Eastern Bluebird

Basics of monitoring Bluebird and other birds nest boxes

Female & male bluebird building nest.

Female & male bluebird building nest.

Female Eastern Bluebird.


The Wood Thrush Shop encourages people to be a little more involved during the period of time a bluebird, chickadee, or some other native bird, is raising their young in a provided nest box. Certainly, these birds are capable of doing all the important work themselves, but by monitoring you will be treated to a very interesting and amazing process. You may even be able to help them should a problem arise, like an ant infestation.
What is monitoring? Monitoring a nest box may include regular observation from nearby, and periodically opening the box, just enough to take a peek to see what phase of the process the nesting birds are in. Monitoring for me means doing a little of both.


Early Monitoring

· Look for signs of interest from birds. Regular daily appearances? Are they bringing nest material to the box, going in, or just perching on it for periods of time?
· Do you see competition for the nest box among different birds? You may see some territorial bouts, or some courtship behavior.
· Just observe a little each day.

Let’s jump ahead and say a pair of bluebirds has indeed chosen your nest box. Congratulations! Now how do you monitor?

· You’ve seen considerable activity by a pair of bluebirds at the nest box. When the Bluebirds are not present open the box and take a good look. What kind of nest material is being used? Bluebirds will most often use pine straw or fine dry grass. A nest may take hours or longer than a week to complete.
· Now you will be looking for that first egg. Bluebirds will typically lay between 3-6 eggs. When the nest appears to be complete it is recommended you begin looking in the nest box in the afternoons or evenings. Why? Because Bluebirds and other songbirds tend to lay eggs during early morning hours. You wouldn’t want to disrupt egg laying. Not that a bluebird would abandon the nest site because of one disruption but repeatedly could be cause. They will lay one egg per day until complete.
· Only after the female has laid the last egg will she begin incubating. Let’s say on the 4th day of monitoring the box you see a fourth egg. I would recommend you do not look on the 5th day in case 4 is where she stopped and is already incubating. Now is the time that I usually refrain from looking in the box unless I have witnessed her leaving the box temporarily to get some food and to stretch. Take note of how many eggs there are and their color. Bluebirds usually lay blue eggs, but sometimes they are white. I continue to observe from a distance, or a walk by close enough to be able to see something that might be of concern.

Bluebirds usually lay four to six eggs. They can range anywhere from off white to light blue to this bright turquoise.

Bluebird nests mainly consist of dried grasses. Dried pine needles are seen often too.


When you are certain the last egg was laid on a particular day, or the next, mark on your calendar, or smart phone, “14 days until hatching”. The female will incubate between 12 and 14 days at which point the babies will begin to hatch. Again, afternoons will be a better time to open the box to monitor. With cool nights and mornings the female will still be sitting with the chicks keeping them warm.
The Fledgling Period
For the next 15 to 18 days the baby bluebirds will be going through tremendous change. Again mark on your calendar the approximate day they will fledge from the box. Just 15-18 days after hatching! Daily brief looks in the box is fine. You may choose to look every two or three days.
 

Just hatched Bluebirds.

Starting to grow feathers. 5-7 days in.

Starting to grow feathers. 5-7 days in.

Almost ready to fledge. 14-16 days in.

Almost ready to fledge. 14-16 days in.

· You will see naked baby birds with eyes close during the first days. Near the end of the first week they will increase in size and begin developing their first feathers.
· By the 9th or tenth day they will be feathered but the feathers continue developing. By this time the babies will have more than three quarters of their final body weight. You may be able to determine the sex of the babies based on color of wing feathers. Those of the male will be bright blue, while females a pale gray-blue.
· At around the 12th or 13th day the babies are quite active in the nest and you may see signs of heads poking out of the entrance hole getting a look at the world. It is at this time we recommend not opening the box to look at them.They may be developed enough to leave the box if frightened.
· Keep observing from nearby and look for increased visits from the adults feeding young.
· In another couple of days babies will be ready to leave the box. Usually it takes a couple of hours for all the babies to finally leave where they will remain in a loose group, staying hidden in trees while the adults continue to tend to their feeding needs.

Congratulations, you have successfully monitored your Bluebird box. Now pull out the used nest material and be prepared for the next pair of birds to come along to begin nesting.

Feeding Bluebirds

Everybody would like to attract Bluebirds. The fact is it is not difficult to attract Bluebirds and the single best way to do that is with a couple of nest boxes placed in good locations as we pointed out in previous blogs. (Click here for tips on bluebird box placement.) We want to help you attract Bluebirds and enjoy the entire experience from courtship to nest building, egg laying to chick development, and finally fledging.

