Competition and predation appeared to be the call of the day for this year’s Tree swallow nesting season.  Normally, our environmental students have been gracious enough to give the nesting boxes a once over prior to the arrival of the tree swallows, bluebirds and other cavity nesters call them their seasonal nursery.  This year amidst COVID 19, nobody was available to do this, so I took it upon myself to give the nesting boxes a looksey and to see if we had any interested parties.  There were far more tree swallows in the field than I had seen in a while.  I couldn’t help but to notice that there weren’t enough nesting boxes to accomodate everyone.  Upon closer inspection, several boxes had decayed to the point where they were unuseable.  I took the trapping mechanism out of the Van Ert trap, and used it as one of the nesting boxes in the field.  Given the fierce nature of the house sparrows this season, this was a mistake, as I learned a few weeks later.  Happy 2020, the year of hindsight!  Next I took several broken nesting boxes and was able to throw together 12 boxes suitable for nesting, as well as 2 additional boxes Tom had located for me.  When all was said and done, we had a total of 36 available nest boxes for use.  Things began well enough, but conditions became rather stressful in the field for the tree swallows.  Of the 26 nests I checked on post fledging,  9 appeared to be successful  3 assumed house sparrow kills, 3 predation, 5 house wren builds 5 no build at all, 1 active bluebird nest. The other 10 nest boxes had been grown over in the vegetation and were clean out of site. So those for now remain a mystery.

juvenile tree swallow

 

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