1
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Mallon JC, Hone DWE. Estimation of maximum body size in fossil species: A case study using Tyrannosaurus rex. Ecol Evol 2024; 14:e11658. [PMID: 39050661 PMCID: PMC11267449 DOI: 10.1002/ece3.11658] [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: 05/30/2024] [Revised: 06/14/2024] [Accepted: 06/16/2024] [Indexed: 07/27/2024] Open
Abstract
Among extant species, the ability to sample the extremes of body size-one of the most useful predictors of an individual's ecology-is highly unlikely. This improbability is further exaggerated when sampling the already incomplete fossil record. We quantify the likelihood of sampling the uppermost limits of body size in the fossil record using Tyrannosaurus rex Osborn, 1905 as a model, selected for its comparatively well-understood life history parameters. We computationally generate a population of 140 million T. rex (based on prior estimates), modelling variation about the growth curve both with and without sexual dimorphism (the former modelled after Alligator mississippiensis), and building in sampling limitations related to species survivorship and taphonomic bias, derived from fossil data. The 99th percentile of body mass in T. rex has likely already been sampled, but it will probably be millennia before much larger giants (99.99th percentile) are sampled at present collecting rates. Biomechanical and ecological limitations notwithstanding, we estimate that the absolute largest T. rex may have been 70% more massive than the currently largest known specimen (~15,000 vs. ~8800 kg). Body size comparisons of fossil species should be based on ontogenetically controlled statistical parameters, rather than simply comparing the largest known individuals whose recovery is highly subject to sampling intensity.
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Affiliation(s)
- Jordan C. Mallon
- Beaty Centre for Species Discovery and Palaeobiology Section, Canadian Museum of NatureOttawaOntarioCanada
- Department of Earth SciencesCarleton University, 2115 Herzberg LaboratoriesOttawaOntarioCanada
| | - David W. E. Hone
- School of Biological and Behavioural SciencesQueen Mary University of LondonLondonUK
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2
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Ritwika VPS, Gopinathan A, Yeakel JD. Beyond the kill: The allometry of predation behaviours among large carnivores. J Anim Ecol 2024; 93:554-566. [PMID: 38459609 DOI: 10.1111/1365-2656.14070] [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: 09/01/2023] [Accepted: 02/06/2024] [Indexed: 03/10/2024]
Abstract
The costs of foraging can be high while also carrying significant risks, especially for consumers feeding at the top of the food chain. To mitigate these risks, many predators supplement active hunting with scavenging and kleptoparasitic behaviours, in some cases specializing in these alternative modes of predation. The factors that drive differential utilization of these tactics from species to species are not well understood. Here, we use an energetics approach to investigate the survival advantages of hunting, scavenging and kleptoparasitism as a function of predator, prey and potential competitor body sizes for terrestrial mammalian carnivores. The results of our framework reveal that predator tactics become more diverse closer to starvation, while the deployment of scavenging and kleptoparasitism is strongly constrained by the ratio of predator to prey body size. Our model accurately predicts a behavioural transition away from hunting towards alternative modes of predation with increasing prey size for predators spanning an order of magnitude in body size, closely matching observational data across a range of species. We then show that this behavioural boundary follows an allometric power-law scaling relationship where the predator size scales with an exponent nearing 3/4 with prey size, meaning that this behavioural switch occurs at relatively larger threshold prey body size for larger carnivores. We suggest that our approach may provide a holistic framework for guiding future observational efforts exploring the diverse array of predator foraging behaviours.
