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Isotopic analysis is destructive and requires that a specimen retains its original (biogenic) chemical composition. A specimen's relative abundance of calcium and phosphorous (Ca/P) or carbonate and phosphate (CO3/PO4) is often used to assess preservation. If a specimen's Ca/P or CO3/PO4 is similar to modern specimens, a specimen's isotopic composition may be biogenic. However, most methods for measuring these proxies are destructive. Moreover the relationships between Ca/P, CO3/PO4 and isotopic preservation are poorly established. In this study, we assessed the ability of handheld X-ray fluorescence (hXRF) to non-destructively evaluate a specimen's preservation by characterizing the calcium to phosphorous ratio (Ca/P). We first established that surface Ca/P (Ca/Psurface) for modern specimens was consistent with expectations for unaltered bone (1.3–2.3). Several specimens had slightly larger ratios, suggesting the currently accepted range may need to be expanded. Second, we tested the ability of Ca/Psurface to detect alteration using twenty Quaternary mammal teeth from Big Bone Lick, Kentucky. Ten specimens had Ca/Psurface between 1.3 and 2.3 and ten had larger ratios, suggesting alteration. Because most methods measure Ca/P in powder (Ca/Ppowder), we compared Ca/Psurface, Ca/Ppowder, and the enamel subsurface (Ca/Psubsurface). With two exceptions, Ca/Psubsurface and Ca/Ppowder were below 2.3, regardless of Ca/Psurface, suggesting that Ca/Ppowder and Ca/Psubsurface underestimate alteration. We next compared Ca/Psurface, CO3/PO4, and carbon (δ13C) and oxygen (δ18O) isotope values for the fossil teeth. Fourteen specimens were identified as altered or unaltered by both proxies, but six specimens only had one altered proxy. Specimens with both proxies altered had lower, less variable δ13C values than specimens with both proxies unaltered. Median δ18O values were similar between these groups. Individuals with altered Ca/Psurface but unaltered CO3/PO4 isotopically resembled specimens with both proxies altered. Conversely, specimens with unaltered Ca/Psurface and altered CO3/PO4 were similar to specimens with both proxies unaltered. Notably, all individuals with both proxies altered had relatively low δ13C values, including a horse and mammoth, which are normally considered grazers (and therefore should have higher δ13C values). These and other altered specimens may be isotopically compromised. Overall, our results suggest that Ca/Psurface is effective at detecting alteration non-destructively, quickly, and affordably, making it an attractive approach for analyzing unique specimens.

Under harsh Pleistocene climates, migration and other forms of seasonally patterned landscape use were likely critical for reproductive success of mastodons ( Mammut americanum ) and other megafauna. However, little is known about how their geographic ranges and mobility fluctuated seasonally or changed with sexual maturity. We used a spatially explicit movement model that coupled strontium and oxygen isotopes from two serially sampled intervals (5+ adolescent years and 3+ adult years) in a male mastodon tusk to test for changes in landscape use associated with maturation and reproductive phenology. The mastodon’s early adolescent home range was geographically restricted, with no evidence of seasonal preferences. Following inferred separation from the matriarchal herd (starting age 12 y), the adolescent male’s mobility increased as landscape use expanded away from his natal home range (likely central Indiana). As an adult, the mastodon’s monthly movements increased further. Landscape use also became seasonally structured, with some areas, including northeast Indiana, used only during the inferred mastodon mating season (spring/summer). The mastodon died in this area (>150 km from his core, nonsummer range) after sustaining a craniofacial injury consistent with a fatal blow from a competing male’s tusk during a battle over access to mates. Northeast Indiana was likely a preferred mating area for this individual and may have been regionally significant for late Pleistocene mastodons. Similarities between mammutids and elephantids in herd structure, tusk dimorphism, tusk function, and the geographic component of male maturation indicate that these traits were likely inherited from a common ancestor.

Understanding seasonal mobility, population connectivity, and site fidelity is critical for managing and preserving migratory species. We investigated the potential of coupling strontium (87Sr/86Sr) and hydrogen (δ2H) isotopes in feathers for quantitatively constraining natal origin for juvenile migratory predatory birds (raptors) using a probabilistic framework. We first calibrated single‐isotope models that predict spatial isotope variability in raptor feathers (called isoscapes) by analyzing and compiling isotope data for juvenile birds with known origins in North America and comparing their values to existing isotopic baselines in precipitation (for δ2H) and bioavailable strontium (for 87Sr/86Sr). We then compared the potential of hydrogen and strontium isotopes for refining geographic assignments either independently or combined. While yielding very different probability maps, hydrogen and strontium isotopes performed equally well at constraining regions of natal origin. However, thanks to the complementarity of these isotopes, dual δ2H and 87Sr/86Sr assignments increased predictive precision by an order of magnitude compared to either isotope alone. Lastly, we used the models to predict natal origin for juveniles with unknown origins that were sampled in southwestern Idaho, USA, during their autumn migration. The precision of geographic assignments for birds with unknown origins varied. Nevertheless, dual‐isotope assignments clearly distinguished individuals born outside of southwestern Idaho, and overall, predicted geographic assignments matched breeding ranges for the study species. Quantitative dual‐isotope geographic assignments enhance our ability to predict natal range of migratory raptors and complement other methods for monitoring movement and population connectivity. Combining isotopic data from feathers with other intrinsic geochemical and genetic data, as well as extrinsic markers, such as transmitters or bands, and niche‐modeling approaches will further refine key nesting areas for migratory birds.

