galloanserae

The turtle-jawed moa-nalo (Chelychelynechen quassus) was a large flightless goose-like duck from the Hawaiian island of Kaua‘i. About 90cm tall (3′) and weighing around 7kg (15lbs), these birds and their relatives were descended from dabbling ducks and existed on most of the larger Hawaiian islands for the last 3 million years or so – before going extinct around 1000 years ago following the arrival of Polynesian settlers.

Chelychelynechen had an unusually-shaped bill, tall and broad with vertically-oriented nostrils, convergently similar to the beak of a turtle. It would have occupied the same sort of ecological niche as giant tortoises on other islands, filling the role of large herbivore in the absence of mammals.

fallowsthorn  asked:

Is there a reason that some baby birds immediately go into cute floof stage right after they hatch (ducks, chickens, puffins), while others (owls, eagles, parrots) become ugly fucklings first? Why are some birds born with more floof than others?

This is a really good question, and the answer boils down to maturation rates and evolutionary strategy! The typical cutesy fluffy babies have a precocial development strategy (they can survive on their own quickly after hatching), where as the bald no-eyelid monstrosities are birds that have an altricial development strategy (dependent on parents for a relatively long time).

Each strategy has its benefits and downsides. For instance, galloanserae are all precocial because they’re prey animals and need to develop quickly for independence, while all raptors are altricial because altricial growth allows for more time developing skill and intelligence at the cost of a lower possibility of making it to adulthood.

There’s actually a gradual delineation between four recognized categories of developmental strategies, as outlined by a Stanford web essay:

“Precocial: Hatched with eyes open, covered with down, and leave the nest within two days. There are four levels of precociality, although only three are found in North American birds. Level 1 of development (precocial 1) is the pattern found in the chicks of megapodes (Australian Malee fowl, Brush Turkeys, etc.), which are totally independent of their parents. The megapode young are incubated in huge piles of decaying vegetation, and upon hatching dig their way out, already well feathered and able to fly. No North American birds show this extreme precociality. Precocial 2 development is found in ducklings and the chicks of shorebirds, which follow their parents but find their own food. The young of game birds, however, trail after their parents and are shown food; they are classified as precocial 3. Precocial 4 development is represented by the young of birds such as rails and grebes, which follow their parents and are not just shown food but are actually fed by them.”

“Semi-precocial: Hatched with eyes open, covered with down, and capable of leaving the nest soon after hatching (they can walk and often swim), but stay at the nest and are fed by parents. Basically precocial but nidicolus, this developmental pattern is found in the young of gulls and terns.”

“Semi-altricial: Covered with down, incapable of departing from the nest, and fed by the parents. In species classified as semi-altricial 1, such as hawks and herons, chicks hatch with their eyes open. Owls, in the category semi-altricial 2, hatch with the eyes closed. If all young were divided into only two categories, altricial and precocial, these all would be considered altricial”

“Altricial: Hatched with eyes closed, with little or no down, incapable of departing from the nest, and fed by the parents. All passerines are altricial.”

Basically, the uglier the baby, the smarter it probably will be… after it gets kicked out of its parent’s basement for freeloading.


@bunkerlad was a great help with this one!