Incubation

From: Heather McCall HeatherMcCall13"at"hotmail.com
To: Bluebird List Bluebird-L"at"cornell.edu
Subject: 5 EABL eggs
Date: Mon, 27 May 2002 13:56:31 -0400

Hi, all. Last Sunday I reported 3 EABL eggs in our nestbox, so we figure the female started laying last Friday. This past Friday my husband reported 5 eggs.

Now I need some clarification about incubation. Am I correct in my understanding that the incubation period does not begin until the female begins sitting on the eggs? Is there a way to determine when that is happening, short of opening the nestbox several times a day? (Trying not to be invasive.) Sometimes I see both parents in the yard. Sometimes if I look around I will find the male perched on top our our house or on a branch at the edge of the woods. If my yard chores take me fairly close to the box, both parents come over from the woods and sit near the box. So my guess would be that so far the female is not sitting.

Heather McCall
Cecil County, MD

From: Keith & Sandy Kridler kridler"at"1starnet.com
To: BLUEBIRD-L BLUEBIRD-L"at"cornell.edu
Subject: bluebird incubation/fire ants
Date: Tue, 28 May 2002 07:32:56 -0500

Keith Kridler Mt. Pleasant, Texas
There are variations between birds on their styles of incubation but I would not open the box too much just to see if the female is sitting on the eggs. The 17 days from first egg to hatching is a good guide of when to expect baby birds as was just posted last night. Or the traditional of 12-14 days after the last egg is laid. Check out the link below and you will see that the females are off and on the nest repeatedly and you might just happen to be seeing them when she leaves for a break. http://www.birds.cornell.edu/birdhouse/news/temp_pilot.html

Fire ants are becoming active and will begin swarming across the southern and middle states with this next batch of thunderstorms. After a rain they wait until the next warm day and all the fire ant mounds in the region synchronize their swarming to minimize losses to predators. The problem here is that very often these queen and king ants will climb posts, poles or weeds or trees to gain height before their maiden flights. They will be accompanied by hundreds of thousands of guard ants to protect them and when they encounter a bird nest they will devour the young birds.

I lost a nest containing 6 House Sparrow babies to them this past weekend and this would be a horrible death. We have covered many different fire ant preventative measures in the archives of Jim McL. WebPages and if you have these ants in your area you probably need to begin taking some measures to minimize losses. KK

Date: Mon, 27 May 2002 15:45:12 -0400
From: Pamela Ford jpford"at"comcast.net
Subject: RE: 5 EABL eggs
To: HeatherMcCall13"at"hotmail.com, Bluebird List Bluebird-L"at"cornell.edu

Hi, Heather. congratulations on your eggs!

The female bluebird will sometimes start incubation a day before the last egg is laid, sometimes a day after the last egg is laid, sometimes she delays incubation even longer (bad weather may trigger this). I've not expiereinced this delayed incubatioin yet.

I live one county from you and just reviewed my records from the last two years and this year (so far). In the backyard nest boxes, which are easier to monitor and therefore report accurate dates, the last 5 clutches, spanning 3 seasons, have begun hatching exactly 17 days after the first egg was laid. Three of these nests had 4 eggs, 2 had 5 eggs, but with no difference to the 17 day from start of laying to start of hatching.

Using this method of estimating, you will have nestlings on June 3.

Pam in Harford County, Maryland
-----Original Message-----
From: owner-BLUEBIRD-L"at"cornell.edu [mailto:owner-BLUEBIRD-L"at"cornell.edu]On
Behalf Of Heather McCall
Sent: Monday, May 27, 2002 1:57 PM
To: Bluebird List
Subject: 5 EABL eggs

...

Date: Thu, 13 Jun 2002 18:07:02 -0400
Subject: Incubation temperature ?
From: Ardith Newbold beaknbill"at"adelphia.net
To: BLUEBIRD-L"at"cornell.edu

Could someone tell me the temperature bluebird eggs need to be for hatching. Something knocked the nesting box off the post. I have two unbroken eggs in my incubator at 99 degrees. I only know about the temp of quail eggs. Hope you can help.

Kindest regards
Ardith

From: "Emily Smith" emilys7"at"earthlink.net
To: beaknbill"at"adelphia.net, BLUEBIRD-L"at"cornell.edu
Subject: Re: Incubation temperature ?
Date: Thu, 13 Jun 2002 20:25:48 -0400

Hello Ardith,

From Stokes' "The Bluebird Book":

"Once incubation starts, the eggs are kept warm all the time. They must be warmed to at least 95 F to develop properly....It is believed that if the eggs get warmer than about 107 F because of overheating in the nestbox, they may die. This is why nest box ventilation is important."

So, it sounds like your incubator temp is just fine. Good luck with your eggs and please keep us posted.

Emily in Efland, NC
where we have had highs in the upper 90s all week, meaning that "Mama Blue" gets to take a break from incubating during the daytime! :)

----- Original Message -----
From: "Ardith Newbold" beaknbill"at"adelphia.net
To: BLUEBIRD-L"at"cornell.edu
Sent: Thursday, June 13, 2002 6:07 PM
Subject: Incubation temperature ?

...

Date: Sat, 15 Jun 2002 08:38:11 -0500
From: Sharon Peregrine Johnson sharonpj"at"swbell.net
Subject: Re: Incubation Period
To: BLUEBIRD-L"at"cornell.edu

My bluebirds layed 6 eggs about 3/4 weeks ago, but they have not hatched yet. I have seen them go in and out of the box. Should they have hatched by now or do I need to give them another 2 weeks? Seems like a very long incubation period. What do you think?

Sharon

From: hubertrap"at"webtv.net (Joe Huber)
Date: Sun, 16 Jun 2002 07:31:28 -0400 (EDT)
To: sharonpj"at"swbell.net, BLUEBIRD-L"at"cornell.edu
Subject: Re: Incubation Period

Hi , Sharon, Bluebirds generally take 12 to 14 days to hatch eggs after incubation starts. Are you sure the female has been sitting on eggs. Eggs can remain in nest many days if not warmed by female. Here comes the purpose of monitoring the box. You need to look in every week to learn what is happening. It doesn't bother Bluebirds to open their box for a few minutes each week. Some people look in every day and it doesn't bother the Bluebirds Checkout this box to be sure eggs are
still there. Joe Huber, Venice, Fl.

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

27.1171494 N Lo -82.4124222 W
He who ask a question is stupid for five minutes, He who never ask a question remains stupid forever, Chinese Proverb.

Date: Sat, 15 Jun 2002 08:38:11 -0500
From: Sharon Peregrine Johnson sharonpj"at"swbell.net
Subject: Re: Incubation Period
To: BLUEBIRD-L"at"cornell.edu

...

Date: Thu, 20 Jun 2002 09:24:20 -0700 (PDT)
From: Kerry Sweet ksweet3450"at"yahoo.com
Subject: Eggs/Incubation
To: Bluebird Messages bluebird-l"at"cornell.edu

Theresa,
I had this information in my Bluebird folder it was
Submitted By:Kathy Bennett
Durhamville, ( Central ) N.Y. in May of 2001

Hope it helps!
Kerry in NE corner of Okla.

