A Year on Planet Earth continues 8pm, Sunday 23 July on ITV1 or you can stream the whole series on ITVX.

Stephen Fry continues his journey through the year. For much of the Northern Hemisphere, Summer is the season of the Sun. By June, we are half-way through our annual journey - the northern pole is in 24-hours of sunlight, while the south is frozen in darkness. But things aren't as simple as hot and cold, this is a season of feast, famine, fire and torrential rain.

In Canada's Rocky Mountains, summers are short. Pika must harvest flowers to feed on before the snow returns, all whilst fending off a few pesky local thieves. For Marion Island’s king penguin chicks, life has frozen to a standstill. Their parents left months ago and the chicks are facing starvation. In Northern Australia, it’s the dry season, and hooded parrots raise their chicks in termite mounds. But it is bushfire season, and approaching flames are threatening their survival. The same winds that fan the flames blow North over the Maldives, changing ocean currents and bringing with them plankton-rich waters.