• Megafauna extinction due more to being hunted by humans than climate ef

    From Gronk@21:1/5 to All on Tue Jul 2 12:46:57 2024
    https://www.eurekalert.org/news-releases/1049981

    The debate has raged for decades: Was it
    humans or climate change that led to the
    extinction of many species of large mammals,
    birds, and reptiles that have disappeared
    from Earth over the past 50,000 years?

    By "large," we mean animals that weighed
    at least 45 kilograms – known as megafauna.
    At least 161 species of mammals were driven
    to extinction during this period. This number
    is based on the remains found so far.

    The largest of them were hit the hardest –
    land-dwelling herbivores weighing over a ton,
    the megaherbivores. Fifty thousand years ago,
    there were 57 species of megaherbivores.
    Today, only 11 remain. These remaining 11
    species have also seen drastic declines in
    their populations, but not to the point of
    complete extinction.

    A research group from the Danish National
    Research Foundation's Center for Ecological
    Dynamics in a Novel Biosphere (ECONOVO) at
    Aarhus University now concludes that many
    of these vanished species were hunted to
    extinction by humans.
    ...


    https://www.cambridge.org/core/journals/cambridge-prisms-extinction/article/latequaternary-megafauna-extinctions-patterns-causes-ecological-consequences-and-implications-for-ecosystem-management-in-the-anthropocene/E885D8C5C90424254C1C75A61DE9D087

    The late-Quaternary megafauna extinctions:
    Patterns, causes, ecological consequences
    and implications for ecosystem management
    in the Anthropocene


    Abstract
    Across the last ~50,000 years (the late
    Quaternary) terrestrial vertebrate faunas
    have experienced severe losses of large
    species (megafauna), with most extinctions
    occurring in the Late Pleistocene and Early
    to Middle Holocene. Debate on the causes
    has been ongoing for over 200 years,
    intensifying from the 1960s onward. Here,
    we outline criteria that any causal
    hypothesis needs to account for.
    Importantly, this extinction event is
    unique relative to other Cenozoic (the last
    66 million years) extinctions in its strong
    size bias. For example, only 11 out of 57
    species of megaherbivores (body mass ≥1,000
    kg) survived to the present. In addition to
    mammalian megafauna, certain other groups
    also experienced substantial extinctions,
    mainly large non-mammalian vertebrates and
    smaller but megafauna-associated taxa.
    Further, extinction severity and dates
    varied among continents, but severely
    affected all biomes, from the Arctic to the
    tropics. We synthesise the evidence for and
    against climatic or modern human (Homo
    sapiens) causation, the only existing tenable
    hypotheses. Our review shows that there is
    little support for any major influence of
    climate, neither in global extinction
    patterns nor in fine-scale spatiotemporal
    and mechanistic evidence. Conversely, there
    is strong and increasing support for human
    pressures as the key driver of these
    extinctions, with emerging evidence for an
    initial onset linked to pre-sapiens hominins
    prior to the Late Pleistocene. Subsequently,
    we synthesize the evidence for ecosystem
    consequences of megafauna extinctions and
    discuss the implications for conservation
    and restoration. A broad range of evidence
    indicates that the megafauna extinctions
    have elicited profound changes to ecosystem
    structure and functioning. The
    late-Quaternary megafauna extinctions
    thereby represent an early, large-scale
    human-driven environmental transformation,
    constituting a progenitor of the Anthropocene,
    where humans are now a major player in
    planetary functioning. Finally, we conclude
    that megafauna restoration via trophic
    rewilding can be expected to have positive
    effects on biodiversity across varied
    Anthropocene settings.

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