Megafauna

thumb|A restoration of the grassland-inhabiting Pleistocene meso-megamammals from Sergipe, Brazil, including: Glyptotherium, Toxodon, Panochthus, Eremotherium, Holmesina, and Pachyarmatherium. In zoology, megafauna are the large animals of a particular region, time, or ecosystem. A human-centric definition of "large body size" for megafauna is a lower bound of 45 kg. For various ecosystems, the defined lower bound ranges from 10 kg lb to 1,000 kg lb. Quotes Hunting by humans played a major role in extirpating terrestrial megafauna on several continents and megafaunal loss continues today in both terrestrial and marine ecosystems. Recent declines of large marine vertebrates that are of little or no commercial value, such as sea turtles, seabirds and marine mammals, have focused attention on the ecological impacts of Bycatch incidental take, or bycatch, in global fisheries. In spite of the recognition of the problem of bycatch, few comprehensive assessments of its effects have been conducted. Many vulnerable species live in pelagic habitats, making surveys logistically complex and expensive. Bycatch data are sparse and our understanding of the demography of the affected populations is often rudimentary. These factors, combined with the large spatial scales that pelagic vertebrates and fishing fleets cover, make accurate and timely bycatch assessments difficult. Here, we review the current research that addresses these challenging questions in the face of uncertainty, analytical limitations and mounting conservation crises. Rebecca L. Lewison, Larry B. Crowder, Andrew J. Read, and Sloan A. Freeman, November 2004 Understanding impacts of fisheries bycatch on marine megafauna Trends in Ecology & Evolution 19 11 598–604 https://www.cell.com/trends/ecology-evolution/abstract/S0169-5347(04)00264-2?_returnURL=http%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0169534704002642%3Fshowall%3Dtrue&mobileUi=0 Charismatic megafauna Charismatic megafauna species may act as both Flagship species flagship and umbrella species. They influence local environments and biotas, determine related ecosystem processes and functions, and are associated with high levels of biodiversity. However, the intrinsic characteristics of megafauna species including long lifespan, large body size, sparseness and/or rarity, late maturity, and low fecundity, as well as high market value, make them very prone to extinction. Up to now, scientific interest and conservation efforts have mainly focused on terrestrial and marine megafauna, while freshwater species have received comparatively little attention, despite evidence suggesting that freshwaters are losing species faster than marine or terrestrial realms. The high susceptibility of freshwater megafauna to multiple threats, coupled with immense human pressure on freshwater ecosystems, places freshwater megafauna amongst the most threatened species globally. The main threats include overexploitation, dam construction, Habitat destruction habitat degradation, pollution, and Invasive species species invasion. Fengzhi He, Christiane Zarfl, Vanessa Bremerich, Alex Henshaw, William Darwall, Klement Tockner, and Sonja C. Jähnig, Disappearing giants: a review of threats to freshwater megafauna WIREs (Wiley Interdisciplinary Reviews) Water 2017 4 3 e1208 https://doi.org/10.1002/wat2.1208 10.1002/wat2.1208 We identified a total of 362 extant megafauna species. We found that 70% of megafauna species with sufficient information are decreasing and 59% are threatened with extinction. Surprisingly, direct harvesting of megafauna for human consumption of meat or body parts is the largest individual threat to each of the classes examined, and a threat for 98% (159/162) of threatened species with threat data available. Therefore, minimizing the direct killing of the world's largest vertebrates is a priority conservation strategy that might save many of these iconic species and the functions and services they provide. William J. Ripple, Christopher Wolf, Thomas M. Newsome, Matthew G. Betts, Gerardo Ceballos, Franck Courchamp, Matt W. Hayward, Blaire Van Valkenburgh, Arian D. Wallach, and Boris Worm, Are we eating the world's megafauna to extinction? Conservation Letters 6 February 2019 https://doi.org/10.1111/conl.12627 10.1111/conl.12627 Zoos worldwide are visited by great numbers of people, and many of these visitors prefer to see large, rare mammals, the so-called charismatic megafauna. Zoos and the researchers who use them also appear to prioritise these species, as evidenced by the number of scientific publications which investigate the welfare of charismatic rather than non-charismatic species. However, the charismatic animals also attract more welfare-related concern from Animal rights movement animal activist groups and the media than the non-charismatics. To this extent the charismatics could be regarded as problematic animals in the zoo. ... However, there is also evidence that their popularity helps zoos achieve their conservation mission, both by increasing funding available for field conservation and by contributing towards education and awareness raising of conservation issues. Nevertheless, the non-charismatics are equally deserving of attention, and more work needs to be done on their welfare. Chapter. Problematic animals in the zoo: The issue of charismatic megafauna by Geoff Hosey, Vicky Melfi, and Samantha J. Ward Problematic wildlife II: New conservation and management challenges in the human-wildlife interactions 485–508 Cham, Switzerland Springer International Publishing 2020 978-3030423346 10.1007/978-3-030-42335-3_15 (edited by Francesco Maria Angelici & Lorenzo Rossi) The extinction of the Australian Megafauna was probably the first significant mark Homo sapiens left on our planet. Yuval Noah Harari, Sapiens: A Brief History of Humankind (2011), Chapter 4: "The Flood" At the time of the Cognitive Revolution, the planet was home to about 200 genera of large terrestrial mammals weighing over fifty kilograms. At the time of the Agricultural Revolution, only about one hundred remained. Homo sapiens drove to extinction about half of the planet's big beasts long before humans invented the wheel, writing or iron tools. Yuval Noah Harari, Sapiens: A Brief History of Humankind (2011), Chapter 4: "The Flood" External links Category:Animals Category:Ecology Category:Zoology