Recently expanded estimates for when humans arrived on Madagascar (up to approximately 10 000 years ago) highlight questions about the causes of the island's relatively late megafaunal extinctions (approximately 2000–500 years ago). Introduced domesticated animals could have contributed to extinctions, but the arrival times and past diets of exotic animals are poorly known. To conduct the first explicit test of the potential for competition between introduced livestock and extinct endemic megafauna in southern and western Madagascar, we generated new radiocarbon and stable carbon and nitrogen isotope data from the bone collagen of introduced ungulates (zebu cattle, ovicaprids and bushpigs,n= 66) and endemic megafauna (pygmy hippopotamuses, giant tortoises and elephant birds,n= 68), and combined these data with existing data from endemic megafauna (n= 282, including giant lemurs). Radiocarbon dates confirm that introduced and endemic herbivores briefly overlapped chronologically in this region between 1000 and 800 calibrated years before present (cal BP). Moreover, stable isotope data suggest that goats, tortoises and hippos had broadly similar diets or exploited similar habitats. These data support the potential for both direct and indirect forms of competition between introduced and endemic herbivores. We argue that competition with introduced herbivores, mediated by opportunistic hunting by humans and exacerbated by environmental change, contributed to the late extinction of endemic megafauna on Madagascar.

Fundamental disagreements remain regarding the relative importance of climate change and human activities as triggers for Madagascar's Holocene megafaunal extinction. We use stable isotope data from stalagmites from northwest Madagascar coupled with radiocarbon and butchery records from subfossil bones across the island to investigate relationships between megafaunal decline, climate change, and habitat modification. Archaeological and genetic evidence support human presence by 2000 years Before Common Era (BCE). Megafaunal decline was at first slow; it hastened at ∼700 Common Era (CE) and peaked between 750 and 850 CE, just before a dramatic vegetation transformation in the northwest that resulted in the replacement of C3 woodland habitat with C4 grasslands, during a period of heightened monsoonal activity. Cut and chop marks on subfossil lemur bones reveal a shift in primary hunting targets from larger, now-extinct species prior to ∼900 CE, to smaller, still-extant species afterwards. By 1050 CE, megafaunal populations had essentially collapsed. Neither the rapid megafaunal decline beginning ∼700 CE, nor the dramatic vegetation transformation in the northwest beginning ∼890 CE, was influenced by aridification. However, both roughly coincide with a major transition in human subsistence on the island from hunting/foraging to herding/farming. We offer a new hypothesis, which we call the “Subsistence Shift Hypothesis,” to explain megafaunal decline and extinction in Madagascar. This hypothesis acknowledges the importance of wild-animal hunting by early hunter/foragers, but more critically highlights negative impacts of the shift from hunting/foraging to herding/farming, settlement by new immigrant groups, and the concomitant expansion of the island's human population. The interval between 700 and 900 CE, when the pace of megafaunal decline quickened and peaked, coincided with this economic transition. While early megafaunal decline through hunting may have helped to trigger the transition, there is strong evidence that the economic shift itself hastened the crash of megafaunal populations.

Despite extensive research on the evolutionary history and ecology of horses, surprisingly little is known about the daily and seasonal movements (i.e. mobility) of extinct species. We used strontium isotope ratios (87Sr/86Sr) in tooth enamel to estimate mobility patterns of equids from two Miocene fossil sites in northern Florida, USA: Thomas Farm (ca. 18 Ma) and Love Bone Bed (ca. 9.5–9 Ma). The species included in our sample have a range of body sizes (45–252 kg) and reconstructed diets. Gomphotheres and tapirs from Love Bone Bed were also included to represent browsers. Based on modern species' behavior, we predicted small-bodied and browsing taxa living in closed habitats had limited mobility and 87Sr/86Sr similar to local northern Florida limestone. We anticipated larger-bodied and grazing taxa living in open environments had increased mobility, with higher and more variable 87Sr/86Sr reflecting larger movements across differing geologies. Contrary to expectations, the majority of taxa at both sites have higher 87Sr/86Sr than expected for local Eocene bedrock and instead are similar to contemporary Late Oligocene to mid-Miocene seawater. The most plausible explanation for these findings is that most individuals foraged close to the paleo-coastline, where vegetation would have been influenced by marine-derived strontium via sea spray or precipitation. Tapirs have considerably higher and more variable 87Sr/86Sr than horses or gomphotheres at Love Bone Bed, which may reflect foraging on aquatic vegetation in the river channel that is preserved at the site. Our results suggest that horses were relatively sedentary in Florida, even during their peak radiation.

The Ancestral Puebloans occupied Chaco Canyon, in what is now the southwestern USA, for more than a millennium and harvested useful timber and fuel from the trees of distant forests as well as local woodlands, especially juniper and pinyon pine. These pinyon juniper woodland products were an essential part of the resource base from Late Archaic times (3000–100 BC) to the Bonito phase (AD 800–1140) during the great florescence of Chacoan culture. During this vast expanse of time, the availability of portions of the woodland declined. We posit, based on pollen and macrobotanical remains, that the Chaco Canyon woodlands were substantially impacted during Late Archaic to Basketmaker II times (100 BC–AD 500) when agriculture became a major means of food production and the manufacture of pottery was introduced into the canyon. By the time of the Bonito phase, the local woodlands, especially the juniper component, had been decimated by centuries of continuous extraction of a slow-growing resource. The destabilizing impact resulting from recurrent woodland harvesting likely contributed to the environmental unpredictability and difficulty in procuring essential resources suffered by the Ancestral Puebloans prior to their ultimate departure from Chaco Canyon.

