave bear bones prove the hyena presence which is similar to other caves in the Sauerland hyena den cave rich region. Additionally some larger wolves subspecies Canis lupusspelaeus bones were found, but only few Crocuta crocuta spelaea remains are present. After taphonomic comparisons to six other hyena and cave bear den caves of northern Germany, this cave can be classified as a cave bear den, which was briefly used by hyenas only for food storage or commuting or cave bear predation site in one part of the Cave. The lion material refers at least to one young adult lioness, one more adult female and two male lions; therefore, at minimum, the remains of four adult individuals are represented. The absence of juvenile lion material, in contrast to cave bear cub remains in the Bilstein Caves, proves that P. leo spelaea did not use this and all other caves in the region to raise their cubs. The bone material from the Bilstein Caves would prove the same hyena-lion antagonism conflict being recently proven for the Perick Caves, Balve Cave or Martins Cave well. Other situations in caves such as the Keppler Cave and the Bilstein Cave initially show the more complex taphonomic situation of lion remains in European caves, especially in cave bear dens, where they seem to have hunted periodically cave bears, such as it is already proven for hyenas in the Sauerland Karst and other caves of Europe.     

Maternal rank is not correlated with cub survival in the spotted hyena, Crocuta crocuta

Reproductive success in female spotted hyenas, Crocuta crocuta,is positively correlated with social rank. High-ranking femalesare known to produce more offspring, but the effects of maternalrank on early cub survivorship have not been investigated. Cubmortality was examined over a 4-year period in one clan of wild-livingspotted hyenas in Kenya. Data were obtained for 100 cubs in63 litters produced by 27 adult females. Survivorship of cubsfrom birth through their first year was examined as a functionof litter size, sex of cubs, and maternal rank. Overall, cubmortality was high (61%). Contrary to expectation, singletoncubs did not survive better than twins, and there was no differencein survivorship between female and male cubs. High-ranking motherswere not more successful at raising twins or daughters thanwere low-ranking mothers. There was no correlation between cubmortality and maternal rank. Peaks in cub mortality coincidedwith life stage events, including mean age of arrival at a communalden, and age at which cubs began visiting kills. Documentedcauses of mortality included intraclan infanticide, disease,orphaning, predation by lions, and a mechanism of filial infanticidethat has not been previously described in this species: selectivelitter reduction by mothers via partial litter abandonment.No instances of facultative or obligate siblicide were detected.During this study, association between rank and number of cubssurviving to 1 year of age appeared to be due to differencesin reproductive output and not differential survival of cubswithin their first year.     

The effect of prey abundance and foraging tactics on the population dynamics of a social, territorial carnivore, the spotted hyena

We used naturally occurring spatial and temporal changes in prey abundance to investigate whether the foraging behavior of a social, territorial carnivore, the spotted hyena ( Crocuta crocuta ), conformed to predictions derived from the ideal free distribution. We demonstrate that hyenas in the Ngorongoro Crater, Tanzania, redistributed themselves from less profitable to more profitable areas, even when this required them to undertake foraging trips to areas beyond their clan territory boundary, or required normally philopatric females to emigrate. As expected for a system with rank related access to food resources in the territory, females of low social status foraged more often outside their territory and were more likely to emigrate than dominant females. Probably because Crater hyenas regularly foraged outside their territories, there was no correlation between clan size and prey density within territories, suggesting that clan sizes may have exceeded the carrying capacity of territories. A substantial decline of the hyena population in the Crater from 385 adults in the mid 1960s to 117 in 1996 was most likely due to a substantial decline of their main prey. The decline in the hyena population was associated with a decline in the size of clans but not in the number of clans. The number of clans probably remained constant due to emigration by females from large clans into vacant areas or clans with no adult females, and because hyenas regularly fed in areas containing concentrations of prey beyond their territory boundary. Between 1996 and 2003 annual recruitment rates of Crater hyenas consistently exceeded annual mortality rates, resulting in an almost doubling of the adult population. This increase was most likely due to an increase in prey abundance, a relatively low level of predation on hyenas by lions ( Panthera leo ), and an absence of high levels of disease related mortality.     

