No matter how they are treated, infertiles quickly become fanatically dedicated to their owner. Unfortunately, this does not always have a happy ending, as they tend to love their owners far more than their owners love them. However, the infertile
worldview believes that negative attention is better than no attention.
Given the manipulated genetic history of sylphs, it is unsurprising that throwbacks (or sports) occur. The most common type of throwback happens when some of the older sylph construct characteristics show through. As with the other oddities, these usually manifest in the infertile gender.
Rounded ears are fairly common. These sylphs are unable to express themselves using ear-points. They tend not to be trusted by other sylphs, perhaps because they can hide their feelings, should they wish.
Tawny eyes, which are not cat-slit, are also fairly common. The main drawback for these sylphs is that they cannot see (as well) in the dark.
From a human point of view, neither of the above differences is important.
Sometimes sylphs who closely resemble the original sylphs are born. They are usually deformed, with poorly formed wings (much as the original infertiles). As the original sylph forms so little of the new genome, these rarely survive long.
The most important throwback is the gwerin. These are so different as to form a sub-species in their own right. Genetically, these look more to their human inheritance. They are pale-skinned and red-blooded. All are infertile, and grow
to a similar height as normal sylph infertiles. From their sylph parents, they usually inherit cat-slit eyes (but not the irises) and manoeuvrable ear-points.
Unlike other infertiles, gwerins confer much honour on their parents. Valued by humans, gwerins are very intelligent and usually become advisers to rulers or nobles. There is jealousy because of their intelligence (from humans, not sylphs), so they usually need the protection of rulers.
Gwerins revere any sylph parent of a gwerin. As they are so long-lived, their own parents are gone long before a gwerin would like, so all parents of gwerins are treated with the same respect. Rare, gwerins are highly sought after, but they can be more mercurial than ordinary sylphs.
Among wild sylphs, gwerins always attain great rank in their own right.
Sylphs are able to eat almost anything. They enjoy a wide variety of plants and these form the staple of sylph diet. Though able to eat grass and leaves, and gain
nutrients from them, they are not digested very well.
Sylphs are fond of fish and fowl, but tend to avoid red meat. They can and, as a last resort, do indulge in red meat, but like grass and leaves, this does not agree with their digestion.
When food is scarce, sylphs slow their metabolism, which prolongs life, but even they eventually starve. An overfed sylph does not get fat, but his metabolism increases.
Choca [chocolate!] is the enslaved sylphs' favourite treat. A sylph will do (almost) anything to get his hands on the stuff, but over-indulgence has consequences on a sylph's delicate digestion. Withdrawing the treat is the worst punishment (almost) a sylph can imagine.