Information from: Donald and Lillian Stokes book: The Bluebird Book

Egg Incubation: Usually begins 5 days after the egg laying starts. Incubation takes about 14 days for the first brood, 13 for the second.

Nestlings

Hatching:
The eggs hatch over a period of a day or more and usually in the order which they were laid. In very warm weather, eggs laid early may start development before incubation begins and hatch several days ahead of the others.

The young break out of the egg with the aid of an "egg tooth", a hardening at the tip of their upper bill designed just for this purpose. Once the young hatch, the egg tooth is re absorbed into the bird's body and disappears.

When you find a piece of eggshell on the ground or in a nest, you can tell if the egg was preyed upon or hatched. Eggs that have hatched have at least a partial straight line of broken shell at the largest diameter of the egg. This is due to the actions of the young bird pecking it's way out.

a shell broken completely irregularly, or just punctured, is more likely the result of predation. After the eggs hatch, the female may remove the eggshells or partially eat them , since they contain nutrients such as calcium.

Behavior of the Adults:

During the first few days after hatching, the female may remain on the nest almost to the extent that she did during incubation. At this point her sittings over the young is called brooding, and its purpose is to keep the young warm. How much brooding she does depends on the weather. In warmer weather the young can be left unattended for longer periods; when it is colder she may need to stay over them almost constantly.

The male may bring food to the nest; the female eats some and feeds the rest to the nestlings. Depending on temperature, she may get off the nest and collect additional food for the young. The parents tend to feed each young an average of two times per hr, no matter what size the brood. Among Western bluebirds, the male continues to bring food to the young birds at the same rate throughout the nestling phase, while the female's visits tends to increase in frequency to the point that they outnumber those of the male. In one study of eastern bluebirds, a different pattern occurred- over the nestling phase, male visits decreased while female visits increased.

You can estimate the age of the nestlings by watching the feeding behavior of the adults. If when the parents bring food to the nest, they go all the way in and do not leave with fecal sacs ( see below), the young are probably 1-5 days old. If then parents go all the way in into the nest to feed the young and leave with a fecal sac, then the nestlings are about 6-12 days old. If the parents just dip their heads into the entrance hole to feed the young, then they are probably 12-18 days old.

If you see one of the adults leave the nest with a white blob in it's bill. This is a fecal sac. The droppings of one of the young all contained in a little membrane.

Bluebird nests are often clean of feces right through the nestling phase. This is especially true of eastern and western bluebirds. Among mountain bluebirds and some other birds, such as tree swallows, droppings begin to accumulate in the nest during the days just prior to fledgling, resulting in a messy nest by the time they leave.

Submitted By:

Kathy Bennett
Durhamville, ( Central ) N.Y.

--- Simon Theresa"at"bowecho.com wrote:
Well, I have two eggs in my BB box.

...

Subject: RE: Incubation
From: "sharonpj"at"swbell.net" sharonpj"at"swbell.net
Date: Thu, 20 Jun 2002 13:27:03 -0400
To: "bluebird-l"at"cornell.edu" bluebird-l"at"cornell.edu

Thought I would post this to the list.

On June 15, 2002, I posted the following Message:

"My bluebirds layed 6 eggs about 3/4 weeks ago, but they have not hatched yet. I have seen them go in and out of the box. Should they have hatched by
now or do I need to give them another 2 weeks? Seems like a very long incubation period. What do you think?"

I got some good pointers from Diane, Evelyn, and Joe about how to check the eggs. However, I decided to wait another week and I am so glad that I did. Two days ago, I checked the nest and found one newly hatched baby. Last night I found at least 3 more. I am going to check again on Saturday when I am not rushing to go to work, treat a sick indoor kitty, preparing for teaching my class, and etc.

While incubation could take only two weeks, it depends upon when the mother actually starts sitting on the eggs. Based upon my situation, it could be several days, and it pays to be a little more patient and not give up too soon. This is the third nesting this summer (first had 4 eggs hatch and babies fledged, and the second 2 eggs hatched and the babies fledged). If all goes well then that brings the count for the summer up to 10/11 new bluebirds.

Sharon in Waco

From: "Emily Smith" emilys7"at"earthlink.net
To: "BLUEBIRD-L" BLUEBIRD-L"at"cornell.edu
Subject: Happy UPDATE (Re: Odd EABL behavior!)
Date: Fri, 21 Jun 2002 19:56:29 -0400

I am the one who posted about odd EABL behavior earlier in the week when Mama was supposed to be incubating -- fluttering at our windows, incezzznt back and forth flying from the nestbox to our gutter, much wing-waving between Mama and Dad, quick in and outs at the box but not much time inside to incubate (or so it appeared), and so on. Tuesday was the worst as this behavior went on all day, then Wed/Thur. it seemed to be mostly a morning thing.

Well....I looked into the box when I got home from work today and what did I see but four tiny beaks!!! (I suspect a fifth one was sleeping, because
there were no signs of any eggs remaining). Woo-hooh!!! :) :) :) And Mom and Dad have been going in and out feeding numerous times during our dinner hour here.

I am so happy! I guess this just goes to prove what some of you told me: never give up! Every time I worry about something with our BBs, they always seem to come through and prove me wrong. They successfully raised five fledglings (whom we still see often in our back yard) earlier this spring, so they must know a lot more than I!

Just wanted to share the good news. Yippee!!!

Emily
Efland, NC

From: "College Town" collegetown"at"I-55.com
To: "Blue Birds" BLUEBIRD-L"at"cornell.edu
Subject: Will alot of rain cause the number of incubating days to increase?
Date: Mon, 1 Jul 2002 09:55:19 -0500

Hi. We have had a lot of rain here in Hammond, Louisiana over the past week. I have 4 eggs that are being incubated. I know that there were 4 eggs that she began sitting on on June 15. So as of today she has been incubating 17 days. I believe the "norm" is 12 -14 days.

The dad is not around much and doesn't bring her food so I know she is off of it more than usual. She eats the mealworms when I put them out so she doesn't have to go far. I sure hope if the eggs hatch he will show up more and help feed.

Kim
Hammond, LA

From: Evelyn Cooper [mailto:emcooper"at"bayou.com]
Sent: Sunday, November 30, 2003 9:43 AM
Subject: Females Incubating

Reading the posts about the female sitting on the nest with her head sticking out reminded me of three summers ago of what I observed in the backyard nestbox . I saw two females fighting over the nestbox . The first morning there was one egg, and the second morning there were 3 eggs. Five eggs were laid in the nestbox . One of the females dumped an egg in the box on the second morning. The female that sat on the nest sat with her head out of the nestbox the whole time. Only one of the eggs hatched. I thought it was because she did not incubate them well.

