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Cianferoni F, Lunghi E. Inferring on Speleomantes Foraging Behavior from Gut Contents Examination. Animals (Basel) 2023; 13:2782. [PMID: 37685046 PMCID: PMC10486601 DOI: 10.3390/ani13172782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
We here provide the first comprehensive analysis and discussion on prey consumed by the European cave salamanders of the genus Speleomantes. Our study stems from the need to shed light on the still unknown foraging behavior adopted by Speleomantes cave salamanders. Starting from the published datasets on gut contents from all Speleomantes species (including hybrids), we here discuss additional information (i.e., species ecology, lower taxonomic level), which were systematically omitted from those data sets. We analyzed a data set consisting of 17,630 records from 49 categories of consumed prey recognized from gut contents of 2060 adults and juveniles Speleomantes. Flying prey accounted for more than 58% of the prey items, while elongated crawling prey accounted for no more than 16% of the diet within a single population. Among the total recognized prey items, only three can be surely ascribed to the group of strictly-cave species (i.e., troglobites), meaning that European cave salamanders mostly forage in surface environment, and therefore represent one of the major drivers of allochthonous organic matter in subterranean environments. Some of the consumed prey seemed to be aquatic, allowing us to hypothesize whether Speleomantes are able to catch prey from a shallow body water. Furthermore, European cave salamanders possess the ability to prey upon taxa characterized by particular anti-predator defenses, while morphological constraints seem to be the most important limit to prey consumption. For each specific case, we provide insights and propose hypotheses concerning the foraging behavior that need to be tested to properly understand the foraging behavior of this cryptic salamanders.
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Affiliation(s)
- Fabio Cianferoni
- Research Institute on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), 50019 Firenze, Italy;
- Natural History Museum of the University of Florence, “La Specola”, 50125 Firenze, Italy
| | - Enrico Lunghi
- Department of Life Health and Environmental Sciences (MeSVA), Università degli Studi dell’Aquila, 67100 L’Aquila, Italy
- Associazione Natural Oasis, 59100 Prato, Italy
- Unione Speleologica Calenzano, 50041 Calenzano, Italy
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Lunghi E, Cianferoni F, Corti C, Zhao Y, Manenti R, Ficetola GF, Mancinelli G. The trophic niche of subterranean populations of Speleomantes italicus. Sci Rep 2022; 12:18257. [PMID: 36309527 PMCID: PMC9617932 DOI: 10.1038/s41598-022-21819-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 10/04/2022] [Indexed: 12/31/2022] Open
Abstract
The determination of a species trophic niche can clarify its functional role within a food web and how prey resources are used in relation with the spatial and temporal variability of environmental conditions. This information may result particularly useful for the implementation of conservation plans of endangered species having a cryptic behaviour or living in places difficult to be surveyed. Here we present the first long-term study on the trophic niche of the Italian cave salamander Speleomantes italicus, a strictly protected facultative cave species that seasonally exploits surface environments (e.g., forested areas) as well as both natural and artificial subterranean environments. We analysed the diet variation of six populations of S. italicus inhabiting natural caves, surveyed 24 times in a full year. During the surveys, all sampled individuals were subjected to stomach flushing and the ingested prey were identified and enumerated; furthermore, salamanders' body condition was also evaluated. The results of the analyses provided the first comprehensive, year-round assessment of the diet for a Speleomantes species. Remarkable divergences in terms of trophic niche and body condition were observed between the studied populations. We found a discrepancy in the foraging activity of the populations located in different areas; specifically, the individuals that experienced sub-optimal microclimatic conditions poorly performed in foraging. Furthermore, we found temporal and spatial variability in the body condition of individuals. Our study highlighted a remarkably high spatial and temporal divergence in the trophic habits of conspecific populations, a feature that may represent one of the major factors promoting the variability of multiple population traits.
