Going through your Wild ass pictures, I see that all green is from the highly invasive Prosopis juliflora s.l. tree, these trees grow at incredible speed in such drylands as this. Do you know if there is any clearing or other management going on there.... Otherwise the future of these asses looks very dark...
I don't know if it is relevent, but these are salt pans and are flooded for half the year (during the rainy season). The trees grow only on the higher ground. During the flooded times, the animals such as the asses, hyaenas, etc, live amongst the trees.
I have no idea on the management of the trees (I didn't know they weren't naturally-occurring there).
@Chlidonias Fortunately Prosopis will die when it is waterlogged. The problem is then only in the flooded areas, because when Prosopis cover gets high enough all other vegetation disappears, they can eat Prosopis seeds as a replacement, but those have unhealthy doses of sugar... My PhD is mostly about these trees, but then in Africa, where they are also invasive, but not so much yet in protected areas....