MEGAFAUNA

'Megafauna' are species of large animals (Greek μεγας, large, + modern Latin fauna, animal). The standard definition includes animals with an average body weight exceeding 100 lb (44 kg) Stuart, A. J. (1991). Mammalian extinctions in the Late Pleistocene of northern Eurasia and North America. ''Biol. Rev''. 66: 453–562.Anon. Quaternary Paleobiology Update. ''The Quaternary Times'' 29 (1): (1999). Available online.Corlett, R. T. (2006). Megafaunal extinctions in tropical Asia. ''Tropinet'' 17 (3): 1–3. Available online (pdf).. This was given by Paul Martin, who first used the term scientifically.
However, definitions of what constitutes 'large' vary, with some authors using a larger minimum such as 100 kgMartin, P. S. & Steadman, D. W. (1999). Prehistoric extinctions on islands and continents. In: ''Extinctions in near time: causes, contexts and consequences'' (MacPhee, R. D. E., ed.), pp. 17–56. New York: Kluwer/Plenum. or 250 kg.Choquenot, D., & Bowman, D. M. J. S. (1998). Marsupial Megafauna, Aborigines and the Overkill Hypothesis: Application of Predator-Prey Models to the Question of Pleistocene Extinction in Australia. ''Global Ecology and Biogeography Letters'' 7 (3): 167-180. It is acknowledged that any particular limit is arbitrary, so some favor not using a single minimum weight.Wroe, S., Field, J., Fullagar, R., & Jermiin, L. S. (2004). Megafaunal extinction in the late Quaternary and the global overkill hypothesis. ''Alcheringa'' 28: 291-331. Available online (pdf).
The term is also used to refer to particular groups of large animals, both to extant species and, more often, those that have become extinct in the geologically recent Quaternary period.
Megafauna animals are generally K-strategists, with great longevity, slow population growth rates, low death rates, and few or no natural predators capable of killing adults. These characteristics make megafauna highly vulnerable to human exploitation. Some authors have argued that this reproductive capacity and ecololgical behaviour are more important than size alone, with some much smaller animals with very low reproductive rates showing 'megafauna' characteristics, such as Tachyglossidae (echidnas) and Megatherioidea (two-toed sloths), about 7 kg and 6 kg respectively, having become extinct in late Quaternary megafaunal extinctions.Johnson, C. N. (2002). Determinants of loss of mammal species during the Late Quaternary 'megafauna' extinctions: life history and ecology, but not body size. ''Proc. Biol. Sci''. 269 (1506): 2221–2227. Available online (pdf).
Large animals with popular appeal, often called charismatic megafauna, are often used by environmentalist groups to promote attention to our damaging of the world's ecosystems.

Contents

Recent extinctions

See also

References

Recent extinctions

Main articles: Pleistocene megafauna

Many species of megafauna have become extinct within the last million years, and, although some biologists dispute it, human hunting is often cited as the cause. Other theories for the cause of the extinctions are climatic change associated with glaciation and the questionable hyperdisease hypothesis.

See also

★ Bergmann's Rule

★ Cope's rule

★ Deep-sea gigantism

★ Fauna

★ Island gigantism

★ List of megafauna recently discovered

★ List of African megafauna

★ List of Arctic megafauna

★ List of Australian megafauna

★ List of Central and South American megafauna

★ List of Eurasian megafauna

★ List of island megafauna

★ List of marine megafauna

★ List of North American megafauna

References

★ A Requiem for North American overkill, Journal of Archaeological Science