There are fish and rodent videos. :lol:
The outdoor life exectancy is based not on a given cat's life but averaging out the early deaths due to traffic accidents and disease. One statistic I have seen is that one in four outdoor cats will be dead from a car by age 5. They also run a higher chance of acquiring feline leukemia or feline HIV and other diseases as outdoor cats. Also skin cancer. I have lost outdoor cats to leukemia (several), one to HIV, and one to skin cancers that developed on the nose (pink nosed cats are more prone to these). One to an outdoor accident, one that just vanished on day.
I do think 2 years is probably too low -- the figure I have seen is age 5, from most rescues. If I average out all the cats we owned in our family, the average age of death does come out to 5 based entirely on loss due to illness, accidents and disappearance, presumed dead.
I now keep all my cats indoors, because I believe the same context applies to cats as dogs -- I'd never leave my dogs roam the neighbourhood for their safety and out of good neighbourliness, but that was the norm in many places until recent memory. Roaming cats are far less 'good neighbours' than roaming dogs too -- I am a major facn of cats and ave four! but personally I am sick and tired of all my neighbours 'cats who come spray all around my little sideyard and on my planter boxes and use them as a litter box. It stinks of cat spray during the summer sometimes. Cats don't just 'go' outside, they go in somebody's garden if they don't use a litterbox! And often it won;t be your own. I tire of listening to neighbour cats all yowling at 3am. And there is a VERY high attrition rate -- we have semi ferals and tame cats roaming around and the semi-ferals all have a better survival rate. Very few pet cats last more than a couple years before they are hot by a car.
It isn't hard to create an interesting, activity-filled indoor environment for cats. All mine are healthy happy, active, have plenty to do inside and access to a safely enclosed outdoor area where they can hide under plants or sit on a window ledge. None of them is remotely interested in being outside to roam but they do enjoy a sunny windowledge inside and like having outdoor access to catch flies and hide among the plants, which they can safely do.
No serious illnesses, all are fit excepting Quincy the fat three legged cat :roll:, they sleep quietly at night and match my waking and sleeping schedule.
I do think over time people living in urban or suburban areas will find it odd that at one time it was considered fine to have cats roaming everywhere just as dogs once did. If I lived in a more remote semi-country area of almost no car traffic, I'd probably keep them outdoors.