Nestbox (Holes/Entrances) Part 1
In addition to the Messages that have appeared on the Bluebird Mailing
Lists on this topic I have the following on my web site:
Subj: Re: Nest Hole Entering
Date: 6/30/99 5:14:11 PM Central Daylight Time
From: PSPARKS"at"farmcredit.com (PAMELA S SPARKS)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: PSPARKS"at"farmcredit.com
To: JoanDavis1"at"AOL.COM, BLUEBIRD-L"at"cornell.edu
Hi Joan,
I also attended the NABS meeting where Kevin Berner said that his field tests
showed that you could extend the nest box roof 7" from the front of the nest
box.
To the best of my recollection and after going over my notes, I think he was
talking in reference to predator control and how a 7" overhang would provide
much more protection than the normally used 2"-4". He also mentioned that as a
secondary benefit, more shade would be provided.
But, what I can't remember Kevin saying or ever remember anyone saying or
reading is how House Sparrows "like to fly straight into the nest box and
Eastern Bluebirds go under the roof and enter the hole". It would be great if
Kevin could address this point. Has any other person on this list-serv ever
heard or read this hypothesis??
Dan Sparks
Brown County Bluebird Society
Nashville, IN
Subj: RE:1&1/8"
Date: 7/13/99 6:47:31 AM Central Daylight Time
From: kridler"at"1Starnet.com (Keith & Sandy Kridler)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: kridler"at"1Starnet.com (Keith & Sandy Kridler)
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD-L)
Keith Kridler Mt. Pleasant, Texas
Here House Sparrows will nest in boxes with a 1&1/4" entrance, a few can enter
1&3/16" I do think 1&1/8" does stop them from nesting here. All entrances are
round holes and 5/8" thick or thicker. Many Eastern Bluebirds were found by
Larry Zeleny to be able to nest in 1&3/8" round holed boxes, very tight fit but
they prefer larger holes (no larger than 1&1/2" or 1&9/16" to keep the starling
out) and since House Sparrows can use a smaller hole than the bluebirds there is
no reason to use any hole smaller than 1&1/2" for eastern bluebirds. For your
chickadees and boxes in areas where no bluebirds would ever use them I would use
the 1&1/8" round hole to be sure house Sparrows don't nest. KK
Subj: Entrance
repair/protection question
Date: 10/22/99 8:06:15 PM Central Daylight Time
From: Orbit352"at"aol.com
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: Orbit352"at"aol.com
To: BLUEBIRD-L"at"cornell.edu
Tom Heintzelman, Milton, Santa Rosa County, FL (western panhandle, inland) USA
About a month ago polycarbonate plate was mentioned as an effective material for
nestbox entrance hole repair and protection from woodpeckers. Aside from hole
size, other dimensions were not discussed. I have some clear 3/16th inch thick
plate pieces that I would like to use for repairs. Sure would appreciate some
recommendations for outside dimensions and shapes to use with my 3/16th inch
material. Also, would it be advisable to remove surface sheen with sandpaper/steelwool?
As always, I thank you very, very much for your input.
Subj: hole
repair/food recipes
Date: 10/22/99 10:08:10 PM Central Daylight Time
From: kridler"at"1starnet.com (Keith & Sandy Kridler)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: kridler"at"1starnet.com (Keith & Sandy Kridler)
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD-L)
Keith Kridler Mt. Pleasant, Texas
Jack Finch uses a 3"X3" aluminum entrance hole guard on all of the boxes he has
made 70,000+! I normally use a 4"X4" replacement. The welding shields are
4&1/2"X5&1/4" and they do drill easily with a forstner style bit at about 850
RPM. I will use them full size since they can't be cut and make two guards from
one shield. Healthy two legged bluebirds have no trouble entering boxes with
slick fronts (PVC, Formica, sheet metal ETC). I have found one legged females
before and they were both using boxes with perches. Most cavity nesters in my
area land on the box with their toes gripping the edge of the entrance hole. I
would sand the sharp edge of the hole where the drill leaves that ridge.
recipes: Good post Ron!!!
Everyone should read Linda Janilla's article that Haleya posted & the recipe is
a favorite of kinglets, Carolina wrens and many other "non seed eaters".
KK
Subj: Front entrance boxes ????
Date: 11/25/99 8:41:02 AM Central Standard Time
From: racheldan1"at"compuserve.com (Dan & Rachel Thomas)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: racheldan1"at"compuserve.com
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD)
I was able to get some scrap cedar, (free) enough to make about 8 BB boxes,
which I plan to give away as Christmas gifts. My question is. . . When it comes
to installing boxes , , , monitoring them etc. Is it easier to work with the
side opening or the front opening boxes??? I'm planning on making the typiclal
NABS box.
