Niche Opportunities Research Articles

Latitudinal gradient in species diversity provides high niche opportunities for a range-expanding phytophagous insect.

When species undergo poleward range expansions in response to anthropogenic change, they likely encounter less diverse communities in new locations. If low diversity communities provide weak biotic interactions, such as reduced competition or predation, range-expanding species may experience high niche opportunities. Here, we investigated if oak gall wasp communities follow a latitudinal diversity gradient (LDG) and if lower diversity communities provide weaker interactions at the poles for a range-expanding community member, Neuroterus saltatorius. We performed systematic surveys of gall wasps on a dominant oak, Quercus garryana, throughout most of its range, from northern California to Vancouver Island, British Columbia. On 540 trees at 18 sites, we identified 23 oak gall wasp morphotypes in three guilds (leaf detachable, leaf integral, and stem galls). We performed regressions between oak gall wasp diversity, latitude, and other abiotic (e.g. temperature) and habitat (e.g. oak patch size) factors to reveal if gall wasp communities followed an LDG. To uncover patterns in local interactions, we first performed partial correlations of gall wasp morphotype occurrences on trees within regions). We then performed regressions between abundances of co-occurring gall wasps on trees to reveal if interactions are putatively competitive or antagonistic. Q. garryana-gall wasp communities followed an LDG, with lower diversity at higher latitudes, particularly with a loss of detachable leaf gall morphotypes. Detachable leaf gall wasps, including the range-expanding species, co-occurred most on trees, with weak co-occurrences on trees in the northern expanded region. Abundances of N. saltatorius and detachable and integral leaf galls co-occurring on trees were negatively related, suggesting antagonistic interactions. Overall, we found that LDGs create communities with weaker associations at the poles that might facilitate ecological release in a range-expanding community member. Given the ubiquity of LDGs in nature, poleward range-expanding species are likely moving into low diversity communities. Yet, understanding if latitudinal diversitypattern provides weak biotic interactions for range-expanding species is not well explored. Our large-scale study documenting diversity in a related community of phytophagous insects that co-occur on a host plant reveals that LDGs create high niche opportunities for a range-expanding community member. Biogeographical patterns in diversity and species interactions are likely important mechanisms contributing to altered biotic interactions under range-expansions.

The impact of invasive Caucasian hogweeds on birds depends on areas of invaded and uninvaded habitats at various scales in Central European uplands

The availability of various habitats increases biodiversity and provides niche opportunities for organisms, although greater habitat diversity may contribute to the spreading of invasive plants. In this study, we aimed to assess the impact of the extent of invasion on bird responses to the availability of their natural habitats. Specifically, we asked whether the Caucasian hogweeds, herbaceous invasive plants spreading in abandoned lands, shape those responses by providing new niche opportunities or limitations and whether these invaders can be tolerated by the bird community. The research was conducted in south-eastern Poland in 2020 on 64 research sites, half of which were located near the Caucasian hogweeds’ invasion. The birds were counted from points within 100 m, while the areas of invaded and uninvaded habitats were measured within 100 and 500 m. The impact of the invaded area was negative for the overall bird abundance and species richness. At the same time, the invasion affected birds differently depending on their nesting/foraging assemblages, the availability of various uninvaded habitats, and the extent of invaded areas. Specifically, the abundance of ground/herb dwellers non-linearly dropped even with small increases of the invaded area suggesting their high sensitivity to invasion. These birds were supported by the agricultural land availability, but only when its area was lower than 1.0 ha and the habitat was fragmented, indicating the value of extensive croplands for ground/herb dwelling species. Ecotone birds benefited from small invaded areas mixed with bushes but suffered when the invaded areas were large. Habitat homogenization by the invader physiognomically similar to shrubs was favoured by bush foragers. Tree foragers preferred forest partitioning near the largest invaded areas. The invaded and uninvaded habitats influenced bird community at a fine scale (i.e. in a 100-m radius), while only crucial areas of meadows, forests and agriculture available in a 500-m radius remained important for the community. This study showed that even a small amount of plant invaders rapidly and negatively affect birds when they grow in open areas and are physiognomically different from these birds’ habitats, while species living in ecotone or trees suffer from severely invaded areas. It suggests the priority of invading weeds’ removal in open areas, regardless of the invaded area, as well as the need to prevent weed development in overgrown areas.

