Chimney Swift research at the Mansfield Dam Station began in earnest in 1989 with the construction of 2 large wooden towers.   These towers are constructed with inside walls of Textured 1-11 siding with the grooves running horizontally. They measure approximately 18" x 18" inside, stand 22' tall and are an integral part of our home.  They have viewing ports on the second story of the house where we are able to relatively easily monitor the home life of the swifts.  We have come to call these the "Twin Towers" in past issues of the Chaetura.  When detailing our observations they are often referred to as the "North Tower" and the "South Tower".  As the Chimney Swift Nest Site Research Project has progressed, we have constructed additional experimental designs.  There are currently 7 towers on the station.  Following are brief descriptions of the other 5:

The Castle is a cinder block tower with 8" thick walls.  It measures 32" x 32" inside, stands 12' tall and is set on a 5' x 5' x 10" concrete slab.  The top opening is reduced down to 16" x 16" and located on the north edge to reduce the amount of sunlight which can reach the inside.  It was completed in 1994.

The Garden Tower is a wooden tower with an inside wall of Textured 1-11 siding with the grooves running horizontally.  It measures 11" x 11" inside, measures 8' tall and stands on 2' tall angle steel legs set in a 3'x 3' x 6" concrete slab.  The top opening is reduced to 11" x 5" and located on the north side.  It was originally a single-walled tower.  However, due to problems with over-heating, a second skin with an insulated space between is planned.

The Prism is a wooden tower with an inside wall of Textured 1-11 siding with the grooves running horizontally.  It is a 3-sided structure measuring 22" x 22" x 22" inside, measures 8' tall and stands on 2' tall pipe legs set in a 3'x 3' x 6" concrete slab.  The top opening is reduced to a triangular opening measuring 9" x 9" x 9" in the northwestern corner.  It has a ¾" airspace with 1/8" hardboard skin on the outside.

The Pool Towers are the newest structures.  They will be described for the first time in this issue of Chaetura.

The first Chimney Swift was sighted over the canyon on  March 28.  Two swifts occupied the North Tower on April 22.

One bird of the pair was unable to cling with its left foot.  When the nest construction began, the structure took on the appearance of a fan opening from one side of the nest wall to the other as opposed to the standard half-cup shape growing uniformly from the center.  This was possibly a phenomena resulting from the inability of the crippled bird to grip with both feet.  Posture on the crippled bird always slanted to the left.

By March 23, 3 eggs had been laid in the North Tower nest.  A surveillance camera was installed in a small hole directly opposite the nest at this time.  A total of 5 eggs were subsequently laid.  Unfortunately, one egg was found  broken on the tower floor on May 30.  One egg hatched on June 13.  Despite the adults' very attentive care, the nestling was found dead in the nest 4 days later.  No signs of injury were evident in the nestling.  However, its development did not correlate with its age.  The remaining eggs were removed after candling revealed that that none were fertile.

Breeding activity continued between the mated pair.  Observations from the video recordings of the North Tower confirmed that the crippled bird was a male.  A second clutch of 3 eggs was laid in the North Tower nest by June 27.  As in the first clutch, 1 egg was found broken on the tower floor in mid-morning.  Following this incident the crippled bird abandoned the nest site.  He was observed "visiting" the nestlings in the South Tower, but was never observed participating in the care of these nestlings.  The female continued to return to the North Tower, but did not attempt to brood her remaining eggs.

The North Tower pair were new breeders in that location.  The female was banded on May 13, 1996 in the spring roosting flock at the Castle.  The male was banded on July 29, 1997 as a nestling.  He was the singleton of the second brood in the South Tower that year and has been referred to in previous reports as "The Slug".

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