黑斑羚粪便中碳同位素揭示的食性变化

利用稳定碳同位素数据(δ13C)分析了南非克鲁格国家公园混食性黑斑羚(Aepyceros melampus)时间和空间尺度上的食性变化,验证了两个假说,即有蹄类食性变化是由生境中木本植物与草本植物的相对配比导致;降雨控制有蹄类生态。结果表明:黑斑羚的食性涵盖了精食者-粗食者采食谱系,且食性中木本与草本比例在不同月间、季节、年度和区域间存在很大变化。栖息于开放性热带稀树草原和草原中的黑斑羚通常采食比生境中更高比例的草本,但在时间尺度上并不恒定。在克鲁格北部的一个区域(Punda Maria) ,黑斑羚采食的草本比克鲁格国家公园中其它任何区域都多。与其它生境相比,在河边的黑斑羚采食草本数量更少,尤其是在食性空间变化更为明显的旱季。因此,我们的数据不支持有蹄类食性组成变化是由生境中木本与草本比例不同造成的假说,食性与降雨量间也无明显的关系。我们的结果支持草本中蛋白含量增加引起黑斑羚采食比例的增加这一模型。粪便中氮含量在时间和空间上的变化很小,揭示在可利用食物中,无论木本还是草本,黑斑羚进行选择采食以保证最好的食物质量。基于这些结果,我们认为更具体的食物选择和可利用性最适采食理论能够更好地解释这种生态学变化。     

What Insights Can Baboon Feeding Ecology Provide for Early Hominin Niche Differentiation?

Several authors have proposed that papionin baboons provide appropriate analogs for early hominin niche differentiation. Savanna-dwelling baboons and australopiths both radiated around the same time after Neogene expansion of C₄ grasslands, likely experiencing similar environmental changes and faced with solving similar ecological problems. We explore the insights baboons may provide into dietary ecology of savanna-occupying hominins. We compare dietary information from stable isotope data for feces, hair, and tooth dentine collagen of modern chacma baboons (Papio ursinus) with dietary data for Plio-Pleistocene papionins and hominins from South African savannas. Results confirm that, like the australopiths, baboons consume substantial amounts of C₄ food sources. However, the magnitude of inter- and intraindividual variation in baboon diets across different seasons and habitats is less than that from specimens of Australopithecus africanus and Paranthropus robustus analyzed to date. Hominins also consumed greater amounts of C₄ resources. Thus, though the data demonstrate that the radiation of both primate groups was closely linked with the spread of C₄ grasslands, hominins were even more extreme ecological generalists than baboons were. The absence of a fixed-diet in papionins implies that it was unlikely that the more ecologically flexible hominins evolved specializations for any one food type, an interpretation consistent with recent carbon isotope, dental microwear, and ecomorphological studies. We propose that researchers place less emphasis on resolving the foods that were most important for hominin differentiation; instead, future research should focus on questions related to ecological generalism.     

Infant feeding and weaning practices in Roman Egypt.

Current knowledge of infant feeding and weaning practices during the Roman period in Egypt is limited to scanty documentary and iconographic evidence. Stable nitrogen and carbon isotope analysis provides another avenue to explore this question. A sample of 49 infant and juvenile human skeletal remains from the Kellis 2 cemetery in the Dakhleh Oasis, Egypt, was used to determine patterns of infant feeding and weaning. delta(15)N values indicate that supplementary foods were introduced at around 6 months of age, and that weaning was complete by 3 years of age. By 6 months of age, delta(13)C values become increasingly enriched over adult values, and reach peak enrichment at approximately 1.5 years of age. Beyond this age, delta(13)C gradually declines to approach adult values. This enrichment in infant delta(13)C values is indicative of consumption of (13)C-enriched supplementary foods. Based on isotopic study of faunal and botanical remains from the ancient village of Kellis, we conclude that at approximately 6 months of age, infants were fed milk of goat and/or cow.     

