How do I defeat Bloodwing in the 'Wildlife Preservation' quest?

Given the limitted amount of info all i can say is you have to do 2 things:

1) go back and level up (more health = more chance to survive) 2) try to get better gear

I could probably give much better advice if i knew which mode you're on, your level, your class and your equipment. Though word of advice, in that map before bloodwing, theres a set of 4 cardboard boxes next to a red chest. if you're on the mission "Doctor's orders", these boxes have a really high chance of spawning loot midgets. so you can farm them for orange gear. (also a chance to spawn jenkins if going for the "challenge accepted" achievement)