One extraordinary family of fish has achieved the ultimate form of gender equality. When it comes to breeding, seahorses do it like no other animal on the planet. Their fierce females refuse to be left holding the baby. So it's the males that carry their brood. In this episode we explore the world of mating seahorses which are the only animals in the world that have a major gender role reversal.

Our frozen planet is changing. In this final episode, we meet the scientists and people dedicating their lives to understanding what these changes mean, not just for the animals and people who live there, but for the world as a whole.
Our journey begins in the Arctic, where every summer huge quantities of ice calve from the edges of Greenland’s melting glaciers. On top of the ice cap itself, glaciologist Alun Hubbard descends into a moulin to try to understand the mechanisms that are driving this historic loss of ice.
Elsewhere in the Arctic, it’s not just land ice that is disappearing. In the Gulf of St Lawrence, Canada, biologists are trying to find out how the loss of sea ice will impact the lives of baby harps. In Arctic Russia, with the loss of summer sea ice, more and more polar bears are arriving on the island of Wrangel. Here, a local ranger and scientists are braving the hungry bears to assess their future survival.
Loss of sea ice impacts not just wildlife but people too. In the remote community of Qaanaaq, Greenland, local Inuit hunters are finding the ice too dangerous to travel and hunt on, risking their traditional way of life. And these changes happening in the Arctic have the potential to affect people far beyond. On Alaska’s open tundra, bubbling lakes hint at the gases being released from the previously frozen soil, including the potent greenhouse gas methane.
There is one place where the full scale of a melting Arctic can be best witnessed - from space. Based in the International Space Station, astronaut Jessica Meir looks down at forest fires across Europe and reflects how our changing weather patterns are interconnected.
Rapid ice loss is also happening across the high mountains of the planet’s continents. Glaciologist Hamish Pritchard uses a sophisticated helicopter-strung radar system to try to quantify how much ice is left in the previously uncharted glaciers of the Himalayas. It’s important as, downstream, some 1.2 billion people rely on glacial meltwater as their primary source of fresh water.
Finally, in Antarctica, we meet Bill Fraser, who has dedicated 45 years of his life to studying the Adelie penguin. Over this period, he has witnessed changes in weather conditions and the extinction of entire colonies. These ‘canaries in the coal mine’ are a sign that all is not well, even in the remotest place on earth. And changes here have the potential to affect all of us, so an international group of scientists is on an urgent mission to assess the stability of a huge body of ice known as the Thwaites ice shelf. If this plug of ice melts and slips into the ocean, it will raise global sea levels, impacting coastal communities across the planet.
The unprecedented changes our scientists are witnessing may be profound, but there is hope that, through a combination of technology and willpower, there is still time to save what remains of our frozen planet.

Deep in the jungles of Taiwan lives female giant golden orb-weaver spider -- among the biggest web building spiders on the planet. With a leg-span of almost eight inches and silk like kevlar, she's a fearsome predator. But the orb spiders must find a way to mate with her male counterparts, who are approximately 10 times smaller and 500 times lighter than she is.

As summer spreads across our planet, honey bees toil, snow geese breed, tadpoles awaken and lions stalk wildebeest in search of lush grass.
Our planet is solar-powered. But due to the Earth's tilt, it doesn't strike its surface evenly. This solar energy arrives in varying amounts at different times of the year. The huge increase that comes with summer also triggers countless migrations.

We may be smart, but we're still discovering animals have countless skills, every bit as impressive. In a world full of unexpected foes, competition is evolution's ultimate driving force. Is the secret behind the incredible diversity of life on earth, and the most extraordinary animal powers.

The third episode takes viewers on a riveting journey to some of the world's most extreme and breathtaking deserts and grasslands, where nature puts on its most dramatic show. It begins in the arid landscapes of Central Africa's Guelta d'Archei and the Namib Desert in Southwest Africa, places where water is scarce, and survival is a daily battle. The focus then shifts to the remarkable adaptability of creatures like ostriches, who brave the scorching heat and predators to raise their young and a handful of leopards who learned to hunt from trees on the African plains.
In Australia, viewers witness the intricate courtship rituals of the spotted bowerbird, a species facing challenges due to climate change. The narrative then takes us to the vast Eurasian Steppe, home to the unique Saiga antelope, and to Brazil's Cerrado, a biodiverse grassland where the elusive maned wolf plays a crucial role in maintaining the ecosystem.
The episode highlights not only the resilience and beauty of these creatures but also the fragility of their habitats, emphasizing the urgent need for conservation efforts.