Mitochondrial phylogeny and systematics of baboons (Papio)

Baboons (Papio, s.s.) comprise a series of parapatric allotaxa (subspecies or closely related species) widely distributed in sub-Saharan Africa. Despite extensive studies of their ecology, morphology, and behavior, disagreement about their phylogenetic relationships continues, as expressed in the current coexistence of at least three major, competing taxonomic treatments. To help resolve this situation, we sequenced approximately 900 bases of mitochondrial DNA of 40 individuals from five of the widely recognized "major" allotaxa. Total sequence diversity (>5%) is high compared to most primate species. Major mitochondrial clades correspond to recognized allotaxa, with the important exception that haplotypes from yellow and olive baboons form a single, monophyletic clade within which the two allotaxa do not comprise mutually exclusive clusters. The major clades fall unambiguously into the pattern: (chacma (Guinea (hamadryas (yellow + olive)))). This phylogeny does not support taxonomies that oppose hamadryas to all other baboons ("desert" vs. "savanna"), but is compatible with the view that all definable allotaxa should be recognized as coordinates, either as "phylogenetic" species or "biological" subspecies. The close relationship and unsegregated distribution of haplotypes from Kenyan and Tanzanian yellow and olive baboons are unexplained, but may reflect introgression across the documented hybrid zone. The overall phylogeny, when combined with paleontological data, suggests a southern African origin for extant Papio baboons, with all extant lineages sharing a common mitochondrial ancestor at approximately 1.8 Ma.     

Geographical patterns of human diet derived from stable-isotope analysis of fingernails

Carbon and nitrogen isotope ratios of human fingernails were measured in 490 individuals in the western US and 273 individuals in southeastern Brazil living in urban areas, and 53 individuals living in a moderately isolated area in the central Amazon region of Brazil and consuming mostly locally grown foods. In addition, we measured the carbon and nitrogen isotope ratios of common food items to assess the extent to which these isotopic signatures remain distinct for people eating both omnivorous and vegetarian diets and living in different parts of the world, and the extent to which dietary information can be interpreted from these analyses. Fingernail delta13C values (mean +/- standard deviation) were -15.4 +/- 1.0 and -18.8 +/- 0.8 per thousand and delta15N values were 10.4 +/- 0.7 and 9.4 +/- 0.6 per thousand for southeastern Brazil and western US populations, respectively. Despite opportunities for a "global supermarket" effect to swamp out carbon and nitrogen isotope ratios in these two urbanized regions of the world, differences in the fingernail isotope ratios between southeastern Brazil and western US populations persisted, and appeared to be more associated with regional agricultural and animal production practices. Omnivores and vegetarians from Brazil and the US were isotopically distinct, both within and between regions. In a comparison of fingernails of individuals from an urban city and isolated communities in the Amazonian region, the urban region was similar to southeastern Brazil, whereas individuals from isolated nonurban communities showed distinctive isotopic values consistent with their diets and with the isotopic values of local foods. Although there is a tendency for a "global supermarket" diet, carbon and nitrogen isotopes of human fingernails hold dietary information directly related to both food sources and dietary practices in a region.     

Detection of breastfeeding and weaning in modern human infants with carbon and nitrogen stable isotope ratios

Carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) stable isotope ratios were longitudinally measured in fingernail and hair samples from mother-infant pairs where infants were exclusively breastfed (n = 5), breast- and formula-fed (n = 2), or exclusively formula-fed (n = 1) from birth. All exclusively breastfed infants had a dual enrichment in carbon ( approximately 1 per thousand) and nitrogen ( approximately 2-3 per thousand) when compared to maternal values. In contrast, breast- and formula-fed subjects had reduced enrichments compared to exclusively breastfed subjects, and the exclusively formula-fed infant showed no increase in delta(13)C or delta(15)N values. This finding of a carbon trophic level effect in breastfeeding infants suggests that (13)C-enrichments of approximately 1 per thousand in archaeological populations are not necessarily the result of the consumption of C(4)-based weaning foods such as maize or millet. During the weaning process, the delta(13)C results for breastfed infants declined to maternal levels more rapidly than the delta(15)N results. This suggests that delta(13)C values have the potential to track the introduction of solid foods into the diet, whereas delta(15)N values monitor the length of time of breast milk consumption. These findings can be used to refine the isotopic analysis of breastfeeding and weaning patterns in past and modern populations.     