Significance Based on “subfossil” skeletal remains it is known that multiple now-extinct giant lemur (primate) species with estimated body masses of up to ∼160 kg survived on Madagascar into the past millennium. In this study, we used ancient DNA methods to sequence the nuclear genome of one of these megafaunal lemurs, Megaladapis edwardsi (∼85 kg). With the power of the nuclear genome, we robustly resolved the phylogenetic relationship between Megaladapis and other lemurs, which had been a lingering uncertainty. We also identified multiple signatures of past positive natural selection across the M. edwardsi genome that support reconstructions of this taxon as a large-bodied, specialized folivore., No endemic Madagascar animal with body mass >10 kg survived a relatively recent wave of extinction on the island. From morphological and isotopic analyses of skeletal “subfossil” remains we can reconstruct some of the biology and behavioral ecology of giant lemurs (primates; up to ∼160 kg) and other extraordinary Malagasy megafauna that survived into the past millennium. Yet, much about the evolutionary biology of these now-extinct species remains unknown, along with persistent phylogenetic uncertainty in some cases. Thankfully, despite the challenges of DNA preservation in tropical and subtropical environments, technical advances have enabled the recovery of ancient DNA from some Malagasy subfossil specimens. Here, we present a nuclear genome sequence (∼2× coverage) for one of the largest extinct lemurs, the koala lemur Megaladapis edwardsi (∼85 kg). To support the testing of key phylogenetic and evolutionary hypotheses, we also generated high-coverage nuclear genomes for two extant lemurs, Eulemur rufifrons and Lepilemur mustelinus, and we aligned these sequences with previously published genomes for three other extant lemurs and 47 nonlemur vertebrates. Our phylogenetic results confirm that Megaladapis is most closely related to the extant Lemuridae (typified in our analysis by E. rufifrons) to the exclusion of L. mustelinus, which contradicts morphology-based phylogenies. Our evolutionary analyses identified significant convergent evolution between M. edwardsi and an extant folivore (a colobine monkey) and an herbivore (horse) in genes encoding proteins that function in plant toxin biodegradation and nutrient absorption. These results suggest that koala lemurs were highly adapted to a leaf-based diet, which may also explain their convergent craniodental morphology with the small-bodied folivore Lepilemur.

Researchers typically assume constant fur and hair growth for primates, but the few studies that have investigated growth explicitly suggest this may not be the case. Instead, growth may vary considerably among individuals and across seasons. One might expect this variability to be most pronounced for species that have seasonally variable activity patterns (e.g., Madagascar&rsquo, s Cheiorogaleidae). In particular, dwarf lemurs (Cheirogaleus spp.) undergo considerable changes in their daily activity levels (torpor) in the austral fall, when nights get shorter. I monitored regrowth of shaved fur patches for eight adult captive fat-tailed dwarf lemurs (Cheirogaleus medius) and gray mouse lemurs (Microcebusmurinus) on a bi-weekly basis for 21 months in total. Regrowth varied considerably both within and among individuals. Overall, fur regrew in spurts and was faster for mouse lemurs (0&ndash, 14 to 215&ndash, 229 days) than dwarf lemurs (27&ndash, 40 to 313&ndash, 327 days). There were significant differences between species and an obvious influence of season for dwarf lemurs, but no clear influence of shave location, age, or sex. Similar trends have been previously reported for captive lemurids, suggesting that seasonal fur growth may be widespread across Lemuroidea. Researchers are cautioned against using primate fur or hair to investigate variables confounded by seasonality (such as diet and body condition) until patterns of growth are better understood.

A new fossil site in a previously unexplored part of western Madagascar (the Beanka Protected Area) has yielded remains of many recently extinct vertebrates, including giant lemurs (Babakotia radofilai, Palaeopropithecus kelyus, Pachylemur sp., and Archaeolemur edwardsi), carnivores (Cryptoprocta spelea), the aardvark-like Plesiorycteropus sp., and giant ground cuckoos (Coua). Many of these represent considerable range extensions. Extant species that were extirpated from the region (e.g., Prolemur simus) are also present. Calibrated radiocarbon ages for 10 bones from extinct primates span the last three millennia. The largely undisturbed taphonomy of bone deposits supports the interpretation that many specimens fell in from a rock ledge above the entrance. Some primates and other mammals may have been prey items of avian predators, but human predation is also evident. Strontium isotope ratios (87Sr/86Sr) suggest that fossils were local to the area. Pottery sherds and bones of extinct and extant vertebrates with cut and chop marks indicate human activity in previous centuries. Scarcity of charcoal and human artifacts suggests only occasional visitation to the site by humans. The fossil assemblage from this site is unusual in that, while it contains many sloth lemurs, it lacks ratites, hippopotami, and crocodiles typical of nearly all other Holocene subfossil sites on Madagascar., Research at Beanka was supported by the National Geographic Society via Waitt Foundation grants W263-13 and W388-15 to DAB, and by the site-managing organization, Biodiversity Conservation Madagascar (BCM). EJdB was supported by a travel grant from the Society for Advancement of Research in the Tropics (Treub Maatschappij). The scientific study authorization was provided by the Bureau du Cadastre Minier de Madagascar with the reference 024/2015. Many thanks to faculty of the Université d'Antananarivo and staff of BCM and Association Vahatra for assistance with permits and logistics. To the staff of BCM and the people of the village of Ambinda, we extend special thanks for hospitality and assistance with fieldwork and information regarding sites and access. Bone specimens were identified from studies of comparative materials at the Field Museum of Natural History, the Université d'Antananarivo, Association Vahatra, Duke Lemur Center, Muséum national d'Histoire naturelle (Paris), the Natural History Museum (London), the Smithsonian Institution, the American Museum of Natural History, and the University of Massachusetts, Amherst. Species identifications were supported in part by NSF BCS-1750598 (to LRG). Isotopic and radiocarbon analyses were supported in part by NSF BCS-1749676 (to BEC).

The Pueblo population of Chaco Canyon during the Bonito Phase (AD 800–1130) employed agricultural strategies and water-management systems to enhance food cultivation in this unpredictable environment. Scepticism concerning the timing and effectiveness of this system, however, remains common. Using optically stimulated luminescence dating of sediments and LiDAR imaging, the authors located Bonito Phase canal features at the far west end of the canyon. Additional ED-XRF and strontium isotope (87Sr/86Sr) analyses confirm the diversion of waters from multiple sources during Chaco’s occupation. The extent of this water-management system raises new questions about social organisation and the role of ritual in facilitating responses to environmental unpredictability.

