Walking With Wikis
This far south, the first day of spring lasts only a few minutes; But it triggers the start of an astonishing story of survival through the polar year.

– Kenneth Branaugh

Spirits of the Ice Forest
General information
SeriesWalking with Dinosaurs
Episode number5
Featured creaturesA flock of Leaellynasaura
Broadcast information
Original airdate1 November 1999
Chronological information
Previous episode
Giant of the Skies
Following episode
Death of a Dynasty

Spirits of the Ice Forest is the fifth episode of Walking with Dinosaurs, set in the middle Cretaceous epoch, roughly 106 MYA.

Full synopsis

A few hundred kilometres from the South Pole, a clan of Leaellynasaura emerge during spring after several months of total darkness. They feed on the fresh plant growth (which has adapted to the changing seasons), and build nests to lay their eggs; a male Koolasuchus also wakes and heads to a river, where he will stay during the summer. Out on the banks of the river, migrating herds of Muttaburrasaurus have also arrived to feed and lay their eggs. When summer arrives, many of the Leaellynasaura clan's eggs have been eaten; however, those of the matriarch hatch successfully. Meanwhile, a male polar allosaur hunts both the Leaellynasaura and the Muttaburrasaurus, the latter species also having to deal with blood-sucking insects. When autumn arrives, the Muttaburrasaurus herd begins to migrate, and the Koolasuchus leaves the river to find a pool for hibernation. During the migration, some Muttaburrasaurus become lost in the forest; they vocalize loudly while trying to return to their herd, preventing the Leaellynasaura clan's sentries from hearing the polar allosaur approaching. It manages to kill the matriarch of the clan. Winter descends and the forest is shrouded in darkness, but the now matriarch-less Leaellynasaura clan is able to stay active, using their large eyes to help them forage for food. The clan and other creatures are also shown to use various methods of coping with the cold such as being frozen alive or suspended animation. Finally, spring returns, and two Leaellynasaura males challenge each other for the right to mate, and the clan establishes a new dominant pair. The closing narration states that continental drift will soon pull this landmass closer to the South Pole, and when that happens, this unique ecosystem will disappear.

In the credits, it is explained that away from the poles, the dinosaurs continued to rule the Earth for another 40 million years before extinction and that the final episode would show how, just before the end of their reign, they had evolved their most infamous predator ever.


106 Million Years Ago (Victoria, Australia)

Alternate Versions

  • In a rerelease, several scenes are either cut or rearranged:
    • The opening scene showing the first day of spring is cut.
    • The Koolasuchus scenes are cut.
    • The Muttaburrasaurus introduction is shortened and merged with the Polar Allosaur's attempted standoff scene.
    • The scene where flies torment the Muttaburrasaurus is cut.
    • The scene where a mammal attempts to raid the Leaellynasaura nests is cut, along with the scene where the a Leaellynasaura hatchling gets lost in the forest.
    • The scene where another flock of Leaellynasaura invade the forest is cut, along with the following scene featuring the Leaellynasaura and Muttaburrasaurus graze near the river.
    • The scene where the forest's inhabitants prepare for winter is cut.
    • The weta and tuatara scenes are cut
  • In a rerelease, two Leaellynasaura hatchlings survive instead of one.
  • In the US dub, the spring scene is moved to the beginning. This also means that it ends with the Leaellynasaura going into semi-hibernation.


  • The episode is titled "Spirits of the Silent Forests" in the companion book.
  • Even though this episode takes place in Australia, the episode itself claims that this is Antarctica.




Original airdate

  • 1 November 1999 20.30 BBC One


  • 2 November 1999 18.30 BBC Choice
  • 6 November 1999 20.00 BBC Choice
  • 7 November 1999 16.25 BBC One
  • 7 November 1999 19.30 BBC Choice
  • 4 December 1999 9.50 BBC Knowledge
  • 26 August 2000 19.05 BBC One
  • 5 February 2003 19.00 BBC Four
  • 16 March 2004 2.15 BBC One
  • 28 October 2006 20.00 BBC Three