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Carrion ecology, i.e. the decomposition and recycling of dead animals, has traditionally been neglected as a key process in ecosystem functioning. Similarly, despite the large threats that inland aquatic ecosystems (hereafter, aquatic ecosystems) face, the scientific literature is still largely biased towards terrestrial ecosystems. However, there has been an increasing number of studies on carrion ecology in aquatic ecosystems in the last two decades, highlighting their key role in nutrient recirculation and disease control. Thus, a global assessment of the ecological role of scavengers and carrion in aquatic ecosystems is timely. Here, we systematically reviewed scientific articles on carrion ecology in aquatic ecosystems to describe current knowledge, identify research gaps, and promote future studies that will deepen our understanding in this field. We found 206 relevant studies, which were highly biased towards North America, especially in lotic ecosystems, covering short time periods, and overlooking seasonality, a crucial factor in scavenging dynamics. Despite the low number of studies on scavenger assemblages, we recorded 55 orders of invertebrates from 179 families, with Diptera and Coleoptera being the most frequent orders. For vertebrates, we recorded 114 species from 40 families, with birds and mammals being the most common. Our results emphasise the significance of scavengers in stabilising food webs and facilitating nutrient cycling within aquatic ecosystems. Studies were strongly biased towards the assessment of the ecosystem effects of carrion, particularly of salmon carcasses in North America. The second most common research topic was the foraging ecology of vertebrates, which was mostly evaluated through sporadic observations of carrion in the diet. Articles assessing scavenger assemblages were scarce, and only a limited number of these studies evaluated carrion consumption patterns, which serve as a proxy for the role of scavengers in the ecosystem. The ecological functions performed by carrion and scavengers in aquatic ecosystems were diverse. The main ecological functions were carrion as food source and the role of scavengers in nutrient cycling, which appeared in 52.4% (N = 108) and 46.1% (N = 95) of publications, respectively. Ecosystem threats associated with carrion ecology were also identified, the most common being water eutrophication and carrion as source of pathogens (2.4%; N = 5 each). Regarding the effects of carrion on ecosystems, we found studies spanning all ecosystem components (N = 85), from soil or the water column to terrestrial vertebrates, with a particular focus on aquatic invertebrates and fish. Most of these articles found positive effects of carrion on ecosystems (e.g. higher species richness, abundance or fitness; 84.7%; N = 72), while a minority found negative effects, changes in community composition, or even no effects. Enhancing our understanding of scavengers and carrion in aquatic ecosystems is crucial to assessing their current and future roles amidst global change, mainly for water-land nutrient transport, due to changes in the amount and speed of nutrient movement, and for disease control and impact mitigation, due to the predicted increase in occurrence and magnitude of mortality events in aquatic ecosystems., (© 2024 The Authors. Biological Reviews published by John Wiley & Sons Ltd on behalf of Cambridge Philosophical Society.)

Competition and facilitation drive ecological succession but are often hard to quantify. In this sense, behavioral data may be a key tool to analyze interaction networks, providing insights into temporal trends in facilitation and competition processes within animal heterotrophic succession. Here, we perform the first in-depth analysis of the factors driving temporal dynamics of carcass consumption by analyzing behavioral patterns (i.e., interactions) and community dynamics metrics (i.e., species richness, abundance, turnover, and diversity) in a Neotropical scavenger guild. For this purpose, we monitored goat carcasses using automatic cameras. From 573 reviewed videos, we registered 1784 intraspecific and 624 interspecific interactions, using intraspecific and interspecific aggressions (n = 2048) as a behavioral proxy of competition intensity. Our results show that resource availability shapes behavioral interactions between vultures, with a specific effect of the different species on behavioral and competition dynamics, showing the existence of a hierarchy between species. Furthermore, behavioral processes linked to carcass opening tended to be facilitative, related to moments of higher tolerance (i.e., lower aggressiveness), thus reducing competition intensity and also affecting community structure and dynamics. This novel framework demonstrates complex ephemeral successional processes characterized by a fluctuation in facilitation and competition intensity during the consumption of an unpredictable resource linked to key ecosystem processes., (© 2024 The Authors. Ecology published by Wiley Periodicals LLC on behalf of The Ecological Society of America.)

