The Eigth Continent "Hawaii"

[DValdron]

what I was wondering is if the Galliformes could fly to Hawaii (I'm assuming the ancestors of the big 4' one were originally flying critters). BTW, if we're assuming that Hawaii is a 'new' continent, never hooked up to any other, how old would it have to be?

Hawaii in our timeline is a million years old. I'm assuming something this size would need at least 10 or 15 million years to form. Possibly as old as 30 or 40.

 

[Dave Howery]

Hawaii in our timeline is a million years old. I'm assuming something this size would need at least 10 or 15 million years to form. Possibly as old as 30 or 40.

if it's 30 million year old, couldn't it have a big Rattite-like bird? Considering that there are no mammals to bother it, and that birds would be there pretty quickly, it seems reasonable that a big vegetarian walking bird could evolve. If there's a niche for a big browsing animal, then convergent evolution could certainly design a bird version of it, even if there are no actual Rattites there...

 

[DValdron]

if it's 30 million year old, couldn't it have a big Rattite-like bird? Considering that there are no mammals to bother it, and that birds would be there pretty quickly, it seems reasonable that a big vegetarian walking bird could evolve. If there's a niche for a big browsing animal, then convergent evolution could certainly design a bird version of it, even if there are no actual Rattites there...

Conceivably. But flight is a very competitive advantage. Look at New Zealand, the biggest predator, the Hasts Eagle kept flying around. Most of the New Zealand birds kept flying.

There have been instances of large flightless birds evolving - the Auks of the northern hemisphere, the Penguins of the South, the Dodos of Mauritious and the flightless Ducks of Hawaii.

If its a sui generis continent, your best bet is likely ducks and other migrators. The only other birds likely to get there are the long distance gliders and scavengers - gulls, petrels albatrosses. Basically, even for birds its not an easy journey.

As to how big your birds get... in the period after the age of Dinosaurs and before mammals really got their groove on, there seems to have been a biological flowering of flightless birds. Nothing managed to get over a thousand pounds, but there were hefty and aggressive specimens.

The existence of a large long term land mass without any competing mammals or reptiles is pretty much unique. It might be an interesting exercise to design the fauna of such a place. Would there be niches, for instance, for land crustaceans to invade empty insect and small animal habitats? Would mollusks rally? Birds would certainly dominate all the significant vertebrate niches, but in what directions would they evolve?

That's the best I can do for guesstimating....

 

[DValdron]

Further to this, Birds actually come to the biological table with a number of built in disadvantages for land critters.

First off, there's a built in lack of stability. Only two limbs for walking around. Which means that with every step, 100% of the birds weight is on one limb 50% of the time. For a quadruped there's four limbs to spread things around on, which means that the average load each limb bears is a lot less. That makes a difference.

Okay, there were a lot of very big, even elephant sized Dinosaurs. T-Rex, Iguanadon, the Hadrosaurs, etc. But still, its a handicap. The real giants among dinos were four footed.

However, the Dinosaurs had a lot of built in stabilizers in the form of their tail. Birds are short tailed. Stability is more difficult.

Other handicaps are harder to get around. No teeth. An evolutionarily shortened gastric passage. These are big handicaps. Mammals and Reptiles evolved a lot of dentitition to be able to access a lot of different materials, including different kinds of plants. For birds, its much harder.

And digesting the stuff is lots, lots, lots harder. Mammal ungulates actually have multiple stomachs to digest woody cellulose. They have immensely long complex digestive tracts. Birds have gone in the opposite direction. Works fine at their current sizes. Ultrabig? Maybe not so well.

Through evolutionary history, the biggest walking birds have ranged in size from about 150 lbs to an upper limit of 1000, with very few getting to that upper range.

We've got a comfortable evolutionary history of large flightless birds or semi-flying birds in the 15 to 40 lb range. Turkeys, Dodos, the Flightless Ducks, and even huge chickens, as well as waterfowl.

If you had an isolated Hawaii that was working with nothing but birds, maybe they'd develop a whole range of flightless species. But I'd say you'd have to do some serious thinking about what species and how they'd evolve and function.

 

[Dave Howery]

The existence of a large long term land mass without any competing mammals or reptiles is pretty much unique.

well, it's pretty much New Zealand on a larger scale (the tuatara is scarcely competition). The biggest limiting factor is lack of time; Hawaii just hasn't been around as long as all the other continents, so birds (and everything else) will have a shorter time to evolve into different forms. Although... where there is opportunity, evolution can step on the accelerator pretty fast. I doubt that our speculative flightless birds will attain moa size, but they can still get up to 4-5' tall. If Hawaii has a good selection of brush, berries, etc. (a moderate-sized if), then it's very likely that a large browser will evolve; there's no good evolutionary reason not to.