I observed this lone baby and his parents all through the summer and winter and up until nesting season. The nestbox they chose to nest in is about 300 yards from my house and I saw what looked like the parents shooing the fledgling away from the nestbox that spring.

Evelyn Cooper

From: JCGARRIOTT"at"satx.rr.com
Sent: Wednesday, April 14, 2004 7:48 PM
Subject: Incubation question

My first nesting pair of EABL had 5 eggs laid by Mar. 28, and it is now Apr 14 and no hatching yet (18 days). I am not sure when she started incubation, though. Mom and pop are still attending and the eggs seem normal. Just getting a little impatient. Is this an unusually long incubation, or is something wrong? We did just go through a week of unusually cold weather. Jim Garriott San Antonio, Texas

From: Pamela Ford [mailto:jpford"at"comcast.net]
Sent: Wednesday, April 14, 2004 8:00 PM
RE: Incubation question

Although the egg laying was complete by Mar 28, the female may not have immediately started incubating, especially if the weather was cold and rainy. In my backyard bluebird box, where I can observe the comings and goings, I've noticed that the female usually starts incubating the day before the last egg is laid. However, this year she didn't start incubating until the day after the last egg was laid. This spring has been very cold and rainy. Give them time.... Pam in Harford County, Maryland

From: Horace Sher [mailto:hjsher1"at"yahoo.com]
Sent: Friday, April 16, 2004 1:29 PM
Subject: eggs not being incubated?

Hello...I have a EABL box with 4 cold eggs since the 4th one was laid about 5 or 6 days ago(about a week) & I didn't see any evidence that incubation had been started. They are still cold today. Which is more likely...(1) the nest has been abandoned because maybe she was scared off or (2) the female has been killed or died or perhaps (3) these are 4 infertile eggs that the female has sensed & thus abandoned? There is a EABL box across the street that recently has a EABL nest almost complete in it..this being done just yesterday & I see EABL in the tree, but obviously I can't tell if these are from the abandoned box or different birds. We've had nice weather...no cats around that I've seen? What's the best explanation? Thanks.... Horace in NC.

From: Phil Berry [mailto:mrtony8"at"mchsi.com]
Sent: Friday, April 16, 2004 1:37 PM
Re: eggs not being incubated?

Leave them be, Horace. She has not decided to start incubation yet. All things in their own time. She may wait another week yet. Phil Berry

From: Jamie Kunz [mailto:jamie-kunz"at"stny.rr.com]
Sent: Friday, April 16, 2004 3:49 PM
Re: eggs not being incubated?

Hello Horace, Its hard to tell why the nest was abandoned *exactly*, usually once the female starts laying eggs she's hard to deter, so I would guess (2) the female has been killed or died.

Ps, are you VERY sure she is not incubating ? Have you checked very early in the AM for her being around ? ---------------------------------------------------- Jim Kunz ...

From: Phil Berry [mailto:mrtony8"at"mchsi.com]
Sent: Friday, April 16, 2004 6:58 PM
Subject: Re: eggs not being incubated?

There seems to be an old wives tale at work here. Just because eggs are left alone in the nest doesn't mean Mom has abandoned them. She can lay all her eggs and leave them alone after laying them. The time they are left alone depends on Mom, I would guess. I wouldn't remove eggs until I was certain she won't incubate. Phil Berry

From: judymellin [mailto:judymellin"at"netzero.net]
Sent: Friday, April 16, 2004 9:22 PM
Subject: Re: eggs not being incubated?

I think Phil has given some very good advice here. I had a nest with cold eggs sit for about three weeks and all the eggs hatched after the female decided the time was right. Last year, I had a nest of eggs that hatched and I NEVER saw the female! I finally saw the male feeding the young and the female appeared as they were about to fledge. I think this is another excellent reason to have more boxes available that are not in use. That way, you can leave the nest for a very long time before you have to make a decision and other pairs still have a place to set up housekeeping. Don't prejudge what the birds will or will not do because they'll fool you every time! Judy Mellin NE IL.

From: Bruce Burdett [mailto:blueburd"at"tds.net]
Sent: Friday, April 16, 2004 7:45 PM
Subject: Re: eggs not being incubated?
Judy, et al, As you say, they can fool you. We've never seen a Bluebird in our yard and probably never will,...too wooded. But I do keep one Bluebird house out there just to see what happens. What usually happens is that Chickadees use it. Two different years, however, they have nested in it and we never once saw either parent bird until fledging time, when they threw caution to the winds and were very visible on and around the house. Until fledging time we'd thought the house was vacant. All seven babies lived and flew, leaving behind a clean green moss nest. And this house was in plain view of the window at our kitchen sink where we saw it all the time every day, 50' away. Bruce Burdett, SW NH....

From: Shane&Emily Marcotte [mailto:marco50"at"bellsouth.net]
Sent: Friday, April 16, 2004 10:20 PM
Subject: Re: eggs not being incubated?

I agree with Judith and Phil and all the others in that we shouldnt take out eggs just because we think there is no activity there. The nest may be cool when you check it........whose to say the mom isnt there when your not? Shane

From: Jamie Kunz [mailto:jamie-kunz"at"stny.rr.com]
Sent: Friday, April 16, 2004 9:14 PM
Re: eggs not being incubated?

In my limited experience of bluebirds over approximately 10 years, the female has predominantly started brooding the day the last egg was laid .. she will leave the initial eggs unbrooded so they will all hatch around the same time when she starts brooding them all at the same time .. I could see *maybe* a day or two delay, but not, what was it a week Horace quoted us ? I'm not an expert but I'm not quoting wives tales either.. I also did follow up to ask Horace to be *absolutely* sure the female is not coming back, check early in the AM and thruout the day .. he could also look to put a feather or piece of grass on top to see if it gets moved ...

From: Chickie [mailto:critters5"at"frontiernet.net]
Sent: Friday, April 16, 2004 4:03 PM
Subject: deserted

Hi Jamie, The same thing happened to me a couple of years back. I kept on monitoring and feeling the eggs. They remained ice cold. I never did find out what happened to mom bluebird.Eventually after quite a long time, I discarded the eggs. A bluebird couple did build a nest in another nest box close by, so I did have babies that year. Thank goodness. Watch for a while and see if there is any action. And I would feel the eggs also. If they remain cold, after a period of time, I would discard the eggs. If the eggs are warm, then probably some beauty is tending to the nest.                                                                                                                             Chickie Smith                                                                                                                      Fonda, NY

From: Jamie Kunz [mailto:jamie-kunz"at"stny.rr.com]
Sent: Saturday, April 17, 2004 6:52 AM
Re: eggs not being incubated?

