Whoooo's Using Box #18?

The bluebird season is well on its way with numerous chicks ready to fly, if they haven't already by now. A few of the nestboxes have been claimed by chickadees, titmice and, in one box, a tree swallow claimed the same one it used last year. When we peeked in the box, a Canada goose feather wafted out and the swallow chased it down and returned it to its proper place. It didn't like our disturbing the decorating scheme.

One box, in particular, has been a big disappointment this year. We are in the fourth year of the monitoring project, and Box #18 has been the most successful in producing little blues. We believe its location near open areas and a few lampposts for perching places contribute to its success. However early in the season, we found feathers (perhaps a mourning dove) at the base of the support pole. There has been no bluebird activity nearby at all. No blues watching us or singing their lilting calls from the trees. Recently, we found owl pellets around the pole so we're sure the box is doomed and an owl is using it as a hunting base. We're going to relocate that box and hope the bluebirds will take an interest again.

This is the first year that we've had nests with six eggs in them and, in fact, there are two boxes with half-dozens in there. If they all hatch, those parents are going to be very busy catching meals for hungry chicks.

Also this year, we've noted a pair of wood ducks hanging around the duck box on the larger of the two ponds. Although bluebirds are our main responsibility, we do keep a watchful eye for all the birds and always have our binoculars in ready-mode. Seeing the wood ducks near the nestbox was exciting and we hope they have decided to use it. At this point we haven't checked the box for fear of spooking the ducks.

As in past years, some nests have been disturbed and the eggs disappeared. In one case, it was a house wren. Those birds are notorious for destroying bluebird nests and tossing the eggs out of the box. Then they go in and build their stick nests on top of the bluebirds' nests and take over. We also believe that snakes have gotten into at least one box. However, it's all part of nature and we keep that in mind.

So at this point, the season already has had a few surprises and we're always interested in whatever we find when we ride the trail. There's still lots of activity to come.

Who We Are and What We do

There are three of us who are devoted to riding the bluebird trail every week from March through August, or whenever the last nestlings have fledged. We keep detailed records of each of the thirty-three nestboxes. We also are avid birders and spend time looking for and at birds as well as listening and identifying them by song, call, and chips. Every time we go out, there is something exciting for us to talk about with each other. It's pooled knowledge and our friendship has become solid because of it.

Although it is not necessary to have three persons to do our assignment, we like it this way because we have backup if one of us is not available on a particular day. One of us is a retired school teacher, another a retired power plant supervisor, and one is a retired manufacturing factory owner. Together it's an excellent team because of our broad background experiences.

The records that we keep on each box are kept in a large notebook. There is one sheet per box with information to be checked off or written in. The categories include: date, monitors' initials, partial or complete nest, number of eggs, number of chicks, and probable number fledged. The last category is always a guess as we usually don't know for sure that the chicks actually flew. They could have been attacked by predators, but we keep a positive view and count them as having fledged safely.

There are other records kept also such as location of the boxes and how the location affects the probability of box use. As a result of these records, we have moved unused boxes to locations that have resulted in nests in those boxes. We don't have it right yet and we expect to move a few more by the next bluebird season. Our project may not be of great interest to many folks but, to us, it's a fascinating study of the Eastern Bluebirds.

So Who Is Really Living Here?

It’s not that we don’t like House Wrens. We do appreciate the male’s beautiful warbling song that lets us know there’s pride in his chosen nest site. It’s just that he has chosen a nestbox that is supposed to be for the Eastern Bluebird. The bluebird builds a tidy nest, usually with pine needles because of their availability but we’ve seen dried grass used also. However, the House Wren stuffs the box with coarse sticks, cramming them in so tightly that it’s almost impossible to check for eggs. The actual nest cup is deep inside along the back side of the box so we dutifully (and carefully) tilt the nest outward and downward in order to see into it. If there are eggs or chicks, we leave them. However, if it’s the beginning of a nest we remove it but, usually, the next week the wren has been at it again.

Now we have discovered something new – new to us, that is. There are double layer nests in some of the boxes. The House Wren is either an opportunist or is lazy but, then, there may be a fine line of distinction there and could be a subject for musing in a different venue. On the bluebird trail here at the garden, we have several nestboxes in which the bluebirds started building nests but, somehow, the wrens took over. After all, they are feisty little birds. In one there was one bluebird egg already laid and we expected to find a few more eggs the following week. Instead, we found a stick nest built on top of the pine needle nest and the bluebird egg was gone.