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Affiliation(s)
- Enrico Lunghi
- grid.9227.e0000000119573309Key Laboratory of the Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China ,grid.158820.60000 0004 1757 2611Dipartimento di Medicina clinica, sanità pubblica, scienze della vita e dell’ambiente (MESVA), University of L’Aquila, Coppito, L’Aquila Italy ,grid.8404.80000 0004 1757 2304Zoologia, “La Specola”, Museo di Storia Naurale, Università degli Studi di Firenze, Florence, Italy ,Natural Oasis, Prato, Italy ,Unione Speleologica Calenzano, Calenzano, Florence, Italy
| | - Fabio Cianferoni
- grid.8404.80000 0004 1757 2304Zoologia, “La Specola”, Museo di Storia Naurale, Università degli Studi di Firenze, Florence, Italy ,grid.5326.20000 0001 1940 4177Istituto di Ricerca Sugli Ecosistemi Terrestri (IRET), Consiglio Nazionale delle Ricerche (CNR), Sesto Fiorentino, Florence Italy
| | - Claudia Corti
- grid.8404.80000 0004 1757 2304Zoologia, “La Specola”, Museo di Storia Naurale, Università degli Studi di Firenze, Florence, Italy
| | - Yahui Zhao
- grid.9227.e0000000119573309Key Laboratory of the Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Raoul Manenti
- grid.4708.b0000 0004 1757 2822Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Milano, Italy ,Laboratorio di Biologia Sotterranea “Enrico Pezzoli”, Parco Regionale del Monte Barro, Galbiate, Italy
| | - Gentile Francesco Ficetola
- grid.4708.b0000 0004 1757 2822Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Milano, Italy ,grid.450308.a0000 0004 0369 268XLaboratoire d’Écologie Alpine (LECA), Université Grenoble Alpes, CNRS, Grenoble, France
| | - Giorgio Mancinelli
- grid.9906.60000 0001 2289 7785Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali (DiSTeBA), Università del Salento, Lecce, Italy ,grid.5326.20000 0001 1940 4177Istituto per le Risorse Biologiche e le Biotecnologie Marine (IRBIM), Consiglio Nazionale delle Ricerche (CNR), Lesina, Foggia Italy ,grid.10911.380000 0005 0387 0033CoNISMa, Consorzio Nazionale Interuniversitario per le Scienze del Mare, Roma, Italy
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The Trophic Niche of Two Sympatric Species of Salamanders (Plethodontidae and Salamandridae) from Italy. Animals (Basel) 2022; 12:ani12172221. [PMID: 36077941 PMCID: PMC9454711 DOI: 10.3390/ani12172221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 08/12/2022] [Accepted: 08/21/2022] [Indexed: 11/30/2022] Open
Abstract
Simple Summary Studies on species’ trophic niches are essential to understand the characteristics of species’ ecology and life traits, as well as to improve conservation strategies. In the absence of competitors, species realize their trophic niche including in their diet the most profitable food resources. In the presence of competitors, species modify their preferences to reduce competition and maintain the highest benefits at the same time. In this study, we assessed the trophic niche of two species of salamanders coexisting in a forested area of Italy and evaluated which might be the mechanisms that these two species adopted to reduce competition. We found that the Italian cave salamander (Speleomantes italicus) mostly consumed flying prey with a hard cuticle, while the fire salamander (Salamandra salamandra) preferred worm-like and soft-bodied prey. In conclusion, we hypothesize that in our case, the two species of salamanders did not have to change their prey preference in order to avoid competition, but divergences in metabolism and behavioral traits likely worked as natural deterrent. Abstract The trophic niche of a species is one of the fundamental traits of species biology. The ideal trophic niche of a species is realized in the absence of interspecific competition, targeting the most profitable and easy-to-handle food resources. However, when a competitor is present, species adopt different strategies to reduce competition and promote coexistence. In this study, we assessed the potential mechanisms that allow the coexistence of two generalist salamanders: the Italian cave salamander (Speleomantes italicus) and the fire salamander (Salamandra salamandra). We surveyed, in April 2021, a forested area of Emilia-Romagna (Italy) during rainy nights. Analyzing the stomach contents of the captured individuals, we obtained information on the trophic niche of these two sympatric populations. Comparing our results with those of previous studies, we found that the two species did not modify their trophic niche, but that alternative mechanisms allowed their coexistence. Specifically, different prey preferences and predator metabolisms were likely the major factors allowing reduced competition between these two generalist predators.
