Incubating Eastern Bluebird

Incubating Carolina Chickadee

Incubating/Brooding Tree Swallow

WOOLWINE HOUSE BLUEBIRD TRAIL FINAL TRAIL RESULTS 2015 – SUMMARY 

The last set of bluebirds fledged early on Sunday, August 30, 2015.

43 Nestboxes Monitored 1-2 x Per Week (5 Were Unoccupied)

EASTERN BLUEBIRDS:

– 52 nest attempts

– 241 eggs laid

– 215 eggs hatched

– 211 bluebirds fledged

CAROLINA CHICKADEES:

– 3 nest attempts

– 16 eggs laid

– 15 eggs hatched

– 15 chickadees fledged

TREE SWALLOWS:

– 8 nest attempts

– 36 eggs laid

– 31 eggs hatched

– 25 tree swallows fledged

Predators:  

2 HOSP attack on Nextbox #34—destroyed TRES egg and 1 TRES fledgling killed just before fledging.  Neck and head pecked with huge hole behind head on top of neck area.  I chose not to post a picture, but I have one.  The hole on the back of the neck is huge.  It appeared the attack took place within a 48-hour period of time of my box check.

NO LOSSES due to blowfly larvae.  DE applied to all nests, all broods.  Only two or three nestings had no blowfly larvae found inside nesting material on nest inspection after fledging.  I will say some nest inspections still showed a few live larvae; obviously not enough to cause harm to the young.

1 Snake at PVC 6-inch width guard (a private nestbox by a homeowner) – resulted in loss of 4 EABL young after 13 days old.  Sometimes the PVC sleeve works; other times not.  The sleeve needs to be smoothed out and waxed periodically.  Sometimes any weed wacker around the base of the sleeve or mowing has cut grass clippings and thrown up dirt sticking to the PVC, creating a grip for predators.  Snakes will grip using their scales to that to cleverly maneuver their way up the sleeve.  The box is at 5 feet off the ground.   The box otherwise did well and fledged another brood after.  Appears to be a hit or miss on the snake there, probably the black rat snake, a native snake that I refuse to kill.   We need snakes to keep our rodent population down in the biological balance of things.  Other note is the rat snakes, being an expert climber, gets to other birds’ nests in trees and shrubs — much of nature we do not see at all.  If you use a PVC sleeve, try a wider one, keep it clean and smooth from any natural materials sticking to it, and use a carnauba car wax all the way top to bottom and buff it smooth.  This might help in future.  Keep wiping it down as necessary with a cloth to keep it free of debris.

Dead or Missing Young: 

8 — Either I removed or the parent birds removed.  One clutch of 5 feathered 12-day old TRES young died—inspected thoroughly for cause—NO TRAUMA and fully feathered–possibly starvation–possible poisoned from insecticides–do not know for sure.  Perhaps one or both parent TRES were killed and during a period of 3 days of rain, making it difficult for them to find flying insects to catch on wing.

Missing or Destroyed Eggs:   

5 — 1 TRES egg was destroyed and removed by HOSP in the school nestcam box.  The rest were removed by parent bluebirds or chickadees.

Unhatched/Unviable Eggs found on or inside nest:  

21

Other Interesting Notes and Events: 

I HAD ABSOLUTELY NO “ACTIVE” House Wren nestings and NO HOUSE WREN ATTACKS (predations) on other species eggs and young.  This is very unusual on my trail as last 3 years I’ve lost bluebird eggs and hatchlings due to House Wren attacks.  I did see a few sticks here and there dropped inside the nestboxes–one stick was dropped on 1 day old bluebird hatchlings.  Perhaps the parent bluebirds fought them off.  Theory only as I did not witness it.  I removed stick on top of the hatchlings.

I HAD ABSOLUTELY NO PREDATIONS of snakes, cats, or raccoons in my *protocol boxes* of pronged out Noel Guards and 8-inch wide wobbling stovepipe baffles.  This is cause for celebrations for me – a FIRST.   Last two years, I’ve had roaming housecats and possibly feral cats cause death to adult bluebirds (many with new hatchlings) getting ambushed on the ground while finding insects to feed their young.  This year, I did not find evidence of cat-caught bluebirds.  It does not mean it did not happen; however, usually I find the remains on the ground near the nestbox.  I was wondering if there was a loss of a parent bird at a few of the nestboxes.   Something got them, but I can’t determine what exactly:  either hit by a car, taken by a hawk, or taken be a cat, or killed by eating insects laced with pesticides.   I do not know.

