The San Antonio Zoo announced Wednesday that its endangered white rhino, Gertrude, died Monday of chronic kidney failure due to old age.

A zoo spokeswoman said Gertrude was 46  - 12 years older than the median life expectancy for southern white rhinos. Gertrude arrived at the San Antonio Zoo in 1970.

Of 168 white rhinos in North America, she was one of the five oldest in the country.

Of 706 white rhinos in zoos worldwide, she was one of 11 oldest white rhinos in the world.