The holotypes of the upper Pleistocene Crocuta crocuta spelaea (Goldfuss, 1823: Hyaenidae) and Panthera leo spelaea (Goldfuss, 1810: Felidae) of the Zoolithen Cave hyena den (South Germany) and their palaeo‐ecological interpretation

The rediscovered holotype skulls of Late Pleistocene Panthera leo spelaea ( Goldfuss, 1810 ) (Felidae) and Crocuta crocuta spelaea ( Goldfuss, 1823 ) (Hyaenidae) from the Zoolithen Cave at Burggeilenreuth, southern Germany, are discussed. The cave became famous mainly due to its rich cave bear bone remains from the late Saalian (OIS 6–8) to Eemian/Weichselian (OIS 3–6) including additionally a third holotype of Ursus spelaeus Rosenmüller, 1794 (Ursidae). The ‘Felis spelaea’ holotype represents an adult male with a strong bite mark on the saggital crest, which was in an early stage of healing. Compared with other European Late Pleistocene lion skulls and skeletons, and with modern African lions, it provides evidence of intraspecific conflict between male Ice Age lions. The holotype of ‘Hyaena spelaea’ is one of several hundred hyena remains from a well‐frequented hyena den cave. The cave was used intensively by Late Pleistocene hyena clans, for collecting lion carcasses in addition to their accustomed prey, as happened in many caves throughout Europe. Ice Age spotted hyena clans might have killed Ice Age steppe lions for many reasons, such as fights over prey and territory, and the protection of cubs, but they did not always scavenge on their carcasses. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154 , 822–831.     

Optimal hunting group size: the need for lions to defend their kills against loss to spotted hyaenas

This paper presents preliminary evidence that kleptoparasitism by spotted hyaenas may influence optimal hunting group size of lions. In the absence of adult male lions, hyaenas can drive female and subadult lions off their kills provided they outnumber the lions by a factor of four. Hence the larger the group of lions on the kill, the greater their chance of defending their food against invading hyaenas. At Savuti, where there was a shortage of adult male lions, the groups of female and subadult lions lost almost 20% of their food to hyaenas. Losses were most frequent for those living in small groups. These lions were often satiated by the time the hyaenas acquired the kill, so the hyaenas did not cause immediate need, yet constituted a constant energy drain on lions by forcing them to hunt more frequently. The implications of these observations for modelling optimal hunting group size of lions are discussed.     

Eavesdropping and Risk Assessment Between Lions,Spotted Hyenas and African Wild Dogs

Vocalizing allows rapid transmission of detailed information beyond line of sight. However, the risk of eavesdropping by unintended receivers means there is also a potential cost to any vocalization. For fugitive species such as African wild dogs the potential cost of attracting dangerous competitors as eavesdroppers is especially significant. Experiments presented here demonstrate that eavesdropping lions Panthera leo were highly motivated to approach playbacks of wild dog Lycaon pictus vocalizations. As lions will kill any wild dogs they can catch, wild dogs risk paying high costs should their calls be detected. Lions were less likely to approach playbacks of spotted hyena Crocuta crocuta whoops, with responses split according to gender: male lions remained quick to approach hyena whoops, but females without accompanying males typically did not approach. Although hyenas seemed at least as capable as lions of detecting playbacks of wild dog calls, they were significantly less likely to subsequently approach them. Analogous to female lions faced with hyenas, the reluctance of hyenas to approach wild dogs may well derive from an assessment of the potential risks involved. We consider the hypothesis that wild dog twitters display counter‐adaptations against eavesdropping, but suggest that this species may best limit the risk of detection by avoiding areas where they are most likely to be overheard by lions.     

The largest European lion Panthera leo spelaea (Goldfuss 1810) population from the Zoolithen Cave,Germany: specialised cave bear predators of Europe

Remains of 13 individuals with 3/1 male/female ratio of the extinct Upper Pleistocene lion Panthera leo spelaea (Goldfuss, 1810) from the Zoolithen Cave near Burggeilenreuth (Bavaria, Germany) include the holotype skull and all paratype material. The highest mortality rate for the Zoolithen Cave lions is in their reproductive adult ages. Bite marks on lion bones or skulls are results of hyena activities, or rare cannibalism of lions under stress situations. Lions were possibly also killed in battles with cave bears during predation on hibernating bears in winter times. This cave bear hunt specialisation in caves overlaps with the ecological behaviour of cave bear feeding by Ice Age-spotted hyenas. Both largest Ice Age predators, lions and hyenas, had to specialise on feeding herbivorous cave bears in boreal forest mountainous cave rich regions, where the mammoth steppe megafauna prey was absent. This cave bear hunt by felids, and scavenging by hyenas and other large carnivores such as leopards and wolves explains why cave bears hibernated deep in to the European caves, for protection reasons against predators. Within such lion–cave bear and even lion–hyena conflicts in the caves lions must have been killed sometimes, explaining mainly the skeleton occurrences in different European caves.     