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Affiliation(s)
- V P S Ritwika
- Department of Physics, UC Merced, Merced, California, USA
- Department of Communication, UCLA, Los Angeles, California, USA
- Life and Environmental Sciences, UC Merced, Merced, California, USA
| | | | - Justin D Yeakel
- Life and Environmental Sciences, UC Merced, Merced, California, USA
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3
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Kane A, Healy K, Ruxton GD. Was Allosaurus really predominantly a scavenger? Ecol Modell 2023. [DOI: 10.1016/j.ecolmodel.2022.110247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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4
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Carnosaurs as Apex Scavengers: Agent-based simulations reveal possible vulture analogues in late Jurassic Dinosaurs. Ecol Modell 2021. [DOI: 10.1016/j.ecolmodel.2021.109706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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5
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Gallagher CA, Chudzinska M, Larsen-Gray A, Pollock CJ, Sells SN, White PJC, Berger U. From theory to practice in pattern-oriented modelling: identifying and using empirical patterns in predictive models. Biol Rev Camb Philos Soc 2021; 96:1868-1888. [PMID: 33978325 DOI: 10.1111/brv.12729] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 04/14/2021] [Accepted: 04/16/2021] [Indexed: 01/21/2023]
Abstract
To robustly predict the effects of disturbance and ecosystem changes on species, it is necessary to produce structurally realistic models with high predictive power and flexibility. To ensure that these models reflect the natural conditions necessary for reliable prediction, models must be informed and tested using relevant empirical observations. Pattern-oriented modelling (POM) offers a systematic framework for employing empirical patterns throughout the modelling process and has been coupled with complex systems modelling, such as in agent-based models (ABMs). However, while the production of ABMs has been rising rapidly, the explicit use of POM has not increased. Challenges with identifying patterns and an absence of specific guidelines on how to implement empirical observations may limit the accessibility of POM and lead to the production of models which lack a systematic consideration of reality. This review serves to provide guidance on how to identify and apply patterns following a POM approach in ABMs (POM-ABMs), specifically addressing: where in the ecological hierarchy can we find patterns; what kinds of patterns are useful; how should simulations and observations be compared; and when in the modelling cycle are patterns used? The guidance and examples provided herein are intended to encourage the application of POM and inspire efficient identification and implementation of patterns for both new and experienced modellers alike. Additionally, by generalising patterns found especially useful for POM-ABM development, these guidelines provide practical help for the identification of data gaps and guide the collection of observations useful for the development and verification of predictive models. Improving the accessibility and explicitness of POM could facilitate the production of robust and structurally realistic models in the ecological community, contributing to the advancement of predictive ecology at large.
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Affiliation(s)
- Cara A Gallagher
- Department of Plant Ecology and Conservation Biology, University of Potsdam, Am Mühlenberg 3, Potsdam, 14469, Germany.,Department of Bioscience, Aarhus University, Frederiksborgvej 399, Roskilde, 4000
| | - Magda Chudzinska
- Sea Mammal Research Unit, Scottish Oceans Institute, University of St Andrews, St Andrews, KY16 9ST, U.K
| | - Angela Larsen-Gray
- Department of Integrative Biology, University of Wisconsin-Madison, 250 N. Mills St., Madison, WI, 53706, U.S.A
| | | | - Sarah N Sells
- Montana Cooperative Wildlife Research Unit, The University of Montana, 205 Natural Sciences, Missoula, MT, 59812, U.S.A
| | - Patrick J C White
- School of Applied Sciences, Edinburgh Napier University, 9 Sighthill Ct., Edinburgh, EH11 4BN, U.K
| | - Uta Berger
- Institute of Forest Growth and Computer Science, Technische Universität Dresden, Dresden, 01062, Germany
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6
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van Bijlert PA, van Soest AJ‘K, Schulp AS. Natural Frequency Method: estimating the preferred walking speed of Tyrannosaurus rex based on tail natural frequency. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201441. [PMID: 33996115 PMCID: PMC8059583 DOI: 10.1098/rsos.201441] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 03/15/2021] [Indexed: 05/21/2023]
Abstract
Locomotor energetics are an important determinant of an animal's ecological niche. It is commonly assumed that animals minimize locomotor energy expenditure by selecting gait kinematics tuned to the natural frequencies of relevant body parts. We demonstrate that this allows estimation of the preferred step frequency and walking speed of Tyrannosaurus rex, using an approach we introduce as the Natural Frequency Method. Although the tail of bipedal dinosaurs was actively involved in walking, it was suspended passively by the caudal interspinous ligaments. These allowed for elastic energy storage, thereby reducing the metabolic cost of transport. In order for elastic energy storage to be high, step and natural frequencies would have to be matched. Using a 3D morphological reconstruction and a spring-suspended biomechanical model, we determined the tail natural frequency of T. rex (0.66 s-1, range 0.41-0.84), and the corresponding walking speed (1.28 m s-1, range 0.80-1.64), which we argue to be a good indicator of preferred walking speed (PWS). The walking speeds found here are lower than earlier estimations for large theropods, but agree quite closely with PWS of a diverse group of extant animals. The results are most sensitive to uncertainties regarding ligament moment arms, vertebral kinematics and ligament composition. However, our model formulation and method for estimation of walking speed are unaffected by assumptions regarding muscularity, and therefore offer an independent line of evidence within the field of dinosaur locomotion.
