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1.
Sulcal patterns were determined from endocasts of fossilTheropithecus (T. oswaldi andT. darti) and compared to the sulcal pattern of extant geladas (T. gelada). A comparison of the configurations of central and arcuate sulci suggests that the cortical motor face representation is relatively enlarged in extantTheropithecus, whereas the cortical motor and sensory face representations were enlarged inT. oswaldi. A relatively expanded sensory and/or motor cortical face representation may be related to masticatory (e.g., “seed-eating”) and gestural (e.g., “lipflip”) functions. SinceT. oswaidi is more derived (expanded) in sensory face representation thanT. gelada, it seems unlikely that it was a direct ancestor of modern geladas. Rather, the two groups were separate by 1.8 million years ago and may have had a most recent common ancestor similar toT. darti from the Hadar Formation of Ethiopia between 2 and 3 million years ago.  相似文献   

2.
Desert locust (Schistocerca gregaria) outbreaks have occurred repeatedly throughout recorded history in the Horn of Africa region, devastating crops and contributing to famines. In June 2009, a desert locust swarm invaded the Guassa Plateau, Ethiopia, a large and unusually intact Afroalpine tall-grass ecosystem, home to important populations of geladas (Theropithecus gelada), Ethiopian wolves (Canis simensis), thick-billed ravens (Corvus crassirostris), and other Ethiopian or Horn of Africa endemics. During the outbreak and its aftermath, we observed many animals, including geladas, ravens, and a wolf, feeding on locusts in large quantities. These observations suggest surprising flexibility in the normally highly specialized diets of geladas and wolves, including the potential for temporary but intensive insectivory during locust outbreaks. To our knowledge, Guassa is the highest elevation site (3,200–3,600 m) at which desert locusts, which require temperatures >20°C for sustained flight, have been reported. Continued monitoring will be necessary to determine whether the June 2009 outbreak was an isolated incident or part of an emerging pattern in the Ethiopian Highlands linked to global warming. The intensive consumption of desert locusts by geladas, wolves, and ravens during the outbreak at Guassa raises concerns about pesticide-based locust control strategies and potential unintended adverse effects on endemic and endangered wildlife.  相似文献   

3.
The subspecific taxonomy and distribution of geladas (Theropithecus gelada Rüppell, 1835) remains uncertain. Recent molecular studies based on mitochondrial sequence data revealed a geographically structured, three-deme population, suggesting that there are three evolutionary units of geladas. However, mitochondrial distributions do not always recover population relationships, particularly in taxa with a complex history of isolation and gene flow. We therefore analysed the nuclear genetic population structure of the global gelada population based on 20 microsatellite loci in 43 samples from across its geographic range. FST values, a STRUCTURE analysis and a principal coordinate analysis (PCoA) confirmed the three-deme population structure corresponding to the mitochondrial population structure. Therefore, our analyses provide additional support for three evolutionary units in geladas, corresponding to (a) a northern (north of Lake Tana, primarily in the Simien Mountains, previously classified as Theropithecus gelada gelada Rüppell, 1835), (b) a central (between Addis Ababa and the highlands east of Lake Tana, previously classified as Theropithecus gelada obscurus Heuglin, 1863) and (c) a southern (south of the Rift Valley, previously tentatively classified as Theropithecus gelada arsi Shotake et al., 2016, Anthropological Science, 124, 157) population. These results pave the way for future conservation decisions and highlight that the gelada population boundaries need more fine-grained genetic sampling and phenotypic analyses, in particular for their taxonomic ranking.  相似文献   

4.
Blood protein polymorphism of gelada baboon (Theropithecus gelada) to the south of the Rift Valley, Arsi Region, were examined for 36 genetic loci using three electrophoresis techniques for 48 blood samples from three localities, and compared with the northern geladas. New variant alleles and genetic markers of Hb-α, PA-2, and TBPA loci were detected. The distribution patterns of the variant alleles of Hb-α, PA-2, TBPA, Pi, Gc, PGM-II, and TBPA loci were localized in the geographic regions of south and north gelada populations, respectively. Genetic variability of southern geladas was estimated as Ppoly=0.083 and , which was comparable to northern geladas. A remarkably high genetic differentiation between the two geographic populations was shown byNei's genetic distance=0.071 and GST value=0.420. Our results of genetic analysis suggest that the southern and northern gelada populations have been separated for several hundred thousand years, and gene flow between the two geographic populations is severely restricted. The southern gelada baboon may be regarded as a distinct subspecies.  相似文献   

