I kept two Toulouse ganders in my flock of chickens and Cayuga ducks for almost two years, thinking I had a pair... I ordered a sexed pair of goslings from Ideal Poultry, named them Kate and William. One died when they weren't very old (still in the kiddie pool "brooder" with the "packing peanut RIR chicks) and I mistakenly thought it was William. I found a young gander - named him Angus - on Craig's List because it was too late to order any more goslings. Angus and "Kate" grew up together, but as time went on, "Kate" became very duck-centric and assisted duck mommas with new ducklings they hatched. Angus preferred to spend time with the chicken flock. No goose eggs. Then "Kate" and Angus began to spar and chase each other, mostly due to "Kate" not wanting Angus anywhere near "her" duck flock. I finally realized "Kate" had been William all this time... They never did real damage to each other, just a lot of honking challenges, some flapping, neck-wrestling and some chasing. I think Toulouse are far less aggressive than other breeds of geese. Anyway, this past Spring, I ordered three sexed goslings and named them Zoe, Dora and Ariel. "Kate" took over their rearing when they were old enough to join the flock and I changed his name to Caleb. Angus is still "chicken-centric" because Caleb doesn't want Angus to get too chummy with HIS three girls. They're still too young for mating, but Caleb has recently started to court them instead of just protect and raise them. He's partial to Zoe. I am hoping Angus will be able to have at least one of the girls for his own partner, come Spring. I just wanted to provide an example of two, mature Toulouse ganders co-existing fairly peaceably for well over a year. Cayugas are a pretty large duck, but I felt it was best to give the ganders some ladies of their own type before Kate/Caleb decided he would challenge the Cayuga drakes for any of their girls. 
