This year has been a tough one for MY bluebirds. I use the word MY because I have had bluebirds in one and many years two boxes for as long as we have lived here (since 1997). But this year has been difficult. There was a pair trying to use the box in the backyard in May, but the tree swallows were protective of that box, even though tree swallows don't nest until later and only raise one brood. But apparently they like to stake out a box in advance of their needs. Now I don't evict tree swallows because they are desirable birds also. In the end they didn't even use this box, perhaps because sparrows took over.
My two boxes in front were also commandeered by sparrows. I have faithfully evicted the house sparrows from all three boxes for the last 6 weeks but they just wouldn't give up. I would open the box and scrape out the nest materials and within a few hours the box was full again. So no bluebirds in either of the two boxes in our front yard. Finally the sparrows did give up but now there has been a male wren filling the boxes with sticks. A male wren will fill every box in the area to the brim with sticks and then only use one box when the female joins him. I was out in my "wild" area in my front yard (My husband calls it my jungle.) and I heard and saw the male bluebird just last week, so I knew he was again in the market for a house. This is probably he and his mate's second nesting. Bluebirds will nest 2 to 3 times in a summer raising usually 4-5 young each time. Sometimes that summer's first brood will even help raise the second brood and so on. What was I going to do with the wrens? So I found an old box without a hook on it and just laid it atop my trellis near the bluebird house and just kept emptying the bluebird box of sticks. Finally as I drove out of the drive this morning, I saw a flutter of blue around the blue bird house and the wren was singing from the trellis box and going in and out of it. So maybe I have finally made peace in the bird world in my yard.
I miss the bluebirds when they are not here. They are such gentle birds and I love their soft bubbly call. Both help build the nest. The female incubates the eggs for about 14 days. But the male is ever attentive. He sits watch in a nearby tree, and occasionally brings the female an insect. Every evening at dusk, the male goes to the box hole and checks on the female before he goes to his night roost. Sometimes he will bring her one last insect before he disappears. Both parents feed the hungry young. They are often seen on various of their hunting perches around the area of the box, from which their sharp eyes spot insects on the ground. Then they flutter down and catch the insect and take it to the young. Shortly after we had moved into our new house, there were a couple of 2 X 2 inch stakes in the backyard put there as markers for the landscapers when they finally came to seed our grass. The bluebirds began using those stakes as hunting perches in the middle of the yard. I always said I was going to make a fortune producing these 2 X 2 stakes, paint them blue and print on them in black: Bluebird Hunting Stick. But I never made good on my plans.
Being a bluebird landlord can be demanding. Some years ago we were having a lot of trouble with predation. I lost two females as they were sitting on the eggs; found her feathers on the ground around the nestbox pole one morning. That made me begin to use a 1 1/2 inch extra block of wood with the hole drilled through it on the front of the boxes as a predator guard. I presumed the predator was a raccoon. But over time I found that the bluebirds did not like using the boxes with the wooden predator block on them.
One year we had quite a bit of trauma. I lost a female who had 1 or 2 day old hatchlings in the nest. I watched the nestbox and the male did try to feed the four little ones for a day. But on Saturday morning as I observed, I saw the male with another female at another empty box. He had decided it was more energy efficient and more likely to be successful if he just started over with another mother. I decided to bring the young nestlings into the house and see what I could do. I got on the Internet and learned that I could feed them moistened puppy chow in little pieces and I already had some meal worms on hand which I sometimes use in rainy cold weather to help the parents out. When I brought the little guys in they were so weak that they could barely raise their head and open their mouth. But I was able to get some food into their throat and they rapidly gained strength. I fed them about every half hour to an hour. This went on through the weekend. But on Monday I had to go to work. My husband said, "I'll feed them 4 times while you're at work, but that's the best I can do for you." Well, I knew that was not going to be enough. My assistant at work called a friend who was a certified animal rescuer and she recommended the Wisconsin Humane Society. They have a baby bird room where they rescue just such orphaned birds. When yy husband took them down to the Humane Society and turned them over, those little ones were strong and energetically begging for food with stretched necks and open mouths. I got a postcard from the Humane Society several weeks later that they had fledged my 4 bluebirds successfully.
Meanwhile, back at home I knew I had to do something else for predation prevention. I already had "squirrel" baffles around the poles, but that wasn't stopping the raccoons. Of course the predator could have been a snake or an owl also. Again I went to the Internet. An article there advised to take hardware cloth and make a rectangular tunnel about 4 inches long and staple it to the house around the hole. This should keep all predators out including owls and snakes. So that is what I did for the next couple years. The only problem was that the bluebirds would not choose that box for their nest if the tunnel was on it ahead of time. So I had to wait until the female had laid some eggs. Then I would staple the tunnel onto the house. She had such urgency to get to those eggs that though confused at first, figured out the way in in about half an hour. The male on the other hand with less urgency took about 2 days to figure it out. But he did learn and entered through the tunnel to help feed the young when they had hatched. I did this for about two years. Then we decided to raise the level of the houses and put a squirrel baffle higher about half way up the pole. This might prevent the raccoons from being able to jump over the baffle and ascend the pole. The problem is that sparrows then will try to nest in the box. At 3 feet high, sparrows do not like to nest. Hence this year I am fighting the sparrows. At one point through the years I set aside one box as a sparrow trap and I have also tried a wire live trap for birds, but neither of these worked very well. You really have to keep your eyes on these traps to be successful. And I found that the sparrows often outsmarted me and just avoided these traps. Right now I am depending on the height of the pole and its baffle and hopefully my new bluebird tenants will be safe. As you can see it is a lot of work being a bluebird landlord.
There is a great site that answers lots of questions about nesting bluebirds and competition from other birds, especially wrens and house sparrows. I always liked having house wrens around but I have learned that maybe I have too many from all the years I have hung little houses for them. Now they are taking over the bluebird nest houses also at least with dummy nests. I think next year I will not put out any house wren houses and will evict the sticks from my bluebird houses. Maybe after a year or two the population around here will go down.