Besides the nest boxes planting native berry producing trees and shrubs, like Dogwood and Beautyberry, for example, having a consistent source of water, and offering an appealing food source like live mealworms are things that will help. Eastern Bluebirds feed primarily on insects and berries, so feeding them is very different than the way we feed other birds. At The Wood Thrush Shop we have a great deal of experience feeding Bluebirds and would like to pass on our tips and tricks to help you have success and enjoy the activity as much as we do. We really don’t think presenting mealworms before Bluebirds are seen is a good strategy. In other words it is not likely to attract them. All you are doing is presenting this very desirable food source to a lot of other birds.

The best time to begin offering live mealworms is when Bluebirds begin consistently checking out a nest-box. Their need for nest boxes takes precedence during the breeding season and will bring them to your yard more predictably and reliably, and potentially for several months. Feeding them then becomes a lot easier after they have found a nest-box.

Seeing Bluebirds perched on top of the box and carrying nest material is a great time to offer mealworms.

Seeing Bluebirds perched on top of the box and carrying nest material is a great time to offer mealworms.

Bluebirds will often cling to the front of the box and look in when interested in a nesting sight.

Bluebirds will often cling to the front of the box and look in when interested in a nesting sight.

Once you see Bluebirds showing interest in a nest box be prepared to offer mealworms. The type of feeder to use is really not very important. My choice of feeder is a small clay dish which is placed on a large rock which is easily seen from the top of the nest-box, just a few feet away. Platform type feeders tend to work very well, too.

Look for an opportunity to walk out to the feeder and offer a small amount of worms, maybe a dozen. THIS IS IMPORTANT! The key is to make sure the Bluebirds are there to see you make the offering.

After placing the worms in the feeder walk away and watch. In most cases you will have immediate success. They fly right down to the dish and gobble them up. I like to repeat this after they consume the first offering just to reinforce the process. I repeat this little scene every time the opportunity arises over the course of the next few days or weeks. Usually 4 or 5 times is enough for the Bluebirds to catch on to what you are doing. If during that first offering they fly away do not leave the mealworms there. The longer the worms are there the greater the likelihood that other birds, like Robins, Mockingbirds, or Starlings see them. If these birds catch on to this offering feeding the Bluebirds will then become almost impossible, not to mention possibly creating enough conflict the Bluebirds may look elsewhere to nest.

Both Mockingbirds and Robins share the same food preferences as Bluebirds and being bigger birds will vigorously defend a food source like mealworms. If you slip up and allow larger more aggressive birds to compete for the worms we suggest a reset. Stop putting out worms for a week or two and begin the process again. Better to be patient than to create an adverse situation.

So, keep the offerings minimal until the Bluebirds really catch on. Then you can increase the amounts of mealworms being offered as they raise their young. Soon they will be anticipating the offering, or even seeking you out in your yard as I’ve experienced in the past.TIPS For Feeding Bluebirds:

  • Offering mealworms when Bluebirds are not present is a sure way to feed a lot of other birds. Wait until you see them before offering.

  • If birds that you do not want are getting the mealworms suspend offering the mealworms for a few days or more and start over using the suggestions we’ve outlined.

  • Bluebirds may partake of other foods like dried mealworms, suet, Bluebird nuggets (a type of suet), raisins, blueberries, chopped apple and grape. Experiment and let us know your results.

  • Location is important. Don’t try to feed them near birdfeeders or a place that gets a lot of bird traffic. Feeding them close to their chosen nest box is easiest but do make sure you don’t let other birds in on the mealworms treat. Some birds may become territorial over the food source and create conflict at the Bluebird box.

  • Some people employ the method of making a sound, like whistling, while they offer the worms. Bluebirds will key in on the sound and associate that with the treat about to be given them. Its simple conditioning. I’m convinced that the Bluebirds we fed behind the store one year became familiar with the sound and sight of my truck arriving in the morning. As soon as I would get out of the truck they would be landing on nearby perches waiting for me to enter the store and bring out worms.

Remember, Bluebirds will not become dependent on the mealworms but will simply take advantage while they are offered. You can suspend feeding Bluebirds any time and not worry that they will be adversely affected.

Domed feeders can be adjusted to help discourage larger birds.

Domed feeders can be adjusted to help discourage larger birds.

