Reproduction
Most calf's (baby Orca's) are born one at a time. But, twins can happen but it's not usual. Calf's are 6.5-8 feet and 400 pounds. Most Orca's reproduce in the winter to early spring. When calf's are born the parent stays with them for one or more years. Here's a fun fact about reproduction. When calf's are born the most common way to be born is the tail first, but sometimes the head is!
http://www.dwarforca.com/images/Orca_Mom.jpg