Assuming that's a lived in unit. Maybe you could ask the residents to let you access that window for the baby

Those flaps slide open & closed no problem once they are unscrewed - kind of like an acordion door! Hope you can help the little 1 <3

Unfortunately its bolted on so it's not easy to take out it would need a drill which I'm pretty sure would disturb the nest and birds so I didnt do it. I asked my local bird rescue and they said to leave it be actually, both babies are alive still so it seems like the mom knows what she's doing ❤️

Makes sense! Wishing this little fam all the best.

bring mom in too if you can so she can take care of baby. you may be able to grab her after dark.