Bluebird feeders can be any small dish or tray. however I would not put this many mealworms out at one time.

Bluebird feeders can be any small dish or tray. however I would not put this many mealworms out at one time.

Barrier type feeders will limit the size of bird that can feed. These feeders may take longer to train your birds to use.

Barrier type feeders will limit the size of bird that can feed. These feeders may take longer to train your birds to use.

……Next week Spring visitors are coming! We will outline some of the more notable feeder birds you may see.

House Wren Competition

After our blog about “dealing with predators and problems” appeared last week we received a couple of comments about House Wrens (HW). One comment referred to the HW as a predator. Technically the HW is not a predator but a competitor, and has been known to pierce eggs and even kill baby birds in the nest box. They also have the unique behavior of filling up several available boxes with their nest material with no intention of using those nests. These are known as “dummy nests”. This is an interesting dilemma because the HW is a native songbird and must be treated as such.

House Wren

House Wren

Carolina Wren

Carolina Wren

The House Wren is not a year round species, like the Carolina Wren, and tends to first appear in this area around mid-April. They are fairly common but many of you will never see one in your yard. In 28 years at my home I have never included the House Wren on my “yard bird” list.

House Wren nest is comprised of course sticks.

HW’s use almost exclusively sticks for nest building so when monitoring your nest boxes this is an easily identified nest. Any advice we can offer to help keep HW’s from doing what they do may “backfire”. Offering more choices of nest boxes can alleviate “pressure” on the one or two already present but may encourage more HW activity. Spending a little time monitoring your boxes can help. For instance, if you find sticks in a nest box where Bluebirds have been building a nest you may remove the sticks. Don’t just drop them on the ground because HW’s will just retrieve them and put them back. Or as we suggest with House Sparrows plug the entrance hole to a box for a while if you see HW activity.

Wren guard diagram.

Bluebird using box with wren guard.

An interesting strategy to try if you have experienced HW issues is the wren guard. The wren guard disguises the entrance hole. (Click here for a more in depth look at the wren guard). The wren guard is best used after a Chickadee or Bluebird, for example, have already fully committed to a nest by laying eggs.

It’s good to remember competition among birds for nest sites can reveal some difficult things about nature.

We hope this helps some of you and next week we will spend a little more time on monitoring Bluebird boxes. Please keep the questions coming. We enjoy being able to address things you want to learn about backyard birds.

Attracting Bluebirds: Dealing with Predators and Problems

Last week we invited you to ask questions you may have about Bluebirds, or any backyard bird subject. Trish Bolian asked us to show the difference in a Bluebird nest and a House Sparrow nest. And because Chickadees often use nest boxes we will show the 3 nest comparison. Thanks, Ms. Bolian.

Eastern Bluebird

House Sparrow

Carolina Chickadee


Unfortunately for nesting birds here in mid-TN there are a number of predators and pests that can deter, disrupt, or destroy an attempt to nest. It’s no different for Bluebirds.

The most common problems are the House Sparrow, Raccoons, and Rat snakes.

Male House sparrow

Female House sparrow

The House Sparrow is perhaps the most common and frustrating to deal with. This introduced tenacious species is particularly noticeable in spring when the nesting season kicks in to high gear. You see them busily building nests in some of the most unlikely places, car washes, in traffic lights, gaps in broken store signs, Home Depot rafters, and in gaps or openings in just about any fast food restaurant. They may suddenly appear in yards and show interest in a nest box. Their nest is course, sloppy, and may contain debris like candy wrappers, cigarette butts, feathers, and odds and ends. These birds are highly motivated and typically get started in early March. House Sparrows have been known to pierce bluebird eggs and/or physically remove them from the nest. And in many cases they will fight the adult Bluebirds, sometimes putting so much pressure on them they decide to abandon. We have seen examples of adult Bluebirds being killed by these violent confrontations. So, what can be done? There are both passive and aggressive techniques that can be employed. The one you choose may depend on your level of past experience with House Sparrows. And we encourage you to under no circumstances allow a House Sparrow to use any of your nest boxes.

Ø If House Sparrows (HSP) begin showing interest in your Bluebird (BB) box by landing on and entering act quickly and plug the entrance hole to deny further access. Given a few days or a week of denied access the House Sparrows may become extremely eager to nest and look elsewhere. Repeat the process if they show up again. We see little evidence of BB nesting in early March but more likely early to mid-April. Be patient. Even if the BB shows up and looks at the box resist the temptation to unplug it, especially if the Sparrows have recently been there. After a few days of not seeing the HSP unplug the box and monitor for possible return. Be more patient than them and you just may win the battle.

