Posted by: Sandy Morrissey | September 18, 2016

Weather Affects Bluebird Nesting Season

Weather always seems to be in the news lately and now it seems to have made a dent in our bluebird population this year.

bb-male-fluffed-feather-to-stay-warm

Bluebird male fluffed up to stay warm in April

This was our 6th year of banding bluebirds and keeping close track of their nesting activity. Although we made a quantum leap in the number of nest attempts (going from a previous high of 115 to a whopping 137 nest attempts), our success rate crashed, going from an average in previous years of 80% success to a dismal 60%. This means we banded and fledged fewer bluebird babies. One good statistic that shows this is the average number of babies banded per nest attempt. For all previous years, the average was 3.3. The average in 2016 was 2.4.

Here’s what I think happened (though I have no scientific proof). We had an extremely mild winter. I don’t think the bluebirds ever migrated. They were fat and ready to lay eggs by early April. By the end of April, we had 56 nests with eggs (as opposed to an average of 34 in previous years).

However, if you recall, April turned extremely cold, with several days of snow and wind chills of 10 degrees. At the time I wondered how the eggs would survive this, and as time went on I learned. Many of those nests failed. The eggs were abandoned. After we removed the failed nests, the bluebirds built again and laid more eggs. Most of these nests succeeded at the usual 80% rate.

bb-egg-snow-on-ground-medium

Nestbox with bluebird eggs, surrounded by snow

But we missed out again when it was time for the second broods. In the cases where the first clutch of eggs failed because of cold weather, the females were then actually laying their third batch of eggs. For many of our bluebirds, this was too much to ask, and they didn’t lay the third clutch of eggs.

 Additionally, we had many nests with abandoned eggs at the end of the season. I surmise the females laid the eggs with normal instincts, but by then it was late in the season and they lost interest along the way.

 As I said, I’m making this all up, but it seems to me the best explanation of our unusual bluebird season. If I am in the least bit right, then we can expect Climate Change to wreak havoc on all our nesting birds. Food supply has to be in sync with the nesting cycle. Almost all baby birds mainly eat insects and there are very few insects around when the temperature dips below freezing. Extreme heat presents other problems. While one fluky-weather nesting season doesn’t constitute Climate Change, it sure shows how unusual weather can affect a whole nesting cycle. Scary.

Posted by: Sandy Morrissey | July 30, 2016

End of the banding season

I banded my last nest of bluebird babies on Tuesday. It was at Pequenakonck Elementary School in N. Salem.

BB last baby banded

There had been several nest attempt in this box, but all failed because of the bad ole house sparrow. Finally success. I had captured the female at an earlier visit and was thrilled that I captured the male. He was my official last band of the season.

BB last adult banded 2016

Today I had my last “recapture.” The story isn’t so happy. Last July I banded a female in box 5 at Gate of Heaven. She incubated the eggs for over a month (into August) but they never hatched. This year I recaptured her in the same box in May. She proceeded to have 3 clutches of eggs this year and none hatched. She is presently still incubating her 3rd clutch which sadly won’t hatch. I know for sure because I opened one today and it was just yoke and white – no embryo development. The male is still around lending support, but all for naught. Too bad.

BB female GoH6 - last band - incubating sterile eggs (Medium)Give this female E for Effort. Each time she lays 5 eggs (once 6 eggs) and all are sterile. Not sure if it is her or her male partner who is the blame. But she had had sterile eggs for 2 years in a row.

This is the first year since I started banding in 2011 that I have had no nests to band in August. Overall, it’s been a very unusual bluebird nesting season. We had a quantum leap in the number of nest attempts – up from 112 last year to 137 this year. But the nest failure rate will be about 40%, up from our usual 20% failure rate. I blame a cold snap in spring for some of this, but not all of it. Hope we go back to “normal” next year.

Now I’ll be busy entering my banding data into the government banding database, plus entering all the nesting activity in all 270 nestboxes we monitored this year. Couldn’t do it without the help of over 30 monitors and untold number of other people who help with our bluebird project. Thanks to all!

