NATURE: "DOLPHINS: SPY IN THE POD"
PBS, 8:00 p.m. ET
Part 1 of 2. Nature established an instant hit, earlier this season, by following scientists who designed intricate robotic approximations of animals and set them loose in the wild, to watch how actual animals interacted with them. Tonight and next week, Nature provides a reprise, and an underwater one at that, by photographing the fish and mammals who encounter the scientists’ ingeniously designed and operated mechanical dolphins. Sometimes, the dolphin footage they capture is completely accidental. Other times, it’s photographed on porpoise. Check local listings.