Any bluebird experts here?

My resident pair of bluebirds have been raising in the same box for their 7th year now and I think they've about played out their string.

Last year she fledged four from the first laying, abandoned three eggs from the second batch during a long hot spell, and then laid 3 more for the final go round but only two hatched from that batch.

This spring she built and laid eggs fairly early due to the early spring and the young fledged nearly a week before I expected them to, only staying in the box 11 days after hatching. Turns out there was only one of them and one other unhatched egg in the nest. When I was sure the nest was empty I cleaned it out and two days later she started building a new nest. The male has been feeding her at the hole for five days now so she is definitely setting eggs again.

I guess my question is whether she might be running out of eggs much like a laying hen does. I've read that birds are only equipped with just so many eggs and when they're all laid that's it. I was afraid due to her age that she wouldn't make it through the winter and a new pair might take over but she appears to be soldiering on. During the winter I had as many as 12 bluebirds here in the yard for brief periods and 8 during most of the winter, but they've all sought different digs after the resident male about wore himself out chasing them relentlessly.

Any wisdom anyone can impart concerning their habits?

Some birds will lay another clutch if the first clutch wasn't that successful.

Blue birds aren't actually blue.

The general rule for most birds is the older the female, the fewer the eggs they are capable of laying.

My question is, how certain are you that its the same female from last year? I remember one Spring our resident female was killed right in the middle of raising a clutch. Dad Bluebird finished raising the brood, and had a new girlfriend within days of the missus's demise.

Multiple females is indeed a possibility. We've seen it on our farm.

You are supposed to move the boxes every few years also...keeps the snakes and other predators guessing.

snakeskinner said:

Blue birds aren't actually blue.

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True, and Cardinals are not red.

There is no pigment in feathers.
The colors we see is refraction from certain gases in the feathers......like a prism does...looks clear but refracts the rainbow.
Put a flashlight behind any feather and turn it on. It is gray, not blue or red or green.

http://indianapublicmedia.org/amomentofscience/blue-birds-blue/
http://www.birdwatchingdaily.com/fe...why-cardinals-are-red-and-grackles-are-shiny/

These two articles suggest that cardinal feathers are red.

I have worked with Frank Newell of the Eastern Bluebird Rescue Group in Warrenton NC for at least 20 years. Bluebirds will usually raise 3 separate nestings of chicks per year...sometimes 4 if the weather is favorable. A male bluebird will tend more than one female at times. I don't know the answer to if bluebirds run out of eggs eventually, like chickens, but I suspect it is probably the case. I'll try to find out. You need to put up some new houses for all those young'uns. They will come back "home" also, but mom and dad will fight 'em off from their house. Keep the houses at least 100 feet apart.

You can buy EBRG bluebird houses from almost any State Employees Credit Union for about $10. The EBRG is a non-profit organization, by the way.

aya28ga said:

The general rule for most birds is the older the female, the fewer the eggs they are capable of laying.

My question is, how certain are you that its the same female from last year? I remember one Spring our resident female was killed right in the middle of raising a clutch. Dad Bluebird finished raising the brood, and had a new girlfriend within days of the missus's demise.

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The female has gotten paler over the years, their feeding station is about 20' from our observation position and their watering dish is about 15' feet plus I use binoculars a good bit so we can tell it's her. The younger birds are more colorful.

41magnum said:

True, and Cardinals are not red.

There is no pigment in feathers.
The colors we see is refraction from certain gases in the feathers......like a prism does...looks clear but refracts the rainbow.
Put a flashlight behind any feather and turn it on. It is gray, not blue or red or green.

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A cardinal's skin is black.

Soilman said:

You need to put up some new houses for all those young'uns. They will come back "home" also, but mom and dad will fight 'em off from their house. Keep the houses at least 100 feet apart.

You can buy EBRG bluebird houses from almost any State Employees Credit Union for about $10. The EBRG is a non-profit organization, by the way.

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I build houses and distribute them to neighbors and friends who will maintain them. I build mine from cypress and Eastern white cedar but the one we have had so much success from is a length of hollow log which is the ideal size inside for bluebirds. We live along a high tension right of way with loads of large open maintained yards for access to crickets and all their favorite insects. I rarely place houses closer than 100 yards from each other but it is difficult to keep the English sparrows out of them if they're too far from a house.

My biggest problem is a next door neighbor who wants bluebirds in his yard in the worst way but we live on a circle and his yard is narrow in the front (pie shaped) and too many trees in the back to suit bluebirds so his answer is to hang boxes all over his yard and the neighbors yard on the other side. At last count he had no less than 10 boxes in his yard and they stay full of house finches, English sparrows and chickadees. I've tried to explain the result of what he's doing to him but this guy is the poster child for ignorant belligerence so I'm stuck with him I guess. It seems to really honk him off because I have them and he can't buy a pair.

Good deal, Blackwater! Bluebirds can use all the friends they can get. Sorry about your neighbor. English sparrows are invasive and one of the bluebirds biggest enemies.

Bluebirds are extremely territorial, and will fight each other like alley cats defending their turf. At least a couple of times each Spring I'll hear a commotion in the yard and see a couple of Bluebirds going at it, rolling around on the ground like a couple of schoolboys in a tussle.

I've set up several of Frank Newell's birdhouses on my property, but the resident pair won't tolerate any neighbors. We only have one nesting pair at any one time.