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Affiliation(s)
- Pasha A. van Bijlert
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Naturalis Biodiversity Center, Leiden, The Netherlands
| | - A. J. ‘Knoek’ van Soest
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Research Institute Amsterdam Movement Sciences, Amsterdam, The Netherlands
| | - Anne S. Schulp
- Department of Earth Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Naturalis Biodiversity Center, Leiden, The Netherlands
- Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
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7
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Murphy KJ, Ciuti S, Kane A. An introduction to agent-based models as an accessible surrogate to field-based research and teaching. Ecol Evol 2020; 10:12482-12498. [PMID: 33250988 PMCID: PMC7679541 DOI: 10.1002/ece3.6848] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 08/17/2020] [Accepted: 08/31/2020] [Indexed: 01/09/2023] Open
Abstract
There are many barriers to fieldwork including cost, time, and physical ability. Unfortunately, these barriers disproportionately affect minority communities and create a disparity in access to fieldwork in the natural sciences. Travel restrictions, concerns about our carbon footprint, and the global lockdown have extended this barrier to fieldwork across the community and led to increased anxiety about gaps in productivity, especially among graduate students and early-career researchers. In this paper, we discuss agent-based modeling as an open-source, accessible, and inclusive resource to substitute for lost fieldwork during COVID-19 and for future scenarios of travel restrictions such as climate change and economic downturn. We describe the benefits of Agent-Based models as a teaching and training resource for students across education levels. We discuss how and why educators and research scientists can implement them with examples from the literature on how agent-based models can be applied broadly across life science research. We aim to amplify awareness and adoption of this technique to broaden the diversity and size of the agent-based modeling community in ecology and evolutionary research. Finally, we discuss the challenges facing agent-based modeling and discuss how quantitative ecology can work in tandem with traditional field ecology to improve both methods.
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Affiliation(s)
- Kilian J. Murphy
- School of Biology and Environmental Science and the Earth InstituteUniversity College DublinDublinIreland
| | - Simone Ciuti
- School of Biology and Environmental Science and the Earth InstituteUniversity College DublinDublinIreland
| | - Adam Kane
- School of Biology and Environmental Science and the Earth InstituteUniversity College DublinDublinIreland
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8
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Dececchi TA, Mloszewska AM, Holtz TR, Habib MB, Larsson HCE. The fast and the frugal: Divergent locomotory strategies drive limb lengthening in theropod dinosaurs. PLoS One 2020; 15:e0223698. [PMID: 32401793 PMCID: PMC7220109 DOI: 10.1371/journal.pone.0223698] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 04/14/2020] [Indexed: 12/15/2022] Open
Abstract
Limb length, cursoriality and speed have long been areas of significant interest in theropod paleobiology, since locomotory capacity, especially running ability, is critical in the pursuit of prey and to avoid becoming prey. The impact of allometry on running ability, and the limiting effect of large body size, are aspects that are traditionally overlooked. Since several different non-avian theropod lineages have each independently evolved body sizes greater than any known terrestrial carnivorous mammal, ~1000kg or more, the effect that such large mass has on movement ability and energetics is an area with significant implications for Mesozoic paleoecology. Here, using expansive datasets that incorporate several different metrics to estimate body size, limb length and running speed, we calculate the effects of allometry on running ability. We test traditional metrics used to evaluate cursoriality in non-avian theropods such as distal limb length, relative hindlimb length, and compare the energetic cost savings of relative hindlimb elongation between members of the Tyrannosauridae and more basal megacarnivores such as Allosauroidea or Ceratosauridae. We find that once the limiting effects of body size increase is incorporated there is no significant correlation to top speed between any of the commonly used metrics, including the newly suggested distal limb index (Tibia + Metatarsus/ Femur length). The data also shows a significant split between large and small bodied theropods in terms of maximizing running potential suggesting two distinct strategies for promoting limb elongation based on the organisms’ size. For small and medium sized theropods increased leg length seems to correlate with a desire to increase top speed while amongst larger taxa it corresponds more closely to energetic efficiency and reducing foraging costs. We also find, using 3D volumetric mass estimates, that the Tyrannosauridae show significant cost of transport savings compared to more basal clades, indicating reduced energy expenditures during foraging and likely reduced need for hunting forays. This suggests that amongst theropods, hindlimb evolution was not dictated by one particular strategy. Amongst smaller bodied taxa the competing pressures of being both a predator and a prey item dominant while larger ones, freed from predation pressure, seek to maximize foraging ability. We also discuss the implications both for interactions amongst specific clades and Mesozoic paleobiology and paleoecological reconstructions as a whole.
