And then there were three.....

At sunrise on Monday, April 25, as the formel grabbed breakfast, there were still two eyasses and one egg in the nest.

The tiercel was keeping the pantry full of supplies including a baby rabbit and another rat, all close at hand for the formel to feed herself and the chicks.

At 8:00 AM, the tiercel bounced in with yet another small furry mammal....

 .... which he proceeded to tear into.

Then followed one of those amazing moments which normally we would never see except for the privilege of the camera feed into the nest.

 The tiercel pulled off small pieces of meat, leaned forward and tenderly fed the formel as she sat on the chicks and egg.

She eventually stood up and moved closer to the increasingly red meal, and he continued to feed her as she stood beside him.

The egg remained in the middle of the action surrounded by the fluffy eyasses.  How could they have fit into their eggs less than 24 hours ago?  There now seemed to be small pip on the remaining egg, and sure enough....

 ...when the formel stood up in the early afternoon, chick #3 was on its way into the world.  Janette Benner captured these images of the hatch.

 Mom watched carefully as her third eyass emerged into the hot Philadelphia afternoon.

By about 3:30, the eyass was fully out of its shell.

The formel moved in to cover the chicks....

and pushed the empty shell farther away.

As she settled in, three small heads appeared.  The hatching was complete.

Soon, she stood up and began to eat.  The hatchling was still wet and bedraggled, and noticeably smaller than its siblings.  Their approximately 36 hour start will give them a size and strength advantage over #3 who will only get its share of food when the other two are sated.

As the formel fed, one of the eyasses was clearly interested and hungry, while the other one gazed up at the window.

Within a couple of minutes, both eyasses  focused in on their feasting parent...

... and crawled towards her over their newly hatched sibling.  She started to feed them....

... and soon #3 was completely tromped under its siblings!

 The formel settled back down on the now sated youngsters....

.... but it wasn't long before the tiercel arrived with fresh food - as if any more were needed!  Appeared to be another baby rabbit.....

Dad was intensely interested in whatever had happened in his absence, peering intently at the formel, willing her to get up, it seemed. 

But she would not oblige, so he stood patiently and waited.  In the close to 85 degree sun we had yesterday in Philadelphia, you can see the tiercel's open beak as he panted in the heat.  The two oldest eyasses also had their heads poked out from under their mother.

So, fast forward to this Tuesday morning, April 26, and early camera watchers saw all three eyasses active.  The tiercel brought in fresh breakfast supplies, and the formel fed the chicks.  Here she is settling down as the morning rush hour starts up in the city.

Eyasses' First Day

After the excitement of the first two eggs hatching, the formel sat quietly on the eyasses for a couple of hours.  When she finally stood up, we had our first glimpse of one of the chicks gazing out.

After inspecting her chicks, she dragged over one of the rat carcasses that the tiercel had brought to the nest....

.... and started to feed the eyasses.

The third egg sat right in the middle of the proceedings!

After she finished feeding the chicks, she had a rat snack herself.  We can rather graphically see the long tail and back legs of the rat lying on its back

The headless hawk!

There is also another dinner item on the rat's left.

The tiercel (dad) returned to the nest and formel flew off for a break from nest duties.  The tiercel is a  devoted father and settled in quickly over the eyasses.

When the formel returned, she wanted to get him up but he would not budge.  She headbutted him gently....

... then paced around while he studiously ignored her.

She finally was able to get him up and off the chicks.

She checked them out....

...then settled down on them.  At first, her wings are tightly furled against her back.

As she relaxes, her wings start to drop down to provide better coverage at the sides....

.... until she is fully relaxed.

It is always somewhat disconcerting when both haggards leave the nest unattended...

 ... but within a couple of minutes it is over and out for the eyasses as they sleep during their first Philadelphia afternoon.

Mom soon returns....

....settles in

.... and starts to preen her feathers.

By 4 PM, it's time to eat again, and the selection in the pantry is becoming more varied, thanks to the tiercel's excellent hunting skills.

Both chicks are strong and eager to eat, which they do voraciously.

These Easter Day chicks seem off to a great start.

Easter eyasses hatch

At 6:35 AM Easter morning, the formel stood up and we saw a newly hatched eyass.

But a surprise - there was a second eyass hatching - we had missed the pipping of that egg yesterday.  The second eyass was still in its half shell.

 

 After inspecting her brood, the formel started to feed #1 from the rat carcass that had been left on the nest overnight.

 

The tiercel flew in and was clearly aware that something momentous had occurred.   He so wanted the formel to get up so he could see what was happening underneath.

He walked around the nest peering fixedly at her, willing her to move....

.... and then practically sat on top of her.

 Despite all his efforts, she would not move, so off he flew.

Then she stood up, and we could clearly see the second eyass working hard to get out of its shell - about 7:35 AM.

Mom was interested by this development....

... but then remembered #1 needed feeding again, so back to the rat, and more tiny morsels for the eyass only hours old but already feeding vigorously.

So now we wait for #3......stay tuned!

A pip! Hatching is happening....

On this rainy Saturday morning, it looks as if the first egg has started to hatch.  A pip appeared in an egg at about 10:40 AM.

Karen McCunney posted these screencaps on the Franklin Hawkaholic Facebook page of the formel seemingly aware that something is happening with one of her eggs.

Here's a close up posted by Larraine Campbell

And now at 12:30 PM, she is back in incubation mode.

