Tagging goslings

[docdubz]

What's the best way to tag goslings? I'd like to keep track of which are male and female from this hatch but I've failed badly in the past.

 

[Percheron chick]

Leg bands. Stay on top of them and swap them out every 2-3 weeks as they grow.

 

[AGeese]

I have numbered bands, but I need smaller sizes.