Isotopic analysis of zoological material in archaeological deposits may help identify the origin of predated individuals. Here we assess the utility of carbon, nitrogen, and sulfur isotope values in bone collagen from zooarchaeological remains for determining the degree to which prehistoric Trinidadians relied on terrestrial prey from coastal and inland localities, as well as how this may have changed over time. We analyzed bone collagen from a variety of marine and terrestrial vertebrates from three coastal Ceramic Age sites in southwestern Trinidad. We also collected and analyzed modern foliage from eight sites at varying distances from the ocean to establish expected isotopic values for coastal ( 10 km from the ocean) environments in the southwestern corner of the island. We anticipated that the earliest human inhabitants at these sites initially exploited marine and local (i.e., coastal) terrestrial prey, but that they eventually depleted local resources, necessitating harvesting terrestrial prey from further inland. Unexpectedly, we find no substantial or consistent isotopic trends over time within sites or among different sites. The majority of harvested prey likely lived 1.5–10 km from the ocean. The combination of nitrogen and sulfur isotope values is effective at distinguishing both plants and terrestrial prey from coastal versus inland localities. Although carbon is less informative at elucidating geographic origin, it is quite effective at distinguishing terrestrial and marine prey and may be useful for separating marine turtles from terrestrial tortoises when working with fragmented material. Results from this study can be used as a model for multi-isotopic research in other island and coastal continental settings.

The Upper Cretaceous Coon Creek Lagerstatte of Tennessee, USA, is known for its extremely well-preserved mollusks and decapod crustaceans. However, the depositional environment of this unit, particularly its distance to the shoreline, has long been equivocal. To better constrain the coastal proximity of the Coon Creek Formation, we carried out a multiproxy geochemical analysis of fossil decapod (crab, mud shrimp) cuticle and associated sediment from the type section. Elemental analysis and Raman spectroscopy confirmed the presence of kerogenized carbon in the crabs and mud shrimp; carbon isotope (δ13 C) analysis of bulk decapod cuticle yielded similar mean δ13 C values for both taxa (-25.1‰ and -26‰, respectively). Sedimentary biomarkers were composed of n-alkanes from C16 to C36 , with the short-chain n-alkanes dominating, as well as other biomarkers (pristane, phytane, hopanes). Raman spectra and biomarker thermal maturity indices suggest that the Coon Creek Formation sediments are immature, which supports retention of unaltered, biogenic isotopic signals in the fossil organic carbon remains. Using our isotopic results and published calcium carbonate δ13 C values, we modeled carbon isotope values of carbon sources in the Coon Creek Formation, including potential marine (phytoplankton) and terrestrial (plant) dietary sources. Coon Creek Formation decapod δ13 C values fall closer to those estimated for terrigenous plants than marine phytoplankton, indicating that these organisms were feeding primarily on terrigenous organic matter. From this model, we infer that the Coon Creek Formation experienced significant terrigenous organic matter input via a freshwater source and thus was deposited in a shallow, nearshore marine environment proximal to the shoreline. This study helps refine the paleoecology of nearshore settings in the Mississippi Embayment during the global climatic shift in the late Campanian-early Maastrichtian and demonstrates for the first time that organic δ13 C signatures in exceptionally preserved fossil marine arthropods are a viable proxy for use in paleoenvironmental reconstructions.

Most studies on roadside soil pollution have been performed in areas where petrol is the main fuel. Very little work has been conducted in regions where diesel predominates. We collected soil samples from four sites that span a precipitation gradient along the Manali-Leh Highway in northwestern Himalaya, India. This road traverses rough terrain and most of the vehicles that travel along it are diesel-driven. At each site, we collected samples at incremental distances from the highway (0, 2, 5, 10, 20, and 150 m), and at each distance we collected samples from three depths (3, 9, and 15 cm). We assessed the concentrations of 10 heavy metals (Al, Fe, Cr, Cu, Pb, Ni, Co, Zn, V, and Ba), total sulphur, and total organic carbon (TOC) at each distance, and we measured the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) at 2 m from the highway. Overall, we found that metal concentrations are low and there is no relationship between concentrations and distance from the highway, or depth within the soil profile. Sulphur concentrations, on the other hand, are high in roadside soils and there is a negative relationship between concentration and distance from the highway. PAH concentrations are low, but the proportion of different ringed species suggests that their source is anthropogenic. Correlations between TOC and the various pollutants further suggest that diesel vehicles and potentially biomass combustion are starting to affect the roadside environment in remote northwestern India. We suggest that pollutant concentrations be regularly monitored.

Evidence of historic predation is important to understand the role that predators play in molding fundamental aspects of primate biology. We examined the geographic demise of Prolemur simus from the perspective of its past behavioral ecology. Using paleontological data from the Late Pleistocene–Holocene deposits at Ankarana Massif, northern Madagascar, we test the hypothesis that 1) multiple predators preyed on P. simus in the past and 2) the dietary preferences and habitat preferences of subfossil P. simus were similar to its extant counterpart. We examined 381 subfossil craniodental remains of P. simus from Ankarana. We used dental eruption and macrowear to assign craniodental remains to relative age classes, and carbon (δ13C) and nitrogen (δ15N) stable isotope values in bone collagen to assess variation in this species’ diet and habitat. Skeletal evidence of predation suggests that multiple predators consumed P. simus in the past. Evidence for carnivoran predatory activity includes punctures on the viscerocranium, posterior neurocranium, and angle of the mandible. Evidence for raptor predatory activity includes talon nicks, punctures, and “can-opener” perforations within the orbits or palate. Stable isotope data suggest that the diet of P. simus was remarkably similar among localities inhabited by this species before human arrival, despite varied environmental conditions. These data suggest that P. simus was likely codistributed with large-culmed bamboo in the past as it is today. The synergistic effects of predation and habitat change may explain the biogeographic retreat of P. simus to its present-day distribution in eastern Madagascar. The study of predator–primate dynamics and interactions across contiguous and fragmented forests will increase our understanding of the impact of such dynamics on primate evolution, and improve primate conservation efforts more broadly.

