Why did PostgreSQL choose an elephant as it's logo?

In the email thread postgreSQL and history of relational databases, Oleg Bartunov states that the logo idea probably originated from a PostgreSQL logo thread on the pgsql-hackers mailing list. Quote:

[...] but if you want an animal-based logo, how about some sort of elephant? After all, as the Agatha Christie title read, elephants can remember ...

David Yang

Also consider the related official "propaganda" page

There you can see that a turtle is used for Japan, which has been discussed before on dba.SE:
Why is there a PostgreSQL Turtle?

.. and on pgsql-general mailing list:
http://www.postgresql.org/message-id/[email protected]

Here is the according Japanese web page:
http://www.postgresql.jp/npo/logo/?searchterm=logo