The question of the whale-bird's eggs

{ Posted on Thursday, August 06, 2009 by Speculative Biologist }
How could a large fully aquatic bird possibly reproduce? This question has been asked by speculative biology writers for quite a while now with not many plausible answers. Live birth is out of the question, seeing as bird lay hard-shelled eggs that could not be replaced by vivipary. Therefore, the possibility of fully aquatic birds has been mostly tossed out the window. Seal-like gannets and other similar creatures that return to land to mate and lay eggs just seem like better ideas. But now, a thread on the Speculative Evolution Forums seems to have produced some interesting ideas for how whale-like birds could actually propagate without needing to return to land.

The discussion began with the suggestion that maybe critiques of Dixon's Vortex are a little too strong and that eggs of such a bird could develop in a way that does not harm the chicks inside. SSJRaptog, a user on the discussion board, suggested that the eggs could have air chambers that allow them to float on the surface like coconuts, with other users suggesting a sticky coating allowing the eggs in a brood to stick together. The main problem with this idea is that they would be easy targets for predators and therefore a vast number of eggs would be required in each clutch or the eggs would need to be attached to coral or mangrove roots so that they are somewhat protected.

The second idea that emerged in the discussion was for the birds to develop a pouch to protect their young. The pouch would either be between the wings with the wings as the folds to the pouch or velcro like feathers protecting the egg clutch (feathers would be required as down is not rigid enough as described by JohnFaa). This concept seems more plausible but the eggs may be subject to deeper waters and slightly more pressure, so it may be just as dangerous as the first.

If this has inspired you to have your own ideas or if you would like to contribute to the discussion, please visit this thread on Speculative Evolution.

3 Response to "The question of the whale-bird's eggs"

You know, the aquavians could do something ecologically to avoid the dangers of pressure on the developing embryo. Think of it like how some sea creatures live today, spending their adult lives in deeper waters hunting for squid, fish, or whatever they have adapted to feed on, and when they come to breed, they give birth in the shallow, food-rich estuaries of the coast. During this time of the year, a hypothetical piscivorous/teuthivorous aquavian would switch its diet to not only include fish and squid, but other food sources. Maybe time its birthing period to coincide with the breeding seasons of sea turtles or sea birds.

That seems to be reasonable, seeing as marine mammals and reptiles due tend to slightly alter their lifestyle to fit the needs of their developing or birthed young.

Like how some of the bigger baleen whales have different grounds for birthing and feeding. I happened to see by accident a documentary on the Discovery Channel which showed that tiger sharks actually would migrate long distances to hang around where turtles and sea birds were birthing, so the idea of "hanging out where the food is" to care for the baby is not too far fetched.

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