Detection of Mycobacterium tuberculosis infection in chacma baboons (Papio ursinus) using the QuantiFERON-TB Gold (In-Tube) assay

Background  Early diagnosis of simian tuberculosis (TB) is vital to prevent transmission of this disease. We evaluated the ability of the QuantiFERON-TB Gold (In-Tube Method) assay (QFG-IT) to detect TB in chacma baboons ( Papio ursinus ).
Methods  Fifty-one baboons were tested using the Tuberculin Skin Test (TST) and the QFG-IT. Baboons testing positive, and animals exposed to infected individuals, were euthanised and subjected to necropsy. Selected tissues were processed for histopathology, mycobacterial culture and genetic speciation.
Results  Tuberculosis was confirmed in one TST positive/QFG-IT positive animal and one TST negative/QFG-IT positive animal. One TST positive/QFG-IT negative animal and five TST negative/QFG-IT negative animals were confirmed uninfected following necropsy.
Conclusion  The QFG-IT correctly detected TB in two baboons, including one TST negative individual and correctly identified six baboons as uninfected, including one TST positive individual. The QFG-IT shows promise as a sensitive, specific test for TB in chacma baboons.     

Stable isotopes complement focal individual observations and confirm dietary variability in reddish–gray mouse lemurs (Microcebus griseorufus) from southwestern Madagascar

We examine the ecology of reddish‐gray mouse lemurs from three habitats at Beza Mahafaly Special Reserve using focal follows and stable carbon and nitrogen isotope data. Focal observations indicate dietary differences among habitats as well as sexes and seasons. Both sexes consume more arthropods during the rainy season but overall, females consume more sugar‐rich exudates and fruit than males, and individuals from riparian forest consume fewer arthropods and more fruit than those in xeric or dry forest. We ask whether these observations are isotopically detectable. Isotope data support differences between seasons and sexes. Nitrogen isotope values are higher during the rainy season when lemurs consume more arthropods, and higher in males than females, particularly during the dry season. However, differences among populations inferred from focal observations are not fully supported. Lemurs from riparian forest have lower isotope values than those in xeric scrub, but isotope data suggest that lemurs from the dry forest eat the least animal matter and that focal observations overestimated dry forest arthropod consumption. Overall, our results suggest that observational and isotopic data are complementary. Isotope data can be obtained from a larger number of individuals and can quantify ingestion of animal matter, but they apparently cannot quantify the relative consumption of different sugar‐rich foods. Combined focal and isotope data provide valuable insight into the dietary constraints of reddish‐grey mouse lemurs, with implications for their vulnerability to future habitat change. Am J Phys Anthropol 155:77–90, 2014. © 2014 Wiley Periodicals, Inc.     

Kinda baboons (Papio kindae) and grayfoot chacma baboons (P. ursinus griseipes) hybridize in the Kafue river valley, Zambia

The ranges of small kinda (Papio kindae) and much larger grayfooted chacma (P. ursinus griseipes) baboons adjoin in the Kafue National Park, Zambia. In a visual survey of baboons at 48 sites in the Kafue River drainage we found that, contrary to previous reports, groups at the species interface near the town of Ngoma are phenotypically diverse and presumably formed by multigenerational hybridization. Mitochondrial and/or Y-chromosome genetic markers from fecal samples (N=164) collected at 29 sites support this conclusion. Groups with phenotypic signs of a history of hybridization also had taxon-specific mitochondria and Y-haplotypes from both parental species. Although the distribution of mitochondrial haplotypes largely mirrored that of external phenotypes, a significant proportion of male specimens from grayfoot as well as hybrid groups carried kinda Y-chromosomes, and kinda Y-chromosomes were involved in all observed cases of mitochondrial/Y-chromosome discordance. These observations are consistent with, though they do not prove, a population history in which the range of chacmas and the hybrid zone have advanced at the expense of the kinda range. They also suggest that, unexpectedly, kinda male×chacma female matings are much more common than the reciprocal cross in the ancestry of hybrids. We suggest that distinctive male kinda behavior and the "juvenile" appearance of kinda baboons of both sexes, perhaps combined with obstetric difficulties of a small kinda female carrying the large offspring of a chacma male, may account for this bias.     

