I have 2 mallards why is one shaped so weirdly

[Mckaykay]

This is my 2nd time to have mallards the 1st time I only had 1 which was a boy. This time I have 2 and have noticed one is drastically different in shape

 

[JacinLarkwell]

The black looks like a runner duck

 

[raingarden]

Somebody messed up. Runners are fun, it's not what you want breeding with your mallards.

 

[JedJackson]

The large one is probably a Rouen. The smaller one looks like a normal mallard. You probably already know the dark, upright one is a runner duck.

 

[Egg Snatcher]

Runner duck

 

[Mckaykay]

The black looks like a runner duck

I know about the runner duck I'm talking about the duck on the left

 

[Mckaykay]

Somebody messed up. Runners are fun, it's not what you want breeding with your mallards.

I know about the runner duck I'm talking about the duck on the left

 

[Mckaykay]

The black looks like a runner duck

This is my 2nd time to have mallards the 1st time I only had 1 which was a boy. This time I have 2 and have noticed one is drastically different in shape

I know about the runner duck I'm talking about the duck on the left

 

[theoldchick]

Wow! It does have a different shape. The tail is stuck straight up! Can't help you though but I'm curious as to what you find out.

 

[Aunt Angus]

Is one a Rouen, maybe?