I HAD ABSOLUTELY NO DEATHS to adult native cavity-nesting birds using my boxes due to HOSP attacks.  I did, however, lose one tree swallow ready-to-fledge in a brood of 4 by a HOSP attack.  Unfortunately this took place at the local elementary school’s nestcam box.   The better news is this attack did not take place while school was in session on live video projection!   This took place on or around the fledge date of the tree swallows near the date of July 20^th.

I HAD ABSOLUTELY NO DEATHS to any species nestlings due to blowfly larvae, with thanks to puffing inside the nesting material food-grade organic diatomaceous earth.

I HAD NO Tree Swallow vs. Eastern Bluebird competition for nestboxes this season.  However, I did have a good year with increased tree swallow nestings.  Unfortunately, I did lose one brood of 5 12-day old tree swallows due to either eating insects laced with pesticides or from starvation.

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AND MORE! …… READ ON BELOW:

The 2-Hole Mansion is in its 6^th year of success EASTERN BLUEBIRDS vs. HOUSE SPARROWS.  No deaths of adult or nestlings from HOSP attacks.   The Mansion fledged 5 bluebirds this season.

I did have to remove two dead young from one nestbox (standard box) manually.  I was not able to determine cause of death.  It was in a box by a pasture — the removed nest was inspected and only dead blowfly were found inside the nest.  Perhaps those two young did not get enough food.  No trauma found on the remains.

What I thought was a nestbox setup knockdown by a bear with live tree swallow young was really a tractor during mowing.  The box, in a public park, is installed on a slight grade.  The mower evidently was on wet grass and slipped down and knocked the whole setup down with live young.  When I arrived (do not know how long it had been), the young were still inside alive and the parent birds were stressed flying around the area.  I was able to reinstalled the setup, all bent up, and get it back so that the parent birds could continue care for the young, which fledged 3 days later!  By the way, how I discovered this is one monitoring week or so later, I saw the mowers and wanted to introduce myself.  It was then they mentioned it to me when I told them I thought a bear knocked it down.  I gave them my contact info (a biz card I keep for my bluebird volunteering effort) and asked them to contact me by phone locally if they notice something wrong with my box setups in the park.   I do have a label with my phone number on all my boxes.

One nestbox had a mixed white and pale blue eggs.  I tried to determine if two females were laying, but could only witness one female bluebird at the box location during the week the eggs were laid, 1 by 1, each day.

Another box had a female bluebird lay 5 eggs, then another female bluebird entered a week later and laid her 4 eggs and buried the first female’s clutch.  There is a possibility they had a fight over the box or the first female bluebird was killed and the 2^nd female found the nestbox soon after and used the nest.  The second clutch of 4 did hatch and fledge.  I found the first 5 eggs inside the nest material when I cleaned the box out.

In spite nesting was a month later this year than average, I had several nestboxes with 3 broods.

Latest fledge ever of bluebirds on the trail since 2007:  August 30^th

I had a good year for Carolina Chickadee nestings.  Only 1 egg of 16 did not hatch.  All others hatched and fledged successfully.

Two nestboxes NOT my protocol and not my property were monitored that existed on installations with no predator guards.  One was a fence line/wood post on a local church’s grounds and the other was on the school property’s ball field on a utility pole.  Box boxes were at about 5.5 feet high off the ground.  Once I established species and final egg clutch laying completed, I fastened securely Noel Guards at those two nestboxes, pronged them out, and conducted twice-a-week surveillance of the nestboxes for activity using binoculars.   Both boxes fledged birds successfully—species were bluebirds.

I know from witnessing this that bird species WILL remove dead young if they are small enough to lift and exit from the 1.5” entry holes.   This is also true for unviable, unhatched eggs, though mostly either the eggs remain in the nest or get buried inside the nest by a parent bird.  In the instance I can do so, after the 4^th day, I will try to manually remove unhatched eggs myself using a plastic spoon.