Seasonality and interindividual variation in mandrill feeding ecology revealed by stable isotope analyses of hair and blood

Mandrills are large-bodied terrestrial forest primates living in particularly large social groups of several hundred individuals. Following these groups in the wild to assess differences in diet over time as well as among individuals is demanding. We here use isotope analyses in blood and hair obtained during repeated captures of 43 identified free-ranging mandrills (Mandrillus sphinx) from Southern Gabon, to test how dietary variation relates to the season as well as an individual's age and sex. We measured the stable carbon (δ¹³C‰) and nitrogen (δ¹⁵N‰) isotope ratios in 46 blood and 214 hair section samples as well as from a small selection of mandrill foods (n = 24). We found some seasonal isotopic effects, with lower δ¹³C values but higher δ¹⁵N values observed during the highly competitive long dry season compared to the fruit-rich long rainy season. Variation in δ¹³C was further predicted by individual age, with higher δ¹³C values generally found in younger individuals suggesting that they may consume more high canopy fruit than older individuals, or that older individuals consume more low canopy foliage. The best predictor for δ¹⁵N values was the interaction between age and sex, with mature and reproductively active males revealing the highest δ¹⁵N values, despite the observation that males consume substantially less animal food items than females. We interpret high δ¹⁵N values in these mature male mandrill blood and hair sections to be the result of nutritional stress associated with intense male–male competition, particularly during mating season. This is the first study showing isotopic evidence for nutritional stress in a free-ranging primate species and may spark further investigations into male mandrill diet and energy balance.     

Metabolic routing of dietary nutrients in birds: effects of diet quality and macronutrient composition revealed using stable isotopes

During fall migration many songbirds switch from consuming primarily insects to consuming mostly fruit. Fruits with more carbohydrates and less protein may be sufficient to rebuild expended fat stores, but such fruits may be inadequate to replace catabolized protein. We manipulated the concentrations and isotopic signatures of macronutrients in diets fed to birds to study the effects of diet quality on metabolic routing of dietary nutrients. We estimated that approximately 45% and 75%, respectively, of the carbon in proteinaceous tissue of birds switched to high- or low-protein diets came from nonprotein dietary sources. In contrast, we estimated that approximately 100% and 20%-80%, respectively, of the nitrogen in proteinaceous tissues of birds switched to high- or low-protein diets was attributable to dietary protein. Thus, the routing and assimilation of dietary carbon and nitrogen differed depending on diet composition. As a result, delta (15)N of tissues collected from wild animals that consume high-quality diets may reliably indicate the dietary protein source, whereas delta (13)C of these same tissues is likely the product of metabolic routing of carbon from several macronutrients. These results have implications for how isotopic discrimination is best estimated and how we can study macronutrient routing in wild animals.     

THE DIETS OF MODERN AND HISTORIC BOTTLENOSE DOLPHIN POPULATIONS REFLECTED THROUGH STABLE ISOTOPES

The δ¹³C and δ¹⁵N compositions of teeth used in combination with existing data provide dietary information for different populations of western North Atlantic bottlenose dolphins (Tursiops truncatus). The dental isotopic signatures of bottlenose dolphins collected during the 1980s significantly differ for coastal and offshore ecotypes and are consistent with reports that coastal forms feed primarily on fish whereas offshore individuals consume more squid. In a second study, the isotopic compositions of teeth from bottlenose dolphins that span a 100-yr period and data from published stomach content analyses as well as field observations made during the past 100 yr provide evidence that coastal bottlenose dolphins from the 1880s, 1920s, and 1980s had similar diets.     

The carbon isotope ecology and diet of Australopithecus africanus at Sterkfontein,South Africa

The stable carbon isotope ratio of fossil tooth enamel carbonate is determined by the photosynthetic systems of plants at the base of the animal's foodweb. In subtropical Africa, grasses and many sedges have C(4)photosynthesis and transmit their characteristically enriched 13C/(12)C ratios (more positive delta13C values) along the foodchain to consumers. We report here a carbon isotope study of ten specimens of Australopithecus africanus from Member 4, Sterkfontein (ca. 2.5 to 2.0Ma), compared with other fossil mammals from the same deposit. This is the most extensive isotopic study of an early hominin species that has been achieved so far. The results show that this hominin was intensively engaged with the savanna foodweb and that the dietary variation between individuals was more pronounced than for any other early hominin or non-human primate species on record. Suggestions that more than one species have been incuded in this taxon are not supported by the isotopic evidence. We conclude that Australopithecus africanus was highly opportunistic and adaptable in its feeding habits.     

