Monday, January 10, 2011

Birds in Review Part V Nesting in Boxes Harmony and Tragedy

Eastern Bluebirds become as anxious and excited for Spring's return as we do. These hardy birds never travel far away during the winter months and will inspect the bird houses beginning in February, choosing the one that most suits their needs. They are very particular but this quaint house has been approved and the seal of approval is seen in the male bird's manner of waving its right wing. If the female agrees, there will be much coming and going in the coming weeks. Once winter has truly retreated, perhaps in March . . . before the leaves are out, before migrating birds have returned, female Bluebirds will be hard at work building their nests. This post is presented so that you may simply scroll through the photos to see the Bluebirds in action as they bring life to the nestbox and garden. The female will start with dried stems and pine needles and later line the nest with softer grasses and sometimes feathers. The male acts mostly as overseer standing guard and defending their home from other birds. From time to time he will go inside to observe how the work is progressing. It is magical to be working in the garden observing their process. Their determination, frolicking, sweet calls and musical songs add an amusing and very satisfying element to the gardening experience.

A male Bluebird is more watchful as green returns to the landscape. Tree Swallows return too, as the days grow longer and there are more active flying insects. They will challenge the Bluebirds for the nestbox, for their south facing and open location is much desired. There is usually a bit of a tussle . . . flurried flight, diving and confrontations on the ground and in the air . . .  with one or more pairs of Tree Swallows. In the end they always settle down and the Tree Swallows go to claim one of the other birdhouses. Tree Swallows and Bluebirds, for many years now, have lived and raised their young as peaceful neighbors here at Flower Hill Farm. If you do not have the space for several nestboxes, and you want to encourage Bluebirds, you might want to place two birdhouses within a few feet of each other. Tree Swallows will raise one brood, while the Bluebirds rear two or three. 

Tree Swallows touch my heart in a special way. Their fluid flight and gurgling song fills the sky as the fresh new greens unfurl and they sail through the air eating countless biting insects. Once a male finds a house and attracts a female they take their time in getting to know one another before building the nest. Often the pair would have raised young together the previous year. They never seem to be in a hurry in any case and will leave their chosen birdhouse for hours each day while feeding. In time the female will begin collecting pine needles and soft dried stems to construct their nest. Both male and female will gather feathers for the final cup. Tree Swallows will compete with other Tree Swallows for housing too. All becomes tranquil, however, when the birds have claimed a house and are content with one another. 

Here is rather unusual coloring for a Tree Swallow. In all my twenty years of observing these birds I have never seen a taupe one. This pair is in the north field, while the other Tree Swallows reside happily in the south field. The Bluebirds are content with the middle garden.  

The female will land and gather dried material then fly back to her house.

Soon after tenderly mating, four to seven white eggs will be laid . . . one per day. Continued copulation might occur to guarantee the chosen male's genes are passed on. Other males may try to copulate with this female too. She can refuse by leaving her tail up but she may feel the other male is a better specimen. She will have choosen her original mate for the house he offers her. In this case I believe these two have raised young here before and thus having had success will be true to one another.

These sweet moment of contentment and security will be shattered soon. It will not be other Tree Swallows or Bluebirds that disturb or threatened their parenting prowess but a tiny fiery House Wren!

House Wren on Elderberries eyeing a Chickadees nest!

Once this little guy arrives . . . all the peace and joy in the garden is shattered. Any bird nesting in a cavity within and around the gardens will have to be on constant watch. The House Wren is beloved by many, but not this gardener, who has witnessed too many times the willful destruction of this bird. Frankly I am not sure if this is a male or female, but what I am certain of is that these birds have cracked Tree Swallow, Chickadee, and Phoebe eggs and worst killed baby Bluebirds. I believe they also killed baby Chickadees. I once welcomed the bubbly song of the House Wren, until I watched with horror how it managed to destroy every other birds hope of rearing young at Flower Hill Farm. I acted quickly, when I understood and now the bird is banished from this land. At least from nesting here, for it can nest at a neighbors and continue to feed here . . . I cannot keep it out. Last year the Bluebirds finally gave up and left, after the Wren stuffed sticks into their nestbox. I would take the sticks out but the wren is so resolved he will not give up. It was in 2008 that a House Wren actually killed six baby Bluebirds and was building a stick nest on top of them. Imagine!

I had noticed the Bluebirds fighting with the House Wren after seeing the latter flying out of their box. I opened the box and saw the tiny bodies of the babies, who had been thriving before, now dead and then to have the sticks just laid on top of them. I felt so low . . . for I had failed them too. They would have been tossed out I suppose but for their being too big for the House Wren to manage. I took photographs of the nest but cannot find them right now. Seeing those helpless baby birds and the despair of the parents . . . and yes it did seem like despair . . .  broke my heart. The parents kept coming to the nestbox until I finally saw them fly away . . . over treetops and beyond. The following year I was more steadfast and there was a happy brood living here.

Tree Swallows were not to return for two years. I had not noticed until too late in 2008 . . .  the House Wren going into their house and cracking their eggs. I saw a Wren throwing the eggs out of the box and then . . . opened it to find the others cracked. I found this in two Tree Swallow houses. 
That year I also watched and could do nothing as the House Wren went into a small cavity in the barn, where the Chickadees had been caring for their young. The hole was too high for me to reach without a ladder. The House Wren was carrying sticks and filling the hole. This would be what is called a 'dummy nest', for they will fill any box or cavity within their desired territory. (Mind that the other birds had been here long before the House Wren showed up!) I could not see inside, but I had observed as both male and female Chickadee brought tiny insects in and out of the nest cavity that spring. They had become very distraught by what appeared the murder of their babies too. I cannot prove this, as I did not see the babies but they did eventually stop returning to the hole. I believe they made another nest and must have been successful. Last year they returned to the cavity and did raise two or more little ones. 
The oddest thing was that a Phoebe had a similar fate the same year. I guess it was just too near the cavity in the barn and so the Wren destroyed their eggs too. I did not understand why the House Wren would care about a mud nest on the ledge of the barn. There were many very unhappy birds here that year. I am diligent about removing the early sticks of the House Wren now, but it is an ongoing contest, for he will continue to bring them back for weeks! The male will fill every cavity within it's territory, while the female will only choose one to lay her eggs in. House Wrens are songbirds and protected by federal laws. Incredulous to me, but we are not allowed to take a nest apart if they have placed a spider egg sac within the nest. I am sure to take out twigs far before that stage. It is not fun to go out into the garden and be cursed by this little bird. I wish it were not such a terrorist and I would gladly provide more housing for it. As it is . . . I always have an empty house in the south field. Alas, its social skills are very lacking. I am sure there will be some who think I am interfering with nature. I am indeed . . . for it is I who put up the birdhouses in the first place. I do not know why the House Wren became so greedy or filled with fear. Its life cannot be worth more than all the lives of the birds it chooses to destroy. I will continue to protect the other birds that live here in harmony. I lost the battle last year in that both Bluebirds and one Tree Swallow pair left after seeing the battle of the sticks between the Wren and myself. I hope to do better this year. Next post will be about Bluebirds rearing their young.

** An ADDED NOTE - Many thanks to Laura at PatioPatch for this important link to a scientist's extensive work studying the House Wren. I highly recommend reading this Audubon report.
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