From the zoo's informative sign:
[quote][B]Meet a Zoo Original[/B]
The swamp gum eucalyptus tree standing before you was one of the original lake-shore plantings at the Zoo, planted sometime around 1925. There are only about 20 of these trees known to exist in California, and this is one of the largest! Swamp gums can thrive in wet areas like the edge of this pond and may reach 80 ft. tall. However, this tree adapted to our windy coastal habitat and has spread out wide instead of tall. In its native Australia swamp gum is a favorite food for koalas and in Tasmania swift parrots feast on the nectar found in the flowers.[/quote]
There's a life-size jayjds2 there for comparison :).