Behavior & MigrationBluebirds Alerting Hosts to Problems

Bluebirds Alerting Hosts to Problems

It is not uncommon to hear anecdotal accounts of bluebirds apparently “alerting” their hosts to problems. Bluebirds do use alerts within their own species. For example, if a predator (or a human) approaches a nestbox, they may dive bomb and chatter excitedly.

Female Eastern Bluebird at mealworm feeder. Dave Kinneer photo.
Female Eastern Bluebird at a mealworm feeder. Photo by D. Kinneer.

People with bluebirds nesting in their backyards often get very attached and familiar with their blue neighbors. It is tempting to anthropomorphize animal behavior, and conclude that these birds try to communicate with us. We do know that pets communicate with humans (by letting us know if they are hungry, for example), but bluebirds are not pets.

However, there are some convincing stories out there, seen through a human filter of course. For example, when mealworm feeders are empty, some bluebirds will come and peck on the owner’s window, appearing to beg for a refill. Here are some other interesting accounts:

  • One day, while I was washing the windows on my house, I noticed a male bluebird flying to the window of our garage. It would tap on the window, look at me, tap some more, then fly to the bluebird house about 30 feet away. The bird continued this action for some time, eventually flying into the garage and tapping on the top of my car.Finally, I walked over to the bluebird house and was surprised to discover that wrens had built their nest inside. I cleared out the wren’s twigs and sticks while talking to the male bluebird, who was not perched on a branch overhead. I went back to window washing, but pretty soon, my little blue buddy was back again. It tapped on the same window, looked at me and tapped some more. Upon inspection of another bluebird house, I found that wrens had piled twigs and sticks in this one too. I cleaned out this house as well. Phyllis R. Katz, Battle Creek, MI. From Birds & Blooms magazine January 2009


  • The female of the Bluebird couple that have nested in my backyard boxes for the past three years has the habit of coming to my windows in the back of the house and fluttering up against them – not hard enough to hurt herself, but hard enough to make a pretty distinct “thwapping” noise. At first I thought she was doing it to get me to refill the mealworm feeder. I was reluctant to reward her thwapping behavior by producing treats, but on one occasion my hubby was so insistent that the poor birds were ‘starving’ that I gave in and filled the feeder. But I soon discovered that filling the feeder didn’t stop the thwapping. I’ve noted this behavior under several different sets of circumstances.1) On one occasion she came repeatedly to my window, and when I would appear at the window she’d fly off to the nestbox and perch on top. When I finally went out to check, I discovered that some paper wasps had started a nest ~ not in the nestbox ~ but on the inside of the stovepipe baffle. Their buzzing against it was making quite a racket. I disposed of the wasps and the window-thwapping stopped.2) In the fall last year, one of my Downy woodpeckers took up residence in the Blues’ old nestbox and began some ‘renovations’ ~ pecking at the inside of the box around the entrance hole, making little wood chips on the inside. (I surmised that Mrs. Downy was not so much trying to enlarge the hole as attempting to make some soft bedding for herself, as when I put some pine shavings in the bottom of the box, the renovations
    stopped.) When the Blues came back a short time later to do their nestbox-checking rounds, Mrs. Blue found the shavings in the bottom of the box and immediately came thwapping at the window. Only seeing me go out and look in the box calmed her down and made her stop. On other occasions she will thwap in the spring when the TRES are checking out one or more of ‘her’ nestboxes.3) She has often come thwapping at the window after laying the first egg in a clutch.

    4) She almost universally comes thwapping, almost frantically, when the eggs begin to hatch, and with each subsequent egg that hatches in the clutch, she comes again.

    5) She will come thwapping when it’s time for fledging, especially if there are other birds in the yard that are too curious.

    6) At this time of year the Blues are not coming to the yard every day, but when they do stop by, Mrs. Blue comes and gives a couple of thwaps “to let me know they are around”.

    I’ve posted some videos of this behavior at Bottom two video files. The 2nd one goes on for almost 9 minutes. That may seem like a long time, but if I ignore her, I’ve had her keep at it for almost an hour! It can be quite unnerving! Usually going outside and looking in the boxes or at least opening the window and talking to her makes it stop. – Cher Layton, NY, The Bluebird Nut


  • This morning while sitting on the patio to watch the original couple come for their morning mealies, I watched them do things a little differently. I assume they were attempting to coax babies to back yard feeder. One would get a mouthful of wormies and sit on top of the box while the other would sit on the fence and call over and over again, looking in the direction that they always fly when they are leaving the box. The female would occasionally get a mouthful of mealies and sit on top of a shepherd’s pole near the box and the male would call over and over again. They would fly off, come back, go inside the box and come halfway out, calling over and over again. This went on for an hour or more, but the babies never showed up.I finally had to get busy with my day, but a little later I saw a female fly up onto my covered patio, right up to the glass door as if looking in and trying to get my attention. She did this more than once, frantically … almost like she was pleading with me to come outside. So I went outside and saw a ‘muscular’ male sitting on the box. He flew when he saw me. (My original couple never flew when I am around. They are quite comfortable having me right near them.) A few minutes later I could hear bluebird calls in several directions.I checked the box and saw the beginning of a new nest, but I don’t know which couple is building. After I came inside I noticed the ‘muscular’ male go in the box and come out with a short twig in his beak. He sat on the fence doing some kind of ‘dance’ with the twig in his mouth, bowing and straightening over and over again. (Sorry, I forgot who posted this – I think it was on the Garden Web Bluebirding Forum)


  • This was more an “after” reaction by the bluebirds rather than an alert aimed at me… Several years ago, when I checked out a box which I knew had nestlings, the EABL parents were calling in what sounded like distress/alarm, flying/perching near the nest, as I approached. When I opened the top and looked in, a male HOSP flew out, and I found one of the nestlings dead and another nearly so. I removed the dead one (later had to do so with the other as well) and moved a short distance away to observe… Within a few minutes the HOSP was back and entered the nest. I ran over, and as the HOSP darted out when I looked in, I was able to bat him to the ground–pretty hard, I may add, both the bat and the ground-hitting. He fluttered away, not looking too steady (hopefully damaged!) and was not seen again (and the following day I was able to trap and kill the female HOSP in a nearby nest). Immediately afterward, as I was checking the remaining nestlings, the parents sat quite close by (the nestbox is near a multiflora bush) and “crooned.” I suppose I expected them to be more upset, probably even dive-bombing me, after such an episode, but they seemed, somehow, to know the danger was over, with no need for further distress calls or agitation. For the remaining couple of weeks they were using the nestbox, whenever I checked, the parents would perch quite close by, still making the soft crooning sounds. It was totally unlike their previous behavior at nest-checking–tempting to believe, anthropomorphically, that they recognized I had helped and were pleased to see me… – Rhonda Watts Hettinger Wilton, N.H.


  • Great-crested Flycatcher: A family of GCFL accepted a wood duck box and laid 5 eggs. When checking the box I inadvertently broke one egg. The female built over the eggs and laid an additional unknown number. Since I did not check the box for fear that they would abandon the box, I therefore didn’t realize what she had done until I cleaned out the box at the end of the nesting season. However, I did see two young GCFL and assumed that they had fledged from this box. In 2008, It seemed to me that the male was very insistent that this box be available. Otherwise, why did he keep weep, weep, weeping at me as if to say: check (anthropomorphizing) the box. And why, after I was able to eliminate the Yellow Jacket nest did they immediately take over the box? – Richard Harlow, Milton, VT

More Information:

A bird does not sing because he has an answer. He sings because he has a song.
– Joan Walsh Anglund, A Cup of Sun, 1967


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