 

[Keenir]

As to how big your birds get... in the period after the age of Dinosaurs and before mammals really got their groove on, there seems to have been a biological flowering of flightless birds. Nothing managed to get over a thousand pounds, but there were hefty and aggressive specimens.

Diatryma was a lightweight?

The existence of a large long term land mass without any competing mammals or reptiles is pretty much unique. It might be an interesting exercise to design the fauna of such a place. Would there be niches, for instance, for land crustaceans to invade empty insect and small animal habitats? Would mollusks rally?

what would the waterfall-climbing fish become, in such a place?

Further to this, Birds actually come to the biological table with a number of built in disadvantages for land critters.



However, the Dinosaurs had a lot of built in stabilizers in the form of their tail. Birds are short tailed. Stability is more difficult.

my guess would be to either make the rear end heavier (as T.rex did - solid bones in tail, hollow in head and arms)....or to simply not run.

how did the Terror Birds of South America keep from topping over as they chased their prey?
(or how did the Elephant Birds of Madagascar keep from getting munched on by fossas and crocodiles?)

Other handicaps are harder to get around. No teeth. An evolutionarily shortened gastric passage.

...and the addition of a crop, which is an extra digestive pouch.

These are big handicaps. Mammals and Reptiles evolved a lot of dentitition to be able to access a lot of different materials, including different kinds of plants. For birds, its much harder.

so they won't eat bamboo. *shrugs*

could they possibly be worse herbivores than the Giant Panda? (whose teeth and gut are still that of a carnivore?)

And digesting the stuff is lots, lots, lots harder. Mammal ungulates actually have multiple stomachs to digest woody cellulose. They have immensely long complex digestive tracts. Birds have gone in the opposite direction.

again, the crop; and if they need to have longer digestive tracts, or other adaptations to process plants, odds are they will, eventually.

besides, weren't the Demon Ducks of Australia actually either herbivores or frugivores? the Diatryma was definately a folivore.

Through evolutionary history, the biggest walking birds have ranged in size from about 150 lbs to an upper limit of 1000, with very few getting to that upper range.

moas, elephant birds, diatrymas, yes?

 

[Keenir]

From there, we can assume a high degree of linguistic and cultural coherence. This will diverge rapidly. But by and large, most of the cultures will be closely related, and languages will be close. The only wild card might be micronesian or melanesian influences.

There would likely be quite a bit of dispersal and cultural and linguistic divergence, but it would be nowhere near as heterodox as the tribes and languages of Africa, the Americas or even Australia. The time scales of these places are all in the tens of millenia. Hawaii's pre-contact history is maybe two millenia, give or take.
.

If I may suggest a possibility - borrow a New Guinea strategy which has helped foster the rise of multiple dialects and languages: when a person dies, the tribe no longer uses that name (or the word), and uses another word for that thing.

ie, if "kia" means "eagle", and a guy named Kia dies, the tribe has to call eagles by another name.

 

[DValdron]

Diatryma was a lightweight?

Comparatively. The largest of the breed stood roughly 5'6" to 6'6" tall and probably no more than 300 to 350 lbs. The Ostrich is as heavy, and taller. The largest Moas, taller and heavier. Elephant Birds way heavier. Drumornis Titan of the Demon Ducks was heavier (by a hair) than the Elephant Birds. The tallest mean and heavies were the Phoruscids, which produced a strapping 10 foot tall monster.

As for New Zealand. New Zealand had mammals once upon a time. They've found at least one thirty million year old fossil which shows that mammals were once endemic to New Zealand. It's not clear why they went extinct. But it may have something to do with the ecological dislocations of the gradual sinking of the rest of Zealandia. Or possibly its related to the New Zealand remnant glaciating during the ice age.

And yes, birds are able to overcome their biological shortcomings and produce new solutions. The survival of the Ostrich in Africa (and at one time Asia), and the Rhea in South America prove that the Ratites were able to hold onto their niche, an the Phororascids in South America actually did quite well in the North American invasion. But for the most part, mammals seemed to consistently outdo the birds to occupy most niches.

Anyway, Tom's continent. Let him populate it.

Just for the record though, when I did my Empire of Mu, I had dinosaurs.