Two Nest Boxes, Two Bird Families: Bluebirds and Tree Swallows!

Text and photos © 2015 Adele Wilson, author of Bonding with the Barn Swallows

Yes!  Tree Swallows have claimed the second nest box!  After the original Tree Swallow nest in Box #1 was hijacked by Bluebirds on May 10th, we finally mounted a second box (Box #2) on May 19th. 

A pair of Tree Swallows claimed Box #2 on May 23rd and have now started building a nest inside of it.  The photo to the right shows the female Tree Swallow peeking out of Box #2 and holding straw in her bill, straw that she would be adding to the nest inside the box  The male is to the left, flying away from the box.

Sadly, however, this pair of Tree Swallows does not appear to be the same pair of Tree Swallows who were chased out of Box #1 by the Bluebirds on May 10th.

I felt so sorry for the female Tree Swallow who had been building a nest in Box #1 for 9 full days when she and her mate were chased away by the Bluebirds.  The female Tree Swallow and her mate kept hanging around my yard for several days thereafter, mating on the fence during the mornings.  I knew that the female was ready to lay eggs and hoped and prayed that she would find a place to lay them.

Back to Box #1:  The Bluebirds seem to be doing fine, and the female has laid five eggs!  The female is often inside the box incubating the eggs, but she sometimes takes breaks and leaves the box, especially during warm afternoons.

While the female is inside the box, the male brings her food and feeds her through the box's hole, just as if he is feeding a baby. This is an excellent way for him to practice what he will have to do once the eggs hatch!

A couple of mornings ago, I observed the female Bluebird peeking out of the hole of the nest box.  Soon the male came to the box and fed her through the hole.  To my surprise, when the male flew from the box, the female left the box and flew after him!  I wonder if she was chastising him for not feeding her often enough.

The size of the hole on a Bluebird nest box easily accommodates Tree Swallows as well as Bluebirds.  In geographical regions where both species breed, the two species commonly compete for nest sites. 

It is often recommended to mount nest boxes in pairs, one for Bluebirds and one for Tree Swallows.  The reason for this is that Bluebirds and Tree Swallows can coexist in the same breeding territory as long as they both have boxes in which to nest.  Also, the Tree Swallows can help defend both boxes from predators by swooping at any bird, animal, or even a human, that comes close to the boxes.

A pair of Bluebirds requires a radius of 300 feet for its territory and will chase away any other Bluebirds within that radius.  However, Bluebirds that are already established in a nest will not chase nearby nesting Tree Swallows away.

Tree Swallows defend a territory from other Tree Swallows, but only within a 100-foot radius.  They will tolerate Bluebirds in their territory because the diets of Tree Swallows and Bluebirds differ immensely.

While Bluebirds feed on insects and larvae on the ground, Tree Swallows feed on flying insects.  Thus, there is no competition for food within the same territory.

The photo on the right shows the male Bluebird, who has just captured some food.

The recommendation is to mount the two boxes, one for Bluebirds and the other for Tree Swallows, no more than five to ten feet apart.   We tried to do that, but were unsuccessful.

We were restrained by the parameters specified by Bluebird organizations and also by restrictions from our landlord.  Bluebird specifications dictate that, in order to help guard against predators (and we have plenty of roaming cats around here), a Bluebird box must be mounted on a pole and in an open area, preferably at least 20 feet from a building, fence, or tree.  Our landlord restricted us from being able to mount the boxes in the middle of the lawn.  The reason for the restriction was that this type of location would add complications to the chore of lawn mowing.

We received permission from our landlord to mount a box near the septic tank opening, which is about 25 feet from our building.  So that is where we mounted Box #1 on April 24th.

It took only a week for birds to claim Box #1, but the birds ended up being Tree Swallows rather than Bluebirds.  After Bluebirds hijacked the box from the Tree Swallows only nine days later, we decided that we needed to mount a second nest box, one for the Tree Swallows.  The photo to the left shows the two Bluebirds on Box #1 the day they hijacked the box.  The female Bluebird is peering through the hole to check the inside of the box.  The male on the roof looks like he is jumping for joy at having procured a suitable nest box!