I forgot to mention I *never* touch the eggs to figure out if incubation is going on, my fingertips are not that well trained to sense that. I always go by whether I see the parents around the nest by checking morning, noon, and evening when in doubt. Of course that is harder if the house is off on a trail somewheres. Easier like mine when there is a cam in it ;-) I asked an ornithologist about this, and while he claims not to be an expert he did say: I'm no expert on this, but in Passerines, I believe their eggs (once incubation has begun) can only go unincubated (and still hatch) for less than a day, at least during cold weather. On the other hand, I've heard that Great Horned Owl eggs, which are often laid in January in the north, can freeze, crack, and still hatch. No way Bluebird eggs can go unincubated for weeks and still hatch, unless, perhaps, they never got incubated to begin with and were just sitting there waiting for incubation to begin, which is possible. Once started however, they must be constantly incubated. I didn't think the eggs could just sit waiting for incubation to begin, learn something new every day .... Jim Kunz

From: judymellin [mailto:judymellin"at"netzero.net]
Sent: Saturday, April 17, 2004 4:46 PM
Re: eggs not being incubated?

Jamie- What your ornithologist friend says is correct- once incubation has started, the eggs are very susceptible to change in temperatures. The difference for Horace- and in my examples- is that there is no evidence that incubation has begun. I think you would easily be able to tell by touch whether the eggs were warm. It's a matter of experience. Judy Mellin NE IL.

From: Keith & Sandy Kridler [mailto:txbluebirder"at"sbcglobal.net]
Sent: Friday, April 30, 2004 8:58 AM
Subject: feeling eggs Keith Kridler Mt. Pleasant, Texas

I know that many people recommend "feeling" the eggs to see of they are warm or being incubated. To me this is a total waste of time most of the nesting season and can actually lead to broken eggs! Bluebird and most birds eggs are optimally heated to 99.5*F or so by the bare skin of the brooding bird. The sensation of heat detected by the human finger depends a lot on how you have worked with your hands during your lifetime! When I was about 11 years old I reached into a nestbox I KNEW had 6 baby titmice in it the day before and I could not tell the difference the following day between a handful of baby birds and a handful of snake filled with baby birds! I had shinned up a dead pine to check this nestbox that my dad had carefully placed way out of my reach with the aid of an extension ladder to keep me from messing with the birds and to this day I still have never found that snake that I threw really hard as I fell down out of the tree....All I could think of on the way down was that I did NOT want that snake crawling on me while I lay dead under that pine..... OK back to 99.5*F! Eggs are cold blooded, they will rapidly lose heat trying to get to the ambient air temperature that surrounds them. The colder it is outside the more wind the quicker the eggs will cool down! How long does a tablespoon full of luke warm coffee hold its minimal heat when it is blowing 20 MPH and near freezing? Female bluebirds often leave the nest for a half hour or more first thing in the morning and egg temperatures plummet as soon as they leave the nest. How warm is your finger? If you have cold hands and the nestbox is dark colored and like in North Dakota yesterday when they hit 93*F abandoned eggs in a hot nestbox could actually have been near 110*F or 12 hours later they dropped more than 50*F. I NEVER recommend that anyone touch or handle a native bird egg! If the female is OLD or has poor nutrition then she might have eggs with dangerously thin shells. I have broken more bluebird eggs in my life than most people will see this year. If you can think of something really stupid then I can tell you "yep I done that or seen that TOO!" What difference does it make if the egg is warm or cold? Under extreme conditions bluebird eggs have hatched from 10 days to 21 days after the last egg was laid in the clutch! High consistent air temperature will begin incubation of the egg before the female is actually brooding and cold temperatures with the lazy female can stretch out the hatch date to a week or so. Anyway put up nestboxes and observe the good and bad things that happen and keep records but always consider the worst thing that could happen if I interfere right now. KK

From: Nancy C. Hebb [mailto:Fencroft"at"msn.com]
Sent: Friday, April 30, 2004 7:35 PM
Subject: Eggs and the Gentler Touch

...I'd like to posit a theory: We woman, with our feather-light touches, can judge the temperature of eggs as our fingers hover over the eggs in question.  We also tend to want to see what we're putting our hands on before touching it (novel thought though that may be).  Thus, we might be given the benefit of the doubt (doubtful?) when it comes to egg touching.  Thus I claim that, having worried about two lone and lonely eggs for more than a couple days, my act of daring to touch them was more a confirmation of suspicion than an invasive tactic. Said two eggs are still lonely.  And cold.  And another nest with, now, two eggs has appeared in a box 30 feet away.  THAT box enjoys actual bird habitation, unlike the first in question, in which the two eggs remain stone cold and alone (if a pair of anything can be said to be alone). No theories: No cats, coons or squirrels and the big white Great Pyrenees dog prevents ingress by such predators in the area of both the boxes in question.  No unusual human or animal or mechanical activity in the area.  Maybe a pair of bird-brained blues?  I'd almost bet the family silverware (which is lightweight stainless, but all I've got) that the new nest of two eggs was created by the same BB pair who appear to have abandoned the first box. Surely if the problem was a jay or HOSP, the eggs would have been destroyed? Mystery of my 2004 bluebird experience... Nancy Hebb in Michigan

From: Kenny Kleinpeter [mailto:kpkmaj"at" cox.net]
Sent: Friday, April 30, 2004 8:35 PM
RE: Eggs and the Gentler Touch

I try to avoid touching eggs as much as possible. It's hard for us to think of eggs as living, breathing animals, but they are. An egg is an external womb. While the eggshell is composed of several layers, it is vulnerable. Eggs have thousands of pores (mostly located on the blunt end) that allow gasses to escape and moisture to enter. Oils from our hands can clog these pores. If handling eggs are necessary, our hands should be washed to minimize bacterial contamination. Those of us on trails should be most cognizant of spreading bacteria from one box where we may remove a feces-laden nest to another where we may handle or touch eggs. There's a great online site that has some fascinating facts about eggs, nests and other good stuff at: http://www.pma.edmonton.ab.ca/vexhibit/eggs/vexhome/egghome.htm

From: Evelyn Cooper [mailto:emcooper"at"bayou.com]
Sent: Friday, April 30, 2004 9:25 PM
Subject: RE: Eggs and the Gentler Touch

I agree with Kenny about avoiding touching as much as possible. I certainly do not think you should touch the eggs every day. I touch mine lightly on the fifth day to see if they have started incubating, and only for that reason. Most times, I do not touch the whole clutch. Today, I had 36 out of 38 fledge....[subsequent post] I touch. Never broken an egg in my seven years of bluebirding! Learned a lot on my own about it too, such as they can stop incubating mid-stream, resume and they hatch on time.Evelyn Cooper Delhi, LA

From: Haleya Priest [mailto:mablue"at"gis.net]
Sent: Saturday, May 01, 2004 8:53 PM
Re: Eggs and the Gentler Touch Haleya Priest Amherst MA