When it comes to mounting the boxes on a pole etc. It is definitely easier to
use a cordless drill to mount the box if you have a front opening box. When it
comes to monitoring the boxes, I like the side opening, which gives the bird a
chance to exit the entrance hole. Still new at bluebirding and would like to
know if there are any advantages of either one.
The boxes that I'm giving as gifts would be to mostly new Bluebirders, who have
no experience with either type of opening.
HAPPY THANKSGIVING
Dan Thomas Lancaster PA
Subj: Re: [Front
entrance boxes ????]
Date: 11/27/99 9:13:58 AM Central Standard Time
From: stillwaterbirder"at"netscape.net (stuart roth)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: stillwaterbirder"at"netscape.net
To: racheldan1"at"compuserve.com, BLUEBIRD-L"at"cornell.edu (BLUEBIRD)
Dan & Rachel Thomas
wrote:
I was able to get some scrap cedar, (free) enough to make about 8 BB boxes,
which I plan to give
...
Hi all;
All my bb boxes have the hole in the front, a removable side panel to view the
inside of the box. with the panel off it still has a plastic wall to protect
both you and the occupant from harm. They are hung on a 45 degree anchore block.
Any bb box you make following the NABS designs would be a great gift.
Happy birding, Stu
************************************************
Stu Roth
Stillwater Birder Co.
Clear View Bird House - A view inside nature
888-668-2627
http://www.stillwaterbirder.com
mailto:stu"at"stillwaterbirder.com
************************************************
Subj: Eastern's
nesting in Arizona/drill tips
Date: 12/11/99 8:25:10 AM Central Standard Time
From: kridler"at"1starnet.com (Keith & Sandy Kridler)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: kridler"at"1starnet.com
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD-L)
Keith Kridler Mt. Pleasant, Texas
The breeding bird survey maps show Eastern Bluebirds nesting in south eastern
Arizona. This is a skip of hundreds of miles between the last known nestings of
Eastern bluebirds in south central Texas then none at all in New Mexico and then
a breeding population! Linda could you do a little checking with your state
wildlife people or simply report on the type habitat these "Eastern" birds are
using?
Thanks Ron for the phone numbers on the 1&9/16" bits! When using hole saws to
drill the entrance, only drill a little over half way and then flip the front
over and finish the hole because you will have half of the "wheel" sticking out
of the bit and this makes it easier to remove. The flat drill bits commonly
called spade or paddle bits really beat and tear the wood out of the entrance
hole leaving jagged edges which appear after a few rains. These splinters are
like daggers on dry days and the bluebirds must push through them to enter and
exit the box. Check all entrance holes during spring clean up and sand those
entrances needing it.
If they cut your
finger they will do the same to the bluebird. Forstner style bits cut very clean
holes but consider using an 1/8" or 1/4" quarter round bit in a router and
"round over" the sharp edge on both sides of the entrance hole. I always rout
mine before I assemble the boxes. With paddle and forstner style bits it is
better to stack drill 4 or 5 fronts at a time with a drill press set around
1,000 RPM and this keeps the backside of the wood from tearing out and leaving
jagged edges as the bit exits the board. KK PS I do use the 1&9/16" bit for my
Eastern Bluebirds nestboxes, It keeps Starlings out and may let in the Great
crested Flycatchers, thus helping one more species of "native" bird. Flying
Squirrels can and do use nestboxes with the 1&1/4" entrance hole in this area.
Subj: Re: 1 9/16
hole saws
Date: 12/11/99 9:20:19 PM Central Standard Time
From: lviolett"at"earthlink.net (Linda Violett)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: lviolett"at"earthlink.net
To: Bluebird-L"at"cornell.edu (Bluebird-L"at"cornell.edu)
Linda Violett - Yorba Linda, Calif.
I see you got the info on where to get the 1 9/16" hole saw. When I first
started building boxes, I got the 1 9/16" hole saw because the WEBL are supposed
to need the little extra room. But now I prefer to use the standard 1.5" hole
cut and then sand the edges (inside and out) until they are softly rounded. Then
I give the entire entrance a good sanding until it is nice and smooth. (This is
all done by hand usually with the accompaniment of Mozart.) The entry holes are
fairly close to 1 9/16" by the time I'm happy with the finished edges and I
think the bluebirds have a more comfortable entryway.
dputman wrote:
Kevin Putman, Yuba City, CA Darn! I had a bunch of information
written down from previous discussions on this listserve, but I've
lost it all now that I need it. I want to purchase a 1 9/16 hole
saw. Who sells them? Thanks, KP
--------------------
Linda Violett - Yorba Linda, Calif.
I see you got the info on where to get the 1 9/16" hole saw. When I first
started building boxes, I
...
