Mountain lions are not normally independent until they are at least a year old. In a study of 1992, Characteristics of a Hunted Population of Cougars in South-Western Alberta by Ross and Jalkotzy it was found that of 30 kittens from 18 litters, the average age of independence was 15.2 months in a range of ages from 10 to 21 months.
In New Mexico, the average age of independence for mountain lions was found to be 14 months for six males and 13 months for nine females in a study which took place in 1996 entitled, Cougars of the San Andres Mountains, New Mexico, by Logan, Sweanor, Ruth and Hornocker.
In a further study concerning southern Florida, young male pumas became independent at 12 to 18 months of age. (Tracking Florida’s Panthers, 1990 by Maehr).
When young mountain lions are about a year old their associations with family members breaks down. Individuals spend more time alone. Litter mates sometimes remain together for a few months during which they continue to use their mother’s home range.
Sometimes a mother will leave her offspring at a kill site within her home range and not return. The intention is to initiate the independence of her offspring.
Once the mountain lion is independent he or she disperses, moving away from the natal area. Sometimes they stay in their natal range until 26 months of age.
From various studies concerning 148 young mountain lions comprising 70 females and 78 males, it was found that young mountain lions usually disperse between the ages of 14 to 21 months which in most cases is prior to reproductive maturity.
Young mountain lions develop permanent canines by eight-months-of-age. There have been occasions when mountain lions have been orphaned at this age and survived. For example, three six-month old kittens were orphaned when their mother was killed by dogs during an attempt to capture her. The kittens remained together for three months. The male kitten managed to kill a deer when he was nine-months-of-age. The two females died before they were a year old.
Note: the source of the information other than stated is Wild Cats Of The World by the Sunquists.