No, I'm not talking about a kind of bird. The term Snowbirds is a uniquely Canadian term used to describe permanent residents of Canada who travel to warmer southern states during our cold winter months. Most leave Canada November or December and return April or May. They are allowed to be out of the country for 183 days or less if they want to keep their Canadian residency status. The common destination points for snowbirds are Florida and Arizona however some go to other southern states. The primary goal is to escape the cold of the northern winters. By far the majority of snowbirds are retirees and senior citizens. In many cases they buy a pre-manufactured home (aka mobile home aka trailer) or condo for their southern lifestyle. Aside of warmer weather, golfing and good food are very tantalizing.
Medical coverage is likely the most important concern for snowbirds. In addition to provincial health plans that are free to every Canadian citizen but does not provide out of country coverage, snowbirds need to buy additional traveller's insurance that will provide health coverage while outside of Canada. Even day trippers (another Canadian term) to the US should carry traveler's insurance.