Just before 6 AM, the peregrines started the day with fair skies, wind from the south at 3MPH, and temp at 61F.  The forecast for the day ahead calls for a chance of showers and thunderstorms, then showers and possibly a thunderstorm after 5pm. Some storms could be severe, with large hail, damaging winds, and heavy rain. High near 83. Light southwest wind increasing to 6 to 11 mph in the morning. Winds could gust as high as 26 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

A line of storms will move through between 3pm-9pm, and will likely affect the evening commute. Some of these storms could be strong/severe.  This is the forecast from the Storm Prediction Center in Oklahoma, indicating the most likely areas to see severe weather tomorrow.  With any strong/severe storm cells, the greatest threats will be strong/damaging wind gusts as well as heavy rain.  As with any thunderstorm, severe or not, lightning is a danger.

The female was seen incubating and brooding first thing this morning.  She didn’t move for the longest time during my morning watch….no way of knowing if third egg hatched?  All eyes are upon the likely remaining two eggs, waiting for them to hatch.  In most years, the eggs tend to hatch close to one another in a fairly well synchronized way, and within 24 – 48 hours of each other.  We have seen the remaining egg shells around the hatchlings.  The adults may move these around a bit with their bills.  They may seem to nibble a bit on the broken pieces, but they don’t have a well developed habit for disposal of the egg shells.  For the most part, the remaining pieces of egg shell will become trampled.  The hatchlings have a delicate white down at birth, with none of the coloration that will come later with true feathers.  They form a feathery white cluster in the first few days and remain in very close contact with one another as though in a rugby scrum!

Just a bit later, around 7:13 PM, the female came roaring back to the nest box, and she provided a nice opportunity to capture an image of her with talons outstretched while landing at outer edge of nest box.  She then saunters over to connect with her first of the year hatchling.  After the past 30 days of shared incubation duties, through day and night, all kinds of weather and temperatures, and who knows what other kinds of issues and distractions, and with a new mate, she must be pleased to see the first egg hatch and the arrival of the first born….yet again the miracle of life!

She spends time cuddling the hatchling and establishing a motherly bond.  Typically the female does most of the brooding of the hatchlings as her mate will handle most of the hunting and delivery of fresh food for the little ones.  It is an awesome sight to watch the chicks beg for food and take turns eating every bit of food that will be delivered!

As early Sunday afternoon rolled along, the skies went from overcast, to partly cloudy, partly sunny to clear skies and bright sun!  Later in the afternoon, was able to finally get back and check for an update, and WOW…..a piece broken shell was sitting next tot he female…right on schedule….FIRST EGG HATCHES!!  Then, just after 7 PM, the female rose up and departed as the male landed at right edge of nest box.  This was a memorable moment, with first looks at the first hatchling….a little white fuzz ball.

Condition At Hatching

The peregrine falcon eyases are semialtricial, nidicolous; covered with off-white (prepenne) down. Semi altricial means: Covered with down, incapable of departing from the nest, and fed by the parents. In species like the peregrine falcon we speak of semialtricial 2, hatch with the eyes closed.  The bill and feet pinkish to pale gray with eyes closed. They weigh about 35–40 g. If eyes open with food-begging first day, they are slitlike. The eyases obtain 2 downy plumages.

Literature cited:

Veldhuis, Froona, Eyases growth and development                                                                                                                                                                                                                                http://falcoperegrinus-froona.blogspot.com/2008/04/eyases-growth-and-development.html

This morning the peregrines encountered overcast skies, with calm wind conditions, and the early morning temp at 47F.  The day ahead forecast calls for rain, mainly before 5pm. High near 52. East wind 3 to 6 mph. Chance of precipitation is 100%. New precipitation amounts between a tenth and quarter of an inch possible.

Just before 5:30 AM this morning, the female rose up off the 4 eggs, and departed out of the right side of the nest box.  Moments later the male entered and settled on the eggs.  Almost thirty minutes later, he became a bit restless, rose up, walked around a bit and settled back down.

Hatching preparations are now underway!

We are almost there. The first egg was laid on April 5th and the second on April 7th. The peregrine falcon starts incubation after laying the second to last egg. So April 10th is the first day. That makes May 11th the 31st day. Incubation usually takes 29-33 days, sometimes 35 days when the breeding couple has left the eggs often. That has not been the case here. Hatching takes about 48 hours from the first pip in the shell membrane until the actual hatch.

In the last 2 days before hatching final preparations are made for a successful hatch process!

* The beak turns towards the air cell.

* The beak breaks through the inner shell membrane.

* The lungs begin to function.

* The yolk sac begins to enter the body cavity.

* The lungs are using the air cell for breathing completely.

* The embryo occupies all of the egg except air cell.

* The neck begins to spasm.

* The egg tooth pips through the shell.

* Exhausted and wet – but alive – the chick has hatched!

There is a lot going on inside. A major operation! How does that tiny creature get him or herself out of the eggshell, out of its tiny sophisticated incubator? That is quite a job and do not underestimate the enormous amount of energy this must take. Making the escape is a process that takes many hours. From the first pip to actually hatching can take over 12 hours!

About three days before hatching, the embryo’s head burrows beneath the right shoulder so the beak is positioned under the wing; against the two membranes separating the embryo from the air space at the large end of the shell. Sometime that same day, due to oxygen depletion, the beak pierces through the membranes into the air space; pulmonary respiration begins. The little chick is starting to make sounds as well; a very weak shri-shri-shri is coming from within the egg. From all eggs that are in this stage. The little ones are telling each other to hatch too, so all of them hatch after each other with a little time interval.

About a day later, with a dwindling oxygen supply, the embryo begins to kick, to twist and to thrust its head and beak backward, until the egg tooth pips the first hole. The chick can now draw breath. As fresh air enters the shell and circulates, the membranes inside begin to dry, and the blood vessels within those membranes begin to shrink.

The embryo continues to pip, kick and twist. Small cracks advance counter-clockwise by millimeters around the big end of the shell. A special “hatching muscle” on the back of the chick’s neck swells to several times its normal size with a great influx of fluid from the embryo’s lymphatic system. Testosterone is catalyzing this. The swelling accentuates sensory signals sent through the neck, stimulating the embryo to further activity. Eventually, the cap of the egg is cracked enough. The embryo pushes it off, unfolds from the tuck, and escapes from the shell.