5.
Studying the dietary flexibility of primates that live in human‐modified environments is crucial for understanding their ecological adaptations as well as developing management and conservation plans. Southern gelada (Theropithecus gelada obscurus) is an endemic little‐known subspecies of gelada that inhabits human‐modified landscapes in the northern central highlands of Ethiopia. During an 18‐month period, we conducted this intensive study in an unprotected area of a human‐modified landscape at Kosheme in Wollo to investigate the feeding ecology of southern geladas and their dietary responses to seasonal variations. We quantified the monthly and seasonal diet data from a band of southern geladas using instantaneous scan sampling method at 15‐min intervals, and green grass phenology and availability using visual inspection from the randomly selected permanent plots. The overall average diet of southern geladas at Kosheme constituted grass blades 55.4%, grass undergrounds 13.2%, grass bulbs 5.6%, grass seeds 5.4%, herb leaves 4.0, fruits 7.3%, and cereal crops 5.6%. Grass blade consumption increased with increasing green grass availability, while underground food consumption increased with decreasing green grass availability, and vice versa. Southern geladas spent significantly more time feeding on the grass blades and herb leaves and significantly less time on bulbs during the wet season than the dry season. Underground grass items (rhizomes and corms) were not consumed during the wet season, but made up 22.3% of the dry season diet. Thus, although grass blades are staple diet items for geladas, underground diet items are important “fallback foods” at Kosheme. Our result shows insights into the dietary flexibility southern geladas adopt to cope with human‐modified landscapes of the north‐central Ethiopian Highlands. Thus, the study contributes to a better understanding of how changing environments shape primate ecology and evolution.  相似文献   

6.
Geladas were long supposed to be the only living primates feeding almost entirely on graminoids and accordingly display dramatic dental and manual adaptive traits. A recent study of Theropithecus gelada, the first in a relatively undisturbed habitat, revealed a more diverse diet, also incorporating large quantities of forbs. The peculiar adaptive traits of T. gelada are also observed in extinct Theropithecus as early as 3.7 Ma. Stable carbon isotopic data of extinct Theropithecus from eastern Africa indicate that specimens older than 3 Ma consumed a significant proportion of C3 plants (on average ca. 40% of total food intake) whereas specimens younger than 2 Ma consumed more C4 plants (on average ca. 80%). Recent paleobotanical evidence suggests that C3 herbaceous plants were still present in non‐negligible proportions in Plio‐Pleistocene lowland tropical ecosystems. Together, the shared morphological adaptive traits of extant and extinct Theropithecus and the varied diets of extant T. gelada suggest that the paleodiets of Theropithecus may have been dominated by herbaceous plants, comprising both C3 forbs and graminoids and C4 graminoids. The changes in stable carbon isotopes could correspond to a replacement of C3 plants by C4 plants within the herbaceous strata rather than a shift from C3 woody vegetation to C4 graminoids. This synthesis highlights the need for a more exhaustive knowledge of the ecology of extant species to achieve meaningful paleodietary and paleoenvironmental reconstructions. A strong selectivity for food resources that are rare in the landscapes (as in T. gelada) should also be considered when interpreting stable carbon isotopes of extinct African mammals (and notably hominids).  相似文献   

