Alpenseen (Alpine Lakes) is a nature documentary that shows us the fascinating world of deep mountain lakes. Here we see the female perch defending her spawn from North American crayfish, and look at the role of glaciers in storing Alpine water.

Alpenseen (Alpine Lakes) is a nature documentary that shows us the fascinating world of deep mountain lakes. In this part, we explore the mysterious "cow tracks" found throughout the Alps in stone. These are, in fact, ancient fossils from the time when this mountain range was an ocean floor.

Alpenseen (Alpine Lakes) is a nature documentary that shows us the fascinating world of deep mountain lakes. In this episode, we'll explore the mysterious "Lake of Blood" and some scandalous interspecies dating!

Alpenseen (Alpine Lakes) is a nature documentary that shows us the fascinating world of deep mountain lakes. From the swiftly flowing streams to the cliffs high above, the area around the lakes hosts a number of different species.

Alpenseen (Alpine Lakes) is a nature documentary that shows us the fascinating world of deep mountain lakes. Here we see many animals emerge from hibernation, and then catch a glimpse of what lies over one hundred meters below the surface.

Alpenseen (Alpine Lakes) is a nature documentary that shows us the fascinating world of deep mountain lakes. In spring, we can witness dramatic moments in the life cycles of many underwater creatures.

Alpine Lakes is a nature documentary, which leads us into the fascinating world of deep mountain lakes. We conquer ice palaces of unsuspected beauty. In the freezers, in which elves, fairies and mountain trolls once did their mischief, we move, using a special breathing technique and with special cameras in search of nocturnal hunters, whose eyes are equipped with residual light amplifying receptors.

The world population continues to grow and time is running out for a solution to the energy question. The Rhein-Main-Neckar Region is working on some concrete answers with the Green Region Initiative.

With temperatures of 20° Celsius (68° Fahrenheit) or more, the sun is shining brightly, the birds are chirping, and the trees are sprouting leaves. No doubt, spring is finally here! This is the time of year when even animals seem to be in a good mood. A video from rheinmaintv. Viel Spaß beim Zuschauen!

Just say "no" to wild animals in the circus: Luna Schweiger fights together with PETA Deutschland e.V. for a ban on wild animals in German circuses.

Winter has finally hit Berlin, causing traffic chaos and a lot of complaining from the locals, but actually some people seem to prefer the snow! (video copyright dpa)

What's cuter than a baby polar bear? Two baby polar bears! The recent birth of twins at the Munich Zoo has caused a media sensation. Watch this report to see for yourself! Copyright: Deutsche Presse Agentur [The German Press Agency]

For the third time, the Day of Sustainability took place through the German state of Hesse. It is intended to inform people about sustainable lifestyles, with this year's motto: Regional, conscientious and fair — sustainable consumption in Hesse. A report from rheinmaintv.

A circus tent full of sustainability experts: This image was presented today to journalists in Frankfurt-Ginnheim, as 300 fourth graders from Frankfurt primary schools celebrated the graduation ceremony of the first Frankfurt "School Year of Sustainability" in the children's Zarakali Circus.

The German band Monsters of Liedermaching sing the song "Nuclear-free Power Plant" — a serious topic performed with perfect charm!