Host cells subdivide nutrient niches into discrete biogeographical microhabitats for gut microbes

Changes in the microbiota composition are associated with many human diseases, but factors that govern strain abundance remain poorly defined. We show that a commensal Escherichia coli strain and a pathogenic Salmonella enterica serovar Typhimurium isolate both utilize nitrate for intestinal growth, but each accesses this resource in a distinct biogeographical niche. Commensal E.coli utilizes epithelial-derived nitrate, whereas nitrate in the niche occupied by S. Typhimurium is derived from phagocytic infiltrates. Surprisingly, avirulent S. Typhimurium was shown to be unable to utilize epithelial-derived nitrate because its chemotaxis receptors McpB and McpC exclude the pathogen from the niche occupied by E.coli. In contrast, E.coli invades the niche constructed by S. Typhimurium virulence factors and confers colonization resistance by competing for nitrate. Thus, nutrient niches are not defined solely by critical resources, but they can be further subdivided biogeographically within the host into distinct microhabitats, thereby generating new niche opportunities for distinct bacterial species.

Increased presence of the invasive, exotic Eurasian Collared-Dove (Streptopelia decaocto) in the Chamela-Cuixmala Biosphere Reserve, Mexico, after hurricane disturbance

Invasive species are a main cause of biodiversity loss, making it important to register their incursion into conserved, protected areas. We evaluated presence of the exotic Eurasian Collared-Dove (Streptopelia decaocto) in and around the Chamela-Cuixmala Biosphere Reserve, Jalisco, after hurricane disturbance. During March to May 2017 and 2018, we carried out 1 km transect surveys at three sites: Chamela Biological Station, Careyes town, and Cuixmala ranch, and conducted observations of the Eurasian Collared-Dove when detected. We also collated records from the eBird database to compare the number of Eurasian Collared-Doves reported before (2010-2015) and after (2016-2020) major hurricane disturbance. We recorded a total of 27 doves over 18 surveys, with the majority of records at the Chamela Biological Station within the reserve. Most sightings were of one dove, but we recorded a group of 4 doves at Chamela in May 2018. Doves spent significantly more time perched around buildings at Chamela in 2018 compared to 2017, and made occasional flights into trees at the dry forest border. The eBird data showed a significant increase in records of the Eurasian Collared-Dove outside the reserve after hurricane disturbance. Our results showed increased presence of the Eurasian Collared-Dove at sites within the biosphere reserve following major hurricane disturbance, possibly due to forest damage creating open-habitat and niche opportunities within the dry forest mosaic. We recommend continued monitoring to restrict establishment of this invasive species in forested areas of the reserve, and evaluate potential impacts on native species.

Retracted: Microalgae as a Renewable Source of Energy: A Niche Opportunity

Retracted: Microalgae as a Renewable Source of Energy: A Niche Opportunity

Oxidative removal of thallium(I) using Al beverage can waste with amendments of Fe: Tl speciation and removal mechanisms

The emerging occurrence of thallium (Tl) in environments arouses the imposition of effective technology for its remediation. Due to the low solubility of Tl(III), the oxidation-precipitation of Tl(I) is considered as an promising removal method. Here, we recycled Al beverage can powder (AlCP) as the substitute for zero-valent Al to conduct the Fenton-like reaction for Tl(I) oxidation and subsequently induced the Tl(III) precipitation via the alkalinization at pH 9.5. The Tl(I) removal mechanisms in AlCP systems with amendments of Fe(III) or Fe(II) were determined in relation to its speciation for both dissolved and solid phases. Results showed that although additions of Fe(III)/Fe(II) prompted the Tl(I) oxidation as compared with the pure AlCP system, they were detrimental to the Tl removal upon the alkalinization. While the greatest removal efficiency was ~ 92% in AlCP/Fe(III)/Fe(II) systems, up to 99.8% of total Tl could be removed from the pure AlCP system. The Tl-XANES data indicated that although Tl(III) dominated the Tl inventory (92 – 95%) on all solids collected upon the alkalinization, it preferred to precipitate as stable Tl2O3 in pure AlCP system but as labile Tl(III) in AlCP/Fe(III)/Fe(II) systems, which might sorb on precipitated Al (hydr)oxides. Such sorbed Tl(III) is subject to reduction and the further dissolution, accounting for the lower removal efficiency for Tl in the presence of Fe(III)/Fe(II). This study corroborated the comparable Tl(I) removal efficiency of AlCP to that of state-of-the-art (nano)composites, providing a niche opportunity to give consideration to both interests in hazard remediation and the waste reduction/reuse.

