Observational research
Whether in a zoo, laboratory or even in the wild, video surveillance systems play a vital role in monitoring animal behavior and associated patterns. Research scientists can use day and night footage from surveillance cameras to remotely record animal behavior that those animals normally wouldn't engage in with humans nearby.
From a research perspective, surveillance cameras and recorders can be used for just about any type of observational research that requires long-term monitoring regardless of the time of day (whether for animals or humans), including sleep behavior patterns, mating rituals and breeding behavior, reactions to medicines in clinical trials, and more.