Obligatory disclaimer: real life sucks. Just ask the
cassowaries, Austrian/Papua New Guinean relatives of the African ostrich. (For
a while, the ostrich has also lived in Middle East, but it is practically
extinct there now). According to the ‘Seven Worlds One Planet’ TV series, right
now the cassowary is on the ropes because of the invasion of the feral
hogs/wild boars into its’ jungle kingdom. And?
And here I just want to elaborate on the case of the
cassowary, (cough. Sorry about the alliteration). Firstly, there are three
species of cassowaries, not just one. However, only one species out of them –
the southern cassowary – is found in Australia proper, and so it is the one
known best, especially by the lay public. Ok.
Second, as far as ratites go, the cassowaries are atypical,
for they live in jungles slash rainforests. The ostrich of the Old World, the
rhea of South America, even the emu of Australia – they all live in open
spaces, on open plains and among the scrubland. Not so the cassowaries, which
are distinctly jungle birds. They are also some of the smaller modern ratites;
only New Zealand’s kiwis are smaller than the cassowaries are.
However, the kiwis are a special case – they are survivors
of an earlier age, when they lived in shadows of much bigger ratites – the moas
and the giant moas, which were among the biggest birds of the Cenozoic, (known
ironically as the Age of Mammals instead). Then the humans arrived, and hunted
the bigger ratites (and many other species of New Zealand birds) to extinction.
The plucky little kiwis survived. (The fact that humans themselves found the
kiwis not to be tasty helped though). Where does it leave the cassowaries?
In the same place as the kiwis, ecologically speaking: both
genera are shy, retiring birds, especially by ratite standards. (There is
nothing shy or retiring about the African ostrich or the Australian emu, for
example). However, while the kiwis are small, the cassowaries are not; the
southern cassowary, in particular, is almost the size of a human and they have
their attitudes, especially the sexually mature males. They also have really
sharp, needle-like claw on their feet, with which they can wound and kill, even
humans; certainly, it is always the right thing to do – to use some sort of a
protective armor – when dealing with cassowaries in captivity or in stressful
situations. As a result, the cassowaries are often called, or considered to be,
the modern analog of the Mesozoic raptors. That is incorrect.
Before Michael Crichton utilized and popularized the word ‘raptor’
for certain carnivorous dinosaurs – i.e., deinonychus and co. – it was used to
define modern birds of prey: eagles, hawks, falcons and owls, to name a few.
Even in this capacity, the term was not very proper – all of those avians
(avian dinosaurs?) are not very closely related to each other; already, in the
20th century people realized that owls were a group onto themselves,
separate from the rest of birds of prey, and by now – 2019 – people have
reclassified the birds of prey into several separate families and genera, so by
now the word ‘raptor’ is used primarily for carnivorous dinosaurs such as
deinonychus, utahraptor, and dromaeosaurus, and not for any of modern birds.
That said, while the term ‘raptor’ is no longer truly appropriate for any of
the modern birds, the various birds of prey, (including the owls), have several
shared characteristics, with the carnivorous way of life being the most obvious
one. There are some exceptions, but ‘exceptions’ is the key word here – all birds
of prey eat meat in one capacity or another, and as such they all have talons
on their legs and hooked beaks. The cassowaries do not have that. Their ‘killer
claw’ is actually a…specialized but primitive characteristic, as far as the
ratites go.
Here is the thing. Ratites evolved as herbivorous animals…
okay, birds. There were flightless carnivorous birds – the terror birds – but they
were not related to the ratites; it is somewhat hard to establish just who their
relatives are, but most scientists claim that it is the seriema, a family of
South American birds; initially, they were considered to be relatives of cranes
and the like, but now scientists believe that they connect the terror birds to
such modern avians as the parrots, the falcons, and the passerines instead.
(Yes, the falcons are not very closely related to other birds of prey such as
the hawks and the eagles – live with it). The ratites have nothing to do with
them; their closest flying relative is the tinamou – a different order of South
American birds; they are this continent’s analog of the game birds of the rest
of the world – but we digress.
The point is that the ratites evolved from an ancestor that
resembled a tinamou closely and the various gamebirds superficially, and was
never a pure carnivore at all. At best it was an omnivore, but aside from the
kiwis, (which are very specialized birds, when you think about it), most
ratites prefer to eat plant matter to animal. This includes the cassowaries, which
eat primarily fallen fruits, (not unlike many other jungle bird species), not
animal matter, as deinonychus and its’ relatives did – and on the other hand,
they are smaller and weaker than the African ostrich is, (proportionally
speaking), and also are less efficient runners than the ostrich. The African
ostrich is the only modern bird, (I think) that has only two toes on each foot.
This makes the African ostrich the bird version of the modern horse, donkey and
zebra – an open-spaces running specialist, who had sacrificed manual dexterity
for speed. Horses, donkeys and zebras are much less ecologically flexible than
the antelopes are, for comparison, and the ratites are also less flexible than
the flying birds are.
…However, ratites themselves are a varied bag, they consist
of several families, and if the African ostrich is the most derived of them
all, then the rest of them are less so. This includes the cassowaries, which
are the biggest jungle-dwelling ratites (and probably the biggest
jungle-dwelling birds, period). They may be big as some of the bigger mammals,
(include modern humans and wild boar), and they can take care of themselves,
(theoretically), but they are nowhere near as formidable as the ‘true’ raptors
of the Mesozoic had been, and they probably do
need human help and intervention, if they are to survive the 21st
century and beyond. Of course, there is also the matter of how to do it – begin
to exterminate all of non-native Australian mammals? This was once tried with
rabbits – not the most formidable
members of that bunch. The result was an epic fail for humans, so obviously
something different must be tried – but what? So far, there is no idea, but
then again, if there were, then real life would not suck so badly, now would
it?
…Well, this is it for now, see you all soon!
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