We know that House Wrens usually choose boxes that are near woody areas and we thought we had placed them far enough from trees and bushy areas. However, now we know these birds will use boxes that are out in open areas and, in fact, will take over the boxes already being used by the bluebirds.

Wrens are known to destroy bluebird eggs by punching holes in them, but they also will attack chicks in the nest and toss them out. They are a major problem if one is trying to have a successful bluebird trail. Obviously we are distressed when we find these stick nests, but we also know that it’s nature at work. But double layers? Oh, come on!

What's New on the DSBG Bluebird Trail

May has been a busy month for the bluebirds at the Daniel Stowe Botanical Garden.  The first brood of chicks from the nest boxes have fledged their nests and we are now seeing the second brood of the year.  We noted that 8 of the nest boxes have a second brood and we counted a total of 28 eggs in those boxes.  We also have one box with an active house wren nest.

If you are monitoring a bluebird box in your own back yard, do not be alarmed to see that the number of eggs in the second brood is smaller than the first.  This is what we are seeing as well. We do have some smaller broods of just one, two or three eggs.

This year on the bluebird trail we had a slightly rare occurence in one of the nest boxes that we did not observe last year.  During our monitoring of the boxes on April 30th we discovered that one nest box contained white eggs!  The photograph above was taken on that day.  After checking the box we drove a short distance away and waited.  Sure enough a female bluebird flew right into the box. The eggs were also consistent with the size of the blue bluebird eggs that we are noting in the other boxes and the nest was consistent with the other bluebird nests.

According to www.sialis.org, up to 4 to 5 percent of bluebirds lay white eggs.  The Sialis website also indicates that white eggs can occur in all three species of bluebirds and that the white eggs are just as fertile as the blue eggs.  From what I read on this website, a female that lays white eggs will always lay white eggs.  So, if we have blue eggs in the same nest box for the second brood, then another female has now inhabited the box.  It will be interesting in the coming weeks to see if we have white or blue eggs in that same box.

As always, one other good thing about being outside monitoring the bluebird boxes is that it affords us the opportunity to see what new visitors we have flying around the garden.  In addition to the usual suspects we saw a few new species of birds during May that we did not see in April.  We observed the Indigo Bunting, American Goldfinch, Barn Swallow, Red-winged Blackbird, Orchard Oriole, Red-eyed Vireo and the Chimney Swift.

When you pay your next visit to the garden I hope you'll take some time and observe the birds as well as the beautiful plants and flowers.  Please drop us a line if you see a species of bird that you do not normally see so that we can be on the lookout for them as well.  Enjoy the garden and happy birding!

What We Don't Want To See On The Bluebird Trail

There have been a lot of things going on during the past few weeks on the Daniel Stowe Botanical Garden Bluebird Trail.  Just in the past week alone we discovered that 19 bluebirds fledged their nests.  We have at least 6 active nests and we have 4 nest boxes that are active with wasps.  We are definitely having more problems with wasps this year than we did last year.

The picture at the right is a picture of what we don't like to see on our bluebird trail.  This is a House Wren nest.  The Migratory Bird Treaty Act of 1918 protects these little native birds that build these big, clunky nests.  The Act makes it illegal to remove active nests or eggs of the House Wren.  It is acceptable to remove House Wren nests without a nest cup or eggs.  You can see from this picture that it would be very difficult to determine whether or not there is a nest cup or eggs in this box.  So, to be on the safe (and legal) side, it is best to let nature take its course at this stage.  This is what makes regular monitoring so important.  Early detection makes it possible to remove the sticks before a nest cup is established and eggs are laid.

We also discovered one nest box being inhabited by a Tufted Titmouse.  This bird is also protected by the same act so she'll be raising her brood without any interference from us.  The Tufted Titmouse makes downy nests of moss, fur, soft plant fibers and occasionally crumpled leaves.  It is easily distinguishable from the pine needle nests that bluebirds build.  It looks extremely soft and comfortable.  If I were a baby bird I think I'd like this nest quite a lot!

We also had one more visitor to a nest box this week that is also protected by the Migratory Bird Treaty Act.  I noticed two tree swallows flying around one of the nest boxes.  One of the birds landed on the front of the box and held on and sang away at the entry hole.  So, next week the monitoring could be very interesting.  We may just get the opportunity to see what the Tree Swallow's nest looks like as well.

So, do pay a visit to the garden soon.  Sit a spell and see what else is flying around in the air besides wasps, bees and pollen.