LIONS

Lions are threatened throughout most of their African range. But nowhere is their condition as perilous as in Kenyan Maasailand, where this large male was photographed. Lions there, which number less than 150, are under imminent threat of extinction from Maasai herdsmen thought to be retaliating against prides who prey on their cattle.

Lions are the only cats that live in groups, which are called prides. Prides are family units that may include up to three males, a dozen or so females, and their young. All of a pride's lionesses are related, and female cubs typically stay with the group as they age. Young males eventually leave and establish their own prides by taking over a group headed by another male.

Only male lions boast manes, the impressive fringe of long hair that encircles their heads. Males defend the pride's territory, which may include some 100 square miles (259 square kilometers) of grasslands, scrub, or open woodlands. These intimidating animals mark the area with urine, roar menacingly to warn intruders, and chase off animals that encroach on their turf.

Female lions are the pride's primary hunters. They often work together to prey upon antelopes, zebras.