7.
Gelada baboons are the sole survivors of the genus Theropithecus and the only known graminivorous primates. They developed special adaptations to their diet such as high‐crowned teeth for processing hard and abrasive feed. The fine‐tuning of salivary protein composition might be another key mechanism that is used by species for adapting to the environment and competing with rivals for exploiting new ecological niches. In order to test whether gelada (graminivorous) and hamadryas baboons (omnivorous) differ in their salivary protein composition, we compared whole saliva samples of captive Theropithecus gelada and Papio hamadryas using gel electrophoresis and tannin‐binding assay. We hypothesized that the amount of proline‐rich salivary proteins with tannin‐binding capacity is higher in baboons consuming a feed with high dicot/monocot rations. Dicots produce tannins as a chemical defense system, discouraging animals from eating them. In contrast to dicots, monocots do not synthesize tannins. The presence of tannin‐binding proteins in saliva should effectively inactivate the dicot tannin‐based defense mechanism and increase the dietary breadth and/or the capability to switch between monocots and dicot leaves. The lack of such tannin‐binding proteins in saliva would indicate a narrow dietary spectrum more restricted to monocots. We found T. gelada to completely lack proline‐rich proteins (PRPs) and tannin‐binding capacity similar to a great variety of other grazing mammals. In contrast, P. hamadryas does possess PRPs with tannin‐binding activity. The findings support a growing body of evidence suggesting a high‐level specialization of T. gelada to grass diets. However, it remains unclear, whether loss of salivary tannin‐binding capacity drove the gelada into its narrow feeding niche, or whether this loss is the result of a long process of increased specialization. Thus, from an ecological point of view, T. gelada appears to be more vulnerable to environmental changes than other baboon species owing to its narrow dietary traits. Am. J. Primatol. 71:663–669, 2009. © 2009 Wiley‐Liss, Inc.  相似文献   

8.
The aim of this study was to investigate population structure and group size of geladas (Theropithecus gelada) at Chenek, Simien Mountains National Park. The study was carried out from January 2010 to June 2011 using total count method by classifying the study site into five different blocks. Size of the group was determined by counting individuals of geladas within an hour interval. A total of 397 geladas were counted and the ratio of adult males to adult females was 1 : 1.25, and this difference showed statistical significant (t = 8.157, P < 0.05). There was also significant difference between adult females with juveniles and infants (t = 21.027, P < 0.05). Population structure of geladas in a band comprised a single reproductive male and a number of females, subadults, juveniles and infants. Fission and fusion of individual geladas among different bands were observed during the study period. Geladas at the study site showed population growth and were seen competing for available food. They also stole food from local people and tourists and were seen to be interactive with people. Thus, the interference of people and livestock within the geladas natural habitat should be minimized to avoid human disturbance on the species and its natural habitat.  相似文献   

9.
Despite significant advances in our knowledge of how testosterone mediates life-history trade-offs, this research has primarily focused on seasonal taxa. We know comparatively little about the relationship between testosterone and life-history stages for non-seasonally breeding species. Here we examine testosterone profiles across the life span of males from three non-seasonally breeding primates: yellow baboons (Papio cynocephalus or P. hamadryas cynocephalus), chacma baboons (Papio ursinus or P. h. ursinus), and geladas (Theropithecus gelada). First, we predict that testosterone profiles will track the reproductive profiles of each taxon across their respective breeding years. Second, we evaluate age-related changes in testosterone to determine whether several life-history transitions are associated with these changes. Subjects include males (> 2.5 years) from wild populations of each taxon from whom we had fecal samples for hormone determination. Although testosterone profiles across taxa were broadly similar, considerable variability was found in the timing of two major changes: (1) the attainment of adult levels of testosterone and (2) the decline in testosterone after the period of maximum production. Attainment of adult testosterone levels was delayed by 1 year in chacmas compared with yellows and geladas. With respect to the decline in testosterone, geladas and chacmas exhibited a significant drop after 3 years of maximum production, while yellows declined so gradually that no significant annual drop was ever detected. For both yellows and chacmas, increases in testosterone production preceded elevations in social dominance rank. We discuss these differences in the context of ecological and behavioral differences exhibited by these taxa.  相似文献   

10.
Animals that live in groups are frequently exposed to conflict situations and must in some way maintain group cohesion. One mechanism that appears to restore social relationships after they have been disrupted by conflict isreconciliation. This study investigated reconciliatory behavior in the gelada baboon,Theropithecus gelada. The subjects were 11 adult geladas, housed in a large outdoor enclosure at the Bronx Zoo/Wildlife Conservation Park, New York. Five-minute focal animal samples following spontaneous aggression were compared with 5-min matched-control samples. The results of this study were: (1) geladas reunited in a friendly way after aggression; (2) former opponents were attracted to one another rather than dispersed from one another after a conflict; (3) most post-conflict reunions occurred within the first 2 min of the post-conflict period; and (4) geladas do not have any specific types of behavior associated with post-conflict reunions as do chimpanzees and macaques. The results of this study support the hypothesis that gelada baboons reconcile after aggression.  相似文献   