Lion density and population structure in the Selous Game Reserve: evaluation of hunting quotas and offtake

In 1992, tourist hunting in the Selous Game Reserve generated 1.28 million dollars for the Tanzanian government, of which 0·96 million dollars were returned to wildlife conservation. Lions ( Panthera leo ) are one of three critical species for tourist hunting, consistently generating 12%–13% of hunting revenue from 1988 to 1992. Because of their ecological and economic importance (and intrinsic value), it is important that lion quotas be set so that offtake is sustainable. The population density of lions in Selous ranges from 0·08 to 0·13 adults km⁻², comparable to unhunted ecosystems. The adult sex ratio (36–41% male) and the ratio of cubs to adults (29% cubs) are similar to those of unhunted populations. The ratio of lions to hyaenas is lower in heavily hunted areas (0·17 lions/hyena) than in unhunted areas (0·43 lions/hyena). Hunting levels between 1989 and 1994 took 2·7–4·3% of adult males annually, which is sustainable. The current quota is 10–16% of the adult male population, which exceeds natural mortality rates for male lions. To remain stable if the quota was filled, the population would have to compensate via increased fecundity, increased juvenile survival, or an altered sex‐ratio. Compensation occurs in Selous by producing (or raising) more male than female cubs (66–81% of juveniles are male). Only 28% of the Selous quota was filled in 1992. The percentage of quota filled (both in Selous and nationwide) has dropped since 1988 as quotas have increased. The current intensity of lion hunting in Selous is sustainable, but the quota cannot be filled sustainably.     

Risk-taking in free-living spotted hyenas is associated with anthropogenic disturbance,predicts survivorship,and is consistent across experimental contexts

Anthropogenic disturbance can have important influences on the fitness and behaviors of wild animals, including their boldness when exposed to risky conditions. We presented spotted hyenas (Crocuta crocuta) from two populations, each exposed to a different level of human activity, with a life-size model hyena representing an intruder from another clan. The high-disturbance population lived adjacent to human settlements, and the low-disturbance population inhabited a relatively undisturbed part of the same national park in Kenya. The mock intruder was presented to individual hyenas to assess their reactions to an alien hyena, and to determine whether their reactions varied with their exposure to anthropogenic activity. We found that human disturbance was indeed associated with hyena risk-taking behavior in response to the model intruder. Hyenas tested in the low-disturbance area exhibited more risk-taking behaviors by approaching the mock intruder more closely, and spending more time near it, than did their counterparts living in high-disturbance areas. Hyenas that spent less time in close proximity to the model had greater survivorship than those that spent more time in close proximity to it, regardless of disturbance level. Furthermore, the individual differences in risk-taking measured here were consistent with those obtained previously from the same animals using a different set of experimental manipulations. However, the experimentally induced behaviors were not consistent with naturally occurring risk-taking behaviors in proximity to lions; this suggests that risk-taking behaviors are consistent within individuals across experimental contexts, but that exposure to lions elicits different responses. Although our results are consistent with those from earlier tests of anthropogenic disturbance and boldness in spotted hyenas and other predators, they differ from results obtained from birds and small mammals, which are generally found to be bolder in areas characterized by human disturbance.     

