Impacts of large herbivores on terrestrial ecosystems

Current Biology, Год журнала: 2023, Номер 33(11), С. R584 - R610

Опубликована: Июнь 1, 2023

Язык: Английский

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The generality of cryptic dietary niche differences in diverse large-herbivore assemblages

Proceedings of the National Academy of Sciences, Год журнала: 2022, Номер 119(35)

Опубликована: Авг. 22, 2022

Ecological niche differences are necessary for stable species coexistence but often difficult to discern. Models of dietary differentiation in large mammalian herbivores invoke the quality, quantity, and spatiotemporal distribution plant tissues growth forms agnostic toward food identity. Empirical support these models is variable, suggesting that additional mechanisms resource partitioning may be important sustaining large-herbivore diversity African savannas. We used DNA metabarcoding conduct a taxonomically explicit analysis diets across southeastern Africa, analyzing ∼4,000 fecal samples 30 from 10 sites seven countries over 6 y. detected 893 taxa 124 families, just two families—grasses legumes—accounted majority herbivore diets. Nonetheless, almost invariably partitioned taxa; diet composition differed significantly 97% pairwise comparisons between sympatric species, dissimilarity was pronounced even strictest grazers (grass eaters), browsers (nongrass closest relatives at each site. Niche weakest an ecosystem recovering catastrophic defaunation, indicating driven by interactions, stronger low rainfall, as expected if interspecific competition predominant driver. Diets more than grazers, which predictably shaped community organization: Grazer-dominated trophic networks had higher nestedness lower modularity. That structured along taxonomic lines complements prior work on how partition parts patches suggests common govern assembly

Язык: Английский

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Food webs reveal coexistence mechanisms and community organization in carnivores

Current Biology, Год журнала: 2023, Номер 33(4), С. 647 - 659.e5

Опубликована: Янв. 19, 2023

Язык: Английский

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A Critical Evaluation of Network Approaches for Studying Species Interactions

Annual Review of Ecology Evolution and Systematics, Год журнала: 2024, Номер 55(1), С. 65 - 88

Опубликована: Июль 26, 2024

Ecological networks of species interactions are popular and provide powerful analytical tools for understanding variation in community structure ecosystem functioning. However, network analyses commonly used metrics such as nestedness connectance have also attracted criticism. One major concern is that observed patterns misinterpreted niche properties specialization, whereas they may instead merely reflect sampling, abundance, and/or diversity. As a result, studies potentially draw flawed conclusions about ecological function, stability, or coextinction risks. We highlight potential biases analyzing interpreting species-interaction review the solutions available to overcome them, among which we particularly recommend use null models account abundances. show why considering across important their consequences. Network can advance knowledge on principles but only when judiciously applied.

Язык: Английский

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The influence of changing fire regimes on specialized plant–animal interactions

Philosophical Transactions of the Royal Society B Biological Sciences, Год журнала: 2025, Номер 380(1924)

Опубликована: Апрель 1, 2025

Ecological effects of changing fire regimes are well documented for plant and animal populations, but less is known about how influences, influenced by, specialized plant–animal interactions. In this review, we identified mutualistic (pollination, seed dispersal food provision), commensal (habitat provision) antagonistic (seed predation, herbivory parasitism) interactions from fire-prone ecosystems. We focused on where a single genus depended one to two genera in family or animal. categorized the partner’s post-fire reproductive mode assess likely outcome ecological functions provided by these Traits underlying specialization ecosystems plants were: mode, time maturity, morphology phenology; and, animals: dispersal, organs, nesting egg deposition substrates, consumption behaviours pollinator behaviours. Finally, number cases stabilizing feedbacks maintained under natural regimes. Potential reinforcing were also identified, more happen abruptly result collapse partnership, partner switching. Our synthesis reveals regime changes impact fire-dependent specialist potentially drive eco-evolutionary dynamics globally. This article part theme issue ‘Novel climate human influences: impacts, ecosystem responses feedbacks’.

Язык: Английский

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Mechanisms of individual variation in large herbivore diets: Roles of spatial heterogeneity and state‐dependent foraging

Ecology, Год журнала: 2022, Номер 104(2)