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Lunghi E, Valle B, Guerrieri A, Bonin A, Cianferoni F, Manenti R, Ficetola GF. Environmental DNA of insects and springtails from caves reveals complex processes of eDNA transfer in soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 826:154022. [PMID: 35202680 DOI: 10.1016/j.scitotenv.2022.154022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 02/01/2022] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
Subterranean environments host a substantial amount of biodiversity, however assessing the distribution of species living underground is still extremely challenging. Environmental DNA (eDNA) metabarcoding is a powerful tool to estimate biodiversity in poorly known environments and has excellent performance for soil organisms. Here, we tested 1) whether eDNA metabarcoding from cave soils/sediments allows to successfully detect springtails (Hexapoda: Collembola) and insects (Hexapoda: Insecta); 2) whether eDNA mostly represents autochthonous (cave-dwelling) organisms or it also incorporates information from species living in surface environments; 3) whether eDNA detection probability changes across taxa with different ecology. Environmental DNA metabarcoding analyses detected a large number of Molecular Operational Taxonomic Units (MOTUs) for both insects and springtails. For springtails, detection probability was high, with a substantial proportion of hypogean species, suggesting that eDNA provides good information on the distribution of these organisms in caves. Conversely, for insects most of MOTUs represented taxa living outside caves, and the majority of them represented taxa/organisms living in freshwater environments (Ephemeroptera, Plecoptera and Trichoptera). The eDNA of freshwater insects was particularly abundant in deep sectors of caves, far from the entrance. Furthermore, average detection probability of insects was significantly lower than the one of springtails. This suggests that cave soils/sediments act as "conveyer belts of biodiversity information", possibly because percolating water lead to the accumulation of eDNA of organisms living in nearby areas. Cave soils hold a complex mix of autochthonous and allochthonous eDNA. eDNA provided unprecedented information on the understudied subterranean cave organisms; analyses of detection probability and occupancy can help teasing apart local eDNA from the eDNA representing spatially-integrated biodiversity for whole landscape.
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Affiliation(s)
- Enrico Lunghi
- Division of Molecular Biology Ruđer Bošković Institute, Zagreb, Croatia; Natural Oasis, Prato, Italy.
| | - Barbara Valle
- Dipartimento di Bioscienze, Università degli Studi di Milano, Milano, Italy; Unità di Climatologia ed Ecologia, MUSE-Museo delle Scienze di Trento, Italy
| | - Alessia Guerrieri
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Milano, Italy
| | - Aurélie Bonin
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Milano, Italy
| | - Fabio Cianferoni
- Istituto di Ricerca sugli Ecosistemi Terrestri (IRET), Consiglio Nazionale delle Ricerche (CNR), Sesto Fiorentino (Firenze), Italy; Zoologia, La Specola, Museo di Storia Naturale, Università degli Studi di Firenze, Firenze, Italy
| | - Raoul Manenti
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Milano, Italy; Laboratorio di Biologia Sotterranea "Enrico Pezzoli", Parco Regionale del Monte Barro, Galbiate, Italy
| | - Gentile Francesco Ficetola
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, Milano, Italy; Laboratoire d'Écologie Alpine (LECA), Université Grenoble Alpes, CNRS, Grenoble, France
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Bullington LS, Seidensticker MT, Schwab N, Ramsey PW, Stone K. Do the evolutionary interactions between moths and bats promote niche partitioning between bats and birds? Ecol Evol 2021; 11:17160-17178. [PMID: 34938500 PMCID: PMC8668740 DOI: 10.1002/ece3.8355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 10/11/2021] [Accepted: 10/28/2021] [Indexed: 11/08/2022] Open
Abstract
Ecological theory suggests that the coexistence of species is promoted by the partitioning of available resources, as in dietary niche partitioning where predators partition prey. Yet, the mechanisms underlying dietary niche partitioning are not always clear. We used fecal DNA metabarcoding to investigate the diets of seven nocturnal insectivorous bird and bat species. Low diet overlap (2%-22%) supported resource partitioning among all species. Differences in diet corresponded with species identity, prey detection method, and foraging behavior of predators. Insects with ultrasonic hearing capabilities were consumed significantly more often by birds than bats, consistent with an evolved avoidance of echolocating strategies. In turn, bats consumed a greater proportion of noneared insects such as spruce budworms. Overall, our results suggest that evolutionary interactions among bats and moths translate to dietary niche partitioning and coexistence among bats and nocturnal birds.
