Date: 6/23/26 5:04 am From: Ross Brittain <rossalanbrittain...> Subject: NSWO nest boxes 2026
Hello All, As some of you may know, I have had an ongoing nest box study for Northern Saw-whet Owls in the WV highlands for several years now, funded in part by the Brooks Bird Club. A student of mine, Levi Summe, and I put up nest boxes in the Mon NF along 72 transects of 3 nest boxes each (1 box along a forest road, 1 box 50m from the forest road and the last box 100m from the forest road). Since most nest boxes for NSWOs are placed along forest roads and have low use rates, my hypothesis is that the owls would prefer boxes further from the road.
This year we had four nesting attempts by the NSWOs, and amazingly, all four boxes appear to have successfully fledged young. I say "appear" because one of the nests was along Canaan Loop Road, which was closed until 6/13 so I couldn't get in to check those boxes. However, I can tell that one box had a nesting attempt and based on the amount of poop and pellets in the box, they appear to have fledged (once you see it, you know). I do know for certain that we banded 14 baby NSWOs in the other three boxes this year. We banded the last of the babies on Father's Day. This year the owls were on eggs much earlier than normal, too. We are usually banding babies between mid June and the first week of July, but this year we banded most of the babies in May and finished the last box on June 21st (the only nest in line with our usual phenology).
Overall, we have had 23 nesting attempts by NSWOs over the last 8 years, which is obviously not a high rate of use... there goes the first hypothesis. But they are being used and I should soon (within the next 2 years) be able to draft a manuscript on nest box preferences for this species in WV. The most nesting attempts we have had in any single year is five, but this year we banded the most babies of any year since there was no predation.
Anecdotally I can say that they do not seem to prefer boxes from the road. Also, they always nest on old squirrel nests made of moss or birch bark strips, so we learned to leave the squirrel nests in place. Lastly, once a box has successfully been used to fledge young, the owls have never reused it. I have had multiple nesting attempts in different boxes along the same transect. I also have had one box with two nesting attempts, but the first nesting attempt was predated before the eggs hatched so it never developed the crust of poop and pellets that the successful nests get. For those transects with multiple nesting attempts, all but one have had at least one year in between the nesting attempts. In other words, this species has low nesting site fidelity, probably due to a combination of the old nests being covered in poop (disease prevention) and because a nesting site likely has fewer prey items around the next year (prey populations need to recover).
