Male Zebra Finch has lost features around head and neck

[Hudsonja]

My bird has lost his feathers around his head and neck, he is in the cage with a female bird who just had babies 3 weeks I have seen them pluck at each other but she has not lost feathers like him

 

[oldhenlikesdogs]

He may be feathering the nest with them, or the female is. What are you providing for nesting material?

Hopefully you are feeding some breeding or conditioning food. Zebra finches will breed continuously if allowed.