Functional traits and nesting habitats distinguish the structure of bee communities in clearcut and managed hardwood & pine forests in Southeastern USA

The role of nesting resources has been largely neglected in wild bee community ecology studies. Anthropogenic forest openings such as clearcuts and roads are common features within the managed forest matrix which may have varying impacts on bee nesting habitats and thus, drive their community structure. We sampled wild bees in mature hardwood, managed pine, and regenerating clearcuts across a gradient from the edge of a road into each site-type. Each site was surveyed for nesting habitat indicators including depth of duff layer, volume of downed wood, decay class of downed wood, and number of snags. Regenerating clearcuts had higher alpha diversity of wild bees than other sites, but displayed higher functional overlap in the bee community, favoring soil nesting groups. Forested sites, especially hardwoods provided more nesting niche opportunities leading to higher functional dispersion, evenness and higher beta diversity, and supported more cavity nesting, softwood nesting, solitary, and early season bees. Nesting habitat indicators explained 53% of the variation in nest guild composition. Cavity nesting bees responded positively to the volume of downed wood, and in a bimodal way to woody decay class. Soil nesting bees responded negatively to the depth of duff layer and presence of snags. Overall, results indicate that regenerating clearcuts are foci of species diversity, while hardwood forests are foci of functional diversity. Hardwood forests may be source of functionally diverse groups of bees, and maintaining patches or swaths of hardwood forests with some downed wood accumulation may be critical for maintaining functional diversity of bees in managed forested ecosystems.

Green hydrogen potentials from surplus hydro energy in Nepal

This paper studies the potentials of green hydrogen production from hydropower energy and its application in electricity regeneration and replacement of petroleum products from the transportation sector in Nepal. The potential surplus hydroelectric energy, and hydrogen production potential from the surplus energy considering different scenarios, is forecasted for the study period (2022–2030). The results showed that hydrogen production potential ranges from 63,072 tons to 3,153,360 tons with the utilization of surplus energy at 20% and 100% respectively, in 2030. The economic analysis of hydrogen from hydropower projects that electricity is valued based on per kg of hydrogen when the surplus electricity is provided at feasible lower price values compared to the US $1.17. This study concludes that hydrogen production from spilled hydro energy and its use in the transportation sector and independent electricity generation is a niche opportunity to lead the country towards sustainable energy solutions and an economy running on hydrogen.

Exploring Value Propositions to Drive Self-Sovereign Identity Adoption

This paper presents research exploring the balancing of interactive friction and value proposition in the context of Self-Sovereign Identity (SSI) technology adoption. This work extends a related investigation of a full agency engagement with a User-Centred Data Ecosystem utilising what is described as a Sovereign Boundary Mechanism (SBM). An SBM is a standardised collection of SSI interactions, which can collectively be described as a metaphorical ring of sovereignty between the participant and the wider network. Within this model participants control identity, relationships, credentials, data streams, and access control. This related work concludes that the developing trend poses significant interactive friction, and that clear and substantive value proposition would be required to drive and sustain participant adoption. This paper explores potential value propositions for SSI, considering theory relating to Privacy, Surveillance Capitalism, and Human Data Interaction; in parallel opinions are drawn from the thematic analysis of interviews with experts in the decentralised field and results from a public survey. This research concludes that the value proposition is unlikely to come from the direct perceived protection of privacy. Also, that the decentralised technologies cannot be marketed solely on the fact that it is decentralised. Instead, value will emerge from the capability of SSI functionality to supersede the centralised model, offering innovation and reduced transactional friction across individual, business and wider society. This research suggests that the SSI community needs to develop a cohesive design strategy, a clear narrative and vocabulary. Value needs to be defined across cultural context, while targeting accessible, high value niche opportunities to build momentum toward sustainable adoption.