南非Hluhluwe-Umfolozi公园植被对非洲狮群大小的影响

非洲狮(Pantheraleo)群处于不断的分裂-聚合过程,其亚群大小与原狮群大小以及诸如狮群捕食成功度、协作幼仔保护及狮群领域防卫等社会性因素有关。我们分析了南非一个保护区(Hluhluwe-Umfolozi公园)15年间的狮群大小,其成年雌狮和成年雄狮群的大小在保护区内呈显著性变化。在开放生境中雌狮结大群,而茂密植被生境中则结小群。雄狮群大小与植被类型无关,但在大的雌狮群分布区域发现大雄狮群。令人惊奇的是,作为幼狮成活率指标的幼狮群大小和雌狮平均幼仔数在保护区内没有显著性差异。我们认为,雌狮群大小的不同是对植被结构的适应,即在开放生境中大群有利于协作狩猎、育幼、共同保护幼仔、应对高强度群间领域防卫竞争。相反,茂密植被中,群间竞争很低,高密度植被覆盖有利于狩猎成功及补偿小狮群对幼仔保护的不足。雌狮平均幼仔数在整个保护区内没有变化,我们认为是由于开放生境和茂密植被对狮群大小起到相似的调节作用     

Sex Differences in Territorial Behavior Exhibited by the Spotted Hyena (Hyaenidae, Crocuta crocuta)

Spotted hyenas ( Crocuta crocuta ) are gregarious carnivores that defend group territories against encroachment by neighboring conspecifics. Here we monitored the behavior of members of one clan of free-ranging spotted hyenas during border patrols, 'wars' with neighboring clans, and other interactions with alien intruders, to document differences between the sexes in territorial behavior in this species. We also examined the possibility that the probability or rate of attack on alien hyenas encountered within the clan's territory would vary with the sex of the intruders. Initiation and leadership of most cooperative territorial behaviors were by adult female clan members, although border patrols were occasionally conducted by groups composed exclusively of resident males. The vast majority of alien intruders into the territory of the study clan were males. Resident females were more likely to attack intruding females than intruding males, but hourly rates of aggression directed by females towards aliens did not vary with intruder sex. Resident males were more likely than resident females to attack alien males, and resident males directed significantly higher hourly rates of aggression towards intruding males than females. Although female leadership in most cooperative territorial behaviors distinguishes spotted hyenas from many mammalian carnivores, other sex differences in the territorial behavior of spotted hyenas resemble those documented in other gregarious predators. Sex differences observed in hyena territoriality are consistent with the hypothesis that male and female clan members derive different selective benefits from advertisement and defense of group territories.     

A clan of Late Pleistocene hyenas,Crocuta crocuta spelaea (Goldfuss 1823), from the Rösenbeck Cave (Germany) and a contribution to cranial shape variability

The remains of a large population of Late Pleistocene Ice Age spotted hyenas (Crocuta crocuta spelaea Goldfuss 1823) are described from the Rösenbeck Cave in the Sauerland Karst of Germany. They include four skulls and 79 other skeletal parts, mainly from adult to senile animals, making this an important Late Pleistocene hyena cave‐den site in Europe. The skulls have been compared with 30 other hyena skull specimens from open air and cave‐den sites in central Europe (Germany, Austria, the Czech Republic and Romania) in order to achieve an understanding of sexual dimorphism in the crania of Ice Age spotted hyenas from the Upper Pleistocene cold period (Weichselian/Wuermian), and the types of injuries that they acquired during their lifetimes. Three different types of cranial shape have been distinguished, one of which appears to have been a consequence of pathologies that developed in response to injuries caused by bites received during the animal's lifetime, as a result of either intraspecies fights or fights with lions. Although cave bears penetrated to great depths within the Rösenbeck Cave for hibernation purposes, hyenas appear to have utilized only a short section of the cave that branched off directly from the entrance area. Hyena cub material is scarce, suggesting that this area was used as a communal den rather than for cub rearing. Bones exhibiting gnaw marks, representing prey imported by hyenas, are also rare but include horse (Equus caballus przewalskii) and reindeer (Rangifer tarandus) remains. The scarcity of bones from hyena prey suggests that this cave was not used as a food storage site. Some Ursus spelaeus cave bear remains, including skulls, show evidence of having been gnawed, chewed and cracked by hyenas, indicating that the hyenas periodically fed on cave bear carcasses in a specialization response to the mammoth steppe megafauna absence of the boreal mountain forest regions. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 191–220.     

