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Spitzer R, Ericson M, Felton AM, Heim M, Raubenheimer D, Solberg EJ, Wam HK, Rolandsen CM. Camera collars reveal macronutrient balancing in free-ranging male moose during summer. Ecol Evol 2024; 14:e70192. [PMID: 39157671 PMCID: PMC11329299 DOI: 10.1002/ece3.70192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 07/29/2024] [Accepted: 08/05/2024] [Indexed: 08/20/2024] Open
Abstract
Understanding how the nutritional properties of food resources drive foraging choices is important for the management and conservation of wildlife populations. For moose (Alces alces), recent experimental and observational studies during the winter have shown macronutrient balancing between available protein (AP) and highly metabolizable macronutrients (total non-structural carbohydrates [TNC] and lipids). Here, we combined the use of continuous-recording camera collars with plant nutrient analyses and forage availability measurements to obtain a detailed insight into the food and nutritional choices of three wild moose in Norway over a 5-day period in summer. We found that moose derived their macronutrient energy primarily from carbohydrates (74.2%), followed by protein (13.1%), and lipids (12.7%). Diets were dominated by deciduous tree browse (71%). Willows (Salix spp.) were selected for and constituted 51% of the average diet. Moose consumed 25 different food items during the study period of which 9 comprised 95% of the diet. Moose tightly regulated their intake of protein to highly metabolizable macronutrients (AP:TNC + lipids) to a ratio of 1:2.7 (0.37 ± 0.002SD). They did this by feeding on foods that most closely matched the target macronutrient ratio such as Salix spp., or by combining nutritionally imbalanced foods (complementary feeding) in a non-random manner that minimized deviations from the intake target. The observed patterns of macronutrient balancing aligned well with the findings of winter studies. Differential feeding on nutritionally balanced downy birch (Betula pubescens) leaves versus imbalanced twigs+leaves across moose individuals indicated that macronutrient balancing may occur on as fine a scale as foraging bites on a single plant species. Utilized forages generally met the suggested requirement thresholds for the minerals calcium, phosphorus, copper, molybdenum, and magnesium but tended to be low in sodium. Our findings offer new insights into the foraging behavior of a model species in ungulate nutritional ecology and contribute to informed decision-making in wildlife and forest management.
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Affiliation(s)
- Robert Spitzer
- Department of Wildlife, Fish and Environmental StudiesSwedish University of Agricultural SciencesUmeåSweden
| | | | - Annika M. Felton
- Faculty of Forest Sciences, Southern Swedish Forest Research CentreSwedish University of Agricultural SciencesLommaSweden
| | - Morten Heim
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - David Raubenheimer
- Charles Perkins Centre, and School of Life and Environmental SciencesUniversity of SydneyCamperdownNew South WalesAustralia
| | | | - Hilde K. Wam
- Department of Wildlife and RangelandsNIBIOÅsNorway
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He F, Svenning JC, Chen X, Tockner K, Kuemmerle T, le Roux E, Moleón M, Gessner J, Jähnig SC. Freshwater megafauna shape ecosystems and facilitate restoration. Biol Rev Camb Philos Soc 2024; 99:1141-1163. [PMID: 38411930 DOI: 10.1111/brv.13062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/28/2024]
Abstract
Freshwater megafauna, such as sturgeons, giant catfishes, river dolphins, hippopotami, crocodylians, large turtles, and giant salamanders, have experienced severe population declines and range contractions worldwide. Although there is an increasing number of studies investigating the causes of megafauna losses in fresh waters, little attention has been paid to synthesising the impacts of megafauna on the abiotic environment and other organisms in freshwater ecosystems, and hence the consequences of losing these species. This limited understanding may impede the development of policies and actions for their conservation and restoration. In this review, we synthesise how megafauna shape ecological processes in freshwater ecosystems and discuss their potential for enhancing ecosystem restoration. Through activities such as movement, burrowing, and dam and nest building, megafauna have a profound influence on the extent of water bodies, flow dynamics, and the physical structure of shorelines and substrata, increasing habitat heterogeneity. They enhance nutrient cycling within fresh waters, and cross-ecosystem flows of material, through foraging and reproduction activities. Freshwater megafauna are highly connected to other freshwater organisms via direct consumption of species at different trophic levels, indirect trophic cascades, and through their influence on habitat structure. The literature documenting the ecological impacts of freshwater megafauna is not evenly distributed among species, regions, and types of ecological impacts, with a lack of quantitative evidence for large fish, crocodylians, and turtles in the Global South and their impacts on nutrient flows and food-web structure. In addition, population decline, range contraction, and the loss of large individuals have reduced the extent and magnitude of megafaunal impacts in freshwater ecosystems, rendering a posteriori evaluation more difficult. We propose that reinstating freshwater megafauna populations holds the potential for restoring key ecological processes such as disturbances, trophic cascades, and species dispersal, which will, in turn, promote overall biodiversity and enhance nature's contributions to people. Challenges for restoration actions include the shifting baseline syndrome, potential human-megafauna competition for habitats and resources, damage to property, and risk to human life. The current lack of historical baselines for natural distributions and population sizes of freshwater megafauna, their life history, trophic interactions with other freshwater species, and interactions with humans necessitates further investigation. Addressing these knowledge gaps will improve our understanding of the ecological roles of freshwater megafauna and support their full potential for facilitating the development of effective conservation and restoration strategies to achieve the coexistence of humans and megafauna.