11.
Predation is widely believed to exert strong selective pressure on primate behavior and ecology but is difficult to study and rarely observed. In this study, we describe seven encounters between lone wild leopards (Panthera pardus) and herds of geladas (Theropithecus gelada) over a 6-year period in an intact Afroalpine grassland ecosystem at the Guassa Community Conservation Area, Ethiopia. Three encounters consisted of attempted predation on geladas by leopards, one of which was successful. All three attacks occurred in low-visibility microhabitats (dominated by tussock graminoids, mima mounds, or tall shrubs) that provided leopards with hidden viewsheds from which to ambush geladas. An additional four encounters did not result in an attempted attack but still document the consistently fearful responses of geladas to leopards. In encounters with leopards, geladas typically gave alarm calls (n = 7 of 7 encounters), reduced interindividual distances (n = 5), and collectively fled towards or remained at their sleeping cliffs (n = 7), the only significant refugia in the open-country habitat at Guassa. Geladas did not engage in mobbing behavior towards leopards. Encounters with leopards tended to occur on days when gelada herd sizes were small, raising the possibility that leopards, as ambush hunters, might stalk geladas on days when fewer eyes and ears make them less likely to be detected. We compare the behavioral responses of geladas to leopards at Guassa with those previously reported at Arsi and the Simien Mountains and discuss how gelada vulnerability and responses to leopards compare with those of other primate species living in habitats containing more refugia. Lastly, we briefly consider how living in multilevel societies may represent an adaptive response by geladas and other open-country primates to predation pressure from leopards and other large carnivores.  相似文献   

12.
Animals derive benefits from living in social groups but sociality also has its costs in that animals must compete with others for resources and mating opportunities. To cope with the conflict aftermath and social damage caused by competitive aggression, several group-living species use a variety of peace-keeping strategies. The affinitive post-conflict reunion of former opponents, defined as reconciliation, is the primary peace-keeping mechanism. In this study, we provide evidence for the occurrence of reconciliation and test some hypotheses on this post-conflict mechanism in geladas (Theropithecus gelada), a species often neglected in the study of post-conflict dynamics. The conciliatory contacts were uniformly distributed across the different sex–class combinations. Different from baboons, geladas did not show any particular kind of affinitive reconciliation behaviour. Notwithstanding the presence of a linear hierarchy, the dominance relationships did not affect the reconciliation dynamics. According to the valuable relationship hypothesis, coalitionary support seems to be a good predictor for a high level of conciliatory contacts. Finally, at an immediate level reconciliation plays a role in reducing renewed attacks by aggressors, which sought conciliatory contact more frequently than victims. In conclusion, even though the study of post-conflict behaviour in geladas needs to be continued, the patchy nature of their social network is a good model for testing some of the theoretical assumptions about primate conflict resolution.  相似文献   

13.
Aggression within a social group may affect bystanders’ affinitive behaviour with other bystanders. After a conflict such affiliations, termed ‘quadratic’, may serve to reduce tension. This particular kind of conflict management has been found in hamadryas baboons. Following the classical and well-established approach for studying post-conflict behaviour [post-conflict/matched control method (PC/MC)], we collected behavioural data on a group of geladas (Theropithecus gelada) in order to check for the presence of quadratic affiliations. A total of 192 PC/MC pairs were collected on both adults and immature individuals. We did not find any increase of affiliation levels between bystanders during PC compared with MC condition. The distribution of affinitive quadratic interactions was not affected by either kinship or relationship quality of bystanders. Moreover, comparison of yawning and self-scratching behaviours (two of the typical non-primate displacement activities under stressful situations) recorded during PCs and MCs did not show any variation in the two conditions. Probably, due to the male tolerance and social cohesiveness in geladas, witnessing a fight does not necessarily induce a sufficient increase of tension in bystanders to be reduced by quadratic affiliation.  相似文献   