Again we have such varying opinions! I am an egg-toucher. KK is right, you can’t tell if the nest is abandoned by one or two touches, but you sure can learn an awful lot about bluebirds by touching their eggs. If the eggs are ice cold I can go back the next time and they might be warm as toast. But if I repeatedly return to ice cold eggs I begin to keep a better eye and ear out to whether they’ve abandoned ship or not. I still don’t recommend removing ice cold eggs for WEEKS because you might be touching them at the wrong times. I believe we sense things through our hands – they may be subtle cues and things we aren’t consciously aware of – but that doesn’t mean they aren’t vitally important. Have you ever sat in front of a fake fireplace fire? Did you notice something was terribly wrong? Subtle but noticeable. No smell, no cricks and cracks and spats of sparks. To me it ain’t a fire without ALL the cues. Same with bluebirding. It wouldn’t be the same if I didn’t touch the eggs. One thing I know for sure, if eggs are warm, I know the parents are alive, well and incubating. I don’t feel all eggs every time. But when I have a hunch to, I do. And IMHO I don’t believe for a minute this makes them inviable. :-) H

From: Evelyn Cooper [mailto:emcooper"at"bayou.com]
Sent: Saturday, May 01, 2004 9:48 PM
RE: Eggs and the Gentler Touch

In my post last evening, I mentioned that a bluebird had stopped incubating in mid-stream for a few days and then resumed. We had one terrible storm and it blew the sign off the post and the nestbox was loose at the bottom. No eggs were broken, but she did not come back and start incubating for about 4 days. I did have other clutches the same age if she had not come back. I thought she might have been killed. I was relieved to feel the eggs warm again and they hatched the same date another clutch just down from her that begin incubating the same time. I think we should really take into consideration every point made and to me I don't think we should touch them or handle them unnecessairly. We should consider valuable information given from Kenny's post.I will take the necessary things with me on my trail to clean my hands after each clutch I touch. Evelyn Cooper Delhi, LA

From: judymellin [mailto:judymellin"at"netzero.net]
Sent: Sunday, May 02, 2004 10:36 AM
Subject: Re: Eggs and the Gentler Touch

I agree with Nancy and Hayela on this but wonder if it is not more of a geographic thing?  I did not open the boxes on our trail yesterday since it was 45° with strong north winds and light rain (yes, it was May 1!) but, on a milder day, I will feel the eggs if I see no activity around the box.  Like Haleya, I will then record whether the eggs are warm or cold and this helps me determine the viability.  In warmer areas, the heat from the eggs might not be as noticeable because they are closer to the air temp but, in April and May- and many times, in June!- those of us in the north can definitely tell a cold one.  I will leave cold eggs for a very long time as long as there are empty boxes for other birds to use and have been surprised at how long cold eggs can sit before incubation starts and still hatch. Judy Mellin NE IL. 

From: Bruce Burdett
Sent: Tuesday, May 04, 2004 8:51 AM
Re: Touching eggs

Charlene, et al, Even if I could think up a reason for touching Bluebird eggs, I don't honestly think I could tell, using my fingertips, whether they were warm, cold, lukewarm, or whatever. And even if I could, how would that information be useful to me as a monitor? How could it affect my monitoring? If they turned out to be, let's say, cold, what could I do to remedy their coldness? I guess I think that once those eggs are laid, their temperature is up to the birds and to their instincts. I gather from what I read that these eggs can tolerate a great deal of temperature variation and still survive, and my interference could easily do more harm than good. Of course, if a person simply ENJOYS touching Bluebird eggs, then that's another matter altogether. Bruce Burdett, SW NH

From: Evelyn Cooper [mailto:emcooper"at"bayou.com]
Sent: Tuesday, May 04, 2004 10:28 AM
RE: Touching eggs

I keep accurate records and that is why I touch them, not because I enjoy it. I can tell exactly when they start incubating and am pretty well on the mark when they hatch. I do enjoy that part of it. I can always tell if they are warm regardless of the temperature outside. I got in the habit of doing this when on the old Transcontinental Bluebird Trail site questions about nest building, incubating, hatch date, fledge date, etc. were asked as a part of our monitoring. It didn't hurt then, and it does not hurt now to do it, but NOT an everyday thing. Evelyn Cooper Delhi, LA Louisiana Bayou Bluebird Society

From: Phil Berry [mailto:mrtony8"at"mchsi.com]
Sent: Wednesday, May 05, 2004 6:27 AM
Re: Touching eggs

Because, if one monitors regularly (once weekly to me) one knows if incubation has started or Mom is lazy. When do you throw out the nest if abandoned? How do you know how long it has been there? My gosh, it takes a simple touch to tell if one is warm or cold. This ain't brain surgery. Phil Berry

From: Dottie Roseboom [mailto:rosedot"at"mtco.com]
Sent: Wednesday, May 05, 2004 8:22 AM
Re: Touching eggs

I love the different opinions & monitoring techniques that I have learned from this list. Because my nestboxes are nearby, daily observation can usually tell me when incubation starts, so I do not take a chance on breakage by touching the eggs. A luxury that trail monitors do not have. And as I always keep extra nestboxes available, I do not remove eggs for at least 3 - 4 weeks after the time that I think they should have hatched. For weekly monitoring, I can see that if the eggs are warm on the first check, that you can assume incubation has begun. But even then, you don't know if incubation started this AM, or just after the cold eggs were touched on the last visit. A rather long time span. Also, some posts have stated that eggs can feel warm, then cool off, but still be viable, so if this happens, I'm not sure that touching the eggs has been of benefit. When would you start the incubation timing on a situtation like this? I wonder how many times eggs have been removed prematurely, because the monitor felt cold eggs after they had been warm? If other nestboxes are available, is there a problem with leaving the eggs for 7 or 8 weeks? Then, knowing the exact timing that incubation began is not so critical, since the monitor will not be so eager to remove the nest. I agree it's not brain surgery. After I see the female incubating, I wait about 11 days, and then every afternoon, when I see the female leave the nest, I quickly peek into the nest. And in a day or two, Wow, the eggs have hatched. For monitors not wanting to bother the nestbox, they can just wait until they observe the parents feeding the young. I appreciate all the great info provided on this list. Dottie Roseboom Peoria IL (central - zone 5)

From: Elaine Piligian [mailto:birdlady5211960"at"yahoo.com]
Sent: Monday, May 10, 2004 2:48 PM
Subject: Bluebird eggs not hatching

I have a dilemma and need some advice. Our bluebird box has 5 eggs in it that should have hatched on or around 4/30. We are now at day 24 since incubation began, so I know something is wrong. The mom and dad bluebirds have been around (although I don't seem them now) but I don't know what to do. Should I assume that this brood will never hatch? Do we get rid of the nest and let the couple start again? Please advise? Elaine Harleysville, PA

From: JCGARRIOTT"at"satx.rr.com
Sent: Monday, May 10, 2004 8:03 PM
Re: Bluebird eggs not hatching

I had almost the exact same circumstance with my first nesting pair. Apparent incubation began Mar 28 after 5 eggs were laid. By April 25, they were still attending the nest and the eggs seemed warm. By April 30, the eggs were cold and appeared abandoned. No reason was ever discovered. After removal of the nest and eggs, they started another nest and currently are in the process of laying (3 eggs so far). Jim Garriott San Antonio

