Of the more than 180 invasive species found in the Great Lakes, two in particular stand out for their indiscriminate devastation: the fast-breeding Asian carp and the deadly sea lamprey. Join the front lines of an urgent battle to limit the impact of their ecological damage.
Liz meets the animal rebels who will stop at nothing to survive. From cockatoos vandalising houses in Sydney, to crabs who hold nemones hostage to protect themselves, it seems there are no lengths these animals won't go to. Liz sets out to see these animals in action, revealing the science behind their extreme behaviours. She meets the sloth whose disgusting hygiene habits may help hide it from predators, the stone martens who cause millions of pounds' worth of damage to cars to protect their territories and the chimpanzees who use bullying tactics to get to the top. As Liz discovers, when life in the wild gets tough, this outrageous behaviour could just be the key to survival.
The Taiga forest, on the edge of the Arctic, is a silent world of stunted conifers. The trees may be small but filming from the air reveals its true scale. A third of all trees on Earth grow here and during the short summer they produce enough oxygen to change the atmosphere.
Canada's Devon Island is the largest uninhabited island in the world--and with good reason. Temperatures below freezing for nine months of the year and an annual rainfall comparable to the Gobi Desert leave the icy landscape so barren that NASA uses it to simulate conditions on Mars. Take an exhilarating expedition into a land where only the most experienced Inuit hunters dare set foot.
The third instalment examines the spiders and others that produce silk. Attenborough visits New Zealand's Waitomo Caves, which are inhabited by fungus gnats whose illuminated larvae sit atop glistening, beaded filaments to lure their prey.