14.
15.
Understanding of the biology of rarity is central to the conservation of some endangered species. Rare taxa are often reported to be specialized, but they are usually poorly studied. The Ethiopian wolf (Canis simensis) is endemic to the Ethiopian highlands and in two major populations, Bale and Arsi in the southern range of the species, it preys almost exclusively upon diurnal rodents all year round, mainly molerats Tachyoryctes macrocephalus and common molerats T. splendens, respectively. Where these large rodents are absent or rare, wolves are expected to rely more heavily on nocturnal rats or livestock. Prey remains in 161 scats from five newly studied populations confirmed that wolves are indeed specialist rodent hunters elsewhere, and that their narrow diets are dominated by diurnal Murinae rats (60–83% of prey occurrences). Swamp rats Otomys typus were the main prey, followed by grass rats Arvicanthis abyssinicus. Common molerats, Lophuromys rats and nocturnal Stenocephalemys spp. constituted the variable portion of the diets, and their proportional contributions varied across populations in relation to elevation and latitude. Towards the north, where the climate is drier and human populations more dense, wolves predate more frequently on rat‐sized prey, including nocturnal species, with implications for the survival of small populations in the Northern Highlands.  相似文献   

16.
The Tetraodontidae family are known to have relatively small and compact genomes compared to other vertebrates. The obscure puffer fish Takifugu obscurus is an anadromous species that migrates to freshwater from the sea for spawning. Thus the euryhaline characteristics of T. obscurus have been investigated to gain understanding of their survival ability, osmoregulation, and other homeostatic mechanisms in both freshwater and seawater. In this study, a high quality chromosome‐level reference genome for T. obscurus was constructed using long‐read Pacific Biosciences (PacBio) Sequel sequencing and a Hi‐C‐based chromatin contact map platform. The final genome assembly of T. obscurus is 381 Mb, with a contig N50 length of 3,296 kb and longest length of 10.7 Mb, from a total of 62 Gb of raw reads generated using single‐molecule real‐time sequencing technology from a PacBio Sequel platform. The PacBio data were further clustered into chromosome‐scale scaffolds using a Hi‐C approach, resulting in a 373 Mb genome assembly with a contig N50 length of 15.2 Mb and and longest length of 28 Mb. When we directly compared the 22 longest scaffolds of T. obscurus to the 22 chromosomes of the tiger puffer Takifugu rubripes, a clear one‐to‐one orthologous relationship was observed between the two species, supporting the chromosome‐level assembly of T. obscurus. This genome assembly can serve as a valuable genetic resource for exploring fugu‐specific compact genome characteristics, and will provide essential genomic information for understanding molecular adaptations to salinity fluctuations and the evolution of osmoregulatory mechanisms.  相似文献   

17.
We analyze geographic variation in morphology for Sierra Nevadan populations of Brown-headed Cowbirds (Molothrus ater) in relation to two levels of geographic structure of populations: 1) subspecies and 2) vocal dialects. Two morphologically distinct subspecies occupy opposite slopes of the Sierra Nevada: M. a artemisiae on the east slope is larger than M. a. obscurus on the west slope, and its juveniles have predominantly white versus yellow rictal (bill) flanges. Populations of obscurus moved into California from the lower Colorado River around 1900 and invaded the western Sierra during the 1930's. A relatively constant type of flight whistle occurs in obscurus populations up to 700 km apart, but east-slope artemisiae are divided into many distinct dialects. The means of seven morphological measurements and of principal component 1 (i.e., body size) for 2,287 individuals show similar clinal patterns for adult males, yearling males, and females over a 60-km north–south transect along the eastern Sierra Nevada: large sizes occur at the southernmost study site at Bishop, decrease clinally to the north to Mammoth Lakes, and then increase clinally to the north from Mammoth Lakes to the northernmost site at Lee Vining. This reversal in cline slope is reiterated for variation in the frequency of white-flanged juveniles. Our data do not support adaptive explanations for the clines. Rather, the most parsimonious explanation is that there has been flow of obscurus genes into artemisiae from the west slope across the crest of the Sierra Nevada into the Mammoth Lakes area. Concordantly, the Sierran crest at Mammoth Lakes is considerably lower than any other point within about 80 km to the north or 180 km to the south. Two other findings strongly support this interpretation. First, wing lengths of our longest-winged samples (at Bishop and Lee Vining) are significantly shorter than those of cowbirds collected in the same region between 1912 and 1922. Second, the wing lengths of Mammoth Lakes adult males and females during 1978–1981 are significantly larger than those of the 1982–1985 period. This putative hybridization must have been rapid, as there have been fewer than 50 years since secondary contact could have occurred. Calculation of the gene-flow parameter Ι of Endler (1977) indicates that the gene-flow rate reported here is higher than for nearly all of the species he surveyed. This gene flow occurs between two subspecies with different flight whistles and across several cowbird flight-whistle dialects within artemisiae. Therefore, vocal differences among these dialects do not appear to be a strong deterrent to gene flow.  相似文献   

