Can donor hair transplant (using FUE) harvest from the side of the head above the ear?

You can harvest anywhere where there is hair.  Arteries and veins are deep within the tissue and it should not affect FUE harvesting.

It depends. If you are destined to be extremely bald, the hair in the area above the ears would likely be lost in time and should not be used in transplantation. This not destined for severe baldness however would typically retain this hair. In these instances, the hair could be used. In a study, I described the "FUE Shave Test which can be used to screen for this and help direct when to extract from this area and when not to. The link at the end of this post gives details on how the "FUE Shave Test"

Below are critical questions that you need answers to before moving forward with an FUE clinic. 1) Is your Doctor the person doing the FUE harvesting or is a Physician Assistant or technician doing the harvesting? 2) How long has your surgeon been doing FUE and FUE harvesting? 3) How many FUE cases does your doctor perform monthly? 4) If your doctor does both Strip and FUE, Does your doctor perform more strip cases then FUE cases monthly?

I frequently do FUE surgeries after previous strip grafting. Primarily  if there is too much tension in the scalp to be able to take an adequate strip to avoid excessive tension on the closure. Also, to select areas such a you mentioned where there is an abundance of density. I frequently remove FUEs from the lateral aspect of the donor above the ears or wherever the densest donor is available. One can palpate or use a doppler to detect where the temporal artery is located to avoid damage. Usually it is located anterior to the ear so can be avoided. 

The theory of 'donor dominance' is that hairs which are likely to present in the long term (ie do not have dihydrotestosterone receptors) are suitable for transplanting.Many men with male pattern hair loss do tend to thin out above the ears but rarely go completely bald in this area.Donor hairs can be used from the scalp above the ears but several things should be considered: if the hairs were destined to fall out in the donor area over time then they will likely fall out in their recipient location over the same time frame, if that area is going to become thinner naturally then taking FUE donor hairs will thin it out more, if the area is harvested agressively and then thins out in the future the FUE scars might become visible.Hair transplant surgeons should be aware of vascular, and neurological, anatomy but this does not influence suitability of a scalp area for donor hair harvesting.

FUE can take hair from above the ears although this area is often less dense than the back of the head where the donor area is thicker in density