2 resident cats stalking, biting at new kitten

I am new to the forum and was reading through it trying to find help for our new kitten. Everyone sound very informative so I thought I would post. Hope someone can help.

We got a 7 week old female kitten,Tooley, about 1 week ago and did the proper introduction to our two fixed male cats (Fergus and Chloe) both of which are approx. 1.5 years old. I know you are probably saying why is one of the male cats named chloe. Its because the vet identified him as the wrong sex when we first got him and by that time we already named him and felt it an injustice to rename him. He seems ok with it though!!!! Anyways, the two male cats get along surprisingly well, besides the odd play fight. As of yesterday the two resident cats will follow the kitten around and get her to the ground and either lay on top of her and bite the back of her neck or grab her and kick her then try to bite the back of her neck. They will let go once she meows/cries loud enough or if she breaks away. Chloe did this first, last night. After he did it once, Fergus came over to Chloe and yowled at him then got on his back and bit the back of his neck until Chloe layed on the ground then they fought for a bit then Fergus left. Then this morning the roles reversed and Fergus went after Tooley then Chloe went after Fergus. Chloe was the first to really take a liking to Tooley and would, at first, play nicely and even clean her. Fergus was scared of her at first and occasionaly hissed at her but not anymore. I think Chloe is the Alpha cat, although hard to tell at times. He was the first cat we got in the house, then Fergus 6 months later.
Any reasoning as to why both Chloe and Fergus would act that way toward Tooley? Also, any remedies? I fear for her safety at times and no longer want to keep them alone together. Thanks

You should still keep them apart, they are displaying typical male aggression/mating behavior, and she could get hurt. It will help when she gets spayed- but that is quite a long way away.

I would recommend you get a book by Pam Johnson Bennett- called cat-vs-cat it has great ideas and tips how to make this work.

Dominance. When one cat grabs the other by the back of their neck, he wants to show who is the boss! My older cat did it to my younger cat in the beginning, but I didn't see him do it in a long time. I guess he feels he already proved he is the boss! But I never felt that my cat was in danger because he didn't even cry , so the older cat wasn't hurting him, just showing he was the alpha-cat.

Thanks for the advice. That makes sense