Human stabilization of river flows is linked with fish invasions across the USA

AbstractAimRiver flow regimes are changing globally as a consequence of human use of freshwater resources. Additionally, rivers are among the most invaded ecosystems. Invasion biology predicts that the establishment and spread of non‐native species might be favoured both by new environmental regimes (niche opportunities) and by human‐mediated dispersal (propagule pressure). Here, we expand on past research by asking whether these two mechanisms act in isolation or whether they interact to facilitate the spread of non‐natives.LocationConterminous USA.Time period1987–2016.Major taxa studiedFreshwater fishes.MethodsFirst, we examined the geography of riverine fish invasions across 1,148 watersheds spanning the conterminous USA. We focused on species richness and the life‐history strategies of non‐native (both translocated and exotic) relative to native species pools. Second, we quantified flow regime alteration as the deviation between observed and expected contemporary flow regimes, using a combination of spectral analyses on long‐term discharge data and random forest models. We focused on two biologically relevant facets of the flow regime: flow variability and flow seasonality. We also estimated metrics of propagule pressure: recreational fishing pressure and socioeconomic activity. We then compared the strength of evidence associating riverine fish invasions with flow alteration, propagule pressure, and interactions between the two mechanisms.ResultsWe found that alteration of flow variability and seasonality is widespread across the conterminous U.S. rivers, and has favoured invasions by filtering specific life‐history strategies. Importantly, high levels of flow stabilization and propagule pressure interacted: where co‐occurring, these two drivers were associated with higher fish invadedness levels than expected based on their individual effects.Main conclusionsOur results underscore the need to consider different drivers of invasion concurrently. Otherwise, important synergistic interactions might be missed that could explain (and guide management strategies to mitigate) the high levels of invasion in fresh waters.

COMPETITIVENESS OF NATIONAL IT COMPANIES IN THE NEW ENVIRONMENT

In the current conditions of the economic downturn, the majority of national companies operating in the field of information entrepreneurship have identified a number of problems related to the assessment of competitors and the need to maintain their own competitiveness. The purpose of the study: on the basis of new global trends, to analyze the competitiveness of domestic IT-firms operating in a post- pandemic situation. The article presents an overview of the current state of Russian IT-companies and their competitive positions based on content analysis and descriptive method. The main results of the study: the general trends and trends in the development of the processes of competitiveness of Russian IT-companies are reflected; it is shown that the information sector has been affected by the non-economic factors of the pandemic, which should be considered not only as threats, but also as opportunities for finding new competitive niches; it is noted that national players, being present in the global market of information goods and services, are actively involved in the global digital space. The result of the study is the conclusion that domestic companies are inferior to foreign competitors in certain positions, but also have competitive advantages in the field of generating and promoting relevant digital technologies of Industry 4.0. The study makes a theoretical contribution to the study of national information sectors and allows us to expand our understanding of the practice of ensuring the competitiveness of IT companies in the changed conditions of 2020-2021.

An invasive grass species has both local and broad‐scale impacts on diversity: Potential mechanisms and implications

AbstractQuestionsThe impact of invasive plant species on native diversity varies with spatial scale, with some invaders leading to broad‐scale diversity declines and others to only local declines. These discrepancies may reflect the invaders” capacity to reduce niche opportunities across spatial scales which can be associated with their functional traits. We investigated impact‐scale relationships and trait‐based mechanisms, in areas invaded by the exotic perennial grass species, Bothriochloa pertusa. We examine root traits specifically, as below‐ground competition was considered particularly important to the success of this species.LocationGrassy “ironbark” woodlands of eastern Queensland, Australia.MethodsWe examined plots with varying degrees of invasion by B. pertusa, at multiple spatial scales (up to 1,000 m2) and analysed changes to the species–area relationships (SARs) with increasing invader cover. Changes to SARs were assessed in relation to the invaders” effect on rare (low patch occupancy) and common species in the community. In a separate analysis within the same habitat, we collected root cores across a gradient of invader cover and analysed changes to community root traits that were considered important correlates of competition for space and nutrients.ResultsInvasion‐induced reductions in diversity were pervasive at all scales investigated, and this was associated with a proportionally greater effect on rare species in the community. In the separate root analysis, changes in community root traits with increasing invader cover were potentially indicative of more intense competition for resources rather than space.ConclusionsThe observed regional‐scale dominance of B. pertusa and associated declines in diversity warrant serious concern for the conservation of native plant communities and species in a region already at risk from other anthropogenic threats. Intense competition for below‐ground resources is likely a contributing mechanism to the success of B. pertusa in this study system. Experimental examination of this and other mechanisms would help to validate these findings.