Subj: sanded smooth holes
Date: 12/12/99 8:33:09 AM Central Standard Time
From: hpandtl"at"crocker.com (Haleya Priest/Thom Levy)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: hpandtl"at"crocker.com
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD)
Haleya Priest Amherst MA
Does it matter if the holes of the nestboxes are really sanded and smooth? Do
they really care???? H
Subj: Sanded smooth holes
Date: 12/12/99 10:09:09 AM Central Standard Time
From: statton"at"toolcity.net (statton)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: statton"at"toolcity.net
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD-L)
Chris Statton
NW PA
Haleya,
The issue of smooth-sanding the entrance holes is quite important for purposes
of helping to minimize feather wear on the adult birds. During nesting season,
depending upon the number of nestings, the adults can go in and out of an
entrance hole literally thousands of times - each time rubbing their feathers
against the inside rim of the entrance hole. If there are sharp or rough areas
on that rim those areas can cause added feather damage. I place some small
scores on the bottom of the smooth rim on my boxes to assist with foot grip in
the holes, but the rims themselves are very smooth.
Additionally, if using wooden boxes, changes in temperature and humidity can
cause the wood to swell and shrink so that once-smooth rims can become rough.
Therefore, the smoothness of the holes should be checked regularly and re-sanded
as needed. I set my 'reminder' on my computer to give me a note the first of
each month to remind me that it's time to check the holes for smoothness.
Subj: Sanded Smooth Holes PS
Date: 12/12/99 10:14:54 AM Central Standard Time
From: statton"at"toolcity.net (statton)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: statton"at"toolcity.net
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD-L)
Chris Statton
NW PA
P.S. Eventually, re-sanding of the holes enlarges them beyond the 'safe'
(standard) size and the box front needs replaced, a new hole-guard needs placed,
or a hole-reducer placed in order to maintain an accurate entrance hole size.
Subj: RE: sanded smooth holes
Date: 12/12/99 10:15:38 AM Central Standard Time
From: kridler"at"1starnet.com (Keith & Sandy Kridler)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: kridler"at"1starnet.com
To: BLUEBIRD-L"at"cornell.edu (BLUEBIRD-L)
Keith Kridler Mt. Pleasant, Texas
The late Art Aylesworth and others noticed that the mountain bluebirds feathers
were getting worn going in and out of 1&1/2" entrance holes thus they pushed for
the larger 1&9/16 entrance hole for them. Larry Zeleny did tests showing all of
his Eastern bluebirds could enter a 1&7/16" entrance hole one summer and most
would still enter a 1&3/8" round hole. Bluebirds have to make many trips a day
in and out and if there is a splinter or series of splinters reducing the size
of the entrance then these will easily part the feathers and can scrape the
bird's skin, at the very least they will "comb" the feathers on every trip. Why
are handrails, baby beds and furniture made from sanded/planed lumber instead of
cheaper "rough cut" lumber, would people really care if builders saved money and
time? :-)
Seriously I believe that Eastern bluebirds do not like a tight entrance hole. I
still believe that this is why Kevin Berner's tests of the Peterson oval
entrance showed that bluebirds prefer this oval over the 1&1/2" round entrance
hole. If made absolutely correctly the Peterson oval equals in square inch size
a hair under a 1&7/8" round entrance hole. It is over 50% larger than the square
inch opening of the 1&1/2" entrance hole! Of course location is more important
than any box style but you might want to sand a couple of your yard boxes and
leave others rough or try a couple of Linda's "two holed" boxes with one
entrance sanded and one really rough and see if your bluebirds care.
Oh did you know that entrance holes may shrink over time? I was surprised when I
measured 25 of my older nestboxes this past spring (made in the mid '60's to
1976 & drilled with "paddle bits) that only one was larger than 1&1/2". Most
were right at 1&7/16"!!! This is measuring with a dial caliper accurate to + or
- .001. It would be interesting for others to take a nestbox to a machinist and
see exactly what size entrance holes we are really using!
Sorry Linda, I just checked your entrances on your box! Both measured 1.501" in
height and 1.475" in width, even totally sealed her cedar box is shrinking in
width! A 1&9/16" hole is 1.5625". KK
Subj:
Smo-o-o-oth!
Date: 12/12/99 12:12:47 PM Central Standard Time
From: blueburd"at"srnet.com (Bruce Burdett)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: blueburd"at"srnet.com
To: hpandtl"at"crocker.com (Haleya Amherst MA Priest)
CC: BLUEBIRD-L"at"cornell.edu (BLUEBIRD-L)
Haleya, et al,
At risk of being tedious, I'll say again that a sharp Forstner bit leaves a hole
whose sides are so smooth that they need no sanding whatsoever. Further, these
bits keep their edges for a good long time, and are easily re-sharpened. (I have
mine done by a guy who knows what he's doing, and has the tools. I wouldn't
dream of trying to sharpen one myself.) Whether the birds care or not, I really
don't know. I do know that not many NATURAL holes ever get sanded.
