Advice and understanding needed

[Wild1]

Hi Guys, I have interesting but also very sad dilemma. I had 2 pairs of mandarin ducks for 3 years, they never bred or even showed signs of mating. Then both males in a very short space of time died. I was left with 2 females. I moved home and now have a very large pond and open area. I have also a pair of Toulouse Geese, a pair of Mallard looking call ducks, and a pair of mini Cayuga. I subsequently bought another pair of mandarins. Immediately in March just after arrival the male changed from Breeding plumage to brown plumage and this kinda shocked me but as fast as it went brown it changed back again to full colour. I bought them as a pair and they seemed paired. The other two females now showed interest in this one male often bullying the paired newcomer female but he stuck with his mate. Then the two original females started mating with each other every day even started laying eggs in a nest box that I had erected. All the time this lesbian activity continued and they constantly bullied the paired female newcomer. They have been together for 4 months now and yesterday I suddenly saw one of the original females harassing and eventually forcing itself onto the new female quite aggressively. The next things was after the commotion and my intervention my new paired female was on the pond surface fluttering its wings and suddenly flung back its head and neck over the back of its body, fluttered its wings a few more times and died. I could not find any evidence of a broken neck but I was shocked to see this. the two older females are constantly chasing the male around but he seems not interested.
Has anyone ever heard of such behaviour?
Will this male eventually pair with one of these remaining females?
Should I remove one female and leave just the male and one female in the pond?
I am quite shocked and devastated, I was really looking forward to a clutch of Mandarin ducklings this year.
Advise greatly sought.
Thanks for reading.

 

[sourland]

If it were me, I would remove the most aggressive female with hopes that he would mate with the other. Good luck.