Faecal isotopic analysis may complement other non-invasive wildlife survey tools for monitoring landscape use by carnivores, such as motion-detecting cameras and non-invasive genetic sampling. We analysed carbon, nitrogen, and strontium isotopes in faecal matter produced by jaguars (

Tenerife Island is well-known for its biodiversity. It boasts the highest elevation in the Atlantic Ocean and its northern and southern slopes have varying moisture and temperature gradients. Consequently, there are multiple spatially discrete vegetation zones, or biomes, recognized on the island that roughly follow elevation. We investigated the extent to which climatic variables as well as soil nitrogen isotope values (δ15N) and weight %N influence spatial isotopic variability in C3 plants during the rainy season and assessed the degree to which foliar carbon isotope discrimination (Δleaf) and δ15N values are able to distinguish biomes. Mean Annual Precipitation explained 71% and 55% of the spatial variability in Δleaf and δ15N values, respectively. Overall, foliar δ15N values tracked those in soils, and soil %N was negatively correlated with both soil and foliar δ15N values. However, there was considerable variability among co-occurring species, as well as among sites within the same biome, which obscured trends among biomes. As a result, only a few biomes were isotopically distinct: Broad-leaved evergreen forest and sub-desert coastal scrub on the northern slope, and summit scrub and sub-desert coastal scrub on the southern slope. Further investigation into the influence of coastal orientation, topography, plant physiology, soil characteristics, as well as seasonal and inter-annual climate variability on foliar isotope values would be fruitful. Nevertheless, these results provide baseline information for researchers seeking to interpret diet and mobility of animals and people, as well as environmental changes over time on Tenerife and other Macaronesian volcanic islands.

Strontium isotope ratios (87Sr/86Sr) are a popular tool in provenance applications in archeology, forensics, paleoecology, and environmental sciences. Using bioavailable 87Sr/86Sr in provenance studies requires comparing the 87Sr/86Sr of a sample of interest to that of 87Sr/86Sr baselines. Historically, these baselines required building empirical datasets from plants or local animals to characterize the 87Sr/86Sr available to local ecosystems (bioavailable 87Sr/86Sr). However, researchers are increasingly relying on modeled bioavailable 87Sr/86Sr maps (called isoscapes). We review the advantages and limitations of existing approaches to mapping bioavailable 87Sr/86Sr for provenance studies and propose a globally applicable, scalable, and editable framework for creating bioavailable 87Sr/86Sr isoscapes. This framework relies on: 1) Compiling global bioavailable 87Sr/86Sr data; 2) Mapping 87Sr/86Sr variability in rocks; 3) Leveraging global environmental covariates; and 4) Applying a random forest regression method that integrates these data to predict bioavailable 87Sr/86Sr. When the random-forest model is applied at the global scale it performs well (explaining 60% of the variance of the global bioavailable 87Sr/86Sr dataset), and accounts for geological, geomorphological and atmospheric controls. In data-rich regions (e.g., Europe), the global bioavailable 87Sr/86Sr isoscape can be successfully extrapolated to broad regions without bioavailable 87Sr/86Sr data. However, we also show that this extrapolation may not be valid in exceptionally geologically complex and data-poor regions (e.g., Madagascar). We suggest research directions to improve the accuracy of global bioavailable 87Sr/86Sr isoscapes, which include: 1) Increasing the collection of bioavailable datasets in data-poor regions; 2) Harmonizing data management practices and metadata collection for bioavailable 87Sr/86Sr data; and 3) Relying on advances in remote sensing and geological mapping techniques to improve geological covariates. While significant potential to refine 87Sr/86Sr isoscapes remains, the data products provided in this review form a basis for using 87Sr/86Sr data in large-scale provenance studies, opening new research avenues in a range of fields.

Stable isotope values in primate tissues can be used to reconstruct diet in the absence of direct observation. However, in order to make dietary inferences, one must first establish isotopic variability for potential food sources. In this study we examine stable carbon isotope (δ(13) C) values for chimpanzee (Pan troglodytes) food resources from two Ugandan forests: Ngogo (Kibale National Park), and Bwindi Impenetrable National Park. Mean δ(13) C values for plant samples are equivalent at both sites. Plant δ(13) C values are best explained by a multivariate linear model including plant part (leaves, pith, flowers, and fruit), vertical position within the canopy (canopy vs. ground), and taxon (R(2) = 0.6992). At both sites, leaves had the lowest δ(13) C values followed by pith and fruit. Canopy resources have comparable δ(13) C values at the two sites but ground resources have lower δ(13) C values at Ngogo than Bwindi (-30.7 vs. -28.6‰). Consequently, isotopic differences between ground and canopy resources (4.2 vs. 2.2‰), and among plant parts are more pronounced at Ngogo. These results demonstrate that underlying environmental differences between sites can produce variable δ(13) C signatures among primate food resources. In the absence of observation data or isotope values for local vegetation, caution must be taken when interpreting isotopic differences among geographically or temporally separated populations or species. Am. J. Primatol. 78:1031-1040, 2016. © 2016 Wiley Periodicals, Inc.