Bruce Burdett, NH Bluebird Conspiracy, Sunapee NH
Subj: Re:
Smo-o-o-oth!
Date: 12/12/99 12:56:09 PM Central Standard Time
From: lviolett"at"earthlink.net (Linda Violett)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: lviolett"at"earthlink.net
To: Bluebird-L"at"cornell.edu (Bluebird-L"at"cornell.edu)
Linda Violett - Yorba Linda, Calif
And . . . I know of no NATURAL holes that have sharp right angles where the
entry meets the bark.
Bruce Burdett wrote:
Whether the birds care or not, I really don't know. I do know that
...
Subj: Re: sanded
smooth holes
Date: 12/12/99 1:35:46 PM Central Standard Time
From: scriv001"at"tc.umn.edu (Dorene Scriven)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: scriv001"at"tc.umn.edu
To: hpandtl"at"crocker.com, BLUEBIRD-L"at"cornell.edu
...
They may not "care", but there will be a lot fewer ruffled and broken feathers!
- Dorene Scriven, Minnesota BBRP
Subj: Re: sanded smooth holes
Date: 12/12/99 1:50:12 PM Central Standard Time
From: scriv001"at"tc.umn.edu (Dorene Scriven)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: scriv001"at"tc.umn.edu
To: ktho"at"kc.rr.com, kridler"at"1starnet.com, BLUEBIRD-L"at"cornell.edu
...
I surely can
empathize with you. I fought like mad to take shop in high school, and was not
allowed (only "home economics" for girls!) I became a carpenter despite them!
Anyhow, the Peterson hole is 1&3/8" by 2&1/4 inch, and this is most easily
drilled by using a 1&3/8 bit (Forstner most people use) and then dropping down
7/8" for centering the second hole. Then you file out the small places on the
sides to make a smooth oval. If the 1&3/8 bit is hard for you to find, you can
start with a smaller and rasp or file it out to proper size. Just be sure it is
no larger. It can even be a little smaller.
We have full-scale
plans for the Peterson box in our information packets for members, or just the
plans alone are $1. The plans are also in our book.
-Dorene Scriven,
Minnesota Bluebird Recovery Program. Box 3801, Mpls, MN 55403.
Subj: Smooth Holes & 1-9/16" size:
Date: 12/12/99 2:12:44 PM Central Standard Time
From: hubertrap"at"webtv.net (Joe Huber)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: hubertrap"at"webtv.net
To: BLUEBIRD-L"at"cornell.edu
Hello all, I've kept waiting for someone to mention using a drum sander to
smooth out entrance holes. I use my hand drill with a 1" diameter drum sander.
It saves lots of skinned knuckles and is quick. They last a very long time also.
Back in the late 70,s or early 80,s I had correspondence with someone about the
need of a 1-9/16 hole size for Mountain Bluebirds. Can't recall the name but
they were determined to make it known. May have been Art Aylesworth or some one
he knew. Will dig thru old letters some day to find out. Any waymy boxes
entrance holes were changed to 1-9/16" starting in the early 80,s. I do believe
Bluebirds like a larger entrance hole for some reason Joe Huber Venice Fl.
Subj: Re: Smooth Holes & 1-9/16" size:
Date: 12/12/99 7:26:18 PM Central Standard Time
From: dmccue"at"usit.net (Dan McCue)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: dmccue"at"usit.net
To: hubertrap"at"webtv.net
CC: BLUEBIRD-L"at"cornell.edu
Joe and all - GREAT IDEA, for some reason, it never entered my pea brain to sand
the holes, but as you say, it only takes a minute ot use a drum sander to smooth
up the hole. A tip of the hat to you Joe, Dan McCue
...
Subj: Re: sanded
smooth holes
Date: 12/12/99 9:09:19 PM Central Standard Time
From: m-r-sumner"at"juno.com (Maynard R Sumner)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: m-r-sumner"at"juno.com
To: BLUEBIRD-L"at"cornell.edu
Haleya,
Not along as it will not cut them.
N43*04.511 W83* 36.447
Maynard R Sumner
Flint, Michigan
...
Subj: 1 9/16 hole size
Date: 12/14/99 2:14:56 AM Central Standard Time
From: dputman"at"syix.com (dputman)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: dputman"at"syix.com
To: Bluebird-L"at"cornell.edu (bluebird)
Kevin Putman, Yuba City, CA
Hatch:
I think I'll just keep on using the 1 9/16". I've watched starlings try to get
into the 1 9/16" entrance, but with no success. The only time I ever actually
found a starling nest in one of my bluebird boxes was when a woodpecker enlarged
the entrance.
