My zebra finch is sad after its nest removal. How can I help?

That can be a general sign of illness, especially if he is sleeping on the floor of the cage (it's hard to tell from your photo). Keeping him warm and eating and drinking can help, however since the behavior has been ongoing for a week it is best to bring him to a vet for a complete exam. Birds are great at hiding illness, so ruling out any issues such as nutrition problems, infections, illnesses, etc with your vet is best.

Remove the cage to a cooler area of the home. Lightly mist her with water or provide a bowl she can bathe in. Make sure she is drinking to keep hydrated and eating normally. If she doesn't perk up in a few hours, you will need to find a veterinarian or an experienced avian veterinarian to examine her.

It sounds as if your female may be sick and it would be best to bring her to a vet ASAP. It is possible she is exhausted from laying the eggs due to malnutrition, has an illness, or even has a stuck egg that is making her ill. Seeking veterinary care in person ASAP is best to try and get her feeling better. You may also need to separate her into a warm hospital cage until you can get to the vet to help make her more comfortable and reduce stress.

If the baby is old enough to be on his own, you may need to separate him to a different cage to avoid being picked on. Making sure he is eating and drinking and seems healthy is also a good idea as birds will sometimes pick on other birds that are ill or injured. Sometimes, parasites or even stress preening can cause a bird to overpluck feathers as well, so adding in enrichment such as fun toys or checking for signs of parasites may also help.

if you took the chicks away that early to begin hand-feeding and taming, having them where the parents can see/hear may help them calm down some. Otherwise, adding in some extra toys and treats for your female to interact with may help her a little. However, it may just take some time since she was busy caring for her babies and probably doesn't understand why they were taken away.

Thank you for using Petco Pet Education Center, formerly Petcoach! The signs you describe are consistent with over grooming, likely from the other bird. This may be due to boredom or overly dominant nature of the cage mate. You can try to provide additional toys and perches in the cage, keep the light cycle in the room stable, and provide a nesting box. I hope this helps and am happy to answer any other questions you may have!

It's possible, however it may be that your finches are nesting together to try and lay eggs/raise a family. They may also be cold depending on their location, and so are staying in the nest for more warmth. Making sure their cage is kept clean, they are not in a drafty or cold area, and that they have access to food and water can help. Checking the nest for any eggs can also alert you to if they are trying to raise a family. If you suspect they are ill, or they are showing symptoms such as completely listless behavior, not eating or drinking, diarrhea, vomiting, etc, then scheduling a vet visit to rule out any health issues is always best.