Why are my ducks yellow?

[moonpiemushroom]

This morning when I let my ducks outside I didn't notice any yellow marking. But when I came back 15 minutes later there seem to be some yellow spots on them? Help me figure out the possibility why. I did change their food recently, I haven't feed them corn in a week and there are no dandelions in my yard.

 

[moonpiemushroom]

It seems like the yellow spots have gone away now.

 

[moonpiemushroom]

Do you have dandelion blooms where they were out?

There are about 6 dandelions in my backyard. They are all separate from each other and seem quite small.

 

[moonpiemushroom]

Looks like egg yolk.

It does look like egg yolk but they have not ever been in contact with eggs.

 

[moonpiemushroom]

Is it sticky/tacky?

My ducks won't ever let me near them
. I don't think I will be able to touch them.

 

[MysteryChicken]

Looks like egg yolk.

 

[JNC]

Does it wipe off?

 

[JacinLarkwell]

Do you have dandelion blooms where they were out?

 

[moonpiemushroom]

Does it wipe off?

I tried spraying one with a hose but it kept running away. I'll try again.

So I tried again, I can't tell if it helped. If it did, it helped a little bit as they are still yellow

 

[MysteryChicken]

It does look like egg yolk but they have not ever been in contact with eggs.

Is it sticky/tacky?