Tree phylogenetic diversity structures multitrophic communities

Abstract Plant diversity begets diversity at other trophic levels. While species richness is the most commonly used measure for plant diversity, the number of evolutionary lineages (i.e. phylogenetic diversity) could theoretically have a stronger influence on the community structure of co‐occurring organisms. However, this prediction has only rarely been tested in complex real‐world ecosystems. Using a comprehensive multitrophic dataset of arthropods and fungi from a species‐rich subtropical forest, we tested whether tree species richness or tree phylogenetic diversity relates to the diversity and composition of organisms. We show that tree phylogenetic diversity but not tree species richness determines arthropod and fungi community composition across trophic levels and increases the diversity of predatory arthropods but decreases herbivorous arthropod diversity. The effect of tree phylogenetic diversity was not mediated by changed abundances of associated organisms, indicating that evolutionarily more diverse plant communities increase niche opportunities (resource diversity) but not necessarily niche amplitudes (resource amount). Our findings suggest that plant evolutionary relatedness structures multitrophic communities in the studied species‐rich forests and possibly other ecosystems at large. As global change non‐randomly threatens phylogenetically distinct plant species, far‐reaching consequences on associated communities are expected. A free Plain Language Summary can be found within the Supporting Information of this article.

Seed dispersal by dung beetles in Ceratocaryum pulchrum (Restionaceae): Another example of faecal mimicry in plants

Faecal mimicry by seeds is a recently discovered phenomenon in plants. Here we demonstrate that seeds of Ceratocaryum pulchrum (Restionaceae) are dispersed and buried by dung beetles, making it the second species, after its sister species C. argenteum, known to exhibit this mode of dispersal. Seeds of C. pulchrum are similar in size, shape and scent to those of C. argenteum and the dung of various mammalian herbivores. The distribution range of C. pulchrum entirely overlaps with that of C. argenteum, but they flower and release seeds six months apart. Several dung beetle species, including both of those associated with C. argenteum, were found to be attracted to C. pulchrum seeds. Seeds were buried in situ by the tunnelling species Copris victorini. Since seeds of both plant species attract several generalist dung beetles, this suggests that speciation in these two species has not been due to evolution for different or specific dispersers but may instead be related to exploitation of temporal niche opportunities.

Advocacy and Collaboration: Advancing Cancer Prevention and Screening.

Cancer prevention and screening is a significant part of the cancer care continuum. Nurses are trusted professionals who can bring stakeholders together and serve diverse groups. This article describes how nurses can advance cancer prevention and screening initiatives in industry, education, legislative advocacy, research, survivorship, and program development and support. An online search and collaborative knowledge revealed examples of nurses leading the way in cancer prevention and screening efforts. Nurse-driven cancer prevention and screening collaborations advance care farther and faster. By creating maximum impact and mobilizing individual passion for a project, any nurse can find collaborative niche opportunities in clinical practice.

Niche opportunity created by land cover change is driving the European hare invasion in the Neotropics

The European hare (Lepus europaeus) was introduced in the late 19th century in Argentina and has since rapidly expanded northwards, currently occupying the Brazilian south and southeast. Although European hare is known to be a farmland specialist in its native Europe, what habitat types or landscape features are facilitating its expansion in the Neotropics are not yet clear. Here we assessed support to the disturbance and biotic resistance hypotheses as general drivers of this invasion. We sampled with camera-traps and track surveys 205 sites in three landscapes in southeastern Brazil. We used occupancy models that corrected for both false positive and false negative errors. The disturbance hypothesis was the top-ranked (w = 0.66) with the amount of field, sugarcane, and managed forests all affecting strongly and positively hare occupancy. Support to the biotic resistance hypothesis was lower (ΔAICc = 2.14; w = 0.23) and partial, since only native forests showed a negative effect on hare occupancy. Our findings indicate that in the expansion front occupancy of this invader is mainly dictated by niche opportunities created by native habitat transformation into agricultural lands. The biotic resistance imposed by remaining native habitats seems to play a secondary role and only due to native forests. We conclude that hare geographical expansion should increase given the prominent role of Brazil as a commodity producer and exporter. Nevertheless, fomenting forested protected areas and improving adherence of rural owners to the Brazilian Forest Act, which protects forests in private rural properties, might help lessen this spread.

Differences among species in seed dispersal and conspecific neighbor effects can interact to influence coexistence

Seed dispersal is a critical mechanism for escaping specialist natural enemies. Despite this, mean dispersal distances can vary by an order of magnitude among plant species in the same community. Here, we develop a theoretical model to explore how interspecific differences in seed dispersal alter the impact of specialist natural enemies, both on their own and though a trade-off between seed dispersal and enemy susceptibility. Our model suggests that species are more able to recover from rarity if they have high dispersal because (1) seedlings are more likely to escape their parent’s natural enemies, (2) adults are more spread out, reducing the chance that a seed will disperse near conspecifics, and (3) seedlings compete less with kin for open gaps. Differences in dispersal do not produce stabilizing mechanisms—species with low dispersal are purely at a disadvantage and do not gain a novel niche opportunity. However, dispersal-susceptibility trade-offs will be equalizing, as species disadvantaged by low dispersal will benefit from being less susceptible to specialist natural enemies. This mechanism, unlike most mechanisms of dispersal-mediated coexistence, does not require that there is an abundance of empty space: high-dispersers gain an advantage by escaping from their enemies, not by colonizing empty habitat. Our study therefore suggests that differences in dispersal are unlikely to promote diversity on their own, but may strengthen other coexistence mechanisms.

