Sunday, January 30, 2011

It's time to clean the nest boxes; spring is almost here

I took a break from shoveling snow to do some annual cleaning of the bird houses. This is a post I write about annually, but it is always a good reminder.

For more information about cleaning details click here and for more information about bird houses click here, and for some general bird stuff on this blog click here

Bird nest boxes need to be cleaned and inspected annually. It is a good time to look for water damage, and a good opportunity to inspect the boxes to see if they need any other repairs. At the minimum, remove the old nesting material, scrape off any mildew, and repack if you will be packing the house with saw dust (see here for more information).

I used to clean and re fill them right after the nestlings would fledge, but now I usually wait until early February to clean and refill the bird houses. I don't know if it is because of wisdom or laziness.

If left empty through the winter, birds may use the empty boxes as roosts. For example, this winter when we had several days below -10 F, flickers roosted in the flicker box and chickadees roosted in the chickadee boxes. However, in the past, squirrels have roosted (albeit temporarily) in the flicker box. But let’s just say that squirrel won’t be telling any of his friends about that warm spot to spend the night. Anyway, I digress, another reason to leave them empty after the nestlings fledge, is that our chickadees typically have two clutches and they will build their second nest right on top of their first nest.

Nevertheless, the sooner you get them repacked, the sooner you can watch for excavation activity. It is always amazing how quickly they start checking out the boxes, especially if we get a few warm days, and the little birds' thoughts turn to love.

Here are some important dates on nesting activities in the Missoula area from my backyard:

Red-breasted nuthatches are the first to begin excavating their selected box- they begin excavating in early to mid February (between February 5 and 21 at my house) and they are usually complete by the first week of April (April 1-9) when they begin to fill their boxes with nesting material.

Black-capped chickadees start excavating about a month after nuthatches, with peak excavating around first week of April (from March 25- April 4), until middle April when they bring in nesting material (April 11-15). But they investigate and start defending nest sites in February.

Northern flickers are on a similar schedule as chickadees and they begin excavating in late March – early April (March 24-April 8), but they search for nesting locations in February and may do some exploratory excavating as early as the beginning of February.


  1. Your right spring is almost there, Thanks for sharing it was a nice article.

  2. Bird box cleaning is on my to-do list today. The boxes are frequently used for winter roosting so I can only clean some of them but the bluebirds are busy house hunting here in GA.

  3. Thanks for the nudge. I'd forgotten all about spring a-coming!

  4. Oh yes! Thanks for the reminder. I'm not sure we had nesters but I do see the chickadees pairing up and they are the ones who check out the birdboxes each year. It'll be interesting to see what if anything is in our two boxes.

  5. Any thoughts on when the Robin's start to return?

  6. I had robins in my backyard on Feb. 16, 2011, and had a western meadowlark on March 5, 2011.

  7. That's helpful tips. Actually there are few nest boxes in front main door. And those were installed by my 12 year son about 2 years ago. He enjoyed watching and feeding birds out there. Few days back I cleaned all of the boxes as it was looking haunted. Your tips are really helpful.


  8. Thanks everyone for the comments. I've been out of the country for the last few weeks so I have a lot to get caught up on- including figuring out what birds have been visiting.
    Robins typically return to Missoula around March 1. For example in 2010, they first came to our garden on March 7 and in 2009, they were back by Feb. 16. I'll keep an eye out today!

  9. Country Mouse- thanks for stopping by!
    Keep me posted on the nesting status. Good luck this year!

  10. Hi Dave - I filled a former bluebird nest box with pine chips and attached it to a post about six feet up in our back yard. A couple of weeks ago, my wife saw a black-capped chickadee pulling some of the wood chips out, but we have not seen any trace of them since. Is it likely they decided against the spot? Is there still time for another pair to take up residence? I wonder what factors may influence their decisions. Do you think six feet is too low?

    Thanks - love this blog!

  11. Oh - I should add that I did narrow the diameter of the hole to about 1 1/4" - 1 1/8."

  12. Hi Greg,
    Thanks for your comments.
    everything seems fine with your box. chickadees (and a lot of other birds) will investigate all potential nest sites pretty early, and catalog them. it is still a bit early for them to actually nest, or excavate, so I am sure everything is fine.
    In general, 6 feet is fine, place the entrance hole away from the prevailing wind, and place the box near a spot where birds can perch (like a tree) before entering the box.
    Keep me posted as spring progresses.
    I hope this helps.