How long cans ducklings be cold for?

[PaisleyChickMama]

I can’t find the answer to this question anywhere. Obviously ducklings are kept out of heat when they are transported at one day old and they do just fine, so I’m wondering how long is too long? The context here is that I’ve integrated my week old ducklings with my older ducklings who are 4weeks, but one is getting picked on I think because she’s yellow and the other ones are darker colors, and they won’t let her near the heat pad and seldom do they cuddle with her like the big ones do with the other little ones. I’m worried about her, and I’m wondering if I can keep her in there for increments so they learn to get along but I need her to stay warm to prevent a loss.

 

[JacinLarkwell]

They only travel (somewhat) safely in the mail because they're crammed together enough for the huddle effect or are mailed with heat pads

 

[PaisleyChickMama]

They only travel (somewhat) safely in the mail because they're crammed together enough for the huddle effect or are mailed with heat pads

That makes sense, they ended up letting her cuddle up but I put her back in the smaller brooder with her siblings under a heat lamp because I was too nervous

 

[CoriM]

A three week difference in age is pretty big at that stage. Maybe you could just keep the two groups together part time so they get used to each other, and then keep all the little ones together so your baby gets the heat and bonding with the youngest ones.