We tried to mount Box #2 about 5 feet from Box #1 where it would have not interfered with lawn mowing.  However, a layer of rock about 6 inches below the surface of the ground prevented the driving of the pole far enough into the soil.

The only option at that point was to mount Box #2 along the horse pasture fence where our landlord had also given us permission.  To mount a nest box along a fence is not an optimal choice because predators can sometimes use a fence to gain access to a nest.  However, this is the only choice our landlord gave us based on avoidance of lawn-mowing complications.

We ended up locating Box #2 between two metal fence poles that are about 4.3 feet high and 8 feet apart.  The box is located 28 feet from a 11-foot high wooden fence post that serves as a lookout tower for several different species of birds.  We are hoping that the fence post is far enough away from Box #2 that a large bird cannot use the post to prey upon the birds using the box.

The photo below, from the morning of May 28th, shows Box #2 on the left, separated from the high fence post by three metal fence poles.

The photo below, from May 20th, the day after we mounted Box #2, shows Box #1 in the foreground on the right, with Box #2 in the background.  The two boxes are about 75 feet apart although in the photo they look closer.  This photo was taken three days before the Tree Swallows arrived and claimed Box #2.  I cannot identify the bird perching on top of Box #2 in the photo, but the Bluebirds from Box #1 are perching on the fence.  The male Bluebird is on the wire at the center of the photo, and the female is on top of the fence pole on the right.

While Box #1 is about 4.3 feet high, we mounted Box #2 a little higher.  The distance from the ground to the lower edge of Box #2 is about 5.3 feet.

The higher a nest box is from the ground, the lesser the chance that House Sparrows will use the box.  This is a matter of great concern because we do have House Sparrows in close proximity, and House Sparrows have been known to enter a nest box and destroy the young of the host species.

The day after we mounted Box #2, I noticed a House Sparrow hovering near the entrance hole of that box and perching on the fence next to the box.  To my delight, the male Bluebird from Box #1 immediately flew to Box #2 and chased the House Sparrow away!

Also to my delight, when the Tree Swallows arrived and began investigating Box #2 on May 23rd, the Bluebirds did not chase them away!  What I had read about Bluebirds and Tree Swallows peacefully nesting near one another had proven true.  To this day, the Tree Swallows are still guarding Box #2, and the Bluebirds have not bothered the Tree Swallows.

The photo below shows Box #2 on the morning of May 24th, just one day after the new pair of Tree Swallows claimed the box.  The male Tree Swallow is perching on the fence pole, while the female is inside the box, peeking out.

Optimally, we should have already had Box #1 mounted by early March when our local Bluebirds start choosing their mates and searching for nest sites.  But we did not get it mounted until April 24th. For one thing, my neighbor was mounting these boxes for me as favor.  For another, it took a great deal of time for us to decide upon a nest box design, plan its location, and gather the parts needed for mounting.  Besides, in early March it was likely that the ground would have been too frozen for driving a pole into the ground.

In early March, no Tree Swallows would have been on the scene.  That is because, while Bluebirds remain in this area all winter long, Tree Swallows are migratory and do not arrive here until early April.  Although Bluebirds tend to be feisty and defensive of their chosen nesting sites, they would not have had any competition from Tree Swallows during March.

If you don't want to miss the news about the hatching of the Bluebird eggs or whether the female Tree Swallow lays eggs in Box #2, you can follow this blog by entering your email address at the top right of this page.

If you have enjoyed these photos, you might want to check out the 117 photos in my book, Bonding with the Barn Swallows.  Many of them show closeups of the baby Barn Swallows that were hatched on my porch during 2011 and 2012.  There are also photos of the parent swallows guarding the nest and feeding their young.  As an extra bonus, the book includes photos of five different juvenile Barn Swallows, just ten days after fledging.  You will be amazed at their varied markings.  The book describes how one special male Barn Swallow communicated to me by his body language on the utility wire and how, only two days later, I discovered what he was trying to tell me.  The book is available at Amazon at:   http://www.amazon.com/gp/product/1494481464/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=1494481464&linkCode=as2&tag=barnswalfrie-20&linkId=5WME3VAHNSX3EXHH

Yes, it was a hijack! Bad news, good news ...

