Interestingly, a sea gull ages all at once - the last few weeks of its life. A thirty-year-old gull can fly as high, attack a school of fish and bear or father baby chicks as well as a one-year-old gull.  Its pituitary hormone levels don't fall until just before its death.

In humans, the aging process starts early and by age 40, our pituitary hormones have drastically fallen over 50%. Notably, growth hormone (GH) and DHEA levels decline each year of life.