Stirge are a secretive sort, and with good reason. Their abilities center around blood and at best this engenders little trust, while at worst it ends in violence. For this reason, those with the Gift of the Stirge use it in such a way as to seem to have another Gift, such as Unicorn, or hide them as being very proficient at mundane skills (expert trackers, doctors, etc.).
Among the abilities that can be attributed to a stirge are the ability to know blood belongs to someone if they have previously met them, tell relatives by the connection their blood shares, follow the path of a person whos blood they have "scented", and know if blood is poisoned or diseased.
There have been stories of stirges that were able to transfer the wounds of one person to another, though the resulting wounds are a mere shadow of the original (and some use this as a form of healing to deal with severe wounds or to pass their own wounds to an enemy). Those stirges with and those without honor tend to almost possess different gifts due to the differing ways in which they use the gift.