No zoo that will take the solitary silverback? He is in a zoo.
Two contracepted females from Chicago are to join Quito in the near future. While Rump and Lash are to remain in a bachelor troop. It is rather difficult to create bachelor troops and it takes lots of trial and error.
As for being genetic castoffs...they just belong to big families. The size of the SSP gorilla population is well over target, so there isnt much room for breeding and more gorillas. Only those with few relatives will be allowed to breed at this time. So some of Jax's males wont be seeing ladies anytime soon and none of them will hear the littel pitter-patter of young gorillas.
Also forgot to mention that Brown Pelicans have been added to the Emerald Forest aviary.