Over 40 years ago, Clifford Jolly noted different ways in which Hadropithecus stenognathus converged in its craniodental anatomy with basal hominins and with geladas. The Malagasy subfossil lemur Hadropithecus departs from its sister taxon, Archaeolemur, in that it displays comparatively large molars, reduced incisors and canines, a shortened rostrum, and thickened mandibular corpus. Its molars, however, look nothing like those of basal hominins; rather, they much more closely resemble molars of grazers such as Theropithecus. A number of tools have been used to interpret these traits, including dental microwear and texture analysis, molar internal and external morphology, and finite element analysis of crania. These tools, however, have failed to provide support for a simple dietary interpretation; whereas there is some consistency in the inferences they support, dietary inferences (e.g., that it was graminivorous, or that it specialized on hard objects) have been downright contradictory. Cranial shape may correlate poorly with diet. But a fundamental question remains unresolved: why do the various cranial and dental convergences exemplified by Hadropithecus, basal hominins, and Theropithecus exist? In this paper we review prior hypotheses regarding the diet of Hadropithecus. We then use stable carbon and nitrogen isotope data to elucidate this species' diet, summarizing earlier stable isotope analyses and presenting new data for lemurs from the central highlands of Madagascar, where Hadropithecus exhibits an isotopic signature strikingly different from that seen in other parts of the island. We offer a dietary explanation for these differences. Hadropithecus likely specialized neither on grasses nor hard objects; its staples were probably the succulent leaves of CAM plants. Nevertheless, aspects of prior hypotheses regarding the ecological significance of its morphology can be supported. Am. J. Primatol. 78:1098-1112, 2016. © 2015 Wiley Periodicals, Inc.

The timing of the human settlement of Madagascar, one of the last large landmasses to be settled by people, remains a key topic of debate in archaeology. Despite decades of research, recent estimates for initial settlement are increasingly divergent and span ca. 9000 years: the widest colonization window for any island within the reliable range of radiocarbon (14C) dating. 14C dating of archaeological sites and remains of butchered animals provide important evidence of when the island was first settled, but the reliability of these dates requires critical evaluation. Applying principles of chronometric hygiene, we present the first systematic review of Madagascar's14C chronology to clarify the island's settlement. Our findings support human presence by at least 2000 cal BP and suggest that an Early Holocene arrival is possible. The nature of such an early presence on the island, however, remains elusive due to a lack of contextual information.

We applied a multi-isotope approach to examine aspects of niche partitioning, competition, and mobility for rodents in the Central Highlands of Madagascar. Specifically, we used carbon (δ13C), nitrogen (δ15N), and strontium (87Sr/86Sr) isotope ratios in bone to investigate diet and mobility for endemic tufted tail rats (Eliurus spp.), and introduced black rats (Rattus rattus) and house mice (Mus musculus) within and outside a fragment of montane humid forest in the Ambohitantely Special Reserve. There was a clear spatial segregation in trapping success for different species: Eliurus was only in the forest interior and edge, Mus only outside of the fragment in a marsh and park housing complex, and Rattus in all habitats except the housing complex. We find only moderate support for mobility of rodents among habitats. Mus may routinely move between the marsh and housing complex. However, regular movement between the forest edge and interior, or between the forest fragment and surrounding grassland is not supported. Taxa appear to target different foods: Rattus tends to feed at a higher trophic level than Eliurus, and Mus consumes some C4 resources. To date, strontium isotopes have been underutilized in ecological research. Here, we show that they are highly complementary to carbon and nitrogen isotope data. Even in localities with relatively uniform underlying geology, it may be possible to distinguish individuals that regularly forage in different habitats.

Questions about how archaeological populations obtained basic food supplies are often difficult to answer. The application of specialist techniques from non-archaeological fields typically expands our knowledge base, but can be detrimental to cultural interpretations if employed incorrectly, resulting in problematic datasets and erroneous conclusions not easily caught by the recipient archaeological community. One area where this problem has failed to find resolution is Chaco Canyon, New Mexico, the center of one of the New World's most vibrant ancient civilizations. Discussions of agricultural feasibility and its impact on local population levels at Chaco Canyon have been heavily influenced by studies of soil salinity. A number of researchers have argued that salinized soils severely limited local agricultural production, instead suggesting food was imported from distant sources, specifically the Chuska Mountains. A careful reassessment of existing salinity data as measured by electrical conductivity reveals critical errors in data conversion and presentation that have misrepresented the character of the area's soil and its potential impact on crops. We combine all available electrical conductivity data, including our own, and apply multiple established conversion methods in order to estimate soil salinity values and evaluate their relationship to agricultural productivity potential. Our results show that Chacoan soils display the same salinity ranges and spatial variability as soils in other documented, productive fields in semi-arid areas. Additionally, the proposed large-scale importation of food from the Chuska Mountains region has serious social implications that have not been thoroughly explored. We consider these factors and conclude that the high cost and extreme inflexibility of such a system, in combination with material evidence for local agriculture within Chaco Canyon, make this scenario highly unlikely. Both the soil salinity and archaeological data suggest that there is no justification for precluding the practice of local agriculture within Chaco Canyon.

