to estimate age they extract a small tooth and count the yearly layers of of cementum

no natural predators males sometimes kill other fighting - or may kill a mother protecting her cubs - males will sometimes eat cubs malnourished mother may eat cubs

hunted for thousands of years for food, clothing, bedding and religious purposes - evidence found in 3000 yo ruins commercial hunting begain in 1500s, flourished in 1700's hunting in 1950's & 60's got large scale with new techs such as planes & snowmobiles using aircraft or motor boats was banned in 1973 most polar bears die from hunting sometyimes killed in personal or property defence banned in norway or russia- regulated in canada, greenland, & US

oil spills threaten by fur losing insulating properties & contaminating food sources

toxic chemicals contamiationg bears - notable pcb's & ddt high on food chain so accrue higher levels

nuclear waste dumoing in artic having effects too

starvation effects subadults who are inexperienced hunters and may be chased from kills hy bigger adults older weaker bears can dieof starvation too

parasitic worm Trichinella in high levels can kill them too most attacks on humans are fatal to teh human since the polar bear sees you as food - unless bear killed first - more willing to attack than other bears usuallyt females with cubs or adolescents these ones scavenge most too

Where do polar bears live, & where do polar bears go?
What Physical Features makes a Bear Polar ?
How do Polarbears get around ?
What & how do polarbears eat?
What do Polarbears do with their time?
Where do baby polarbears come from?*Still under construction*
When and how do Polarbears die? - Dealings with Humanity *Still under construction*