One wondering what could happen, can follow well documented histories of zoos in Poland attacked in 1939.
In Poland many animals were quickly killed in bombing, but far more died from stress from loud explosions and fires. Soon afterwards, animals started dying from starvation. The first to die were seals, sealions, pelicans and other fish-eating animals, because fish transports ran out. Afterwards died monkeys and apes, carnivores, birds of prey and fruit-eating birds because fruit and meat could not be obtained.
Source (in Polish) book: Karol Łukaszewicz - Ogrody Zoologiczne. Wczoraj, dziś, jutro.
Karol Łukaszewicz • Ogrody zoologiczne. Wczoraj, dziś, jutro
Unlike the invasion of Poland in 1939, the invasion of Ukraine in 2022 is in winter, with temperatures in Kyiv falling below freezing. This means that a longer power outage will kill many primates and other tropical animals.
It is sad, the only hope that the war will be stopped quickly.