nesting season

Heartwood Bluebird Boxes

Last week, we discussed our favorite overall bluebird house, the ATZ Woodcrafters Classic Bluebird box. This week we will go over our more decorative bluebird boxes. Our preferred options are produced by Heartwood and made by hand down in Star, Mississippi. Founded 20 years ago by brothers Jerry and Larry Glass, these two brothers transitioned from building houses for people to wood creations for local craft fairs and at their mother’s suggestion, began building bird houses. Fast forward to today, and their unique but practical bluebird boxes have become a perennial favorite of ours.

We are especially fond of the models shown here for their practicality and versatility. They work well on our three piece pole setup, ($58 with tax) a 4x4 post, fence, or even tree. All open from the front, top down, for ease of monitoring and cleaning between each nesting. With Mother’s Day just a month away, they also make great gifts!

Models shown:

(White: Bluebird Manor, $85)

(Yellow: Bluebird Bright, $85)

(Natural: Bluebird Bunkhouse, $92)

Get Ready for Bluebirds Now

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, or directly back to you in an email.    

Birds are beginning to sing and exhibit other courtship behaviors. The breeding season is fast approaching.  Eastern Bluebirds have already begun searching and competing for mates and potential nest-sites.  If you had planned on replacing an old nest box or moving one to a new location we suggest you do it now. And make it a point to clean out old nests now.  Old nests will not prevent a Bluebird from building a new nest on top, however, the old nest debris is by now decaying and damp and can be a home to insects, like ants, which can be of great harm to hatched chicks.   

Many of you in past weeks have seen multiple Bluebirds land on and look in nest boxes. (See video) In the video you will see classic courtship behaviors like wing fluttering. They may even carry some nest material to the box.  This is not actual nesting but all part of courtship and choosing a nest site which the female will eventually approve. 

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.  Some eager Bluebirds may begin nesting 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 successful nesting.  The most common fallacy we here from people is “I hear they need wide open spaces”.  This is definitely not true.  In fact, a lot of what you hear about the needs of Bluebirds is very much over stated.  Bluebirds adapt very nicely to all kinds of situations including wooded yards.  If Bluebirds needed the “perfect setup” as described by the many articles you find on the internet they would be extinct by now. These perfect nest-sites generally never existed in nature and have only been determined by humans.

In fact, before people started putting out nest-boxes for Bluebirds they nested in natural cavities including ones in trees. Bluebirds are considered a secondary cavity nester which means they will not excavate a nest, like a woodpecker does, but use one that has already been created.  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 an example of Bluebirds’ adaptability.   Offer a couple of nest-boxes in good locations and see what happens.  

 Here are a Few Tips to Choose a Location:

  • Position the nest box adjacent to the most open location available in your yard.  Trees being around or close by are not a deterrent.

  • Bluebirds are typically more sensitive to nesting near 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 about 100 feet away, or out of sight of feeding stations. 

  • You may have heard that nest boxes need to face east.  This is a good strategy to avoid prevailing weather patterns and rain but not at all necessary. My most successful box over the years faces northwest. 

  • 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.  Our pole system for Bluebird boxes will put the box at 5’ high after installation (convenient for monitoring and maintenance) and allows for a baffle if you’ve had a history of raccoon or rat snake predation.  Bluebird boxes can be mounted on fences, and utility poles, and even outbuildings. The National Bluebird Society changed their opinion about tree mounting only a few years ago.   Obviously a tree is a more vulnerable location when considering predators.

  • How many boxes can be offered in a typical yard situation?  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.  In most cases backyard songbirds are too territorial to tolerate nesting close to one another, unless they are colony nesters like Purple Martins.  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.

  • 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. The sooner they know the box is there the more likely they will consider using it this season.

Get busy now and have fun with attracting Bluebirds this spring and summer.