Apparent Comparative Advantage and Development Space in Women’s Apparel Trade

This study investigates the apparent comparative advantage of the world’s top five women’s apparel exporters in order to anticipate the development of future international women’s apparel markets using Vollrath’s Relative Trade Advantage (RTA) Index and market share analysis for both aggregate and disaggregate trade data from the UN Statistics Database for the years 1993-2007. Findings show the complexity of the comparative advantage concept and indicate that appearances can be deceiving. Outstanding performance for exporters based on RTA values at the aggregate level does not necessarily mean outstanding performance at the subcategory level. Furthermore, market share analysis shows that new players are making a strong showing in the women’s apparel trade. Niche opportunities are revealed for the current export leaders, as well as up-and-coming apparel exporters. The results suggest that Vollrath’s RTA Index, heretofore little used in the apparel trade area, offers a useful additional perspective on comparative advantage and should be considered for use in future apparel trade studies.

Vertical stratification collapses under seasonal shifts in climate

AbstractAimTropical forests are vertically complex, and offer unique niche opportunities in the form of climate, habitat and resource gradients from ground to canopy. Rainforest species organize within this vertical spatial gradient and recent macroecological research suggests that the highest levels of vertical stratification occur in structurally complex and climatically stable tropical rainforests. However, although the classical view of the tropics is that of aseasonality, particularly in temperature, there is strong seasonality in rainfall. Thus, we predict considerable variation in vertical stratification in time, characterized by a seasonal restructuring of communities across vertical space.LocationSierra Llorona, Colón Province, Panama.TaxonAmphibians.MethodsWe performed 121 ground‐to‐canopy surveys across the wet and dry seasons for amphibians. Using a bootstrap simulation method we calculated species‐specific and community‐wide vertical height and abundance shifts between seasons. Separately, we tested the importance of vertical height and season on the vertical distribution of species using a redundancy analysis, and employed linear models to explore turnover in species composition across vertical height between seasons.ResultsOur results show a clear downward shift of 5 m in height in amphibian communities from the wet season to dry season. We also observe significant changes in species composition across vertical strata in both seasons, driven primarily by nestedness in the dry season (loss of species over height) and genuine turnover in the wet season (loss and addition of species over height).Main conclusionsThe exploitation of canopy microhabitats and resources in the wet season resulted in complex patterns of stratification, whereas drying flattened the distribution and simplified the composition of arboreal communities. As such, pattern and process in the vertical dimension is not static in time but rather exists as a dichotomy with inverse patterns between wet and dry seasons. Complex, multidimensional distributions of diverse rainforest communities can be simplified by climatic constraints – an important consideration as anthropogenic climate change increases the magnitude of seasonal swings in temperature and precipitation.

The Great American Biotic Interchange revisited: a new perspective from the stable isotope record of Argentine Pampas fossil mammals

This study aims at assessing resource and habitat use, niche occupation and trophic interactions from a stable isotope perspective on fossil mammals from the Argentine Pampas during the Great American Biotic Interchange (GABI). We present stable isotope data of more than 400 samples belonging to 10 mammalian orders and spanning a temporal range from ~9.5 Ma to ~12 ky. Rodents, notoungulates and pilosians record an increase in the consumption of C4 plants, whereas litopterns and cingulates show δ13C values that remain mostly within a C3-dominated diet. Our stable isotope data indicates that the expansion of C4 vegetation opened up new niche opportunities, probably alleviating resource competition among endemic taxa. Gomphothere, equid and camelid δ13C records show a broad variability pointing to consumption of C3 and mixed C3-C4 vegetation. This flexible dietary behavior may have facilitated the successful settlement of immigrant groups in South America. In the case of carnivorous taxa, Late Miocene pre-GABI endemic sparassodonts consumed prey from C3 environments, whereas immigrant carnivorans preferred prey from mixed C3-C4 areas. Our research contributes to the study of the GABI from a different perspective as stable isotope records permit to characterize, from a (semi)quantitative standpoint, ecological traits within extinct fauna.