The word "description" should be omitted.
"Polar Spade-Leafs": That should probably be "Polar Spade-Leaves".
Unless the creator specifies otherwise (such as for "deer", "sheep", and "moose", or "geese" or "mice"), general English grammar rules can be applied to the plural of an organism name.
"large number Pink Phlyers": "large number of Pink Phlyers".
Although "population" refers to a lot of organisms, I get the feeling that "its" would be more appropriate. Consider: "The U.S. population has stated its opinion" relative to "the citizens of the United States have stated their opinion."
I wonder...by what standard of decay does something fall into the "detritus" category? If something is overripe, but not mere sludge, does that count as "detritus"?
"More striking": This sentence needs to be revised.
"Similarly though": This sentence needs to be revised: I suggest a comma.
"their mate": This is a pluralization error.
"birth two": "Give birth to two"
"Tundra": This should not be capitalized.
This is an important detail: this species lives in a high-latitude cold environment, but it has large skin-wings, no pelage, very large wings for its body size, and a small body size. Some accommodations need to be made within some combination of design, habitat, migratory patterns, or use of shelter.
I'll have to get back to this later.