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Affiliation(s)
- Fengzhi He
- Key Laboratory of Wetland Ecology and Environment, State Key Laboratory of Black Soils Conservation and Utilization, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Shengbei Street 4888, Changchun, 130102, China
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, 10099, Germany
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Ny Munkegade 114, Aarhus, 8000, Denmark
| | - Jens-Christian Svenning
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Ny Munkegade 114, Aarhus, 8000, Denmark
| | - Xing Chen
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany
- Institute of Biology, Freie Universität Berlin, Königin-Luise-Str. 1-3, Berlin, 14195, Germany
| | - Klement Tockner
- Senckenberg Society for Nature Research, Senckenberganlage 25, Frankfurt am Main, 60325, Germany
- Faculty for Biological Sciences, Goethe University Frankfurt, Max-von-Laue-Straße 9, Frankfurt am Main, 60438, Germany
| | - Tobias Kuemmerle
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, 10099, Germany
| | - Elizabeth le Roux
- Center for Ecological Dynamics in a Novel Biosphere (ECONOVO) and Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Ny Munkegade 114, Aarhus, 8000, Denmark
| | - Marcos Moleón
- Department of Zoology, University of Granada, Avenida de Fuente Nueva S/N, Granada, 18071, Spain
| | - Jörn Gessner
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany
| | - Sonja C Jähnig
- Leibniz Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 310, Berlin, 12587, Germany
- Geography Department, Humboldt-Universität zu Berlin, Unter den Linden 6, Berlin, 10099, Germany
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Hecker LJ, Edwards MA, Nielsen SE. Assessing the nutritional consequences of switching foraging behavior in wood bison. Ecol Evol 2021; 11:16165-16176. [PMID: 34824819 PMCID: PMC8601871 DOI: 10.1002/ece3.8298] [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: 06/08/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 12/02/2022] Open
Abstract
Diet is one of the most common traits used to organize species of animals into niches. For ruminant herbivores, the breadth and uniqueness of their dietary niche are placed on a spectrum from browsers that consume woody (i.e., browse) and herbaceous (i.e., forbs) plants, to grazers with graminoid-rich diets. However, seasonal changes in plant availability and quality can lead to switching of their dietary niche, even within species. In this study, we examined whether a population of wood bison (Bison bison athabascae) in northeast Alberta, Canada, seasonally switched their foraging behavior, and if so, whether this was associated with changes in nutrient acquisition. We hypothesized that bison should switch foraging behaviors from grazing in the winter when standing, dead graminoids are the only foliar plants readily available to browsing during spring and summer as nutritious and digestible foliar parts of browse and forbs become available. If bison are switching foraging strategy to maximize protein consumption, then there should be a corresponding shift in the nutritional niche. Alternatively, if bison are eating different plants, but consuming similar amounts of nutrients, then bison are switching their dietary niche to maintain a particular nutrient composition. We found wood bison were grazers in the winter and spring, but switch to a browsing during summer. However, only winter nutrient consumption of consumed plants differed significantly among seasons. Between spring and summer, bison maintained a specific nutritional composition in their diet despite compositional differences in the consumed plants. Our evidence suggests that bison are selecting plants to maintain a target macronutrient composition. We posit that herbivore's can and will switch their dietary niche to maintain a target nutrient composition.
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Affiliation(s)
- Lee J. Hecker
- University of AlbertaEdmontonAlbertaCanada
- Royal Alberta MuseumEdmontonAlbertaCanada
| | - Mark A. Edwards
- University of AlbertaEdmontonAlbertaCanada
- Royal Alberta MuseumEdmontonAlbertaCanada
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Lundgren EJ, Schowanek SD, Rowan J, Middleton O, Pedersen RØ, Wallach AD, Ramp D, Davis M, Sandom CJ, Svenning JC. Functional traits of the world's late Quaternary large-bodied avian and mammalian herbivores. Sci Data 2021; 8:17. [PMID: 33473149 PMCID: PMC7817692 DOI: 10.1038/s41597-020-00788-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/30/2020] [Indexed: 01/29/2023] Open
Abstract
Prehistoric and recent extinctions of large-bodied terrestrial herbivores had significant and lasting impacts on Earth's ecosystems due to the loss of their distinct trait combinations. The world's surviving large-bodied avian and mammalian herbivores remain among the most threatened taxa. As such, a greater understanding of the ecological impacts of large herbivore losses is increasingly important. However, comprehensive and ecologically-relevant trait datasets for extinct and extant herbivores are lacking. Here, we present HerbiTraits, a comprehensive functional trait dataset for all late Quaternary terrestrial avian and mammalian herbivores ≥10 kg (545 species). HerbiTraits includes key traits that influence how herbivores interact with ecosystems, namely body mass, diet, fermentation type, habitat use, and limb morphology. Trait data were compiled from 557 sources and comprise the best available knowledge on late Quaternary large-bodied herbivores. HerbiTraits provides a tool for the analysis of herbivore functional diversity both past and present and its effects on Earth's ecosystems.
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Affiliation(s)
- Erick J Lundgren
- Centre for Compassionate Conservation, School of Life Sciences, University of Technology Sydney, Ultimo, Australia.
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark.
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark.
| | - Simon D Schowanek
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark.
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark.
| | - John Rowan
- Department of Anthropology, University at Albany, Albany, NY, 12222, USA
| | - Owen Middleton
- School of Life Sciences, University of Sussex, Sussex, UK
| | - Rasmus Ø Pedersen
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
| | - Arian D Wallach
- Centre for Compassionate Conservation, School of Life Sciences, University of Technology Sydney, Ultimo, Australia
| | - Daniel Ramp
- Centre for Compassionate Conservation, School of Life Sciences, University of Technology Sydney, Ultimo, Australia
| | - Matt Davis
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
- Natural History Museum of Los Angeles County, Los Angeles, CA, 90007, USA
| | | | - Jens-Christian Svenning
- Center for Biodiversity Dynamics in a Changing World (BIOCHANGE), Department of Biology, Aarhus University, Aarhus, Denmark
- Section for Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Aarhus, Denmark
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