I've read about starlings in different places being somewhat smaller, supposedly
in the South, for example. I don't doubt that starlings can come in different
sizes, especially in varying environs. Either starlings are generally smaller in
the particular Oregon location that you mentioned or this was an exceptional
case (of a starling entering a 1 9/16 hole). Could it be possible that the
entrance holes were actually larger than 1 9/16? I always wonder about these
kinds of reports; I agree with Keith K. in that the only reliable way to know
the actual size of an entrance hole is to use Vernier calipers to measure it.
And it may require several rotated measurements to make sure the hole isn't
slightly oval.
Another point that Keith mentioned: I, too, have found that nestboxes will
sometimes shrink after a couple of years--along with the entrance hole
dimensions (one of the reasons that I'm sticking with 1 9/16"). I built wood
duck boxes from rough-cut Doug. fir that shrunk dramatically; the lids were all
stuck on, and the entrance hole was decreased by about 1/8" to 3/16" in
diameter. It seemed to be mostly cross-grain shrinkage. The degree of shrinkage
will depend on the type / age of wood, I assume (I recall a previous discussion
about young vs old / fast vs slow tree growth that probably applies here).
Keith is right: it would be interesting for us to actually measure the entrance
holes of our boxes to see how much difference there is between "believed" vs
actual hole size.
Subj: Re: 1 9/16
hole saws
Date: 12/13/99 4:12:10 PM Central Standard Time
From: birdsfly"at"innercite.com (Hatch Graham)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: birdsfly"at"innercite.com
To: dputman"at"syix.com
CC: Bluebird-L"at"cornell.edu (bluebird)
Hi Kevin:
I agree with Linda. 1½" works just fine for Western Blues. The late Art
Aylsworth argued for the larger size because he was in an area (Montana) where
both species occur and they are better for the Mountains. The folks in Oregon
strongly opposed the larger size for Westerns there and protested to NABS on the
original standard calling for the larger size for both MOBL and WEBL. They are
adamant that Starlings can squeeze into the 1-9/16" opening.
I've seen
Ash-throated Flycatchers wriggle a little getting in and out of the 1.5" but
doesn't stop them from using them.
Hatch.
...
--
Hatch Graham, Editor, Bluebirds Fly! California Bluebird
Recovery Program
El Dorado County "at" 3100 ft, Lat 38°37'43"N, Long 120°37'47"W
-------------------------------------------------------------------------
for the encouragement and conservation of cavity nesters -especially bluebirds-
anywhere in the West
Subj: 1 9/16
hole size
Date: 12/14/99 2:14:56 AM Central Standard Time
From: dputman"at"syix.com (dputman)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: dputman"at"syix.com
To: Bluebird-L"at"cornell.edu (bluebird)
Kevin Putman, Yuba City, CA
Hatch:
I think I'll just keep on using the 1 9/16". I've watched starlings try to get
into the 1 9/16" entrance, but with no success. The only time I ever actually
found a starling nest in one of my bluebird boxes was when a woodpecker enlarged
the entrance.
I've read about starlings in different places being somewhat smaller, supposedly
in the South, for example. I don't doubt that starlings can come in different
sizes, especially in varying environs. Either starlings are generally smaller in
the particular Oregon location that you mentioned or this was an exceptional
case (of a starling entering a 1 9/16 hole). Could it be possible that the
entrance holes were actually larger than 1 9/16? I always wonder about these
kinds of reports; I agree with Keith K. in that the only reliable way to know
the actual size of an entrance hole is to use Vernier calipers to measure it.
And it may require several rotated measurements to make sure the hole isn't
slightly oval.
Another point that Keith mentioned: I, too, have found that nestboxes will
sometimes shrink after a couple of years--along with the entrance hole
dimensions (one of the reasons that I'm sticking with 1 9/16"). I built wood
duck boxes from rough-cut Doug. fir that shrunk dramatically; the lids were all
stuck on, and the entrance hole was decreased by about 1/8" to 3/16" in
diameter. It seemed to be mostly cross-grain shrinkage. The degree of shrinkage
will depend on the type / age of wood, I assume (I recall a previous discussion
about young vs old / fast vs slow tree growth that probably applies here).
Keith is right: it would be interesting for us to actually measure the entrance
holes of our boxes to see how much difference there is between "believed" vs
actual hole size.
Subj: Nestbox
Entrances for MOBL
Date: 1/16/00 2:46:58 PM Central Standard Time
From: country.potter"at"dlcwest.com (Karyn Mossing)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: country.potter"at"dlcwest.com
To: BLUEBIRD-L"at"cornell.edu
Hi Everyone!
We are trying to decide what type of hole to use for MOBL nest boxes. Some
research indicates both the Peterson oval and slotted are preferred by
Bluebirds.
Will the oval and slotted both work for MOBL, and if so what would be the
dimensions of the oval be? (the 2 1/4" high by 1 3/8" wide as indicated in the
Peterson plans?) Would the slotted entrance be 1 9/16" high?