Monitoring Bluebird Boxes

It’s great that so many people are interested in providing nest boxes for Bluebirds, and because of these efforts Bluebird populations are extremely robust. We encounter customers, though, that ask a lot of questions they would have the answer to if they just monitored the nest box a little. We do not mind answering the questions, it’s very much part of the job.

Most of the time when we mention to a customer they should consider monitoring the box their response is “I don’t want to disturb them or scare them away”. If done properly neither of those things will happen. Not only is it interesting and a great nature and biology lesson, you can predict within a day or two when the babies will leave the box. And another reason to monitor is you may actually keep something bad from happening to the babies. I’ve often told customers of the time my son, who I taught to monitor, discovered one of our boxes with four two day old Bluebird babies was infested with ants. In just 48 hours, since the last monitoring, ants had found the newborn babies and were likely going to consume them given enough time.

We carefully removed the babies and placed them in a little box, then removed the entire nest from the box while the female watched from a nearby tree limb. We first cleaned all the ants out of the now empty nestbox and made sure no more would climb the pole. Then we constructed a rather poor replica of the nest using their preferred nest material pine straw. After the nest was back in the box we then removed all the ants from the babies by using a drinking straw to blow the ants off and then placed them back in the box in the clean nest. In all it took us about 20 minutes. The female returned to the box about 10 minutes after we completed the cleaning. Even after removing the nest and handling her babies the female came right back to them because the instinct to raise her young is that powerful. So, monitoring which really just consists of taking a peak for a few seconds will definitely not scare the birds away. Bluebirds tend to be quite tolerant of our presence. Usually they patiently watch as I monitor. Once in a while they will swoop at you clicking their beak in protest. But they will not abandon a nest because of brief looks in the box.

Monitoring Tips

  • Observing from a distance is important monitoring, too. Seeing bluebirds come and go is an indication they are showing an interest in choosing the box. If you see the pair on and in the box take a moment after they leave to go look inside. You will likely observe nest building at some point. Pine straw and fine dry grasses are the preferred nest material.

  • Bluebirds tend to lay eggs in the morning hours. The female will lay one per day until done, usually between three and six. Four and five eggs seem to be the most common numbers. She will not begin incubating until all the eggs are laid. So, at this stage I would recommend monitoring in the afternoon so as not to disturb egg laying in the morning. Or, again, if you see the female exit the box take a moment to go look. Take notes. It’s helpful to increasing your knowledge of the process.

  • When I monitor and see 4 eggs and she is not incubating yet that tells me she has probably one egg to go. I will make note of the date because we know Bluebirds incubate for 12-14 days and then should see babies.

  • Once I am certain she is incubating I do more monitoring from a distance. If you see the female exit the box and fly off that’s a perfect time to approach and take a look. Be gentle and quiet. I like a box that has a door that opens down as opposed to up. It is so much easier to monitor in a subtle way. I also take pictures to share with people.

Eggs laid before incubation.

Fledglings days after hatching.

Fledglings about a week after hatching.

  • Now the babies have hatched and I’ve noted the date because we know the babies will take about 14 days to develop and be ready to leave the box. This is known as the fledgling period.

  • I will monitor daily until by my calculations tell me there are just 2 or 3 days to go until they fledge. At this stage of their development the babies may be fearful enough to want to get out of the box if you open it. I monitor from a distance watching the parents as they make repeated trips with food to satisfy all those appetites.

  • Hopefully, the calculations are right and you may get a chance to see babies fledge. You will see more animated behavior from the parents as the first and second babies are about to come out for their first flight. Do not be alarmed if all the babies don’t fledge at the same time. It may take several hours for all to fledge.

