The newsreel includes the following plots: Part 1, Plot 1. Traveling frogs. Mountain landscape in Bulgaria. View of Bila Planina mountain, rivers, swamps. Grass frogs in the water. Zoologists catch frogs, ring them, and release them. Zoologists climb to the top of the mountain, catch frogs in mountain streams and ring them - put on two rings. Zoologists study how grass frogs descend from the mountains into a swamp in the spring, and in the fall ascend to the mountains for the winter by land. Rattlesnake. Desert landscape. A rattlesnake is crawling. 2 part. The rattlesnake hunts a mouse: it watches over it, bites and then swallows it. 3-rd plot. European mink. View of the stream. Mink in the grass, digging a hole. Frog in the grass. A mink builds a nest of grass in a burrow. Mink cubs in the nest. The mink is looking for prey: it hunts fish in the river, frogs, mice and other small rodents.