Stable nitrogen and carbon isotope ratios in bone collagen as indices of prehistoric dietary dependence on marine and terrestrial resources in southern California

The ratios of 15N to 14N and 13C to 12C tend to be higher in marine than in terrestrial organisms. The concentrations of these isotopes in human bone collagen consequently can be used to make inferences about the contribution of marine and terrestrial resources to prehistoric diets. The utility of studying 15N/14N and 13C/12C ratios in conjunction with each other is illustrated by our analysis of 40 human burials from archaeological sites in the Santa Barbara Channel area of southern California. The mean delta 13C and delta 15N values (in per mil) of collagen from these skeletons decrease progressively from the Channel Islands (delta 13C = -14.0, delta 15N = +16.3) to the mainland coast (delta 13C = -14.5, delta 15N = +14.9) to the interior (delta 13C = -17.2, delta 15N = +10.9). These data suggest that Indians living on the Channel Islands during the late prehistoric period were heavily dependent on marine resources. The inhabitants of the mainland interior, in contrast, had a diet composed largely of terrestrial foods. From their isotope ratios, it appears that the Indians who lived on the mainland coast consumed a mixed diet containing substantial quantities of both marine and terrestrial resources. Differences in 15N/14N and 13C/12C ratios of individuals from mainland sites dating from the early and late prehistoric periods show that the marine component of the diet increased substantially through time. These isotopic data are consistent with pathological, faunal, and artifactual evidence of increased marine resource exploitation during the late prehistoric period.     

Intraspecific variation in hair delta(13)C and delta(15)N values of ring-tailed lemurs (Lemur catta) with known individual histories, behavior, and feeding ecology

Stable carbon and nitrogen isotope compositions were analyzed from hair samples of 30 sympatric ring-tailed lemurs (Lemur catta) inhabiting the Beza Mahafaly Special Reserve, Madagascar. All lemurs were known individuals involved in a longitudinal study, which allowed us to explore the degree to which group membership, sex, health status, and migration influenced their stable isotope compositions. The differences in delta(13)C and delta(15)N values between groups were small (<1.5 per thousand) but highly significant. In fact, each group was tightly clustered, and discriminant function analysis of the stable isotope data assigned individuals to the group in which they were originally collared with over 90% accuracy. In general, the differences between groups reflected the degree to which they utilized forested versus open habitats. As open habitats at Beza Mahafaly often correspond to areas of anthropogenic disturbance, these data suggest that isotopic data can be useful for addressing questions of lemur conservation. There were few sex differences, but significant differences did occur between individuals of normal and suboptimal health, with those in poor health (especially those in the worst condition) being enriched in (15)N and to a lesser degree (13)C compared with healthy individuals. Moreover, lemurs that had emigrated between 2003 and 2004 had different delta(13)C and delta(15)N compositions than their original groups.     

Do "savanna" chimpanzees consume C4 resources?

Several stable carbon isotopic studies have shown that South African australopiths consumed significant quantities of C(4) resources (tropical grasses, sedges, or animals that eat those foods), but relatively little is known about the consumption of such resources by chimpanzees. Here, we present stable carbon isotopic data for 36 chimpanzee hair samples from Fongoli, one of the driest and most open areas inhabited by chimpanzees. These data suggest that the Fongoli chimpanzees consume little in the way of C(4) vegetation or animals that eat such vegetation, even though these resources are locally abundant and preferred fruits are more widely scattered than at most chimpanzee study sites. The homogeneity of the Fongoli results is especially striking and recalls the narrow isotopic distribution of stenotopic savanna mammals. This is in stark contrast to what has been observed for australopiths, which had highly variable diets and consumed about 35% C(4) vegetation on average. Carbon isotope data for modern and fossil Papio depict a dietarily variable genus with a tendency to consume C(4) vegetation. This trophic flexibility, or willingness to consume C(4) savanna resources, may make Papio a more profitable ecological analog for australopiths than chimpanzees.     

