2-Holed Mansions
in Connecticut
2-Holed Mansions
in Connecticut
Test on Bet Zimmerman's Trail
Years 2007 & 2008
Western Bluebirds on my California trail learn to control 2-Holed Mansions without the need for me to trap House Sparrows. This experiment was intended to see if those results could be duplicated on an Eastern Bluebird trail.
Bet Zimmerman of Connecticut agreed to place 2-Holed Hanging Mansions on single-box sites (2 acre forage territory per box) with House Sparrow (HOSP) and Bluebird competition and follow the "Possible Keys to Success" per my web page at: http://home.earthlink.net/~lviolett/keys.html.
The only monitor HOSP control measures shall be removal of HOSP nests and eggs each week. No trapping of House Sparrows (HOSP) will be done in conjunction with Bluebird/HOSP battles. Nestboxes used by small birds such as Chickadees or Titmice can be protected by adding hole reducers/spookers.
Correct Spacing is Important: Doubling up boxes in a Bluebird territory does not result in twice the number of Bluebirds fledged from a site. From the aerial photo of this site, it looked like boxes were placed much closer than the standard recommended 300-foot spacing for Bluebird boxes and I asked Bet (the monitor) to provide information on the approximate spacing.
Bet's logs state: "Measured distance between boxes, approximately 300 feet except for 150 feet between H-12 to H-10 and H-11 to H-10. Box 6X is 50 feet from H-10, 200 feet from H-9."
Translation: Every box has some other box within 300 feet and one 2-holer (H10) was placed only 50 feet away from a 1-holed box (not shown on original map) where homeowners have allowed House Sparrows to nest. Bet explained that she had visualized territories would fan outward from central cluster. That is possible but Bet did not set up the experiment on standard single-box sites as had been requested.
EXTRA BOXES: At the end of the 2007 season, Bet updated the map to show homeowner 1-holed boxes (labeled with "x". Clustering extra boxes in a HOSP-infested area will create a colony of HOSP (similar to HOSP taking all crevices in a tiled roof). My recommendation is not to saturate a site with extra boxes unless the monitor wants to trap.
Before the 2008 season, seven (plugged) 1-holed fence-mounted boxes were unplugged by another monitor.
My expectations for this experiment:
1) HOSP battles are expected at all box locations because of the history of HOSP usage on this previously-neglected 1-holed box trail.
2) Adult Bluebirds should be able to safely escape any attacks in 2-holers by flying out the extra hole. If there are no other boxes within their territory, Bluebirds should continue their battle with HOSP until the 2-Holer has been secured.
Bet said she has never had any adult Eastern Bluebirds trapped/killed by HOSP in her 1-holed boxes. Therefore, even if adult Eastern Bluebirds escape from HOSP attacks on this tiny 2-holed trail, the experiment would not establish any difference (adult survival) between Bet's 1-holed boxes and 2-holers.
3) Bluebirds can usually fledge some chicks in a clustered (HOSP colony) arrangement even during the first (most difficult) transition year but the concentration of boxes/HOSP in a Bluebird territory is a hindrance. See results of clustered 2-holers at: http://home.earthlink.net/~lviolett/testmirada.html
Bet Zimmerman is providing online logs of this experimental trail (plus the 1-holed homeowner box) at: http://www.sialis.org/trailhilllog2007.htm.
DATE
H-9
(2-Holer)
200 feet from the 1-Holed Nestbox
Homeowner 1-Holer 50 feet from H-10 and 200 feet from H-9
H-10
(2-Holer)
50 Feet from 1-Holer and 150 Feet from H-12
H-11
(2-Holer)
150 Feet from H-10
H-12
(2-Holer)
150 Feet from H-10
Winter (Jan-07) Acorns ? -0- -0- -0- 3/11/07 1/2" HOSP nesting material (left as-is to verify) HOSP nesting material removed Acorn Shells Acorn Shells Male Bluebird in tree 3/16/07 3" HOSP nest material (left as-is to verify) 3" HOSP (left as-is) -0- -0- -0- 3/24/07 Completed HOSP nest with lots of grape vines (left as-is to verify) HOSP pair flying away from box. Nest removed. Acorn Shells Bluebird pair in tree
-0- -0- 4/5 & 4/7 HOSP Nest Removed (no eggs) Male in Box HOSP Nest Removed
-0-, little grass Bet saw box on very low limb during a drive-by & stopped to rehang
HOSP Nest/no eggs (assumed removed)
-0-, little grass 4/13/07 Some HOSP material removed Little grass removed Some shells (acorn) Box hung higher Lifter broke, no check 4/22/07 1" Nesting Material left as-is to verify Little HOSP material removed -0- Same nest material left as-is to verify -0- 4/28/07 HOSP nest (no eggs) removed 1" HOSP material removed -0- Tufted Titmouse (seen) building nest. Hole Reducer to protect TUTI Recommended but wasn't added.
