Flora and fauna of a tidally locked planet
Imagine a world much like Earth, except it is nearly tidally locked to its star, making a complete revolution every few thousand years. The planet is far enough away that there is a band of livable area ~300 hundred miles across. Everything on one side is scorching desert, everything on the other side is ice, and both of these regions are impassable and deadly. I want to avoid vast oceans - let's say no more than 30% of the livable band can be water, and preferably the water is in lakes rather than oceans.
I know that winds are a serious problem for such a planet. It would be very windy and rainy all the time. There would also be no night-time (or true day-time either).
What effect does this have on the flora and fauna of this world? With no night, I imagine we would have no nocturnal hunters. With no seasons, hibernation makes no sense, squirrels won't store nuts away for the winter. But what would replace these, if anything? What sort of animals would thrive?
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1 answer
A paper I found suggests that the sunlit side might not be a burning desert as long as the planet isn't to close to the star.
Basically the difference in heat between the light and dark sides would cause a Hadley cell to wrap around the planet, circulating the heat from the light to the dark constantly (that constant wind you mention), and the increased circulation causes more clouds to build up over the substellar point, which is the point on the planet where the star would be seen directly overhead, and where radiation is most intense. The clouds over the substellar point then create a shield for the ground below as most of the harmful radiation is reflected away.
The high albedo clouds can allow a planet to remain habitable even at levels of radiation that were previously thought to be too high, so that the inner edge of the habitable zone is pushed much closer to the star.
That area would also get a lot of rain because of that cloud cover, and so could avoid the hot eyeball scenario you describe.
Edit: By having the orbit a little closer to the star you'd be able to burn through that cloud cover and push back the ice on the night side more, which would weaken the Hadley cells. You'd still have a lot of rain around the edges of this desert zone, but then the hot eyeball earth would be very likely.
All that aside, life would find its niches, ranging all over the terminator from full light to full dark, and probably even examples of things living in the most extreme areas, especially if the Hadley cells keep hot dry air moving into the darkness and cold wet air moving out into the light.
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