Europe's first Upper Pleistocene Crocuta crocuta spelaea (Goldfuss 1823) skeleton from the Koněprusy Caves: a hyena cave prey depot site in the Bohemian Karst (Czech Republic)

One of the Europe's most complete Crocuta crocuta spelaea (Goldfuss 1823) skeletons from the Kon?prusy Caves, Bohemian Karst (Czech Republic) is an older pathological (hindlimb arthritis) and possibly smaller female individual. Few other cannibalistically scavenged hyena remains of older animals demonstrate a ‘small population’ that used the Main Dome area as a den site, which was marked well by faecal pellets. A large amount of megafauna prey was accumulated, and bones were further damaged or cracked. These hyenas hunted Przewalski horses dominantly, as has been documented all over the Bohemian Karst at several Late Pleistocene hyena den caves. The mammoth was mostly absent, instead the woolly rhinoceros was one of the meat colossi with indestructible bones also found in the Main Dome. These are the best indicators for hyena den sites identifications in general. Those massive bones found are left in repeating damaged ways and mainly as shafts and exposed best with bite marks in the bone spongiosa. Rhinoceros carcass body parts were removed by hyenas from the scavenging sites of the nearby surroundings, which they deported to the ‘prey storage den’-type site in the Main Dome area of the Kon?prusy Caves.     

Prey selection and prey preferences of spotted hyenas <Emphasis Type="Italic">Crocuta crocuta</Emphasis> in the Etosha National Park,Namibia

The feeding ecology of the spotted hyena Crocuta crocuta was studied in the central and eastern part of the Etosha National Park, Namibia. Hyenas mainly hunted migratory ungulates such as springbok Antidorcas marsupialis, zebra Equus burchelli, and blue wildebeest Connochaetes taurinus, but also resident species such as the greater kudu Tragelaphus strepsiceros and gemsbok Oryx gazella. There were, however, major differences in the species most frequently killed by hyenas in central and eastern Etosha. The preferred prey species of spotted hyenas in central Etosha was springbok, whereas regarding the abundance of zebra and wildebeest, these two species were rather avoided. In contrast, the prey species preferred by hyenas in eastern Etosha was kudu. Zebra and gemsbok were taken in proportion to their abundance, whereas wildebeest and springbok seemed to be rather avoided. Differences in prey selection and preferences were also reflected in differences in hunting group sizes. In eastern Etosha, where spotted hyenas frequently hunted larger prey, hunting group sizes were significantly larger compared to those in the center of the park.     

Society, demography and genetic structure in the spotted hyena

Spotted hyenas (Crocuta crocuta) are large mammalian carnivores, but their societies, called 'clans', resemble those of such cercopithecine primates as baboons and macaques with respect to their size, hierarchical structure, and frequency of social interaction among both kin and unrelated group-mates. However, in contrast to cercopithecine primates, spotted hyenas regularly hunt antelope and compete with group-mates for access to kills, which are extremely rich food sources, but also rare and ephemeral. This unique occurrence of baboon-like sociality among top-level predators has favoured the evolution of many unusual traits in this species. We briefly review the relevant socio-ecology of spotted hyenas, document great demographic variation but little variation in social structure across the species' range, and describe the long-term fitness consequences of rank-related variation in resource access among clan-mates. We then summarize patterns of genetic relatedness within and between clans, including some from a population that had recently gone through a population bottleneck, and consider the roles of sexually dimorphic dispersal and female mate choice in the generation of these patterns. Finally, we apply social network theory under varying regimes of resource availability to analyse the effects of kinship on the stability of social relationships among members of one large hyena clan in Kenya. Although social bonds among both kin and non-kin are weakest when resource competition is most intense, hyenas sustain strong social relationships with kin year-round, despite constraints imposed by resource limitation. Our analyses suggest that selection might act on both individuals and matrilineal kin groups within clans containing multiple matrilines.     

