Lovebirds that kill

Question
I have three lovebirds that were born in my apt. about 10 months ago. Two
are peach faced like their parents and the third one came out yellow. The
father is passive and the mother flew out the window about three months
ago. So I was left with four altogether. Two days ago I noticed one of the baby
lovebirds fighting with the yellow lovebird very aggressively. My wife saw the
same thing as she was going to work. Yesterday as I was going to work, I
noticed that the same two were fighting aggressively again. The peach faced
started attacking the yellow one right after I put their food in. Normally I have
two trays filled with food and I put a bowl full of water to drink. The lovebirds
usually pair up and go to one side and start eating. As the yellow one went to
his usual tray to eat, he was being aggressively chased by the peachfaced.
Each time he did this, I would tap the cage so that they would stop and they
did. I had to stop this aggressive behavior at least 4 times because he didn't
want the yellow one to eat. I went to work thinking nothing. When I returned
home,  I turned on the light and saw that my yellow lovebird was laying dead
on the bottom of the cage. I looked at his head and his head was covered all
in blood. It was obvious that he was attacked. As I approached the cage, I
opened up the cage and the same bird that was attacking him earlier went
and landed right on top of his dead body and looked at me without moving,
almost as if claiming he did it. Then he started preening his dead head which
was covered in blood and so his beak had blood when he jumped off. What I
don't understand is why he would do this. I feed my birds everyday, I've had
lovebirds for 4 years now, I give them love, I put them on my shoulder, I buy
them toys, clean their trays everyday, and then this happens. Can you tell me
why you think they acted in this manner? I thought they were lovebirds not
killbirds.

Answer
I had something simaler happen I had three pale colored lovies together very pale colors not often seen in petshops and two lutinos which are bright yellow with red cheeks in the same cage they got along ok teh yellows kept togethe rand the other bythemselfs they were all 4 months old at the ime and one night I heard hte birds tweeting and it was idsturbing my sleep so I went and told them to be quite and covered them u better...the next mroning I relized they werent tweeting for the fun of it(which they did many many times before) but because tone of the paler colroed birds wasattacking the yellow birds all the palebirds were biting the yellow birds feet and legs and they were smeared in blood but not dead I was shocked removed my beauitufl lutino birds and promply sold the three killer birds as a group. The two lutinos healed nicely with some anti biotic onitment ad were placed with my normal geen male nad they took to each other right away without problem this is my experiance with these birds which are very far from lovebirds if you ask me the way they squabble budgies are more "lovebirds" then these guys...the only thing to do now is bury your bird if you havent done so already and watch for any more loody beaks...bloody tails or feet and genral beak fighting or chasing each other of the groun you have left if you notice such things you must buy extra cages and seperate the birds.