Text and photos © 2015 Adele Wilson, author of Bonding with the Barn Swallows

Bluebird, May 10, 2015

Yes, it was a hijack! The Eastern Bluebird, so charming and friendly to humans, can be quite nasty toward other birds. Eastern Bluebirds can fight ferociously to defend a nest – or even to seize a nest from another bird, as they did in my yard on May 10th. (See my previous post, “The Hijacking of the Nest Box – Who will win?”, at http://barnswallowfriends.blogspot.com/2015/05/the-seizing-of-nest-box-who-will-win.html.)

During this past March (2015), I did not observe as many Bluebirds around here as I had during March 2014.  Why?  There could be several reasons.

Bluebird, Nov. 9, 2014

For one, we had unseasonably wintry weather here during November 2014.  It was extraordinarily cold, and we had two snowfalls that month – quite unusual for this area.

During the winter of 2013 to 2014, each month I would observe at least one Bluebird around my yard.  But this past winter was different.  The Bluebird shown on the left that I saw on November 9, 2014, would be the last Bluebird I would see until March 9, 2015.  On March 9th I sighted a pair of Bluebirds, one at a time, on the wire across the road from where I live.  I did not see any Bluebirds near my yard until March 23rd.

Although our local Bluebirds stay around during the winter, they are unaccustomed to extremely cold weather during the month of November.  As winter approaches, Bluebirds look for warm places to roost during frigid nights.  They often roost either inside the nest boxes they used during the past summer or inside building structures where there are entrance ways into attics or crevices that lead to the undersides of roof beams.  These birds can also roost in pre-existing cavities within large tree trunks, places where they have nested during warmer weather.

However, when it came to finding warm winter roosting spots, I don’t think our Bluebirds had much warning last fall with our sudden frigid temperatures and snow storms.  It is said that one of the worst enemies of the Bluebird is “Jack” – Jack Frost, that is.  With “Jack” descending on us so quickly during late 2014, I think it caught the Bluebirds off guard, and some of them may have perished that month.

Our past winter of 2014 to 2015 was extremely cold, but we did not have the record-breaking amount of snowfall that the Northeastern US received.  Nevertheless, Jack Frost may have played a role in diminishing our Bluebirds’ winter survival rate.

An unusual event began taking place around here in mid January 2015 – one that may well have had a negative impact on our local Bluebirds’ survival.

In mid-January, a contractor hired by our local power company began chopping down trees and branches that were threatening to fall on power lines during high winds and heavy snowfall.  The process was noisy and lasted for several weeks.

If any of those trees contained old woodpecker holes in which Bluebirds were roosting at night, the tree-cutting process could have caused some of our Bluebirds to lose their warm, nocturnal sleeping stations, resulting in the demise of those birds.

I did notice that, when the contractor first began cutting trees, a Pileated Woodpecker began appearing at my suet feeders and continued to do so for many weeks thereafter.  I have wondered if the tree-cutting resulted in the removal of dead tree trunks inside which the Pileated Woodpecker had been finding beetle larvae.  Pileated Woodpeckers are able to feed on that type of larvae during the cold months.  The answer is unclear, but it seemed that SOMETHING had brought that Woodpecker out in the open at exactly that time. 

Female Pileated Woodpecker, morning of Jan. 12, 2015

Since we had so few Bluebirds around this past March, I took that as an imperative to put up a Bluebird nest box.  I began talking to my very mechanical next-door neighbor about it.  Perhaps, if we put up a nest box, a pair of Bluebirds would find it and raise some babies in it, resulting in an increased Bluebird population in our neighborhood during the spring of 2016.

By mid-April I had purchased a Bluebird nest box.  I had already purchased one last October at a craft show, but that one was too heavy to be mounted on a thin pole.  The reason for mounting the box on a pole would be to help guard against predators.