Ø You may also pull out HSP nests and destroy eggs. Again, if this does not fit your philosophy at least plug up the box. Just don’t let them have it.

Ø We have two different Sparrow traps that can be effective. The Van Ert Sparrow trap is one that mounts inside the box and has a spring loaded mechanism that releases a door quickly closing the entrance hole thus trapping the bird inside. Pros and cons: this is a trap you should be monitoring frequently. It is best used if Bluebirds have not been present, only Sparrows. It is perfect for catching a Sparrow that has already begun nest building. After installing the trap use the Sparrows nest material taken from the box and drop it on the ground below the box. Sparrows will almost certainly go to that nest material and attempt to put it back in the box. Perfect. They go in trip the mechanism and will be caught as indicated by the bright orange marker displayed in the entrance hole. Just releasing them will put you back to square one. Relocating probably requires up to 10 miles. Relocating is not recommended and technically violates laws on transporting wildlife. The other option is to dispose of the bird. This is a touchy subject and one to be considered and decided by the individual. House Sparrows have been heavily factored into the beginning of the decline of Bluebirds many years ago. They are an introduced, non-native species therefore unprotected by law.

Magic Halo

Magic Halo

Sparrow Spooker

Sparrow Spooker

Ø Contraptions like the Magic Halo works quite well although we’ve seen HSP’s totally disregard it at times. The only place I’ve seen the Magic Halo available is on Amazon. The problem with the Halo is it is difficult to adapt to a bluebird box. For some reason it was made more with intent to keep Sparrows off bird feeders. The basic idea of the Halo is to create a vertical column of monofilament (fishing line) around the box. These are relatively easy to construct and one can use materials around the house to improvise. HSP’s are visibly bothered by the contraption and are reluctant to land on the box or go to the entrance, but not Bluebirds. Another contraption you may see is called the Sparrow Spooker. I am less confident in this one because I have no practical experience with it. Anything is worth a try when it comes to discouraging HSP’s. For more information about discouraging HSP’s visit the North American Bluebird Societies (NABS) website at www.nabluebirdsociety.org and Click here to visit their page on House Sparrow control.

Above all before taking action please positively identify the bird going into your nest box. Be sure it is a House Sparrow. Any other native species should be welcomed and have a chance to use the box.

Click on the picture to read more on raccoons from Tennessee watchable wildlife.

Click on the picture to read more on raccoons from Tennessee watchable wildlife.

Click on the picture to read more on rat snakes from Tennessee watchable wildlife.

Click on the picture to read more on rat snakes from Tennessee watchable wildlife.

Raccoons and Rat snakes are formidable predators and can be dealt with in much the same way. Raccoons are intelligent and great climbers, and Rat snakes are supreme climbers. Not all of us presenting Bluebird boxes will encounter these two but if you experience regular and on-going visits from Raccoons at your bird feeders we would encourage you to employ a Raccoon baffle on a pole to protect your Bluebird box. We carry baffles that will fit a metal pole up to 1 ¾” diameter, and wood posts up to 3 5/8” (todays 4x4). It should be noted a squirrel baffle may or may not stop either one of these predators. YouTube is loaded with videos of raccoons negotiating around a squirrel baffle.

Box placement has proven to be a factor, too. My 10 box Bluebird trail in a field has had no predation by Raccoons in many years of service. Boxes placed more in field and meadow situations tend to see less raccoon activity. Boxes placed adjacent to woodland and stream environments tend to see more. In this situation placing a nest box on a tree is not advised. This goes for rat snakes, too. A good raccoon baffle should stop both raccoons and rat snakes the vast majority of the time. For do it yourselfers you may want to check out the National Bluebird Society website for plans on PVC baffles and other critter stopping hardware and tips. Click here for NABS Predator control page.

Cats account for the majority of damage to bird populations in general. If you have a cat that is mostly outdoors and does a lot of hunting please reconsider this practice, but also we would recommend not having birdhouses or feeders until such time that you no longer have a cat. No guard or baffle stops a cat and most of the time a cat is waiting for its prey on the ground. Bluebirds are primarily ground feeders and become an easy target.

We can’t protect Bluebirds from every possible dangerous scenario in nature but it’s been through efforts of homeowner and Bluebird organizations that Bluebird numbers are strong today. Through a thoughtful and common sense approach to placement of boxes, observation, and monitoring we can continue to help Bluebirds thrive and enjoy being a part of the process and their success. As always we are available for on sight consultations and in-store recommendations.

