Temporarily marking newborn chicks

[hanabi]

I tend to be a little pedantic about the genetics and family lineage of my finches. I also on occasion have to use fosters to raise some of my newborns, but I unfortunately do not have a large number of fosters. As a result I have, on occasion, been forced to place, for example, chicks from several phenotypically normal Star finches under the same fosters. Naturally enough there is then no way to determine the lineage of each chick, i.e., which chick belongs to which biological parent.

I'm thinking other breeders must have faced this problem in the past and would have a solution, thus this post to the forum. Does anybody have any good ideas? I'd tried marking the chicks with a water-based marking pen, but that simply rubs off in a day in the high humidity environment that is the parents' warming. As a test, I've also minimally marked a chick (body and tiny feathers) with an oil-based marker, and while there were no apparent health side-effects, it also rubbed off in a very short time. I've also carefully looped a tiny piece of wire around the leg of a chick, but the skills required to do that safely are akin to microsurgery, and in the end the fosters quickly removed it.

I guess I need to think more "outside the box" but I'm stumped for new ideas (apart from more fosters). Something like a more-resistant but non-permanent marker? paint? something? that is both safe and will last until I ring the chicks at age 10 days. Any ideas?

Cheers.

[MisterGribs]

Beet juice! It will stain the chicks in a non toxic way for a while, especially if they are feathered. I have used it before. You can stain the tails for one batch, the heads for another, and so on. You can also use food dye, the gel kind works best, especially on feathered or downy chicks.

[hanabi]

MisterGribs

Thanks for your reply. Beet juice is a great "outside the box" idea but it is expensive here. Nonetheless you've given me an idea: food colouring. It's inexpensive, non-toxic, and if used undiluted should stain the skin strongly. I'm not sure about longevity but I'll give it a try and see.

[Icearstorm]

hanabi

If you try food coloring, I'd recommend staining their undersides so the parents don't see the color and harm the chicks trying to remove it. Then again, if the nest box is dark, it shouldn't matter.

[lovezebs]

hanabi

A bit of food colouring, different coloyrs for different chicks.

[wilkifam]

Was wondering the same thing. I'll try food coloring too!