Опубликована: Ноя. 23, 2022

Abstract Many populations of consumers consist relatively specialized individuals that eat only a subset the foods consumed by population at large. Although ecological significance individual‐level diet variation is recognized, such difficult to document, and its underlying mechanisms are poorly understood. Optimal foraging theory provides useful framework for predicting how might select different diets, positing animals balance “opportunity cost” stopping an available food item against cost searching something more nutritious; composition should be contingent on distribution food, individual foragers selective when they have greater energy reserves invest in high‐quality foods. We tested these predicted niche differentiation quantifying environmental (resource heterogeneity) organismal (nutritional condition) determinants widespread browsing antelope (bushbuck, Tragelaphus sylvaticus ) African floodplain‐savanna ecosystem. quantified individuals' realized dietary niches (taxonomic richness composition) using DNA metabarcoding fecal samples collected repeatedly from 15 GPS‐collared (range 6–14 per individual, median 12). Bushbuck diets were structured spatial heterogeneity constrained condition. observed significant partitioning plants bushbuck both within between two adjacent habitat types (floodplain woodland). Individuals with home ranges closer together and/or had similar vegetation structure (measured LiDAR) ate supporting prediction heterogeneous resource promotes differentiation. good nutritional condition significantly narrower (fewer plant taxa), searched their intensively (intensity‐of‐use index), higher‐quality (percent digestible protein) than those poor condition, endogenous because can time nutritious Our results support predictions optimal about energetic basis provide potentially generalizable understanding width governed animal behavior physiology landscapes.

Язык: Английский

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DNA Metabarcoding Illuminates Seasonal Dietary Pattern and Niche Partitioning by Three Sympatric Herbivores

Ecology and Evolution, Год журнала: 2025, Номер 15(4)

Опубликована: Апрель 1, 2025

Diet composition is among the most critical dimensions of animal ecology, yet seasonal dietary diversity has rarely been investigated in sympatric herbivores. This study used DNA metabarcoding to conduct an analysis variations diet and trophic niches for sika deer, Reeves' muntjac, Chinese hare Taohongling National Nature Reserve (TNNR). The results showed that Smilax china (11.79%) was leading food eaten by deer summer, whereas dominated Rubus spp. (36.42%) Loropetalum chinense (25.48%) winter; accounted majority muntjac's throughout year. In comparison, primarily consumed from winter spring but changed Poa annua (10.81%) Setaria viridis (23.05%) summer fall. Compared other seasons, significant differences (Shannon index, p < 0.05) occurred showing higher items across three herbivorous. Nonmetric multidimensional scaling (NMDS) suggested partitioning hares compared two ruminants. Both muntjac occupied a wider niche breadth reflecting generalised feeding habits (Sd: Ba = 0.06; Rm: 0.04) lower fall (Ba 0.01) with stronger selectivity specialization, which consistent optimal foraging theory. Notably, no difference indicated (p > 0.05). overlap indices were 0.989 (fall) 0.831 (winter) between indicating similarity overlap. However, plant taxa abundance ratios may facilitate partitioning. herbivores reflected plant-herbivore interactions correlated strategies, coexistence reduce competition co-occurring species dimension.

Язык: Английский

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Assessing the influence of body size on patterns of dietary niche segregation among the ungulate community in Yellowstone National Park, USA

Mammalian Biology, Год журнала: 2024, Номер 104(4), С. 431 - 445

Опубликована: Май 15, 2024

Язык: Английский

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Quantifying mammalian diets

Mammalian Biology, Год журнала: 2022, Номер 103(1), С. 53 - 67

Опубликована: Окт. 14, 2022

Abstract We propose a quantitative approach for categorising mammalian diets based on the taxonomy of food items and parts consumed (the form food). Our analysis covers 82% species alive today. The diet information comes from different data sources—textbooks, datasets peer-reviewed literature includes transformation narrative into qualitative data. link database nutrient composition analyse distribution macronutrients across taxonomic groups map them to dental morphology eaters. results show associations between complexity concentrations some nutrients. highlights omnivory as multi-faceted concept—there are many kinds omnivores within dietary space we report. developed dataset proposed relating chemical offers basis future comparative studies living fossil mammals. With this study, make accompanying large-scale publicly available online ( https://www.mammalbase.net ).

Язык: Английский

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DNA analysis of scats reveals spatial and temporal structure in the diversity of harbour seal diet from local haulouts to oceanographic bioregions

Marine Ecology Progress Series, Год журнала: 2024, Номер 743, С. 113 - 138

Опубликована: Авг. 22, 2024

Predation shapes ecosystems, and quantifying the impacts of predation on distribution abundance prey requires substantial effort at appropriate spatial temporal scales for diet estimation predators. Here, we present estimates a marine predator (harbour seal Phoca vitulina richards i ) from scat collections (n = 3420) sampled multiple haulout sites 64) in Strait Georgia other coastal regions around Vancouver Island, British Columbia, Canada, between 2015 2019. DNA metabarcoding hard part analysis were used to identify proportion sizes species consumed, respectively. We found that harbour seals consumed 62 primary species. Diversity was highly affected by number samples collected varied small (haulout sites) as well among broad bioregions. Three 5 dominated depending location, season, year, including Pacific hake Merluccius productus , herring Clupea pallasii walleye pollock Gadus chalcogrammus . Within Georgia, both male female more areas seasons which they abundant. Harbour wide size range also species, region. These results indicate foraging is influenced local composition prey. Attempts model impact concern risk bias their underrepresenting uncertainty if variation not accounted for.

Язык: Английский

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