Get Ready for Bluebirds

In the coming weeks we will be sharing information about Bluebirds. We would like to address specific questions and concerns you may have that can then be shared with everyone. If you have questions regarding Bluebirds please email us at thewoodthrushshop@gmail.com and we’ll provide answers in our weekly blog.

Have you been watching and listening? Birds are singing and going through some of the motions of courtship. The breeding season is fast approaching. Its evident Eastern Bluebirds have already begun searching and competing for mates and potential nest-sites. Several times in the past few weeks I’ve seen multiple Bluebirds land on and look in the nest boxes around my yard. (See video) In the video you will see classic courtship behaviors like wing fluttering.

Although most Bluebirds won’t begin their first nesting until early to mid-April, their search for nest sites will typically intensify in the last weeks of February and into March. A few eager Bluebirds may get on nest as early as mid-March.

You may think you don’t have the right situation for Bluebirds because you’ve heard they have very specific needs for a nest-box location. Not true. Most things you hear about what Bluebirds need are very much over stated. Bluebirds adapt very nicely to all kinds of yard situations. If Bluebirds needed the “perfect setup” as described by the many articles you may read about them they would be extinct by now. These perfect nest-sites generally never existed in nature.

natural bb nest.jpg
IMG_3692-009.jpg

In fact it’s interesting to consider where Bluebirds nested before people started putting out nest-boxes. Bluebirds are considered a secondary cavity nester which means they will not excavate a nest, like a woodpecker, but use one that has been created already. Once upon a time secondary cavities were in great supply but through habitat loss and competition Bluebirds were “forced” to adapt to birdhouses, or what we refer to as nest-boxes. Using nest-boxes is example of Bluebirds adaptability. Offer a couple of nest-boxes in good locations and see what happens. If you already have nest boxes now is a good time to make sure they are cleaned out and free of old debris left over from last year’s nesting’s.

Here are a Few Tips on Choosing a Location:

Ø An open lawn area may be preferable but not absolutely necessary. Choose the most open location available in your yard even if it means there will be a little more human traffic.

Ø Bluebirds are typically more sensitive to a lot of bird traffic, so it’s not recommended nest boxes be placed near bird feeders. What’s a comfortable distance? It’s impossible to be exact but we would suggest 50 to 100 feet away, or out of sight of feeding stations.

Ø You may have heard that nest boxes need to face east. While this may be helpful to keep wet weather from being a detrimental factor this is not something Bluebirds require.

Ø A Bluebird box does not need to be on a pole. The advantage of a pole is it allows you to position the box in the location you determine to be the best. Bluebird boxes can be mounted to trees, fences, and utility poles. A height of 4’ or 5’ is sufficient. Our pole system for Bluebird boxes will put the box at 5’ after installation.

Ø How many boxes can be offered in a typical yard situation? So, there is no harm in offering lots of nest boxes (birdhouses) in your yard but do not expect them to all get used at the same time especially if they are close in proximity to one another. For instance, two nest boxes within 25 feet of one another are not likely to be occupied simultaneously. Birds are too territorial to accept this situation unless they are colony nesters like Purple Martins and Cliff Swallows. But feel free to decorate your yard with lots of birdhouses if that’s your thing. Offering multiple nest-boxes is great and it does lessen the competition for a single box but do consider the nature of the species you are trying to attract and what kind of setting would be most appealing.

Ø We are often asked “when is a good time to put up a bluebird box”? Every day is good. However, it is a great time to do so in the next few weeks because the breeding season is fast approaching. The sooner they know the box is there the more likely they will consider using it this season.

And PLEASE, PLEASE, PLEASE remember do not let your desire to attract Bluebirds cause you to clean out other songbird’s nests like Chickadees, Wrens, Tufted Titmice, or White-breasted Nuthatch. In no way does cleaning out these birds nests ensure you will get Bluebirds. Chickadees typically nest earlier than Bluebirds and only once. So PLEASE let the Chickadees have the box if they have begun to nest.

Bluebirds will nest up to 3 times per season and have plenty of time. Even if you do not get Bluebirds during the first nesting there is still time for two more. Besides, if a Bluebird wanted the nest-box it would easily out-compete a Chickadee. Enjoy the fact that you’ve attracted a native songbird to your nest-box and watch the process. It’s a lot of fun.