My neighbor was studying the specs for mounting the nest box. We began planning the location of the box in accordance with permission from our landlord and the guidelines for mounting Bluebird boxes.

Tree Swallow on wire

On April 17th, my neighbor and I were standing on our porch, discussing plans for the nest box. I pointed to a Tree Swallow that was perching on the nearby wire and told my neighbor, “That’s what we’ll probably get: Tree Swallows.” I said this because it was well past the beginning of the first brooding season for Bluebirds. Bluebirds can build two or three nests per season, but the first nesting season generally begins in March. By April 17th, our local Bluebirds were probably well underway with their first nests of the season.

I then told my neighbor not to be disappointed because “we might not get a Bluebird.” Just as I said the word “Bluebird”, an uncanny event occurred. A Bluebird landed on the wire right above our driveway! See “Did the Bluebird hear me call its name?” at https://www.facebook.com/notes/adele-barger-wilson/did-the-bluebird-hear-me-call-its-name/10153174426857040. The photo below shows the Bluebird that landed on the wire that moment.

The Bluebird that landed on the wire when I said "Bluebird"

We finally got the nest box mounted on April 24^th.  According to my research, we were far too late to have Bluebirds claim the box for their first nest of the season.  

Tree Swallows claim nest box, May 1, 2015

Just as I had suspected on April 17th, when I had pointed to the Tree Swallow on the wire, we did not get Bluebirds claiming the box. On May 1st a pair of Tree Swallows showed up and began building a nest inside the box that very day.

We were so fortunate to get birds claiming the nest box only one week after we had mounted it!  Although they were not Bluebirds, I was overjoyed!  Tree Swallows eat flying insects, acting as a natural form of pest control.  And we would be helping to increase our local population of this species, a species that I had not begun to observe in this neighborhood until April 2013.

But on May 10^th, the nest was hijacked!  The poor Tree Swallows!  The female was still in the process of building a nest inside the box that morning, when, not just one, but TWO male Bluebirds appeared and fought over the box.  One Bluebird won, and then started fighting the male Tree Swallow for possession of the box.

Sadly for the Tree Swallows, the Bluebird and his mate won.  They began adding to the nest, building its edges up higher.

The magical part of the story is that yes, the Bluebird DID hear me call its name on April 17^th while I was talking to my neighbor on the porch!  Yes, we did get Bluebirds!

Feeling sorry for the Tree Swallows who lost their nest, I convinced my neighbor to put up a second nest box, which he mounted on May 19th. The new nest box was mounted about 75 feet from the first one. It was the best location given the parameters for the mounting of Bluebird boxes and restrictions by my landlord regarding the location of the box.

Immediately, the two Bluebirds who had claimed the first nest box began perching on the second box and investigating it.  Oh no, I thought, will the Bluebirds prevent other birds from using the second box?  The Bluebirds had seized their current box from the Tree Swallows; would they also keep the second box under guard?

Below is a photo, taken May 20th, of the second nest box in the background, with the first nest box in the foreground.  The Bluebirds who were nesting in the first nest box are perching on the fence near the second (more distant) box!  The male Blue bird is on the top fence wire, and the female is on the second fence pole to the right of the second box.  I do not know what type of bird is perching on top of the second box!

So, did any birds end up claiming the second nest box?  And how about the Bluebirds?  Did they continue to use the first box, or did they shift to the second box?  And did any eggs get laid in the first box?  You can follow this blog at the upper right to find out!

I first began having intimate encounters with wild birds when Barn Swallows nested on my porch during 2011 and 2012.  During those encounters, I became convinced that humans and birds can develop meaningful rapports, communicate with each other, and enjoy mutually beneficial relationships.  You can read about how one special Barn Swallow communicated to me in my book Bonding with the Barn Swallows, available at Amazon at:   http://www.amazon.com/gp/product/1494481464/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=1494481464&linkCode=as2&tag=barnswalfrie-20&linkId=5WME3VAHNSX3EXHH