For more information about Bluebirds and monitoring please visit the National Bluebird Society website. http://www.nabluebirdsociety.org/bluebirdfacts.htm


Wood Thrush Notes

Yellow Cardinal in TN

A backyard feeding station in Harriman, TN, in Roane County has quite an unusual visitor.  They have a yellow Cardinal visiting on a regular basis.  Yellow Northern Cardinals have been seen in at least 4 different states the last ten years but remain a rarity.  What causes a bird that is normally red to be yellow?  Basically, the red, orange, and yellow colors in birds’ feathers are created with carotenoid pigments derived from the foods they eat. In the male Northern Cardinal, yellow pigments from the diet apparently are converted to red by a specific enzyme. In a very rare genetic mutation, probably affecting fewer than one in a million cardinals, that enzyme is lacking, so the conversion to red doesn’t occur and the feathers are bright yellow instead. 

Get Ready Now for Nesting Season

Just two weeks from now we will say hello to February, perhaps our coldest and potentially snowiest month.  But you can always count on a few days that warm to the 60’s and suddenly bird activity ramps up.  Some birds will begin singing and some, like the Carolina wren, may actually begin nest building. 

The Carolina wren, as you have probably seen, chooses some pretty odd locations to build a nest and often times in  places humans find annoying, like in a gas grill, or canoe, for example.  They often choose locations like covered porches, garages, and garden sheds.  Every spring we receive several calls from people who suddenly find themselves with a bird nest full of babies in a troublesome location.  If you have experienced this scenario get ahead of the game and block access to these locations as soon as possible. 

And now is a very good time to review the nest box successes and failures you had last year and make adjustments if necessary.  If a nest box has been in the same location a couple of years with no activity go ahead and try a new location.  Move it soon.

Clean out old nests now if you haven’t already before birds begin new nest building.  Of course, birds will build on top of old nests but that can be a problem as insects like ants will find the old decaying nest attractive.  I have saved baby birds from certain death as the ants were beginning to eat them alive.

If you’ve never offered a Bluebird box consider putting one up in the month of February.  Even though the majority of Bluebirds won’t begin nesting until April they will do a lot of surveying of potential places to nest Feb. thru March.

National Bird feeding Month and the GBBC

February is National Bird Feeding Month and the Great Backyard Bird Count.  Many of you look forward to the count and sharing your data to help bird experts better understand the distribution and relative numbers of the different species of feeder birds. More info on the GBBC next week

Visit www.birdcount.org for more info on the GBBC.

Goldfinches Beginning to Nest

While many of our most familiar backyard birds are near the end, or have already concluded, their breeding season, for the American Goldfinch it is just beginning.  Many of you have already seen a reduction in goldfinch numbers at your feeders as they begin to move away from feeders toward nesting areas. Goldfinches typically nest in June and July when certain nest materials, and more of their food sources, become available. 

The goldfinch’s main natural habitats are weedy fields and floodplains, where plants such as thistles and asters are common.  So, if you live close to one of these types of areas you may continue to see good numbers of goldfinches at your feeders.  If you live in a more forested area you will likely see far less goldfinches until they finish nesting.  So, don’t be concerned that something has happened to “your” goldfinches or you’ve done something wrong. They are simply transitioning into their nesting phase and will return to feeders in due time. 

The male and female locate a suitable nest site together. Nests are often near water.  At Hidden Lakes Park on McCrory Ln, which borders the Harpeth River, goldfinch nests are common to see.

The male may bring nest materials but the female builds the nest, usually in a shrub or sapling in a fairly open setting rather than in forest interior. The nest is often built high in a shrub, where two or three vertical branches join; usually shaded by clusters of leaves from above, but often open and visible from below. 

The nest is an open cup of rootlets and plant fibers lined with plant down, woven so tightly that it can hold water. The female bonds the foundation to supporting branches using spider silk, and makes a downy lining often using the fluffy “pappus” material taken from the same types of seedheads that goldfinches feed on. It takes the female about 6 days to build the nest. The finished nest is about 3 inches across on the outside and 2-4.5 inches high.

The female incubates about 95% of the time and takes 10-12 days. The male brings food to the female while she incubates.  The young leave the nest after 11-17 days. Both sexes tend to the young and are fed a regurgitated milky seed pulp.  Insects are rarely part of their diet.

Goldfinches are monogamous per year but commonly change mates between years.