Nature's contributions to people (NCP) may be both beneficial and detrimental to humans' quality of life. Since our origins, humans have been closely related to wild ungulates, which have traditionally played an outstanding role as a source of food or raw materials. Currently, wild ungulates are declining in some regions, but recovering in others throughout passive rewilding processes. This is reshaping human-ungulate interactions. Thus, adequately understanding the benefits and detriments associated with wild ungulate populations is necessary to promote human-ungulate co-existence. Here, we reviewed 575 articles (2000-2019) on human-wild ungulate interactions to identify key knowledge gaps on NCP associated with wild ungulates. Wild ungulate research was mainly distributed into seven research clusters focussing on: (1) silvicultural damage in Eurasia; (2) herbivory and natural vegetation; (3) conflicts in urban areas of North America; (4) agricultural damage in Mediterranean agro-ecosystems; (5) social research in Africa and Asia; (6) agricultural damage in North America; (7) research in natural American Northwest areas. Research mostly focused on detrimental NCP. However, the number of publications mentioning beneficial contributions increased after the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services conceptual framework was implemented. Human-ungulate interactions' research was biased towards the Global North and Cervidae, Suidae and Bovidae families. Regarding detrimental NCP, most publications referred to production damage (e.g. crops), followed by biodiversity damage, and material damage (e.g. traffic collisions). Regarding beneficial NCP, publications mainly highlighted non-material contributions (e.g. recreational hunting), followed by material NCP and regulating contributions (e.g. habitat creation). The main actions taken to manage wild ungulate populations were lethal control and using deterrents and barriers (e.g. fencing), which effectiveness was rarely assessed. Increasing research and awareness about beneficial NCP and effective management tools may help to improve the conservation of wild ungulates and the ecosystems they inhabit to facilitate people-ungulate co-existence in the Anthropocene., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

Anecdotic citations of food wasting have been described for parrots, but we lack a comprehensive knowledge about the extent of this behaviour, and its ecological and evolutionary implications. Here, we combine experimental and observational approaches to evaluate the spatial, temporal, typological and taxonomic extent of food wasting by parrots, to identify the ecological and evolutionary factors driving food wasting, and to assess the incidence of two ecological functions derived from food wasting, such as food facilitation to other animal species and secondary seed dispersal. We found that food wasting is a widespread behaviour found in all the studied parrot species. However, the proportion of food wasted differed among species and throughout the year. Parrots wasted more food during the non-breeding season, when they relied on exotic plants and on unripe fruits or seeds. We also recorded 86 animal species feeding on the food wasted by parrots, 27 of which potentially acted as secondary seed dispersers. Overall, our study emphasizes the universality of food wasting among parrots, and the important implications that this behaviour may have for the species involved (i.e., the parrot, the plant, the other species feeding on wasted food), and for the functioning of the whole ecosystem.

Understanding the distribution of biodiversity across the Earth is one of the most challenging questions in biology. Much research has been directed at explaining the species latitudinal pattern showing that communities are richer in tropical areas; however, despite decades of research, a general consensus has not yet emerged. In addition, global biodiversity patterns are being rapidly altered by human activities. Here, we aim to describe large-scale patterns of species richness and diversity in terrestrial vertebrate scavenger (carrion-consuming) assemblages, which provide key ecosystem functions and services. We used a worldwide dataset comprising 43 sites, where vertebrate scavenger assemblages were identified using 2,485 carcasses monitored between 1991 and 2018. First, we evaluated how scavenger richness (number of species) and diversity (Shannon diversity index) varied among seasons (cold vs. warm, wet vs. dry). Then, we studied the potential effects of human impact and a set of macroecological variables related to climatic conditions on the scavenger assemblages. Vertebrate scavenger richness ranged from species-poor to species rich assemblages (4-30 species). Both scavenger richness and diversity also showed some seasonal variation. However, in general, climatic variables did not drive latitudinal patterns, as scavenger richness and diversity were not affected by temperature or rainfall. Rainfall seasonality slightly increased the number of species in the community, but its effect was weak. Instead, the human impact index included in our study was the main predictor of scavenger richness. Scavenger assemblages in highly human-impacted areas sustained the smallest number of scavenger species, suggesting human activity may be overriding other macroecological processes in shaping scavenger communities. Our results highlight the effect of human impact at a global scale. As species-rich assemblages tend to be more functional, we warn about possible reductions in ecosystem functions and the services provided by scavengers in human-dominated landscapes in the Anthropocene., (© 2019 John Wiley & Sons Ltd.)

The distributional patterns of actively moving animals are influenced by the cues that the individuals use for choosing sites into which they settle. Individuals may gather information about habitat quality using two types of strategies, either directly assessing the relevant environmental factors, or using the presence of conspecifics or heterospecifics as an indirect measure of habitat quality. We examined patterns of heterospecific attraction with observational time-series data on a community of seven waterbird species breeding in artificial irrigation ponds. We fitted to the data a multivariate logistic regression model, which attributes the presence-absence of each species to a set of environmental and spatial covariates, to the presence of con- and heterospecifics in the previous year and to the presence of heterospecifics in the same year. All species showed a clear tendency to continue breeding in the same sites where they were observed in the previous year. Additionally, the presence of heterospecifics, both in the previous year and in the same year, generally increased the probability that the focal species was found breeding on a given pond. Our data thus give support for the heterospecific attraction hypothesis, though causal inference should be confirmed with manipulative experiments.