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Affiliation(s)
- T. Alexander Dececchi
- Division of Natural Sciences, Department of Biology, Mount Marty College, Yankton, South Dakota, United States of America
- * E-mail:
| | | | - Thomas R. Holtz
- Department of Geology, University of Maryland, College Park, Maryland, United States of America
- Department of Paleobiology, National Museum of Natural History, Washington, DC, United States of America
| | - Michael B. Habib
- Integrative Anatomical Sciences, Keck School of Medicine of USC, University of Southern California, Los Angeles, California, United States of America
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9
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Woodward HN, Tremaine K, Williams SA, Zanno LE, Horner JR, Myhrvold N. Growing up Tyrannosaurus rex: Osteohistology refutes the pygmy " Nanotyrannus" and supports ontogenetic niche partitioning in juvenile Tyrannosaurus. SCIENCE ADVANCES 2020; 6:eaax6250. [PMID: 31911944 PMCID: PMC6938697 DOI: 10.1126/sciadv.aax6250] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 11/01/2019] [Indexed: 06/10/2023]
Abstract
Despite its iconic status as the king of dinosaurs, Tyrannosaurus rex biology is incompletely understood. Here, we examine femur and tibia bone microstructure from two half-grown T. rex specimens, permitting the assessments of age, growth rate, and maturity necessary for investigating the early life history of this giant theropod. Osteohistology reveals these were immature individuals 13 to 15 years of age, exhibiting growth rates similar to extant birds and mammals, and that annual growth was dependent on resource abundance. Together, our results support the synonomization of "Nanotyrannus" into Tyrannosaurus and fail to support the hypothesized presence of a sympatric tyrannosaurid species of markedly smaller adult body size. Our independent data contribute to mounting evidence for a rapid shift in body size associated with ontogenetic niche partitioning late in T. rex ontogeny and suggest that this species singularly exploited mid- to large-sized theropod niches at the end of the Cretaceous.