I am no longer experimenting with hardware cloth screen on nestbox floors.  Though I agree it helps with keeping nests drier, I do not find them helping keeping blowfly larvae from young as the larvae still sit inside the nest material at night, not falling below the nest through the gaps in the screens.  I am only using diatomaceous earth in ALL nests, all broods, to eradicate ALL parasites inside the nest material, mostly to eradicate blowfly larvae, but also mites and ants.

Due the nestboxes being well designed – the Carl Little Design – I have had NO WET NESTS from rain water getting inside the boxes and NO HEAT deaths due to inadequate ventilation, even with boxes in the sunlight.   The hottest day I logged this year along the trail was about 96 degrees.  Once it gets higher than 98, I would be concerned and would attempt to shade the boxes manually.  This was not necessary this year.

I did notice some nestboxes always occupied every year were NOT occupied this year.  I am thinking it is because we had a loss of bluebird populations in our area, all over Virginia, to severe winter weather and repeat freezing temperatures (enough to freeze homeowner’s pipes!).

I had one newly-installed nestbox by request of a neighbor that was late in the season (Memorial Day weekend).  It went unfound and unoccupied this year.  Next year, I expect it to be discovered and used.

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By:  CBB    Owner-Manager of the Woolwine House Bluebird Trail, Est. 2008.

Pretty Eastern Bluebird egg clutch.

OK, so you see us here. Please feed us!

Pretty Eastern Bluebird young soon to fledge. Don’t you love their color? I never use flash photography on the young birds inside the nestbox. That is very intrusive!

Mixed color clutch. I watched this box daily. I did not see more than one female laying in this box. Each egg was laid consecutively each morning, one by one. It appears the first egg was pale blue, the second egg was even paler blue, than the next 3 eggs were white. Perhaps her pigment gene in her oviduct was weak–possibly a first time laying female.

This is the nestbox that had live tree swallow young in — knocked down to the ground by a tractor mower!  NOTE THE PICTURE WAS ORIGINALLY CREATED THINKING IT WAS A BEAR THAT KNOCKED DOWN THIS SETUP WITH LIVE BIRDS–IGNORE THE TEXT IN THE PICTURE THAT SAYS “BEAR” attack.

When I opened the box, this is what I found. I reinstalled the nestbox with the young stil inside and readjusted the nest. The parent TRES returned to feed and the young fledged 3 days later!

NOTE THE PICTURE WAS ORIGINALLY CREATED THINKING IT WAS A BEAR THAT KNOCKED DOWN THIS SETUP WITH LIVE BIRDS–IGNORE THE TEXT IN THE PICTURE THAT SAYS “BEAR” attack.

2-Hole Mansion in its 6th year of success. See 2-Hole Mansion page for story. EABL vs HOSP. I plan to replace the mansion, either refinished or with a new one. I may refurbish this one as a display to educate others about this nestbox option where trapping HOSP is not possible.

Typical successful nestbox setup on my trail. Note the one-inch conduit, 8-inch wide wobbly stovepipe (blowing slight in the winds in this picture), stovepipe set up high on the one-inch conduit and just under the nestbox, the Carl Little nestbox design, with a vinyl-coated Noel Guard over the entry hole and PRONGED out to help deter any possible predator like slithering snakes that would get past that stovepipe. This nestbox is a new install for 2015. Pretty scenery.

I use a shallow white bucket to clean all fledged nests out of the nestboxes, including any detritus. I then dissect the used, soiled nests to see what’s going on inside that nest during the nesting cycle. What I find inside is very educational. In this picture, you’ll see DEAD BLOWFLY LARVAE. Thank you diatomaceous earth!

When I install new nestboxes, this is what my car looks like. I can do this all by myself!

A box on a utility pole? This is a huge accident waiting to happen for nesting birds. I added a pronged out, sturdy Noel Guard–pronged out–and did a surveillance of activity on the box after I counted the final clutch of eggs. The baby bluebirds fledged. It is MUCH better to install boxes on poles and use predator guards under and on the nestbox. Installing nestboxes on 4×4 wood posts, fences, sidings of buildings, tree trunks, and on utility poles generally will not fledge bird families. It is just too easy for predators to get to this type installation. What’s the point? This box is at 5.5 feet high off the ground. Again, note the Noel Guard is pronged out and away from bird feathers and is applied with 4 screws and washers on each corner.

Equipment on the trail. Nest inspected and dissected.