Ducklings… need help with breeds

[Poultry mum]

I have 2 ducklings that have hatched from my own flock… they are both 2weeks old tho they are 2 days apart…
I have muscovy and Cayuga (males and females in both) and they all run together.. I know my male Cayuga (jack) has taken a particular liking to my scovie girls…

my question is this why is there such a HUGE size difference between the ducklings and is there anyway at this age to tell if they are pure breeds or more likely cross breeds…
And is the size difference something to do with the fact that the little yellow one (quackers) had ligament issues when he/she hatched…
Both ducklings also hatched 5-3 days earlier than muscovy (35 days) hatching time but later than Cayuga hatching time (28 days)

 

[Crazy Maizie]

It would be easier to tell if we can see their faces, but I'm betting the black and yellow one is muscovy or a muscovy mix.
I hatched 3 pure muscovies and one was a runt compared to the others. If the yellow one had issues while hatching that can definitely play into their rate of growth.

 

[Poultry mum]

It would be easier to tell if we can see their faces, but I'm betting the black and yellow one is muscovy or a muscovy mix.
I hatched 3 pure muscovies and one was a runt compared to the others. If the yellow one had issues while hatching that can definitely play into their rate of growth.

Here is a photo of there faces sorry best I’ve got atm will try and get some better ones later today

 

[Poultry mum]

Black and yellow (daffy) hatched on day 30 and yellow (quackers) hatched on day 32…

 

[Crazy Maizie]

Definitely muscovy for both. Daffy is most likely a mix and I'm guessing male. The vast majority of muscovy mixes are males. Quackers - not sure if it's a mix or not. Could be pure muscovy. You will know once they grow a bit.

 

[Poultry mum]

Definitely muscovy for both. Daffy is most likely a mix and I'm guessing male. The vast majority of muscovy mixes are males. Quackers - not sure if it's a mix or not. Could be pure muscovy. You will know once they grow a bit.

Brilliant thanks… you’ve just confirmed everything I was thinking