Human societies depend on an Earth system that operates within a constrained range of nutrient availability, yet the recent trajectory of terrestrial nitrogen (N) availability is uncertain. Examining patterns of foliar N concentrations and isotope ratios (δ 15 N) from more than 43,000 samples acquired over 37 years, here we show that foliar N concentration declined by 9% and foliar δ 15 N declined by 0.6–1.6‰. Examining patterns across different climate spaces, foliar δ 15 N declined across the entire range of mean annual temperature and mean annual precipitation tested. These results suggest declines in N supply relative to plant demand at the global scale. In all, there are now multiple lines of evidence of declining N availability in many unfertilized terrestrial ecosystems, including declines in δ 15 N of tree rings and leaves from herbarium samples over the past 75–150 years. These patterns are consistent with the proposed consequences of elevated atmospheric carbon dioxide and longer growing seasons. These declines will limit future terrestrial carbon uptake and increase nutritional stress for herbivores. Fil: Craine, Joseph M.. Jonah Ventures; Estados Unidos Fil: Elmore, Andrew J.. University of Maryland; Estados Unidos Fil: Wang, Lixin. Indiana University; Estados Unidos. Purdue University; Estados Unidos Fil: Aranibar, Julieta Nelida. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina Fil: Bauters, Marijn. University of Ghent; Bélgica Fil: Boeckx, Pascal. University of Ghent; Bélgica Fil: Crowley, Brooke E.. University of Cincinnati; Estados Unidos Fil: Dawes, Melissa A.. Swiss Federal Institute for Forest, Snow and Landscape Research; Suiza Fil: Delzon, Sylvain. Universite de Bordeaux; Francia. Institut National de la Recherche Agronomique; Francia Fil: Fajardo, Alex. Centro de Investigación en Ecosistemas de la Patagonia; Chile Fil: Fang, Yunting. Chinese Academy of Sciences; República de China Fil: Fujiyoshi, Lei. Research Institute for Humanity and Nature; Japón Fil: Gray, Alan. North American Electric Reliability Corporation. Centre for Ecology and Hydrology; Estados Unidos Fil: Guerrieri, Rossella. Consejo Superior de Investigaciones Científicas. Centre de Recerca Ecológica I Aplicacions Forestals; España Fil: Gundale, Michael J.. Swedish University of Agricultural Sciences; Suecia Fil: Hawke, David J.. Ara Institute of Canterbury. Department of Science and Primary Industries; Nueva Zelanda Fil: Hietz, Peter. University of Natural Resources and Life Sciences. Institute of Botany; Austria Fil: Jonard, Mathieu. Université Catholique de Louvain; Bélgica Fil: Kearsley, Elizabeth. University of Ghent; Bélgica Fil: Kenzo, Tanaka. Forestry and Forest Products Research Institute. Department of Plant Ecology; Japón Fil: Makarov, Mikhail. Moscow M.V. Lomonosov State University; Rusia Fil: Marañón Jiménez, Sara. Universidad de Granada; España. Consejo Superior de Investigaciones Científicas. Centre de Recerca Ecológica I Aplicacions Forestals; España Fil: McGlynn, Terrence P.. University of California; Estados Unidos. Natural History Museum of Los Angeles County. Department of Entomology; Estados Unidos Fil: McNeil, Brenden E.. West Virginia University. Department of Geology and Geography; Estados Unidos Fil: Mosher, Stella G.. University of Cincinnati; Estados Unidos Fil: Nelson, David M.. University of Maryland; Estados Unidos Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Universidad Nacional de la Patagonia Austral; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Roggy, Jean Christophe. Institut National de la Recherche Agronomique; Francia. Ecologie des Forêts de Guyane; Francia Fil: Sanders Demott, Rebecca. Boston University; Estados Unidos Fil: Song, Minghua. Chinese Academy of Sciences; República de China Fil: Szpak, Paul. Trent University. Department of Anthropology; Canadá Fil: Templer, Pamela H.. Boston University; Estados Unidos Fil: Van der Colff, Dewidine. South African National Biodiversity Institute; Sudáfrica Fil: Werner, Christiane. Albert Ludwigs University of Freiburg; Alemania Fil: Xu, Xingliang. Chinese Academy of Sciences; República de China Fil: Yang, Yang. Chinese Academy of Sciences; República de China Fil: Yu, Guirui. Chinese Academy of Sciences; República de China. University of Chinese Academy of Sciences. College of Resources and Environment; República de China Fil: Zmudczyńska Skarbek, Katarzyna. University of Gdańsk; Polonia

Big Bone Lick (BBL) in northern Kentucky, USA has been a critical geologic site in the historical development of North American Quaternary vertebrate paleontology since the 1700s. Sedimentology, geoarcheology, paleontology, accelerator mass spectrometry radiocarbon and optically stimulated luminescence dating, and stable carbon and nitrogen isotope analyses were undertaken to develop a chronostratigraphy and history of erosion and deposition for the site to provide a foundation for understanding taphonomy, and species extinction and adaptation to periods of climatic and environmental change. Three geomorphic surfaces are recognized at BBL representing significant periods of floodplain aggradation since the last glacial maximum (26.5–19 ka) dating to the Oldest Dryas (Tazewell, 25–19 ka), the Older Dryas (Cary, 14–12 ka), and late Holocene (5 ka to the present). Unconformities suggest significant periods of degradation during the transitions from cold and dry to warm and moist climates from the Oldest Dryas (Tazewell) to Bølling Oscillation, from the Older Dryas (Cary) to the Allerød, and from the Younger Dryas (Valders) to the Holocene Climatic Optimum. Increased anthropogenic activities since ~ 5 ka may have increased soil upland erosion and floodplain aggradation. Stable isotopes demonstrate that the landscape has been dominated by C 3 vegetation since the last glacial maximum.

Humans first arrived on Madagascar only a few thousand years ago. Subsequent habitat destruction and hunting activities have had significant impacts on the island's biodiversity, including the extinction of megafauna. For example, we know of 17 recently extinct ‘subfossil’ lemur species, all of which were substantially larger (body mass ∼11–160 kg) than any living population of the ∼100 extant lemur species (largest body mass ∼6.8 kg). We used ancient DNA and genomic methods to study subfossil lemur extinction biology and update our understanding of extant lemur conservation risk factors by i) reconstructing a comprehensive phylogeny of extinct and extant lemurs, and ii) testing whether low genetic diversity is associated with body size and extinction risk. We recovered complete or near-complete mitochondrial genomes from five subfossil lemur taxa, and generated sequence data from population samples of two extinct and eight extant lemur species. Phylogenetic comparisons resolved prior taxonomic uncertainties and confirmed that the extinct subfossil species did not comprise a single clade. Genetic diversity estimates for the two sampled extinct species were relatively low, suggesting small historical population sizes. Low genetic diversity and small population sizes are both risk factors that would have rendered giant lemurs especially susceptible to extinction. Surprisingly, among the extant lemurs, we did not observe a relationship between body size and genetic diversity. The decoupling of these variables suggests that risk factors other than body size may have as much or more meaning for establishing future lemur conservation priorities.

