What kinds of nests and other protections do the different species make for their eggs, and what differences do they have from one another in that respect (I mean, surely the nesting habits of something a snawk or sansaws is different from the coastwoodufo or underswooper? What are their mating habits, what are their courtship rituals like (how are the tail fans used in different species? what about the "invisible" colors, which we obviously can't see, what are the different patterns for the different species?) social habits (not much for these ones, though, still probably some: how territorial are they? Do they roost in pairs?) What is a typical "day" like for one of them, compared to another: you could talk about things like small-ish deviations in their activity hours, for one thing. Differences in vocalizations (do they vocalize? I'd assume they have something, considering that saucebacks ancestrally echolocated). Any sexual dimorphism should be noted. Unique feeding preferences or habits, however slight, such as methods of dispatching different prey native to their respective environments.
I should note that this is mainly filler to give them "flavor", and for each species more of a distinct "personality" which is honestly my main complaint, rather than any functional paucity of information.