Photo by Ann Batdorf, courtesy Smithsonian’s National Zoo One of the National Zoo’s female lions, Lusaka, died Thursday evening, zoo officials said Friday. In a statement, the Zoo described Lusaka as “elderly,” and noted that her health had been in decline for several months while she recovered from having a large, cancerous tumor removed from her back. Lusaka had been at the National Zoo since September 2003, after having been rescued from a private…