Monkeys can certainly survive in North America. The Mystery Monkey of Tampa is proof enough of that. But for them to survive here, they have to get here--the monkeys that were here, the Platyrrhines, aren't the ones to survive in a place like Tampa.
Most people enroll in Part A. when they are first eligible for Medicare because there is no premium for Part A if you have. worked and contributed to Social Security for at least 10 years. However, when you should. enroll in Part B depends in large part on how many employees work for your employer.
For most people, the initial enrollment period for Medicare Part A and Part B starts 3 months before their 65th birthday and ends 3 months after their 65th birthday. After initial open enrollment there are two open enrollments each year where you can switch your plan or add to it.