Biogeochemical and craniometric investigation of dietary ecology, niche separation, and taxonomy of Plio-Pleistocene cercopithecoids from the Makapansgat Limeworks

Three sympatric fossil cercopithecoid genera (Cercopithecoides, Parapapio, and Theropithecus) occur in Members 3 and 4 at the Makapansgat Limeworks hominin locality, South Africa, and their presence in a single ecosystem suggest a certain degree of ecological and/or dietary differentiation between taxa. Here, we explore the extent of dietary niche separation amongst these taxa using stable isotope (13C/12C, 18O/16O) and trace-element (Sr, Ba, Ca) analyses of fossil tooth enamel. In particular we searched for evidence of subtle niche separation between the more closely related, morphologically similar taxa of the genus Parapapio, as uncertainties exist around their taxonomy and taxonomic identification. Given these uncertainties, craniometric analyses were also performed to ground the dietary interpretations in a morphological context. The results found no clear taxonomic signal in the craniometric data for the Parapapio sample, and further indicate that this sample was no more variable morphologically than a single, geographically circumscribed, extant chacma baboon sample. In contrast, two overlapping dietary ecologies were found within this same Makapansgat Parapapio sample. Additionally, two widely differing dietary ecologies were found within the Cercopithecoides williamsi sample, while results for Theropithecus darti indicate a predominantly C4 diet. Hence, although biogeochemical dietary indicators point towards distinct dietary ecologies within and between fossil genera at Makapansgat, within the genus Parapapio disjunctions exist between the dietary categories and the taxonomic assignment of specimens.     

Distribution and population estimate for the chacma baboon (Papio ursinus) in KwaZulu-Natal, South Africa

We report the current species distribution and population estimate for the chacma baboon (Papio ursinus) in KwaZulu-Natal Province (KZN), South Africa, based on an analysis of estimated area of occupancy and estimated home range size. This estimate suggests a total population size of approximately 11,000 individuals for KZN. Much of the province is uninhabited, with a density in occupied areas of approximately 1.8 animals per km(2). The current population size may be more than an order of magnitude smaller than historical population size. Chacma baboons now exhibit a highly fragmented and discontinuous distribution in KZN, with 58% of the population residing within protected areas, and more than half of these troops reside in areas >1,500?m above average sea level. The small population and highly fragmented distribution of chacma baboons in KZN, combined with rapidly increasing human population size and transformation of natural habitat, suggest this species requires greater conservation attention.     

Fallback foods and dietary partitioning among Pan and gorilla

Recent findings on the strong preference of gorillas for fruits and the large dietary overlap between sympatric gorillas and chimpanzees has led to a debate over the folivorous/frugivorous dichotomy and resource partitioning. To add insight to these arguments, we analyze the diets of sympatric gorillas and chimpanzees inhabiting the montane forest of Kahuzi-Biega National Park (DRC) using a new definition of fallback foods (Marshall and Wrangham: Int J Primatol 28 [2007] 1219–1235). We determined the preferred fruits of Kahuzi chimpanzees and gorillas from direct feeding observations and fecal analyses conducted over an 8-year period. Although there was extensive overlap in the preferred fruits of these two species, gorillas tended to consume fewer fruits with prolonged availability while chimpanzees consumed fruits with large seasonal fluctuations. Fig fruit was defined as a preferred food of chimpanzees, although it may also play a role as the staple fallback food. Animal foods, such as honey bees and ants, appear to constitute filler fallback foods of chimpanzees. Tool use allows chimpanzees to obtain such high-quality fallback foods during periods of fruit scarcity. Among filler fallback foods, terrestrial herbs may enable chimpanzees to live in small home ranges in the montane forest, whereas the availability of animal foods may permit them to expand their home range in arid areas. Staple fallback foods including barks enable gorillas to form cohesive groups with similar home range across habitats irrespective of fruit abundance. These differences in fallback strategies seem to have shaped different social features between sympatric gorillas and chimpanzees. Am J Phys Anthropol 140:739–750, 2009. © 2009 Wiley-Liss, Inc.