We review the ecology of lynx in the northern part of its range, drawing heavily on the results of recent research from that region. Snowshoe hares form the bulk of prey items in essentially all studies and at all periods in the cycle, but use of alternative prey, often red squirrel, increases as hares become scarce. Caching of freshly killed prey is rare, although carrion is consumed, primarily during periods of food shortage. Habitat use by lynx varies geographically, but tends to track that of snowshoe hares. Lynx prefer older (>20 years old) regenerating forest stands. Mature forest stands are often used but rarely selected. Most lynx dens found to date have been associated with blowdown or deadfall trees in regenerating stands. Lynx maintain mostly exclusive intrasexual territories, based on social intolerance and mutual avoidance. Male home ranges tend to be larger than female ranges. There appears to be no linear relationship between hare abundance and lynx home range size, although lynx do increase their home range size dramatically following the cyclic hare crash. Male and female home ranges generally overlap completely while within-sex overlap is usually modest; related females may tolerate greater overlap.