Another nature flick, Penguins, is due to reach Disney+ in 2020.

There's plenty of pressure on Disney to recruit A-list actors for roles like this. It knows that services like Netflix can attract their own top-tier documentary narrators, and it wouldn't do if Disney+ arrived with docs that didn't have a similar cachet. This could convince parents and nature lovers that it's worth sticking with Disney+ when they might otherwise give it a pass.