Thanks to any one with some guidance.
Karyn in Canada - where it is cold (if you know Celcius temperature, how does
-40 to -50 with the wind chill sound!)
Subj: Re: Nestbox Entrances for MOBL
Date: 1/16/00 9:44:43 PM Central Standard Time
From: hubertrap"at"webtv.net (Joe Huber)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: hubertrap"at"webtv.net
To: country.potter"at"dlcwest.com, BLUEBIRD-L"at"cornell.edu
Hi Karyn, The research on hole preference by bluebirds has little effect on them
using a nest box. I would guess that 90% of the boxes in use today are round
holes. They are eagerly accepted if they are located in suitable locations.
Round holes are easier to make. The slot needs to be a little less than 1-9/16"
to keep starling out . The wide hole gives more room to enter than a round
1-9/16" hole. ^The mountain Bluebird will use what is available. Those tests of
boxes also show that house sparrows prefer slots over others. This means little
because the sparrow will try to take any box another bird has. Perhaps your
boxes are located where no sparrow are. Don't be to concerned about type of
entrance.
Charter member NABS, Charter member OBS, Life member OBS Joe Huber
hubertrap"at"webtv.net
http://community.webtv.net/hubertrap/HOUSESPARROWCONTROL
http://community.webtv.net/hubertrap/RoostingBluebirds
Subj: Re: Nestbox Entrances for MOBL
Date: 1/17/00 7:15:12 PM Central Standard Time
From: lviolett"at"earthlink.net (Linda Violett)
Sender: owner-BLUEBIRD-L"at"cornell.edu
Reply-to: lviolett"at"earthlink.net
To: Bluebird-L"at"cornell.edu (Bluebird-L"at"cornell.edu)
Linda Violett - Yorba Linda, Calif.
Bob, hanging boxes do not deter HOSP in any way. The 2-holed hanging boxes I
experimented with this year, however, do seem to give the advantage to
bluebirds. While my HOSP problem was reduced in 2-holed hanging boxes, Dick
Purvis's trail (1-holed hanging) had increased HOSP.
RWil2654"at"aol.com wrote:
Hi Karyn
I use 1 9/16" round holes and not sure they are necessary but it is commenly
accepted practice. I have used larger and smaller ones all seems to make
little difference. I suggest that you look at DickPurvis's hainging boxes if
you have a problem with HOSP. Check it out at the following address.
http://hometown.aol.com/jimmcl/bbbox/nestbox/hangit.gif
Bob Wilson
2654 Sperber Lane
Grand Junction, CO 81506
(970) 242-5190
39* 06.21N
108*33.61 W
4,635 elevation
http://www.crosswinds.net/~bluebirdbob/
http://www.dnr.state.co.us/wildlife/volunteer/bluebirdproject.htm
Date: Thu, 17 Feb 2000 12:07:10 -0600
From: "Wright, Merlin C."
To: "'bdarnell"at"centurytel.net'"
, "Bluebirds"at""
Subject: RE: Bluebird houses with semishaped holes
Steve Gilbertson has been making 4 inch round PVC bluebird houses for a long
time but recently started making a 'Gilwood box' for bluebirds that uses a
semicircle entrance similar/like the one described below.
Merlin Wright at Brownville Nebraska
-----Original Message-----
From: Bill Darnell
Another item the Martin people are mentioning is a crescent shaped hole, which
several think deters HOSP. Think of a 3" diameter circle, then cut it in half
with a line drawn across horizontally. Then measure down 1 3/16" from the top,
and draw another horizontal line. That space from the line to the top of the
circle is the hole. The hole would have to be 1 1/2" for the Bluebird because
the body is wider than I martin, I believe.
Date: Tue, 23 Jan 2001 07:09:08 -0600
From: "Keith & Sandy Kridler" kridler"at"1starnet.com
To: "BLUEBIRD-L" BLUEBIRD-L"at"cornell.edu
Subject: cowbird size
Keith Kridler Mt. Pleasant, Texas
Brown headed cowbirds can sometimes squeeze into bluebird boxes and lay their
eggs. I happened to have one in hand yesterday and using a dial caliper I
checked it's size. I was surprised to see that this male bird was just over 1"
tall from skin on it's back to skin on it's breast bone. While it's width from
wing to wing when measured right at the shoulder and squeezed real tight was
over 1 and 3/8". In the natural wing position it was over 1 and 5/8" wide.
This got me to thinking about other birds and types of entrance holes. The
Starling Resistant Entrance Hole (SREH) is a very short flat bottomed crescent
only 1 and 3/16" tall made by drawing a 3" round circle and cutting this height
crescent off the top.