18.
Comparison of the skulls of Papio baringensis Leakey 1969 from the Chemeron Formation and P. quadratirostris Iwamoto 1982 from the Usno Formation with those of Theropithecus gelada, T. brumpti, T. darti, T. oswaldi, and several species of Papio indicate that the species from Chemeron and Usno exhibit all, or most, respectively, of the shared derived characters of Theropithecus. We propose that they be removed from Papio and placed in Theropithecus as T. baringensis and T. quadratirostris. Comparison of the specimens of T. baringensis and T. quadratirostris with those of T. brumpti indicate that the former two species have some of the derived characters of T. brumpti but are primitive in others. We propose that the three species form the following phyletic lineage: T. baringensis-T. quadratirostris-T. brumpti. With these referrals, there are now six species of the genus Theropithecus. Based on geologic grounds, the specimens from Chemeron are about 4.0 million years (m.y.), that from Usno between 3.3 and 3.4 m.y., and those of T. brumpti between 2.0 and 2.8 m.y. in age. We also show that the most complete specimen of Papio sp. nov. from Olduval Gorge belongs to T. oswaldi. With the removal of these specimens from Papio, the East African fossil record of this genus, apart from isolated teeth, comprises only 21 specimens, while that of Theropithecus comprises at least 300 specimens.  相似文献   

19.
Conspicuous colored patches on animals often serve as sexually selected signals that advertise male quality. Such colored traits facilitate assessment of risks associated with a specific contest or benefits associated with a specific mate choice. Here, we investigate whether a colored patch of skin on the chests of male geladas (Theropithecus gelada) is a sexually selected signal. Specifically, we examine the relationship between color (redness), social status (a proxy for reproductive success), and age. We use observational data from known individuals from a population of wild geladas living in Ethiopia. We digitally quantified chest color using a previously-validated method for measuring color under field conditions. Results from this study are consistent with the hypothesis that redness is a quality signal in males. Baseline color correlates with status even when controlling for age. Indeed, males with redder chests were members of “better” groups: 1) leader males—the only males with reproductive access to females—had the reddest chests, and 2) within leader males, males with large units (>6 females) had redder chests than males with small units. At present, we are unable to address whether male chest color is directed at potential rivals or mates. Nevertheless, our data support the hypothesis that quality signals should prevail in large, fluid groups, where it is unlikely that individuals recognize all other group members. If individual recognition is limited in gelada society, this would favor the evolution of alternative means of assessment for making reproductive decisions.  相似文献   

20.
The Early/Middle Miocene boundary locality Sandelzhausen (MN5, southern Germany) yielded three beaver teeth: one lower incisor fragment and two strongly worn upper premolars, a right and a left one. The latter are so similar in wear, height, size, and enamel pattern that they probably represent one individual. Although the teeth have been referred to Chalicomys jaegeri Kaup, 1832 (e.g., Hugueney 1999, Fahlbusch 2003), it seems more likely that they belong to Steneofiber depereti Mayet, 1908. However, the assignment of the present material to either one of these species is difficult, because in the advanced wear stage some diagnostic characteristics cannot be assessed. As to ecological implications for the locality Sandelzhausen the taxonomic identity of these two beaver species may not be important. Both are known from riverine, lacustrine or swamp sediments, and it can be assumed that they usually lived in close vicinity to water. Thus, the presence of beaver remains supports the presence of water at Sandelzhausen. However, the teeth might have an allochthonous origin from creeks of the rising Alps.   相似文献   

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