Likely not the same female. The male generally initiates the mating and nesting. Bluebirds are not monogamous and do not mate for life. Mine started nest building on March 8th this spring and a Cooper's hawk nearly killed the female after she laid her second egg. He broke her wing tip and I was able to catch her with a fish net on the ground. Within a couple hours of her calling from the ground, another female had shown up and was being pounded by the male every time she got close to the box. I took her inside and put her in a parakeet cage and fed her for about 20 days with mealworms which she was used to eating outside. Less than 2 hours after I caught her and removed her nest, the male had accepted the other female and she was building. She is now setting 5 eggs. I released the injured female about 6 miles away in a park and she was able to fly enough to stay off the ground. I knew the hawk would get her if I left her and no telling what the future nesting results would have been. I've had birds raise up to 5 clutches a year. Normally the first 2 clutches are 5 eggs and the rest are 4 or less. The early warm ups the last few years has screwed up the first clutch because of eggs being chilled before the female started setting. Also, feeding mealworms will ensure healthier fledglings because the adults don't feed as many insects which have been exposed to pesticides. I made the mistake of spraying flowers with permethrin one year for Japanese Beetles. The adults fed the dying beetles to nearly fully feathered fledglings and it killed them all.

I've got three boxes on a open area,around three acres,that stay full all summer...I clean the boxes out after the babies leave to keep disease down,and before you know it they've started again.Ive counted as high as 21 at a time in late summer,mostly young ones.Some of the breeding pairs look pretty bad by the time Fall rolls around.Also,I don't open the boxes when they're feeding,but all three boxes have bluebirds about to leave the nest already.

I had my first ones nesting in our new house. She had 5 eggs and all was good. I hadn't checked in a week or so and when I did the eggs were gone. The house is up about 6 foot from the ground. I used a white vinyl post in thoughts a snake couldn't climb it. The closest tree is about 2-3 foot away. Anybody got any ideas what may have happened.

ncscrubmaster said:

I had my first ones nesting in our new house. She had 5 eggs and all was good. I hadn't checked in a week or so and when I did the eggs were gone. The house is up about 6 foot from the ground. I used a white vinyl post in thoughts a snake couldn't climb it. The closest tree is about 2-3 foot away. Anybody got any ideas what may have happened.

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House wrens or Carolina wrens will kill the young and drive the parents away sometimes. Those are some vicious little birds.
And with a tree 2-3 feet away it could have been a snake or a squirrel that robbed the nest.

If the eggs are gone and the nest is otherwise undisturbed it was a snake, most likely a Black rat snake. The only way to keep them out is to put a baffle on the pole holding the bird house, and sometimes even that doesn't work. I make my baffles out of stovepipe with wire mesh in the top end, and hang them with plumber's hanger tape.

Yep, I agree with Aya. More than likely a snake.

Eric Revo said:

House wrens or Carolina wrens will kill the young and drive the parents away sometimes. Those are some vicious little birds.
And with a tree 2-3 feet away it could have been a snake or a squirrel that robbed the nest.

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I'm wondering if this happened to the young in my birdbox this year. It would be the second time in two years. Last week, I saw a bunch of ants around the opening to the box. Looking inside to see the dead young birds.

I guess I thought they couldn't climb that slick post. I will have to work on that and also may need to kill some snakes. I hate them things.

ncscrubmaster said:

I guess I thought they couldn't climb that slick post. I will have to work on that and also may need to kill some snakes. I hate them things.

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I've learned a Black Rat snake can climb just about anything. The baffle on a pole usually works, as the snake climbs up the pole inside the baffle and gets stopped by the wire mesh inside.

And we don't kill our Black Rat snakes; they're just too good at catching vermin like voles, mice/rats, copperheads, etc, not to have around.

Homebrewale said:

I'm wondering if this happened to the young in my birdbox this year. It would be the second time in two years. Last week, I saw a bunch of ants around the opening to the box. Looking inside to see the dead young birds.

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Another bluebird disaster! After my nesting pair fledged their single bird I cleaned out the nest and within 2 days she was building again. They hatched three this time and fed them hammer and tong until about a week ago before stopping their trips to the nest. I knew the young were feathered out but didn't think them ready to fledge and yesterday noticed she was starting a nest in another box about 100 yards away so I went out this morning to check the nest and found flies working in the hole and the unmistakable odor of decay. Pulled the nest and found the little buggers dead and hosting maggots. They were within a few days of fledging when the parents abandoned them for some reason. There was no sign of disturbance in the nest and they were nestled together appearing to have just died in situ. No sign of any wrens or English sparrows around the nest and we spend a good bit of time watching the box and would have seen that type of activity?????? Might be a young pair of birds as the old pair were getting pretty old, so maybe this new batch will be more successful.

It could be parasites. Sometimes birds that nest in boxes or cavities can be afflicted by parasites especially mites or blowflies.

Clean the old nest out of the box and wash the inside of the nest box down with a real mild bleach and water solution.

Here's what I found in my bluebird house last week. There were 5 newly hatched chicks, but not for long.

Some solutions to prevent snakes from climbing the pole to your bluebird house is:

Bunched up fish net material around the pole. The snakes will try to go through it and get tangled
Carpet tack strips. Nail them on the post with the sharp tack ends on the outside
Aluminum cones like you see on duck houses.

snakeskinner said:

Blue birds aren't actually blue.

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I was taught this by a college professor, too, and never understood it. But I also remember a discussion, that without light, there is no color. In other words, in total darkness, no color. So, is there a level or type of light in which a bluebird is not, er, blue?