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Affiliation(s)
- Holly N. Woodward
- Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences, 1111 W. 17th St., Tulsa, OK 74104, USA
| | - Katie Tremaine
- Department of Earth Science, Montana State University, P.O. Box 173480, Bozeman, MT 59717, USA
- Museum of the Rockies, Montana State University, 600 W. Kagy Blvd., Bozeman, MT 59717, USA
| | - Scott A. Williams
- Museum of the Rockies, Montana State University, 600 W. Kagy Blvd., Bozeman, MT 59717, USA
| | - Lindsay E. Zanno
- Paleontology, North Carolina Museum of Natural Sciences, 11 W. Jones St., Raleigh, NC 27601, USA
- Department of Biological Sciences, North Carolina State University, 3510 Thomas Hall, Campus Box 7614, Raleigh, NC 2769, USA
| | - John R. Horner
- Chapman University, 1 University Dr., Orange, CA 92866, USA
| | - Nathan Myhrvold
- Intellectual Ventures, 3150 139th Avenue Southeast, Bellevue, WA 98005, USA
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10
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Healy K, Carbone C, Jackson AL. Snake venom potency and yield are associated with prey-evolution, predator metabolism and habitat structure. Ecol Lett 2019; 22:527-537. [PMID: 30616302 DOI: 10.1111/ele.13216] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/15/2018] [Accepted: 12/01/2018] [Indexed: 01/17/2023]
Abstract
Snake venom is well known for its ability to incapacitate and kill prey. Yet, potency and the amount of venom available varies greatly across species, ranging from the seemingly harmless to those capable of killing vast numbers of potential prey. This variation is poorly understood, with comparative approaches confounded by the use of atypical prey species as models to measure venom potency. Here, we account for such confounding issues by incorporating the phylogenetic similarity between a snake's diet and the species used to measure its potency. In a comparative analysis of 102 species we show that snake venom potency is generally prey-specific. We also show that venom yields are lower in species occupying three dimensional environments and increases with body size corresponding to metabolic rate, but faster than predicted from increases in prey size. These results underline the importance of physiological and environmental factors in the evolution of predator traits.
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Affiliation(s)
- Kevin Healy
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland.,School of Biology, University of St Andrews, St Andrews, KY16 9TH, UK.,School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Chris Carbone
- Institute of Zoology, Zoological Society of London, London, UK
| | - Andrew L Jackson
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
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11
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Abstract
Obligate scavengers such as vultures provide critical ecosystem services and their populations have undergone severe declines in Asia and Africa. Intentional poisoning is a major threat to vultures in Africa, yet the impact on vulture populations of where poisoned carcasses are positioned is not known. We used re-sightings of 183 African white-backed vultures captured and tagged in two regions of South Africa, some 200 km apart, to estimate spatial differences in relative survival rates across life stages. Juvenile survival rates were similar in the two regions, whilst subadult and adult survival rates differed significantly. Using agent-based modelling, we show that this pattern of relative survival rates is consistent between regions that differ in intensity of poisoning, despite the proximity of the two regions. This may have important consequences for vulture conservation and the targeting of conservation efforts, particularly with regard to the efficacy of “vulture safe zones” around vulture breeding populations.
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12
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Rothschild BM, Naples V. Apparent sixth sense in theropod evolution: The making of a Cretaceous weathervane. PLoS One 2017; 12:e0187064. [PMID: 29095949 PMCID: PMC5667833 DOI: 10.1371/journal.pone.0187064] [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: 05/03/2017] [Accepted: 10/12/2017] [Indexed: 11/17/2022] Open
Abstract
Objective Two separate and distinctive skills are necessary to find prey: Detection of its presence and determination of its location. Surface microscopy of the dentary of albertosaurines revealed a previously undescribed sensory modification, as will be described here. While dentary “foramina” were previously thought to contain tactile sensory organs, the potential function of this theropod modification as a unique localizing system is explored in this study. Method Dentary surface perforations were examined by surface epi-illumination microscopy in tyrannosaurine and albertosaurine dinosaurs to characterize their anatomy. Fish lateral lines were examined as potentially comparable structures. Result In contrast to the subsurface vascular bifurcation noted in tyrannosaurines (which lack a lateral dentary surface groove), the area subjacent to the apertures in albertosaurine grooves has the appearance of an expanded chamber. That appearance seemed to be indistinguishable from the lateral line of fish. Conclusion Dentary groove apertures in certain tyrannosaurid lines (specifically albertosaurines) not only have a unique appearance, but one with significant functional and behavior implications. The appearance of the perforations in the dentary groove of albertosaurines mirrors that previously noted only with specialized neurologic structures accommodating derived sensory functions, as seen in the lateral line of fish. The possibility that this specialized morphology could also represent a unique function in albertosaurine theropods for interacting with the environment or facilitating prey acquisition cannot be ignored. It is suggested that these expanded chambers function in perceiving and aligning the body relative to the direction of wind, perhaps a Cretaceous analogue of the contemporary midwestern weathervane.