From: Elaine Piligian [mailto:birdlady5211960"at"yahoo.com]
Sent: Tuesday, May 11, 2004 11:08 PM
Subject: bluebird eggs not hatching

Yesterday I posted a request for advice for a clutch of bluebird eggs that has not hatched yet.  We are now 25 days since the last egg was laid.  Just to be clear, the female bluebird did incubate these eggs for the first two weeks (just like we have seen before many times.)  However, in the last 10 or so days, the parents are no longer sitting with the eggs.  They come and go, look into the box, go in and come out, but the mother is no longer staying with the eggs.  There are no blowflies or bees or anything wrong with the nest.  Everything looks in order; the eggs have not been disturbed.  The parents have been seen checking out another empty bluebird box that we have nearby.  The weather has been quite warm the past few days.  Should we remove only the eggs and see if the female will lay another clutch? Elaine Harleysville, PA

From: Linda [mailto:linyl "at"alltel.net]
Sent: Wednesday, April 13, 2005 10:23 PM
Subject: Incubation

Hello. I'm into the 5th year of BBing. Incubation takes about 2 weeks. Could someone tell me exactly how long the female BB sits on her eggs between eating times each day during incubation?

Birder in NW GA.

Keith Kridler Mt. Pleasant, Texas
Linda, Cornell is right in the middle of research where they are tracking the incubation rhythm of different females from all parts of the country. Each female seems to set her own schedule but it is also dependant on
weather.

Eggs are extremely hardy and will remain viable and able to hatch when
exposed to temperatures below 32*f to about 104*F. The optimum temperature
for an egg to hatch is just about 99*f. If the eggs are kept too long above
or below this they can develop the embryo but there can be problems with the
baby birds nerve tissue or muscle tissue.

As soon as the female leaves the nest the eggs begin to cool. With
temperature data loggers in the nest you can see within a minute or two when
she leaves and how cold the eggs get and then when she returns and begins to
warm up the eggs.

It is not unusual for a female bluebird to leave the nest up to 7 times
during the day. I notice that MANY female bluebirds tend to leave the nest
just before sunrise, at first light and return within a half hour or so
depending on the individual female.

Predators, traffic, other birds ETC. can get the female to flush from the
nestbox so each female, each nesting is a little different. It seems
sometimes that a female might have elevated body temperature and this leads
to eggs being incubated too hot also as they stay as warm or as cold as the
females body temperature.

THERE I just used five paragraphs to tell you I can't answer your
question:-)) KK

Linda, and bluebirdsters:
Sometimes the male brings food to the female while she is incubating the eggs. So, at those times she doesn't have to leave too often. That only answers part of your question. I don't have the answer to the rest!

Good birding, Larry H. Joplin MO.

Western and Mountain bluebirders: Does the female get fed by the male at times while she is incubating as does the EABL?

Good birding, Larry H. Joplin MO.

It has been my experience that the male will feed the female if she cannot leave the box during incubation. It depends alot the weather conditions, super bad weather i.e. last May we had snow for 5-6 days in a row. Early nests were abandon. It seemed that the adults deemed their survival more important than the eggs. I had 3 early nests that failed. I had data loggers in these nests that recorded temperatures 5-6 degrees F below freezing.If the weather is just inclement for the day the males will bring the female food. I had data logger in situations like this also. Temperatures recorded were very consistent show the female never left the box 80-90 degrees F.

The bluebirds that I get here are the lovely ones Mountain Bluebirds:)

Dick Stauffer
Olds Alberta
50 miles north of Calgary

From: Bet Zimmerman [mailto:ezdz "at"charter.net]
Sent: Thursday, April 14, 2005 12:42 PM
Subject: RE: Incubation

Hi Linda – I think it mainly depends on temperature. Books say incubation for eastern bluebirds (EABLs) is 12-18 days, and 13-14 days for mountain (MOBL) and western (WEBLs.)  Last summer on a third nesting I was concerned that two of my nests might have been abandoned because when I monitored I hardly ever saw the females sitting on the eggs.  I guess it was too warm and they just didn't need to brood as often. Bet from CT

From: eindians [mailto:eindians "at"zoominternet.net]
Sent: Thursday, April 14, 2005 9:44 PM du
Subject: Re: Incubation

Linda,

      I also wondered the same thing, so last year during the first nesting I watched and recorded the trips the female made in and out of the box. Here are 2 of the days I watched,  the first chart the high for the day was 43, the second chart the high was 83.

             5/2/04                                           5/10/04                  

     in box      out box                           in box      out box

     10:09       10:39 AM                       10:52       10:58 AM

     10:46       11:50                             10:59       11:08

     11:59       12:00 PM                       11:11       11:13

     12:06       12:29                             11:19       11:24

     12:39       12:59                             11:30       11:42

      1:02         1:18                              11:48       12:07 PM

      1:24         1:43                              12:11       12:17

      1:47         2:07                              12:19       12:24

      2:16         2:45                              12:33       12:42

      2:52         3:22                              12:43       12:47

      3:29         4:01                              12:55       12:59

      4:09         4:37                                1:04        1:07

      4:43         5:15                                1:12        1:15 - quit recording

      5:24         6:03                                HIGH - 83 - SUNNY

      6:09         6:38

      6:49         7:12

      7:25 - in box for the night

      HIGH - 43 RAINED ALL DAY

      I fed 450 meal worms during the 40 degree day, and 50 during the 83 degree day, the eggs hatched on the 83 degree day - 13th day.

     Evan - 15 miles South of Youngstown,Ohio

From: Chuck Jensen [mailto:cjensen"at"dts9000.com]
Sent: Friday, April 15, 2005 9:16 AM
Subject: RE: Incubation

Evan,

Interesting stuff. Measured from the start of the day until 1-2:00am, it's interesting that the female was actually off her nest longer during the cold day (perhaps feeding to keep her own body temp up) at 94 minutes versus 87 minutes during the hottest day...a bit counterintuitive in that we would think that she would be on the nest more during cold weather to maintain nest temp and would feel free to roam more during the hotter day when the nest cooling rate would be lower. These are the kinds of problems we have when the EABL doesn't study up and know what they are supposed to do.

Chuck

I see the male feeding the female plenty times in the nestbox when she is incubating. I even saw them fly to the power line right outside my den and he flew down and got an insect and fed it to her on the power line. Melted my heart away!

Evelyn

I have a pair of EABL nesting in one of my three boxes. I also have for the first time in my backyard, Rufous Sided Towhees and White-Throated Sparrows among many other species.
My question is: The female EABL has laid her first egg this morning. The morning temps are in the low 40's. Will she sit on this one egg to incubate or wait until all the eggs are laid? If she lays four or five eggs, will the first egg be okay even with the low temperatures if she does not sit on it?
I have disposed of 11 HOSP so far this season.
Thanks,
Ruth from Souderton
Eastern PA

From: Kathy Johnson
Sent: Sunday, April 24, 2005
RE: EABL here & Others

She will not start sitting on the eggs till all are laid, because she needs all the eggs to hatch at about the same time, so she's not feeding and incubating at the same time. She will usually start sitting on them immediately after she lays the last one, but not necessarily. The eggs will be ok till she starts incubating.

