I quite agree with you Titus that common birds are not as common everywhere. This means every species needs to be thought of. Again, remember that today's endangered and globally-threatened species were once common but their populations shrunk over time. Although research and conservation efforts are currently highly priced for the threatened species, it would be good if we also considered other species alongside since no species is an island, they all interact and these interactions have implications (and complications) which affect each participant.
That said, I'll be on the lookout of the said species. I remember close to end of last year counting over 100 Marabout Storks arriving for roost a the Kenya Institute of Monetary Studies (route 29/30, Survey, Thika Superhighway). Another group (tens of them) lives/roosts at Kenya Breweries' area on your right as you descend the GSU hill, check on your right on the trees along the river.
All the best everyone.