I’m sorry it took me so long to reply to your question. It is a very busy time of year for cavity nesting monitors! I don’t think that having the 15 watt light on would have any effect on their nesting habits. They may have built the nest there for the added warmth. In what part of the country do you live?

My guess would be that she is incubating eggs if she is on the nest continuously. My experience is that once a bird starts incubating eggs they seldom, if ever, leave the nest. Usually their partner will bring food to the nest for the setting bird or they will switch off sitting on the nest, depending on the species. Steller’s Jays eggs are incubated by the female for 17 or 18 days.

You may be able to get up above the nest so you can see into it and find out how many eggs she has in the clutch (if she will leave the nest when you get close enough). Don’t worry about “scaring” her away, she will come right back after you leave and continue incubating. They will usually have 4 to 6 blue-green eggs speckled with dark spots. Once they hatch, the chicks should be old enough to fledge at around 16 days.

If you are able to see the eggs in the nest and especially if you know approximately when you first noticed her sitting there all the time, you may be able to figure out when the babies will hatch. Once they hatch you will know because both parents will be flying off to feed the little ones. You can observe them close up when the parents are gone but don’t handle the chicks and don’t disturb them at all once they are around 13 days old to prevent them from flying out of the nest too early.

Please keep me updated on their activities as I love to talk to other folks about what’s going on in their neck of the woods.

Happy Birding!