1. Beta-carotene that is not converted into vit A serves a protective barrier against disease. 3. VITAMIN A DEFICIENCY Vitamin A utilized in the body is dependent on 1. Quantity stored in liver a. Deficiency symptoms appear in 1-2 years due to high amounts stored in liver 2.
Wild Lifespan. In their natural wild habitats, cockatiels, on average, live between 10 and 14 years, indicates Animal Diversity Web via the University of Michigan. Their average age for passing away is younger in the wild than it is in captivity. Captive Lifespan Cockatiels that are kept as pets -- or that live in other captive settings -- can stay alive for up to 25 years or so.
this is what i've found in my research: Life Expectancy: The average life expectancy of a healthy, well-fed and regularly exercised cockatiel is 15 to 20 years. Sounds like he has about 5 good years left in him. heres a site that may help u: http://www.pluspets.com/birds/pet-birds/cockatiel.aspx