Kathy Johnson
Flemington, NJ

From: Tommy [mailto:tmathis840"at"comcast.net]
Sent: Monday, April 25, 2005 7:27 AM
Subject: bluebird incubation question

I have a bluebird nest with 4 eggs in it. The mother is apparently sitting every day, but the eggs have been in the nest for almost 28 days now. Are the eggs going to hatch, or has the time passed for a successful nest?

Thanks
Tommy

Tommy--are you up North somewhere? We've been getting a blast of unusually cold weather even this far south (Northern FL). Cold temps can slow or delay embryo development--the female may be sitting on the eggs, but maybe she can't raise the egg temp enough to properly incubate so the embryos can develop. I wouldn't give up on the nest yet--the bird will probably know if the eggs are infertile before too long, though if the bird is young (a first-time mom), it may take a while to figure it out. See my other recent post to the BB-list in reply to another bluebirder with potentially abandoned eggs ("Re: Abandoned eggs? Cold & Heat effects on eggs")--I gave a more thorough explanation in that one.
Good luck!
Elizabeth Farley
Northern FL

From: Lawrence Herbert [mailto:lherbert"at"4state.com]
Sent: Monday, April 25, 2005 6:16 PM
Subject: 28 days...

Tommy and Bluebirdsters:
IMO it looks to me like she is incubating a failed clutch of four eggs.
Once incubation starts (it goes from 12 to 14 days in EABL) if she is disturbed for quite some time, or is away from the nest for any reason during cold weather, then the eggs may chill down and the nest will fail.

The majority of us have experienced a very cool late April, so there will be some failures due to "weather." (Especially Ohio, Indiana and western Pennsylvania the last couple of days).

Tommy, you didn't say where you are but my guess is the cool weather was the culprit.

Good birding, Larry H. Joplin MO.

From: Tommy [mailto:tmathis840"at"comcast.net]
Sent: Tuesday, April 26, 2005 6:02 AM
Subject: Re: bluebird incubation question

I'm in North Georgia and we have been having some unusually cool nights. For the past 2 nights, we have had frost warnings...but luckily the temps only reached 34 degrees. Today is the 29th day since the last egg was laid. Mom and Pop will still both go in the house and look around, pop will leave and mom will stay for a while. I would hate to give up on them as we are soooo looking forward to our *FIRST* EABL nesting. :)

Tommy
Rome, GA

Tommy – as you probably know, incubation does not begin until the last egg is laid, so that’s when you usually start counting. However, in some cases, e.g., when weather is cold, start of incubation may apparently be delayed for a week or so. Once they start incubating, eggs should hatch in 12-14 days. (I assume you’re talking about Eastern bluebirds?)

As Elizabeth notes, temperature may be a factor, or the male may be infertile.

You might try candling one of the eggs to see if there is any development. Candling refers to the process of illuminating the contents of an egg. It's a relatively simple process. Basically in a dark place, hold up and shine a light a small penlight type flashlight through the egg. Keep the egg in it's normal upright position and don't overheat it with the light bulb! Be very careful when you are holding the egg so you don't accidentally crack it! A few seconds is long enough to see what you need. If it’s totally clear inside, that means no development. If its all or partly dark, or has a “blood ring” there may be some development, but it may have been arrested.

There are some really good chicken candling pictures at http://www.homestead.com/shilala/candling.html

If the female has REALLY been incubating for 28 days, I would remove the eggs, and hope she starts over. Otherwise, she’s wasting her time…. I know it’s terribly disappointing…

Bet from CT

From: Tommy [mailto:tmathis840"at"comcast.net]
Sent: Tuesday, April 26, 2005 10:21 PM
Subject: Re: bluebird incubation question

It is an EABL, sorry for not stating that. It has been 29 days since the last egg was laid. She has been sitting on them, inconsistently, ever since. I haven't noticed her or him, for that matter today....I hope they haven't moved on. I'll give it until the weekend, then clean out the nestbox, if they haven't hatched by then.

Thanks for all the info.

Tommy
Rome, GA

Well she did not have the 5th egg yesterday.............

Crystal~Georgia

She may have stopped at 4.

Shawn in Sevierville, TN

I am a little worried something may have happened to the female. I work so I miss a lot that happens during the day. I got a peek in the box today as Mrs Blue was not at home. I figured she would be incubating. I have not seen a Blue all afternoon. Nor did I see them this morning.

1. Can she wait before she incubates, I thought they started as soon as the last egg was laid

2. How long should I wait?

I hope not!

According to "The Bluebird Monitor's Guide", "Some females incubate their eggs more diligently than others do. Female Eastern Bluebirds spend an average of about two-thirds of their daylight hours on the nest. Experienced females often incubate more diligently than first-timers. Eggs that are poorly incubated and allowed to cool are not harmed, but they can take up to five or six days longer to incubate than eggs maintained at optimum incubating temperature." Maybe she was on the nest while you were at work, and was out for a dinner break when you found the Mrs. missing. Keep watching for them. I don't know how long to tell you to wait (hopefully some more seasoned Bluebirders than myself can shed some light on that question. We have had rainy weather here the past few days, and I didn't see the couple (together or separate) at all today myself. This afternoon when I got home, the sun came out, so I'm guessing they were out to dinner.

Shawn in Sevierville, TN

You wrote"

"1. Can she wait before she incubates, I thought they started as soon as the last egg was laid

2. How long should I wait?"

The female can wait several days or a week before incubating.

Sometimes they start incubating before the last egg has been laid (i.e the next to the last one)

Sometimes they can start incubating and stop for a few days and then resume incubating. The eggs usually hatch on time. (at least they did in my
experience)

How long should you wait? I would leave them there at least three weeks or a month. We've had reports on this List of eggs hatching that have been in the nest for a month. I think to bother a nest any sooner than that would not be the thing to do. I have so many nextboxes that a pair could build in to start over if they choose too.

At the end of last nesting season, one female incubated 6 weeks. She finally abandoned on her own. If it had been on a first or second cycle for me, I would have removed the eggs at least after 4 weeks.

I know it is hard to figure out what is going on but give them time and whatever, don't remove the nest and eggs for a while yet.

Evelyn Cooper...
Delhi, LA

Evelyn, Thanks for your post. It is very helpful. My mother blue wasn't on her nest again today but I could tell she has been turning the eggs at some time. She might be there at night without my seeing her. The eggs were cold this afternoon. I got used to seeing both of them around most all of the time when she was laying eggs. Don't understand why daddy B. is seldom here now.
Nina

From: Chris&Crystal Hill [mailto:crystaljhill"at"msn.com]
Sent: Friday, April 29, 2005 7:25 AM
Subject: EABL Female Incubating Eggs

Whew! of course I over reacted (again lol)

I went out yesterday when I got home from work to check the box. Not a blue in sight.
I did my routine of tapping on the box several times and talking just in case Mrs was home.
Nothing.
I slowly opened up the box, and out she came. She's back!!! well I guess she never really went anywhere.
I quickly closed the box and left.
I am so glad she was on those eggs............And after I came in I watched from the window, and Mr showed up checking out the box to let her know it was okay to come back in.