Infanticide by Male Lions Hypothesis: A Fallacy Influencing Research into Human Behavior

Recently, familial abuse and killing of children have been correlated with infanticidal behavior by nonhuman male animals which is postulated to be genetic. However, infanticide by males as an evolutionary mechanism is unlikely to occur in primates, and is equally unlikely in lions. To investigate the sexual selection hypothesis of infanticide for lions, four questions should be considered: (1) because they all mate freely with lionesses, are male pride lions closely related? (often they are not), (2) do males kill the young cubs when they join a pride? (few such cases have been observed), (3) do the females then mate with the new males to produce offspring? (yes), and (4) do the males remain with the pride for over two years to protect this new generation? (often not). Field data indicate that in NO instance do we know that male lions killed cubs in a new pride, mated with their mother, and then remained with the pride to protect their own young. Rather, female lions may kill more cubs than males and certainly cause many more cub deaths by allowing them to starve, [ infanticide by male lions, infanticide hypothesis, faulty science]     

African Wild Dogs as a Fugitive Species: Playback Experiments Investigate How Wild Dogs Respond to their Major Competitors

It has been suggested that African wild dogs Lycaon pictus need exceptionally large home ranges (and hence occur at such low densities) because they are limited by competition with larger sympatric carnivores, namely lions Panthera leo and spotted hyenas Crocuta crocuta. To investigate this relationship at a proximate level and explore which factors mediate it, we conducted audio playback experiments examining how wild dogs responded to the simulated proximity of either lions or hyenas. The principle finding was that wild dogs consistently moved directly away from lion roars, but when played hyena whoops either stood their ground or, later, moved off in a random direction. These results suggest that lions represent an immediate high‐level threat to wild dogs that is invariably best avoided, whilst the threat from hyenas may not be so great or perhaps is simply unavoidable. Wild dogs appeared to make some assessment of ambush risk during interactions with lions, illustrated by the varying latency to their retreat in habitats of differing vegetation density (and hence ambush potential). Additionally, packs with younger pups were more likely to alarm call and exhibited a slower rate of retreat in the hour following exposure to lion roars. Other variables investigated (competitor group size, lion sex, presence of pups) failed to explain variation in wild dogs’ responses.     

The TD6.3 faunal assemblage of the Gran Dolina site (Atapuerca,Spain): a late Early Pleistocene hyena den

Ethological studies have shown that besides human groups, large-medium carnivores have bone-collecting habits. The research developed since the last half of the twentieth century has attempted to characterise the carnivore’s accumulations and to identify them in the archaeo-paleontological record. At present, we have diagnostic criteria that define the accumulations produced by hyenids (mainly, Crocuta crocuta), thereby allowing us to differentiate them from the other accumulating agents. The faunal assemblage recovered at the Early Pleistocene TD6.3 layer of the Gran Dolina site is characterised by the presence of typical elements described in hyena dens: presence of small carnivores remains, high bone breakage, low epiphysis survival and a high frequency (>30%) of specimens with carnivore induced modifications, including large amounts of digested bones. However, attritional mortality profiles, hyena’s cubs remains, mid-shaft bone cylinders or differential anatomical composition among different weight-sizes, have not been observed or are ambiguous. In addition, anthropic evidences are scarce and concentrated in the uppermost section of the layer. TD6.3 is the result of an accumulation produced by hyenas using the cave as a den, in alternation with sporadic occupations by hominin groups. TD6.3 shows that hyena fossil accumulations may present great anatomical and taxonomic variability.     

Dispersal Status Influences Hormones and Behavior in the Male Spotted Hyena

Male spotted hyenas (Crocuta crocuta) reach puberty at 24 months of age and then invariably emigrate from their natal clans 1 to 38 months later. Thus there are two classes of reproductively mature males in everyCrocutaclan: adult natal males born in the clan and adult immigrant males born elsewhere. In one free-living hyena population in Kenya, these two groups of males were compared with respect to measures of aggression, social dominance, sexual behavior, and circulating hormone levels. Adult natal males engaged in higher hourly rates of aggression than did immigrants, won all fights with immigrants, and were socially dominant to immigrants. In addition, adult natal males engaged in far lower hourly rates of sexual behavior with resident females than did immigrants, and natal males were never observed to copulate with natal females. Mean basal plasma cortisol values did not differ between the two groups of adult males, but cortisol concentrations in immigrants were positively correlated with tenure in the clan and with immigrant male social rank. Adult natal males had plasma testosterone levels significantly lower than those of immigrants. Social rank and plasma testosterone values were positively correlated among immigrant males. Thus two different relationships appear to exist between circulating testosterone and social rank in maleCrocuta:one apparent in immigrants and the other in natal adult males. Our results suggest that dispersal might disinhibit testosterone secretion in postpubertal male hyenas.