Wood duck boxes are horizontal ovals usually 3" tall and 4" wide but one of
the publications from the Minnesota Wildlife division has a hole made with three
different drill sizes to make a fallen down snowman looking hole. It is still 4"
wide and three inches tall but to make the hole start with a 3" drill bit sized
hole, then use a 2" bit and move horizontally 1/4" on each side and drill the
entrance twice now making the hole 3" tall and 3 and 1/2" wide. Exchange drill
bits again and put in a 1" bit and again move over 1/4" each way and drill twice
more and you now have a 4" wide by 3" high entrance that is designed for
breastbone height and also allows for the wood duck wings width right at the
shoulder bone. This tighter hole was designed to fit the contour of the duck's
body and is smaller than most books recommend. It is designed to keep the
smaller raccoons out of the nestboxes that are found raiding duck boxes in
Minnesota. The regular sized oval hole is made only with a 3" bit and then move
over 1" and drill the horizontal oval hole. Draw these two entrance holes on
paper to see what they look like, cut the " fallen snowman" hole out and lay it
over the regular oval to see the size reduction.
Digging back through my old papers I finally found the letter from Dr. Larry
Zeleny he wrote in regards to an article I wrote for the "Bluebird News" (Texas
publication started in Jan. 1988) in May of 1989 concerning the use of the 1 &
9/16" round entrance and he states, "There is no real evidence that the 1&1/2"
hole is too tight a fit for Eastern or Western Bluebirds anywhere. In fact most
if not all birds of these two species can enter and will use boxes with 1&3/8"
round holes, although these are a slightly tight fit and should not be
recommended for general use." Basically the letter is against any hole even
close to the size where a starling can enter the box. The 1 & 9/16" round hole
is just a tiny bit smaller than the 1&5/8" hole that starlings all over the
country can enter. Anyway back to bird sizes, I got out the live trap and common
grackles and red winged blackbirds are also far wider than they are tall
measured with a caliper. Anyone have a bluebird they can measure? Bluebirds can
enter 1&3/16" horizontal slots easily and so can the larger Starling when this
is placed on Purple Martin houses.
Just a few tidbits for the list to debate since it is getting real close to
nesting season:-) KK
Date: Mon, 14 May 2001 17:35:16 -0400
From: "Anne Little" aglmkt"at"home.com
To: "Bluebird L" BLUEBIRD-L"at"cornell.edu
Subject: hole size on BB boxes
By mistake we had one of our members build a ton of boxes using a hole size
of 13/8 instead of 11/2 (eastern Bluebirds - Virginia). The boxes were installed
but no bluebirds nested only Chickadees and Tree Swallows. The question I have
concerns the Tree Swallows. Does anyone know if these boxes will trap the
juvenile tree swallows inside the box with the hole size so small? No eggs have
been laid in the boxes so we could remove them before it is too late. Please
advise if you can.
Anne Little
Date: Mon, 14 May 2001 17:40:19 -0500
From: "Keith & Sandy Kridler" kridler"at"1starnet.com
To: "BLUEBIRD-L" BLUEBIRD-L"at"cornell.edu
Subject: Re: hole size
Keith Kridler Mt. Pleasant, Texas
You can easily enlarge the entrance holes to 1&1/2" by using a cordless drill
and a forstner style drill bit. By attaching a small block of wood that already
has a 1&1/2" hole to your nestboxes and line it up to where it overlaps the too
small hole you can now safely drill the extra 1/8" of wood and make the hole the
right size for Eastern Bluebirds. You might be able to drill them without the
extra block but this will make a neater and easier job.
I would recommend borrowing a 12 volt or higher voltage drill and getting an
extra battery and you should be able to drill about 100 boxes without a
recharge. For those with older boxes and worn or rough entrance holes running a
forstner style bit through the entrance every couple of year will also remove
any burrs. If you have a choice buy the forstner style bit with a "saw tooth"
rim. It cuts cleaner holes. KK
Date: Mon, 14 May 2001 22:50:19 EDT
From: TomGaryH"at"aol.com
To: Bluebird-L"at"cornell.edu
Subject: Re: hole size (forstner drill bit & foot holds)
Keith says:
You can easily enlarge the entrance holes to 1&1/2" by using a cordless
drill and a forstner style drill bit. By attaching a small block of wood that
already has a 1&1/2" hole to your nestboxes and line it up to where it overlaps
the too small hole you can now safely drill the extra 1/8" of wood and make the
hole the right size for Eastern Bluebirds.
In February of this year I bought a saw tooth rimmed 1 9/16" forstner drill
bit for $7.00 + 3.95 S&H from Woodworker's Supply, 1125 Jay Lane, Graham NC
27253, (336) 578-3001, Sales (800) 645-9292. Shipment took only a few days. I'm
sure they have a 1 1/2" forstner bit, but I don't know if it would be saw
toothed.
