[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Emu distribution
On Sat, 10 Jun 2000, dbensen wrote:
> importantly) nasty predators which the emus have only been in contact with for
> a few thousand years. Dingos are as foreing to Australia as humans are and
> it's not surprising that they have decimated native population. This fact
> tells us nothing about ecology except that introduced predators are bad news,
> and we knew that already.
Two things: Emus are not like Dodos walking up to sailors and letting them
knock them on the head. They are very wary of predators! And they are
experts at concealing their nests. This is partly aided by a total lack
of movement at the nest (male incubates without food and water for entire
2+ months). Indeed, they have been exposed to many predators and have
evolved very successful tactics to avoid predation.
Secondly, extinctions at the K/T may have involved invading
predators. There was a massive invasion of mammals apparently sweeping
from North to South Northern America just at this time. So called
Condylarths are probably all herbivores. However, they may have had some
as yet undiscovered predators among them. It would be very unusual to
have an immigration which included only herbivores--as if an International
check-point existed: "Sorry, herbivores only may enter."