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Affiliation(s)
- Lorinda S. Bullington
- MPG Ranch MissoulaMissoulaMontanaUSA
- Department of Ecosystem and Conservation SciencesUniversity of MontanaMissoulaMontanaUSA
| | - Mathew T. Seidensticker
- MPG Ranch MissoulaMissoulaMontanaUSA
- Northern Rockies Research & Educational ServicesLoloMontanaUSA
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Manenti R, Piazza B. Between darkness and light: spring habitats provide new perspectives for modern researchers on groundwater biology. PeerJ 2021; 9:e11711. [PMID: 34395066 PMCID: PMC8320523 DOI: 10.7717/peerj.11711] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/10/2021] [Indexed: 11/20/2022] Open
Abstract
Springs are interfaces between groundwater and surface habitats and may play an important role in the study of subterranean animals. In this systematic evidence review and meta-analysis, we explore whether observations of stygobionts in springs are relevant and more common than observations of epigean animals in groundwater. We searched the Web of Science database for papers on groundwater fauna and spring fauna. For each paper we found, we recorded whether the paper reported the occurrence of typical stygobionts in springs, of surface animals in groundwater, or of the same taxa in both habitats. If so, we recorded how many such species were reported. We also recorded the scientific discipline of each study and the year of publication. Our search yielded 342 papers. A considerable number of these papers reported stygobionts in springs: 20% of papers dealing with groundwater fauna and 16% of papers dealing with spring fauna reported the occurrence of stygobionts in spring habitats. Both the number of papers that mentioned stygobionts in springs, and the number of stygobiont species that were documented in springs, were higher than equivalent measures for the occurrence of surface fauna underground. We also detected a positive relationship between year of publication and the number of reports of stygofauna in springs. To broaden the insights from biological research on underground environments, we suggest that springs should be considered not only as simple sampling points of stygobionts but also as core stygobiont habitats.
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Affiliation(s)
- Raoul Manenti
- Department of Environmental Science and Policy, Università degli Studi di Milano, Milano, Lombardia, Italy.,Parco Regionale del Monte Barro, Laboratorio di Biologia Sotterranea "Enrico Pezzoli", Galbiate, Italy
| | - Beatrice Piazza
- Department of Environmental Science and Policy, Università degli Studi di Milano, Milano, Lombardia, Italy
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Ecological Observations on Hybrid Populations of European Plethodontid Salamanders, Genus Speleomantes. DIVERSITY 2021. [DOI: 10.3390/d13070285] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Speleomantes are the only plethodontid salamanders present in Europe. Multiple studies have been performed to investigate the trophic niche of the eight Speleomantes species, but none of these studies included hybrid populations. For the first time, we studied the trophic niche of five Speleomantes hybrid populations. Each population was surveyed twice in 2020, and stomach flushing was performed on each captured salamander; stomach flushing is a harmless technique that allows stomach contents to be inspected. We also assessed the potential divergence in size and body condition between natural and introduced hybrids, and their parental species. Previously collected data on Speleomantes were included to increase the robustness of these analyses. In only 33 out of 134 sampled hybrid Speleomantes we recognized 81 items belonging to 11 prey categories. The frequency of empty stomachs was higher in females and individuals from natural hybrid populations, whereas the largest number of prey was consumed by males. We compared the total length and body condition of 685 adult salamanders belonging to three types of hybrids and three parental (sub)species. Three group of salamanders (one hybrid and two parental species) showed significantly larger size, whereas no difference in body condition was observed. This study provided novel ecological information on Speleomantes hybrid populations. We also provided insights into the potential divergence between hybrids and parental species in terms of size and body condition. We discuss our findings, and formulate several hypotheses that should be tested in the future.
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