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Archive for February, 2016

February 20th  was not a typical February day.  A week earlier, the temperature was near zero.  Today it reached 60 degrees.  No snow on the ground.  Cloudless, sunny sky.  A nice day to be outdoors for any reason.  In addition to the usual a variety of backyard birds our group of 17 birders was hoping to see wintering ducks, a reported Great Horned Owl and, of course, a Bald Eagle.

We didn’t find a large variety of birds, the owl couldn’t be found, no ducks around but we did find Bald Eagles.  One full adult, with white head and tail, posed on a tree top giving us good views and chance for some photos.  The bird was more than one-half block away and Steve Gold took this photo through a spotting scope, something he never tried before.  As a result, the quality is not top-notch, but it does serve as a memento of the day.

Eagle at Croton 2016 (more…)

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Finally, a new Post

Last week was a momentous week.  It started on Sunday.  That was my birthday.  It was also the day that I closed my store, the Wild Bird Center, that I have been running for the past 17 years after retirement from corporate life.  The following day I officially became an unemployed bum.  I entered into the next phase of my life with plenty of unscheduled time on my hands.

I haven’t posted anything here for many moons falling back on the excuse that I did not have enough time.  Now that lame excuse no longer applies.  So I will attempt to post on a more regular basis, maybe several times per week.  I expect that most posts will have some kind of connection with birds, nature and life as we known it.  I’ll try to keep each post both interesting and to some extent educational.

Here is my first new post.  Let me know if you like it.  It is loosely based on a short item that appeared in a recent issue of the Bronx River-Aound Shore Audubon Society newsletter

 

Stick Figures

The students in Mr. Howards’s second grade classroom were glued to the window watching a pair of house wrens bringing sticks and twigs to a bird house to use in building their nest.  Some sticks were tiny, other were slightly larger.  Still others were so big that the wrens had difficulty getting them through the small entrance hole.  The wren would turn its head, twist its neck, and bend the twig until somehow the wren forced it into the nest box.Birds Nest

This was more fun than watching some electronic screen.  Nature was happening in front of the eyes.  They marveled at the number of trips the wrens made delivering building material.  It seemed like a continuous stream.

“How many sticks does it take to build a nest?” one boy asked.  Mr. Howard didn’t know but turned the question back to the students.  “How many do you think they need?” he asked.  “Any ideas?”  The responses ranged from one hundred to a zillion.  “And how can we find out for sure?”

The class decided the only way to know for sure would be to actually count all the sticks.  But first they had to wait for the baby wrens to grow up and leave the nest.  So for the next few weeks they continued to watch as the adults came and went bringing food for the nestlings.  When the babies finally peeked out of the hole they were thrilled.  They cheered at the youngster’s first attempts at flying.  Finally the nest was quiet.

Now it was time to count the sticks.  Mr. Howard gathered them all up into a large box.  There were a lot.  House wrens are notorious for completely stuffing a nest box with sticks.  The class divided into teams with each team receiving a handful of sticks which they counted into neat piles of ten.  Mr. Howard recorded all their results on the big whiteboard.

When all the counting, adding and totaling was done the children knew there were exactly 1,308 sticks in the bird house.  That was many more than the estimate of 100 but less than a zillion.  And each stick had been personally delivered by one of the adult wrens.  Sometimes they delivered more than one stick in a single visit, but even so, building a nest was a major undertaking.

The wrens took about two days to gather enough sticks to construct their nest, or about 600 sticks per day. If they worked an eight hour shift that would amount to 75 sticks per hour.  Despite the fact that on some trip they brought two or three sticks in a single beak full, it took a lot of trips, on average, maybe, one visit every five minutes.

That is not unusual.  One scientific study counted the actual number of trips that barn swallows made to construct their nest.  Swallows build their nest by bringing beak fulls of damp mud and plastering the mud to a vertical wall.  It is like working with modeling clay. Adding one small beak full of mud at a time they construct a larger nest.   When the mud dries, the result is a strong adobe nest in a very safe location. The scientific research revealed that the swallow made more than 1200 trips delivering mud. Since wrens and swallows are fairly small birds, they do not build enormous nests.  Their nest may only be a few inches in diameter.  Obviously larger birds need bigger nests.  And sticks and mud are much too small to be practical.  Large birds such as hawks and owls use larger construction material.  They choose branches and limbs up to a few feet long and at least one inch in diameter.  They carry this heavy-duty nesting material to the nesting site in their talons, not in their beaks.

Bald eagles build some of the largest nests, sometimes over six feet or more in diameter.  It takes a lot of work to construct a nest that large.  So they reuse the same nest year after year just adding some additional nesting material each year.  Their nests just keep getting bigger and bigger.  The nest not only gets wider, it gets deeper every year.  There is a report of one eagle high in a tree top in Ohio that was reused for 35 straight years until it became so large and heavy that the tree could no longer support it and it crashed to the ground.  Experts estimated that it weighed at least one ton when it fell.

At the opposite extreme are hummingbird nests.  A typical hummingbird nest may be only the size of half a walnut shell, maybe an inch in diameter and one-half inch deep.  That is too small to use twigs in the construction.  Instead the female (It is always the female. The male doesn’t do any of the building.) gathers grasses, plant down, lichen then uses spider webbing or sticky silk from cocoons to lash the materials together forming a nest.

Whether it is built of sticks, grass, mud or branches, a nest is a major construction project.  And birds do not have even the most basic construction tools – no hammers, saws, or nails.  Moreover, they do not have hands or fingers that allow them to easily maneuver various construction materials.   Despite the lack of tools, birds manage to build their nest every year.

And if they should choose to build near a school building, children may watch their effort and momentarily reconnect with nature.  And effective teachers may turn it into a learning experience involving a fun math project.

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