Grass & Moss
5/3/07 HOSP nest (no eggs) removed 1/2 HOSP nest (no eggs) removed -0- Tufted Titmouse still building nest HOSP material over moss; left as-is 5/6/07 HOSP nest (1 egg) removed 1/3 HOSP Nest; Added 1.25" thin metal hole reducer to deter HOSP at 1-holer. -0- TUTI nest (no nestcup) HOSP? nest (left as-is to confirm) 5/8/07 HOSP nest (no eggs) removed One piece of grass removed. -0- TUTI nest (no nestcup) HOSP? nest (left as-is to confirm) 5/15 & 5/16 HOSP nest & 4 eggs removed Wren sticks TUTI nest (no eggs). 1&1/4" Thin Wooden Hole reducers added. HOSP nest & 1 egg (removed) HOSP nest & 1 egg (removed) 5/19/07 -0- Moved box a few trees further north
HOSP 3 eggs (removed) TUTI nest (no eggs). HOSP nest & 2 eggs (removed) -0-
5/26/07 -0- HOSP nest & 2 eggs (removed) HOWR sticks over TUTI nest HOWR sticks, removed all and found 2 old TUTI eggs under nest HOSP nest (no eggs) removed 6/2/07 Several inches fresh green leaves (left as-is) HOSP Nest (no eggs) removed HOSP Nest (no eggs) over old TUTI base. HOSP portion removed. -0- HOSP nest, 5 eggs removed 6/9/07 Flying Squirrel came out of box HOSP Nest & 5 eggs removed No change Few grass pieces -0- 6/16/07 Just leaves 1" HOSP material removed Removed old TUTI nest base & hole reducer -0- -0- 6/22/07 Chunks of grass w/leaves 2 HOSP eggs/nest removed -0- 1" HOSP material removed -0- 6/30/07 -0- 1/4" HOSP/egg removed (male on roof) -0- -0- EABL tall nest & 1 egg 7/6/07 -0- HOSP Nest (no eggs) -0- -0- 3 EABL eggs (incubating) 7/14/07 More grass w/tunnel; Flying Squirrel inside 5 HOSP eggs oiled by monitor "to avoid harassment of Bluebird nest" -0- -0- 3 EABL eggs (incubating) 7/21 & 7/22 Not Disturbed Oiled eggs gone, bigger nest (removed) -0- -0- 2 EABL chicks 7/28 & 7/29 No Squirrel seen -0- -0- -0- 2 EABL chicks, only female adult seen (single?) 8/5/07 -0- -0- -0- -0- EABL Fledged HOSP Eggs laid in each box during 2007 = 5 HOSP Eggs (2-holed) 18 HOSP Eggs (1-holed post-mounted box) No HOSP Eggs (2-holed) 3 HOSP Eggs (2-holed box) 6 HOSP Eggs (2-holed box) End of 2007 Data Before the 2008 season, an unknown monitor unplugged seven post-mounted 1-holers.
During March 2008, the group of 1-holed post-mounts already had 2 House Sparrow nests.
2008
Begins
H-9
(2-Holer)
250 feet from the 1-Holed Nestbox
Homeowner 1-Holer 250 feet from H-9
H-10
(2-Holer)
Before 2008 season, box moved 1/2 mile down road
H-11
(2-Holer)
230 feet from H-12
H-12
(2-Holer)
150 Feet from H-10
3/15/08 Flying Squirrel -0- -0- Flying Squirrel -0- 3/29/08 No Fly Squirrel -0- -0- No Fly Squirrel -0- An interesting observation from the 2007 data is that House Sparrow activity was significantly greater in the (lower) post-mounted 1-holed box than in any of the hanging 2-holed mansions.
Following is an excerpt from Bet's web site http://www.sialis.org/hosp.htm regarding House Sparrow control
"If a HOSP shows an interest in a box that bluebirds have claimed, immediately lower the height (temporarily) of the bluebird house to about 4 feet. Put up another house a few feet away at a much higher height (around 7-9 feet) and if possible closer to a nearby house or other man-made building. The House Sparrow will often move to the new, higher house. This can facilitate inbox trapping."
This experiment seems to show that House Sparrows preferred the 1-holed post-mounted box over (higher) hanging 2-holed boxes. The reason for the preference is not known.
MAINTENANCE: Hanging boxes do not require the trouble and expense of post equipment. The only box maintenance necessary is to periodically check to make sure that the 1/4" hanger rod piercing the roof (secured with lock nuts) is nice and tight and to prune branches so there is a clear path to lift the box up and down through the tree.
Bet and her husband, Doug (pictured) preferred using a ladder rather than a pole to lift boxes into the tree.
TRAPPING: These boxes can be used in conjunction with trapping. At test sites, however, no trapping is permitted. If trapping and other gadgets or techniques (pairing) are implemented in conjunction with 2-holed box experiments, successes tend to be credited to monitor actions rather than Bluebird actions.
Trail Details:
Bet did a great job of documenting 2007 events with photos. Only three eggs were seen in the Eastern Bluebird nest and close (zoomed in) inspection of the egg photo shows what looks to be a tiny spot (hole) in the upper egg and small (non-pierced dent) in another. There were House Wren problems in a nearby Titmouse box and that could explain why only three eggs were in the nest and why only two eggs hatched.
Another interesting observation is that Bet's notes refer to the nest in this deep box as being "tall". Some monitors don't build deeper boxes because they think Bluebirds will simply fill the box with a high nest and, thus, negate any advantage of building deep boxes. Notice in the two photos (below) that only the side rim of the nest is tall. The second photo shows chicks snuggled deep within the nest center so that they are within a couple of inches of the floor. (The label at the back of the box in the first photo will give perspective to the relationship of the chicks to the floor in the second photo.)
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