I don't have experience with Tree Swallows, but I would bet the 1 3/8" hole
size would not stop chicks from fledging. It is my understanding that the
important thing is that the chicks be able to get to the hole, i.e., inside foot
holds need to be adequate from the top of the nest to just below the entrance
hole.
Tom in NW Florida
Date: Mon, 28 Jan 2002 14:02:05 -0800
From: Hatch Graham birdsfly"at"innercite.com
To: NESTBOX-L"at"cornell.edu (NESTBOX-L)
CC: "BB-L (BLUEBIRD-L)" BLUEBIRD-L"at"cornell.edu
Subject: Re: chickadee/swallow specs
We use a standard bluebird nestbox for most species. 1.5" (sometimes
1-9/16th) works for all the species because a cavity is a cavity. Most of these
birds depend on a primary cavity-nest builder like the woodpeckers for what they
get in nature. Most of the woodpeckers build closer to a 2 to 2.5" hole.
We reduce the size to prevent use by House Sparrows and predation by Corvids
and other larger birds; but we have chickadees, titmice, nuthatches, tree and
violet-green swallows, Bewick's and House Wrens using the standard bluebird box.
Those who argue for biodiversity and want to attract a greater variety of
species have used the smaller hole-sizes and the result has been less diversity
rather than more. Why exclude the bluebirds? If bluebirds are so abundant,
simply put up more houses at less than the territorial distance that prevents
bluebirds from nesting in all of them. If this causes swallows to increase and
use more than their share, then pair the boxes at about 15' distance or less.
This is closer than most swallows will tolerate intraspecific rivalry. I have
had paired boxes with the following combinations: WEBL/TRES, ATFL/WEBL, OATI/WEBL,
OATI/TRES, WBNU/WEBL, WEBL/HOWR (must be 15' or less), HOWR/TRES (same). Another
way to insure diversity is to locate the boxes in the preferred habitat of the
target species.
Last year, I fledged 6 TRES from a Kestral box with a 3" hole. In compiling
our annual report, I see that Kevin Putman had 38 nestings fledging 105
bluebirds in his 46-box Wood Duck trail; besides the bluebirds he also had 4
kestrel nestings for 20 fledgings, and 9 Barn Owls with 35 young fledged.
My thesis is: Make the entrance as large as you can commensurate with protection
of resultant users. I like to promote all cavity-nesters who've taken short
shrift over the years.
Good luck to you.
Hatch Graham, Cal Bluebird Recovery Program
Editor, Bluebirds Fly!
Somerset, El Dorado Co, Calif
Writing from 3100' in the Central Sierra where it's been snowing all day.
Rob Yaksich wrote:
Rob Yaksich
Albuquerque, NM
cloudy and showers possible (THANK GOD!)
Hello friends-
I was looking at some specs on the BHNW site and had a question about
entrance sizes. It listed the size for tree/violet-green swallows as
1 3/8" diameter, just a bit bigger than the 1 3/8" mentioned for
mountain chickadees and rb nuthatches. Since I am trying to
attract all four of these birds at my State Park in a
heavily forested, steep-walled canyon above Santa Fe,
would it be feasible to make some smallish houses with
the 1 3/8" entrances to accommodate (sp?) all 4
species? I know that probably isn't likely, but I
wanted your thoughts. Is it really true that swallows
will enter a hole 1 3/8" diameter? That seems awfully
skinny. THANKS!
R
From: "Gary Springer" springer"at"alltel.net
To: rangerrobnm"at"yahoo.com
Cc: "BLUEBIRD-L" BLUEBIRD-L"at"cornell.edu
Subject: Nestbox hole sizes
Date: Tue, 29 Jan 2002 03:24:05 -0500
Hi Rob,
I don't have the exact entrance hole sizes for the species you mentioned but
here in Georgia I have far more success attracting various small cavity nesting
song birds by offering standard bluebird size nest boxes with inch and a half
holes.
For years I offered nest boxes with smaller holes of inch and a quarter and
inch and an eighth hoping to get chickadees and titmice to use specific boxes
but they ignored the boxes with the smaller holes and instead used the boxes
with larger inch and a half holes.
In my opinion, cavity nesting birds prefer a hole somewhat larger than the
smallest diameter they can access. But, because the smallest hole the bird can
access provides the most protection from predation, it is best that we use this
smaller hole to provide maximum protection from predators(which in the case of
Eastern Bluebirds is a round hole of inch and a half diameter).
Offering all boxes with the larger entrance hole permits each species to
select any box they prefer and increases the odds there will be one box which
they can enter which is also positioned exactly as it likes with the surrounding
habitat it prefers.
After incubation begins you can attach a hole restrictor to reduce the hole
to the size recommended for the species that occupies each box, thus precluding
larger birds from evicting them.
Gary Springer
Real Bird Homes.com
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