A new advocacy paper says that divided giraffe populations have not exchanged genetic material - interbred - in over a thousand years. They highlight lack of interbreeding among the Masai giraffes of Tanzania and Southern Kenya that are separated geographically by the Great Rift Valley. Some say that increases the risk of birth defects, but 'risk' is so overused and abused in modern Western culture that it is hard to know how valid that is, while the New York Times and other outlets have touted studies claiming the risk in marrying a cousin is trivial.(1)
The good news is that the area in question has substantial tourism and therefore conservation revenue. That is a key way to keep local people improving their lifestyles as the rest of the world does. In areas where trophy hunting, as an example, was banned, conservation efforts and tourism went down(2) and more people were injured as unculled animals ventured into villages and attacked. You don't risk your profit center so eco-tourism like hunting and safaris keep native species robust.
The authors believe it is possible to do better, and that may be needed if American estimates are accurate and giraffes in East Africa are more 'endangered' than local experts have stated. One way to improve would be less habitat loss, but more more dense cities first require affordable energy, and groups like the World Bank have refused to fund any centralized energy scheme that isn't alternative. Until then, people will rely on wood and dung for fuel, and cause higher emissions than all of agriculture in the world combined, in remote villages. There is also a problem of poaching but that is tiny. Yes, Asian countries love magic potions and folk remedies made from exotic animals, and American progressives love anything that sounds like an Asian supplement, but that is an issue for India and China more than Africa. Hunting is too large a profit center for poaching to be anything less than a death sentence if caught, and it is nearly impossible to import a trophy without a legal chain of custody.
There is no realistic way to open up corridors, and no evidence giraffes would use them, since some herds have not added new members for over 100,000 years.
(1) In the US, 30 states have restrictions on cousin marriage while Europe, which has far more restrictions on abortion than nearly all of the US, has no problem at all with it. And they love to ban things, they once banned 'ugly' fruit.
(2) Mozambique manages lion hunting quite well and has had no detrimental impact on the wildlife population while gaining big money for its conservation programs. Botswana, on the other hand, listened to white activists in western countries and banned elephant hunting - only to reverse course when tourism and hunting income plummeted. Meanwhile, as elephants increased they were killed in self-defense when attacked and killed people - no revenue at all.