An hour later, the tiercel returns, and as he and the formel switch over, we get another glimpse of the pipping egg, and how it has changed position since the view an hour ago.  This changeover is now so smooth and fast, one has to be very adept to do a good screencap - thanks to Marge Goodman,

This screen cap from Janette Benner has the tiercel carefully inspecting the situation

Last year, when the pipping began, John Blakeman sent us this very helpful commentary about the haggards' response when the eggs start to hatch:

John Blakeman comments:

"I think all of this [formel's restlessness] is a response to pipping sounds and perhaps even some very soft vocalizations from the eyasses yet in the egg.

Both haggards, when incubating, can feel the movements of the unhatched eyasses, very much as a human mother can feel the movements of her unborn baby.

I'm certain that this begins to turn on mothering behaviors; hence the increased activities. The formel realizes now that she's not just sitting on three inert white objects that feel good to have against her naked brood patch. Now, things are discernibly (but invisibly) happening down there.

With new sounds and tiny motions in the egg, a whole new set of behaviors is being prompted. Motherhood is a profound phenomenon, across all species. (We men pretty much don't get it, just inexplicably watch it.)

But as the formel knows and shows, things are starting to happen down there. We are all excited."

--John Blakeman

Incubation - what is happening?

The hawks have now settled into the incubating their three eggs.  Here is the information that John Blakeman shared with us last year on this amazing process:

John Blakeman tells us:

"The laying of the third egg initiated sincere, authentic developmental incubation. Until then, the formel had been sitting loosely on the eggs. She was merely keeping them slightly warm, not the prolonged and enduring 100 degrees F (or so) temperature needed for incubation.

Until the appearance of the third egg, sitting had been merely maintenance. The embryo of the first egg was not developed much, if at all. A fertile egg kept at the start between 40, 50, or 60 degrees or so simply just sits there, viable and alive, but with no growth of the organism inside.

At this point the baby hawk, which is called an eyass (EYE-ess) not a "chick" by those who know raptors, is only a mass of undifferentiated cells in the blastodisc on the surface of the yolk.

With proper incubation now beginning at consistent warm egg temperatures, the blastodisc cells will begin to grow, using the lipids in the yolk for energy, and the proteins and minerals in the egg white as building materials for the new tissues and organs.

The egg, or at least the developing embryo, will now start to metabolize, to take in and use oxygen and give off and expel carbon dioxide. Of course, the egg and developing embryo have no functioning lungs or other structures to accomplish these gas exchange processes. Oxygen goes in and carbon dioxide comes out of the egg through the shell, which on a microscopic level is rather porous.

In the next 28 days or so the egg will actually lose weight, as water evaporates out through the shell. The rate of this water loss is important and can signal the rate of development of the embryo and eyass inside. Rapid loss of water will kill the egg, and no loss of water would indicate that the embryo is already dead. The moist skin of the formel’s brood patch (bare skin on her lower chest/belly area) will help to control the moisture in the egg.

But these should not be concerns. This is an experienced, successful pair of red-tailed hawks who incubated, fed, and fledged three eyasses last year. They’ve done this before and know what to do, so we needn’t be concerned.

Here are some things to look for, and one thing not to be concerned about.

First, only the formel has a distinct, naked brood patch under her chest and belly feathers. The tiercel retains his downy feathers, so when he sits to incubate during the times the formel gets up, stretches, preens, defecates, and otherwise attends to herself, the eggs cannot be kept quite as warm as when they are in direct contact with the formel’s naked brood patch skin. This is one reason the formel does most (but not all) of the incubation. She’s just much better equipped, both physically and mentally, for this important job.

And to do that, watch now how she settles on the eggs. Until the third egg was laid, she and her tiercel just sort of plopped down gently on the eggs. Now, once she realizes that another will not be coming (red-tails in the Midwest and East virtually never produce four eggs), she will be much more diligent in settling upon them. She will sink a bit more slowly, and will often gently rock back and forth to position the eggs right up against her brood patch.

I have to think that this is a profoundly satisfying and rewarding feeling for the mother, to have those eggs right against her body. After she’s been away and resumes incubation from her colder mate, I’m sure she feels the slightly cooler egg temperatures. It must be gratifying for her to get them all cozy once again.

And that’s the second thing observers will note. From time to time, the eggs will be left unattended out in the cold air, often for 10 to 20 minutes or more. We’ve seen this already, many times. But true incubation hadn’t started yet, so there was no problem. Now, with development of the embryo in the blastodisc, an overly long period of cooler temperatures will kill the eyass.

All of us who have watched red-tail nests have been really anxious about these long, egg-cooling intervals. But in virtually every case, except with first-year or inexperienced adults who do often fail to keep the eggs warm enough, experienced adults like these know just when to get back on the cooling eggs and resume real incubation.

Why, then, do the parents allow these unattended, periodic cooling periods? We don’t know. I speculate that it may have something to do with oxygen diffusion and absorption into the liquid tissues of the egg and embryo. As you might have recalled from high school chemistry, the warmer a liquid is, the less gas remains dissolved in it. You didn’t drink that warmed-up soda after the carbon dioxide diffused away from it as the soda got too warm.

So, it’s possible that once a day or so the parents allow the egg to cool a few degrees for 10 or 20 minutes, allowing more oxygen to diffuse through the shell and become dissolved in the egg fluids. A breath of fresh air, as it were, for the developing eyasses.

Or, perhaps it just doesn’t make any difference with the oxygen, and the egg grows well enough with these periodic uncovered periods.

Either way, don’t be concerned until the egg remains uncovered for 45 to 60 minutes or so."

--John Blakeman