Crystal~Georgia

From: Nina Everett [mailto:NINAUT"at"CHARTER.NET]
Sent: Friday, April 29, 2005 7:28 PM
Subject: Re: EABL Female Incubating Eggs

I am so afraid my nest has been abondoned. Haven't seen either bird since Tues. The five eggs look fine but are cold.

I am really upset about this. Guess all I can do is wait to see what happens.

Nina

Dear People on the list.... This is an egg question to anyone who knows a lot about EABL eggs being viable after cooling. The question is this... After the female has started incubating her eggs & suppose she stays away for a good time (actually how long?) for some reason or another, & the eggs start getting cool, e.t.c., how much of a cool down can the eggs have & still be viable? I know obviously that the eggs can't freeze. But they can probably experience some cooling down from the 95 degree optimum temp. The scientific question is how much? I believe I read somewhere that cooling in the 1st week is tolerated much more than in the 2nd week. Would that be true? Any answers or info about this?
Thanks for any good answers... Horace in N. C.

Horace, I can only tell you my one experience about this. I had two clutches being incubated about 200 yards apart. After three days of incubation the first week, I thought one had abandoned hers. They stayed cold for 4 days and then she resumed incubating. These eggs hatched on the same day as the one beside it. Quite a learning experience for me on that one.

Evelyn Cooper
Delhi, LA

From: Trish Culpepper [mailto:trishkcully"a"earthlink.net]
Sent: Wednesday, March 15, 2006 1:37 PM
Subject: Very Determined Mama Bluebird

Trish Culpepper - Frankston, TX
Mama Bluebird had laid five eggs total in the nest as of yesterday, so we decided we better get the sparrow spooker on. My husband went out to do that after work yesterday. He tapped on the door before opening it, but Mama Bluebird was sitting on the nest and determined not to leave. He closed the door and proceeded to install the spooker. She sat on her eggs the whole time he was attaching the spooker without budging. He calls bluebirding "my hobby", but it's fun to watch him get a big kick out of it also. I was gone at the time, but he called me to tell me all about it. When I got home, I decided she needed a treat for all her hard work, so I took some mealworms out and whistled as I approached. She flew out immediately, but just to a nearby tree to watch what I was doing. I left her a few mealworms for her hard day's work and left her alone to tend to enjoy her treat and tend to her eggs. (:

When a bird has laid all its eggs, does it sit on nest until eggs hatch or do they leave nest some times?

Hi,
Hi,
Most birds leave the nest on a frequent but short basis depending on the temperature and weather, unless they are penguins. My female Bluebirds don't leave the nest much while they are incubating; dad brings her food. Once they hatch, as I'm sure you know, it's a full time job all day long bringing the babies food.

Rob Barron

From: Kathleen Arnold [mailto:koscharn"at"cox.net]
Sent: Wednesday, May 17, 2006 11:08 AM
Subject: RE: Bird sitting on eggs

The mother leaves occasionally to feed herself. The time off the nest varies from bird to bird, and also depends how long it takes her to find a few insects. The nest cools down a little when the mother leaves, but not enough to stop incubation of the eggs.

Kate Arnold, Paris, Texas

Yesterday mom laid her 4th egg. Remember the first one ended up with a hole
in it. She did not lay an egg today so I am assuming that she is done
laying eggs now. Typically when will she start the incubation period? Is
there a way I can tell? Then about 12 days should I start to see
hatchlings?

It is really hot and winter here today and I have not seen my blue's around
at all?

Steve Murphy
Rochester, MN

From: Steve Murphy Home [mailto:thcri"at"qwest.net]
Sent: Thursday, June 01, 2006 6:52 AM
Subject: Getting to know me

One mistake I thought I really made when placing my house was the fact that I put it right next to our garden. We like to work in the garden at night and now I fear I would scare mom away during this time especially which is incubation. At least I think it is anyway. It now is 5 days after last egg was laid. However, last night will out there with the tiller getting the soil ready mom would fly around in and out of her nest even while I was within 10 or 15 ft of the nest. I just did not seem to bother her like in the past. Do bluebirds get use to certain people as when my wife came around then mom was not so brave and left?? I told my wife we had to leave at 8:00 an hour before dark to not upset incubation.

Another thing that I can not find on the web or anything is how do we know when they are in the incubation process. I know it can happen up to two weeks after the last egg with the colder weather slowing the process down.
It has been fairly warm here and I don't see my blues around as much as I use to, are they incubating?

Steve Murphy
Rochester, MN

Keith Kridler Mt. Pleasant, Texas
Bluebirds do tame down quickly if you follow a routine and don't remove their eggs:-)) If you seem to ignore them as you work the garden they will often begin to follow you as they do lawn mowers and other livestock and begin dropping down and picking up food that you stir up.

99% of the bluebirds will begin incubation of their eggs either with the next to last egg being laid or within 24 hours of the last egg being laid. A hen waiting 2 weeks after the clutch has been laid is probably a once in a 1000 nests. During incubation the eggs will be about 99*F when the hen leaves the nest. Eggs have very little mass and depending on the ambient temperature as soon as the female leaves the nest they begin to rapidly lose heat. (Take a 1/2 teaspoon of scalding coffee and see how long it remains hot outside in 40*F temperatures!)

Anyway if you carefully touch the eggs right after the female leaves the nest most people can feel that they are warmer than their finger tips. If so she is incubating. When eggs are freshly laid they have a dull appearance.
After a week to 10 days of incubation they will begin to look polished as she turns the eggs and they rub up against the other eggs.

....

1. I don't see my bluebirds around much anymore. I know they are
incubating but they never are on top of the house at all anymore. They use
to sit there a lot during the day and now not at all.

2. One of the 4 eggs has what looks like a scratch in it. Does this mean
anything or is this just from turning the eggs?

Steve Murphy
Rochester, mn

ps: caught another HOSP today!! This makes 6 in less than a week.

Sometimes Bluebirding is like watching a plant grow - you see the most when you look away for a while!
Good luck Steve

You won't see the mom because she is sitting on the eggs most of the time.
Now that they are not courting, the father will be guarding from somewhere nearby, rather than sitting on the top of the house.

Sometimes there are marks on eggs, and I wouldn't worry about it. Marks can appear when the egg is laid, because the blue color gets applied unevenly, and they might show up when she turns the egg over. She could also bring some dirt in on her feathers and a little might get on the shell. I would leave it alone and just observe.

You are doing well with your sparrow trap. Keep up the good work!

Kate Arnold
Paris, Texas