Stable carbon and oxygen isotope ratios in tooth enamel and bone hydroxyapatite are used to answer a variety of ecological questions. Researchers employ chemical treatments to reduce contaminants that may interfere with the isotope ratios in hydroxyapatite. Chemical treatment should remove exogenous as well as non lattice-bound molecules without affecting the isotopic composition of the biogenic carbonate or introducing secondary carbonate material. However, there is growing concern that some of the most frequently used chemicals may alter biogenic isotope ratios, thus compromising isotope data. Despite a considerable body of literature, there is still no consensus as to which chemical treatment methods are “the best”. Here we test the isotopic effects of a suite of chemical experimental treatments on modern and fossil enamel carbonate, including six published protocols. We also test the degree to which carbon and oxygen isotope ratios in bone and dentine are affected by commonly used treatment chemicals. We conclude that treatment with hydrogen peroxide followed by Ca-buffered acetic acid yields the “best” results. This combination results in less extreme carbon, oxygen, and weight percent carbonate values compared to other treatments. Although sequential treatment with sodium hypochlorite (bleach) and Ca-buffered acetic acid produces similar results for enamel, bleach is not recommended for tissues with a higher organic content, such as bone or dentine.

The mobility and dietary preferences of now-extinct proboscideans have not been comprehensively examined in the central USA. We used stable carbon (δ13C), oxygen (δ18O) and strontium (87Sr/86Sr) isotopic signatures in molar enamel to investigate the foraging ecology of four mastodons (Mammut americanum) and eight mammoths (Mammuthus spp.) from southwestern Ohio and northwestern Kentucky. We tested two hypotheses: (i) these individuals were nomadic migrants that were passing through the region when they died; and (ii) mammoths and mastodons foraged in different environments. Unexpectedly, our results suggest that 11 of the 12 sampled individuals were regional residents. With the exception of one mastodon, 87Sr/86Sr ratios for proboscideans and regional water samples were statistically indistinguishable; slightly lower ratios for waters suggest glacial loess has an impact on modern samples. Amongst the individuals identified as residents, 87Sr/86Sr ratios indicate that mammoths and mastodons foraged in discrete geographical areas, and δ13C values imply dietary differences between the genera, which is consistent with our expectations. Oxygen isotope values may be able to distinguish animals that lived during the Last Glacial Maximum (LGM) from those that lived more recently. Three mammoths and one mastodon yielded δ18O values that are similar to modern regional precipitation and surface water, but too high for estimated drinking water during the LGM. We propose that these individuals lived during a relatively warm period following the LGM. Compellingly, the mammoth with the highest δ18O value also has the lowest δ13C value, suggesting that this individual was alive after regional vegetation shifted from open parkland to deciduous forest dominated by C3 species. Our results demonstrate that a wealth of information can be gleaned from fossil museum specimens and lay a foundation for future work on the foraging ecology of proboscideans and other extinct megafauna from the Midwest USA.

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.

Calcium stable isotope ratios are hypothesized to vary as a function of trophic level. This premise raises the possibility of using calcium stable isotope ratios to study the dietary behaviors of fossil taxa and to test competing hypotheses on the adaptive origins of euprimates. To explore this concept, we measured the stable isotope composition of contemporary mammals in northern Borneo and northwestern Costa Rica, two communities with functional or phylogenetic relevance to primate origins. We found that bone collagen δ(13) C and δ(15) N values could differentiate trophic levels in each assemblage, a result that justifies the use of these systems to test the predicted inverse relationship between bioapatite δ(13) C and δ(44) Ca values. As expected, taxonomic carnivores (felids) showed a combination of high δ(13) C and low δ(44) Ca values; however, the δ(44) Ca values of other faunivores were indistinguishable from those of primary consumers. We suggest that the trophic insensitivity of most bioapatite δ(44) Ca values is attributable to the negligible calcium content of arthropod prey. Although the present results are inconclusive, the tandem analysis of δ(44) Ca and δ(13) C values in fossils continues to hold promise for informing paleodietary studies and we highlight this potential by drawing attention to the stable isotope composition of the Early Eocene primate Cantius.

Coastal proximity, wind direction, and amount of precipitation can all influence the distribution of marine sulfur on land. However, the relative importance of these different factors to vegetation is not well constrained, and previous research has been geographically limited. Here we use sulfur isotope (δ34S) values for total sulfur in foliage to assess the spatial distribution of marine-derived sulfur (+15.6 to +21‰) on the island of Trinidad. We expected that plants that receive heavy precipitation and are located on windward coasts (along the east and north coasts) would have higher δ34S values resembling marine sulfur, whereas areas with low precipitation or on leeward coasts (i.e. the west and southwest) would have lower values. Samples were collected along an east-west transect that spanned the island's width, as well as 18 additional sites across the island. As anticipated, along the transect, plant δ34S values are highest on the windward coast (ca. +17.4‰). Values decline ca. 9‰ within 1.5 km, and another ca. 6‰ within 10 km from the east coast. Island-wide, plants from the north and northeast exhibit the highest δ34S values (+16.2 to +20.4‰), while those from the southwest have markedly lower δ34S values (ca. +9.6‰). Overall, we find that a marine sulfur signal is most pronounced for sites within 1.5 km of the ocean yet may still be detectable within 10 km of the ocean for sites that receive abundant precipitation or are on a windward coast. Our data also suggest that anthropogenically-derived sulfur is utilized by vegetation growing in roadside and urban settings on the island.