The purple martin is the largest swallow in North America. Being the largest species of swallow, however, doesn't mean its large compared to other birds. At about seven inches in length, the purple martin is a little smaller than a cardinal. Males are glossy blue or purple and appear black unless viewed up close. Males their purple after their second year. Females are dusky grayish purple with white underparts. Both males and females have forked tails. These birds are powerful and flyers and spiral in all directions in of flying insects such as moths and dragonflies. Hunting martins in spectacular aerial that delight those who are lucky enough to them. They often chatter, squeak, and squawk in flight.