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Affiliation(s)
- Bruce M Rothschild
- West Virginia University College of Medicine, Department of Medicine, Morgantown, West Virginia United States of America.,Carnegie Museum, Pittsburgh, Pennsylvania, United States of America
| | - Virginia Naples
- Northern Illinois University, DeKalb, Illinois, United States of America
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13
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Galetti M, Moleón M, Jordano P, Pires MM, Guimarães PR, Pape T, Nichols E, Hansen D, Olesen JM, Munk M, de Mattos JS, Schweiger AH, Owen-Smith N, Johnson CN, Marquis RJ, Svenning JC. Ecological and evolutionary legacy of megafauna extinctions. Biol Rev Camb Philos Soc 2017; 93:845-862. [PMID: 28990321 DOI: 10.1111/brv.12374] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 08/26/2017] [Accepted: 09/01/2017] [Indexed: 12/30/2022]
Abstract
For hundreds of millions of years, large vertebrates (megafauna) have inhabited most of the ecosystems on our planet. During the late Quaternary, notably during the Late Pleistocene and the early Holocene, Earth experienced a rapid extinction of large, terrestrial vertebrates. While much attention has been paid to understanding the causes of this massive megafauna extinction, less attention has been given to understanding the impacts of loss of megafauna on other organisms with whom they interacted. In this review, we discuss how the loss of megafauna disrupted and reshaped ecological interactions, and explore the ecological consequences of the ongoing decline of large vertebrates. Numerous late Quaternary extinct species of predators, parasites, commensals and mutualistic partners were associated with megafauna and were probably lost due to their strict dependence upon them (co-extinctions). Moreover, many extant species have megafauna-adapted traits that provided evolutionary benefits under past megafauna-rich conditions, but are now of no or limited use (anachronisms). Morphological evolution and behavioural changes allowed some of these species partially to overcome the absence of megafauna. Although the extinction of megafauna led to a number of co-extinction events, several species that likely co-evolved with megafauna established new interactions with humans and their domestic animals. Species that were highly specialized in interactions with megafauna, such as large predators, specialized parasites, and large commensalists (e.g. scavengers, dung beetles), and could not adapt to new hosts or prey were more likely to die out. Partners that were less megafauna dependent persisted because of behavioural plasticity or by shifting their dependency to humans via domestication, facilitation or pathogen spill-over, or through interactions with domestic megafauna. We argue that the ongoing extinction of the extant megafauna in the Anthropocene will catalyse another wave of co-extinctions due to the enormous diversity of key ecological interactions and functional roles provided by the megafauna.
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Affiliation(s)
- Mauro Galetti
- Departamento de Ecologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), 13506-900, Rio Claro, SP Brazil.,Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Marcos Moleón
- Estación Biológica de Doñana, EBD-SCIC, Consejo Superior de Investigaciones Científicas, Sevilla, Spain.,Departamento de Zoología, Universidad de Granada, Granada, Spain
| | - Pedro Jordano
- Estación Biológica de Doñana, EBD-SCIC, Consejo Superior de Investigaciones Científicas, Sevilla, Spain
| | - Mathias M Pires
- Departamento de Ecologia, Universidade de São Paulo, São Paulo, SP Brazil
| | - Paulo R Guimarães
- Departamento de Ecologia, Universidade de São Paulo, São Paulo, SP Brazil
| | - Thomas Pape
- Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | | | - Dennis Hansen
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, 8057 Zurich, Switzerland
| | - Jens M Olesen
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Michael Munk
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Jacqueline S de Mattos
- Departamento de Ecologia, Instituto de Biociências, Universidade Estadual Paulista (UNESP), 13506-900, Rio Claro, SP Brazil
| | - Andreas H Schweiger
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Norman Owen-Smith
- Centre for African Ecology, School of Animal Plant and Environmental Sciences, University of the Witwatersrand, Wits 2050, South Africa
| | - Christopher N Johnson
- School of Biological Sciences & Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Tasmania, Hobart, Tasmania, Australia
| | - Robert J Marquis
- Department of Biology and the Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, St. Louis, U.S.A
| | - Jens-Christian Svenning
- Section for Ecoinformatics & Biodiversity, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
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