 

 

Posted by: Sandy Morrissey | July 19, 2016

Proof there can be incest in the bluebird world

A nesting pair in a box at St. Andrews Golf Club are at the same time, husband and wife and brother and sister!

I managed to capture both the male and female and was amazed to discover that both were from the same brood born in another nestbox at St. Andrews last year. Their band numbers were only 2 digits apart.

In the six years that I have banded – over 2000 bluebirds – this is the first time I’ve proven that there can be incest among bluebirds. I’ve always wondered how they could tell a sibling from a non-sibling. Apparently, they can’t.

This couple is on their second brood. The first was successful and the second looks like it will be too. The nestlings show no abnormalities.

My recaptures have shown that bluebirds do not disperse far from their natal nest site. The farthest any has traveled is under 4 miles. So it would make sense that the available mates might be relatives.

Always interesting things to discover along the bluebird trail.

St Andrews female sibling

Female who mated with her brother.

 

male BB St Andrews

Male who nested with his sister

 

 

 

 

 

 

 

 

 

Posted by: Sandy Morrissey | May 8, 2016

We’ll have lots of busy Bluebird Moms

We now have 56 bluebird nests with eggs, and Moms will be busy – as they always are.

Opened this nestbox, just as the 5th egg was hatching.

BB chick hatching 1

BB chick hatching 2

 

BB chick hatching 4

 

This nest has 6 eggs. Best present for this Mom is not flowers, but lots of insects.

You can help by planting Native Plants – which our native insects require.

Happy Mother’s Day to all the hard working Moms!

 

Posted by: Sandy Morrissey | May 4, 2016

1st Bluebird babies! 1st Tree Swallow Eggs

1st bluebird nestlings have been born in our area, which is Westchester County, NY. Banded our first nestlings on May 2. They were born on April 26.

1st nestling band of year - Rock 3A (Medium)

Out of curiosity, I decided to check the date of when the first nestlings were born in our area since I started this banding project in 2011:

2011   April 27
2012  April 20 (after very warm winter)
2013   May 4
2014   May 7
2015    May 1
2016   April 26 (warm winter but cool spring)

I’ve heard from readers in the south. Their bluebirds are a month ahead of us here in the northeast. I also think they get 3 broods, which is highly uncommon here. Lucky them!

Someone said “go” among the Tree Swallows, and they’ve started laying this week. The earliest date of first egg was April 28th. I expect a lot of reports of Tree Swallow eggs this week.

TS 1st eggs of 2016 (Medium)

I expect more eggs to be laid in this typical Tree Swallow nest lined with feathers

We don’t get many Black-capped Chickadee nests, because we locate our boxes in areas that are more open than the chickadee usually likes. However, we occasionally do get one. I’m enjoying this chickadee nest at Harts Brook Park, which is near my house in Hartsdale.

Chickadee nest

The first egg just arrived in this chickadee nest when I checked on May 2nd. Hopefully the competing tree swallows and house wrens leave it alone. The bluebird has often nested in this box, but it chose another this year.

 

 

 

 

Posted by: Sandy Morrissey | April 29, 2016

Zero to 45 in 10 days!

We now have 45 bluebird nests with eggs. All happened in the past 10 days.

We have 3 nests with 6 eggs. So looks like my prediction of a higher than normal number of nests with 6 eggs will come true.

We have three nests of white eggs.

BB White eggs

Two are in nestboxes in Gate of Heaven Cemetery. Most interesting is I captured the female in one of the nests and she wasn’t banded. I was sure she would be either one of two females that produced white eggs in the past two years. Or, I though she might be an offspring of one of these females. That would have contributed to the theory that producing white eggs is a genetically passed on trait.

I  have banded all of the offspring of the two females laying white eggs at Gate of Heaven. So I was most surprised when I captured the female in one of this year’s nest of white eggs. She wasn’t banded!

Here’s my first band of the year:

1st band of year - Gate of Heaven 8

I will report back when I capture the other female with white eggs at Gate of Heaven. Since less than 5% of females lay white eggs, it will be most amazing if she isn’t one we’ve captured before – or an offspring.

At the French-American School of NY, there is another interesting nest of white eggs. One of the eggs appears tinged with blue. I believe the blueish egg is from another female. A case of “egg-dumping.”

FASNY BB white  eggs - 1 blue

There’s always interesting sights along our bluebird trails!

 

 

 

 

Posted by: Sandy Morrissey | April 23, 2016

Someone said “Go”

Most of we bluebird nest monitors were looking at completed nests with no eggs for quite a long time – thru the cold weeks of April. Then this week (after a week of warm temps)  someone said “go” and the egg-laying commenced!

We have at least 12 nests with bluebird eggs all throughout the county. Leading the way is Lasdon Park and Arboretum, which has 4 nests in its 4 locations. To top that off, it has one nest of 6 eggs.

I predict we will get several nests with 6 eggs this spring, like we did in the spring of 2012, after an unusually warm winter. But while this winter was warm, we had several cold weeks in early spring. So my prediction of lots of 6-egg nests may not come true. As always, time will tell.

6 BB eggs at SGC (Small)

 Nest of 6 eggs. Will we see many of these this year?

 

Posted by: Sandy Morrissey | April 12, 2016

Early Nest with Eggs fails

Checked on that super early nest with eggs on Sunday. Sadly, the nest failed. Two eggs were missing and one of the two in the box had been broken open. All was cold.

Failed BB early nest - broken egg (Medium) (Small)

The egg yoke proves the eggs were laid recently. I believed they were abandoned.

 

When I arrive in the area of the box, a Tree Swallow was perched nearby. No bluebirds in sight.

Tree Swallow - Outhouse Orchard (Small)

Does this guy have egg on his face?

I was cheered to see a pair of bluebirds guarding their box further down the road at Baxter Preserve. The female has a band. The nest looks ready, but they are being smart about not laying eggs until it gets warmer.

 

BB pair Baxter 2 - f w band (Small)

And I was delighted to see a gorgeous Pine Warbler singing in a tree near the nestbox at Baxter Preserve.

Pine Warbler - Baxter Preserve (Small)

Pine Warblers are one of the earliest warbler migrants. Too bad it is just passing through.

Posted by: Sandy Morrissey | April 3, 2016

1st Bluebird Eggs this year

Found 4 bluebird eggs in a nestbox located on Outhouse Orchard in North Salem today. Since bluebirds lay one egg a day, the 1st egg had to be laid March 31 or a few days earlier. I had checked this nestbox on March 28 and there were no eggs. So it is even possible the 1st egg was March 29. 1st eggs 2016 Outhouse box5 (Medium)Looking at my records, this is the earliest date that bluebird eggs have been laid since I’ve been keeping detailed records as of 2011.

Of interest, I checked my data for the date of the first egg in the past 6 years, with the previous winter’s weather in parenthesis):
2011 – April 9 (average winter)
2012 – April 1 (very warm winter)
2o13 – April 14 (average winter)
2014 – April 16 (severe winter)
2015 – April 13 (severe winter)
2016 – March 31 (very warm winter)

Following the last warm winter of 2011-2012, we had our previous earliest date for 1st egg, plus we had six nests where bluebirds laid 6 eggs. This was highly unusual. We usually only get 1 or 2 or no nests each year with 6 eggs. It will be interesting to see if we get a lot of nests with 6 eggs this year following this warm winter.

That said, the spring is starting off cool. Note the snow around the nestbox with the 1st bluebird eggs:

Outhouse box 5 w 1st eggs 2016 (Medium)

After a few warm days, we are getting an Arctic blast of high winds and temps in the 20s. I will be most curious to learn if these bluebird eggs survive. Time will tell.

 

Posted by: Sandy Morrissey | March 30, 2016

Bluebirds now building nests

Saw my first bluebird nesting activity this weekend at Rockefeller SP. While most nestboxes still remain empty, a few early birds, like humans, want to be in 1st place.

IMG_1413 (2) (Medium)

Look closely and you’ll see a band on this female.

 

 

 

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