Alcoa Anglesea day 13

The Falcon and the Squirrel

I came across these superb pictures made by Chad & Chris Saladin.
The pics were shot in April. Hillary of Hilliard Bridge sat in a close tree, when a squirrel started making his way up toward her. She watched intently as the squirrel checked her out from a branch right across where she was perched. Then the squirrel started up her branch. Hillary gave the defensive posture, then lunged a bit toward the squirrel, and he scooted the other direction.
It is as if Hillary is saying: Don't you know who I am? Do you want to end up as my dinner, come on and make my day.
And gone he was the squirrel, a fascinating interaction between raptor and potential prey. Peregrine falcons do catch squirrels. But not like this. The squirrel in a tree is much faster than a peregrine falcon.
But Chris and Chad have seen Hillary dining on a squirrel once.......
The pics are magnificent. Thank you Chris and Chad Saladin!

Quest of Rochesters travels

September 7 th: Quest has really settled down in her Summer territory. She has found herself a save place full of prey. Here she can practise her hunting skills and feed herself to build up power and strenght. It is great for her that she has flown all the way from Rochester, New York to Cape Cod. It is such a wonderful start for a young peregrine falcon. And it makes us all very happy to know she is doing well!

Alcoa Anglesea day 12

Alcoa Anglesea day 7

Embryonic development, day 5

Embryo on day 5

Day 5

The embryo uses oxygen and disposes of CO2. Both have to be transported from and to the embryo. In the first 2-3 days the early embryonic germ layers (ectoderm, mesoderm, and endoderm) in the blastoderm are just few and so oxygen can be obtained easily. But as soon as the layers increase the embryo needs a infrastructure within the egg for the oxygen, bourishment and protection.

The 3 extra embryonic membranes are formed from the primitive germ layers within the egg. Everything needed for the development of the embryo is on board of the egg. Water, nourishment and energy like fat are there for tissuegrowth and everything needed to maintain the proces. The only things needed are warmth and oxygen.
On the 5th day of the emebryonic development:

* The somites extend to the tip of the tail.

* The toes begin to form.

* The allantois is visible coming off the hindgut.

* The allantoid circulation is commencing

* The Erythropoiesis starts in the yoke sac

* The embryo starts to move with head and neck region

* The amnion strats to contract

* The proteinase is starting

Alcoa Anglesea: day 6

Extra embryonic membranes

After the gastrulation, the development of the extra-embryonic membranes is the most important event in the early embryonic stages. It's like setting up camp. In the first 2 days oxygen exchange is possible through th eeggshelle. But when the celllayers get thicker the embryo needs a proper circulation from itself to the eggshel to get enough oxygen. And one from his foodsupply - the yolk- to his body.

Evolution has figured out an amazing way to do that.

On the third day of incubation, blood islands begin linking and form a vascular system, while the heart is being formed elsewhere. By the 58 th hour of incubation, the heart and vascular systems join, and the heart begins beating. Two distinct circulatory systems are established, an embryonic system for the embryo and a vitelline system extending into the egg. In later stages of embryonic development, there are two distinct extra-embryonic blood systems. One system, the vitelline system, transports nutrients from the yolk to the growing embryo. from the fourth day on, it oxygenates blood. The other blood system, made of allantoic vessels, is concerned with respiration and the storage of waste products in the allantois. When the chick hatches, both circulatory systems cease to function.

The three extra-embryonic membranes are formed from the primitive germ layers:

The Yolk Sac

The yolk sac surrounds the yolk and draws nourishment from it. Blood islands, which eventually form channels followed by vessels, are derived from the mesoderm. These blood vessels, the vitelline vessels, extend to connect with the ovessels coming off the heart of the embryo. The cells lying next to the yolk become more and more specialized to digest the yolk and pass its nutrients on to the neighboring vitelline circulation and thus to the embryo

The Amnion

Ectoderm and somatic mesoderm surrounding the embryo, form a protective covering over the embryo called the amnion. The inner layer of cells secretes amniotic fluid in which the embryo floats. This fluid keeps the embryo from drying out and helps protect it when the egg is jarred.

The Chorio-Allantoic Membrane

Ectoderm and somatic mesoderm form the chorion which lines the eggshell and performs gas exchange and waste elimination. The allantois is the embryo's connection to the chorion. It appears as a balloon-like structure coming off the hindgut at about day 5. It carries with it the allantoic vessels coming off the heart. The allantois grows larger as the chick grows, wraps around above the chick, and fuses with the chorion. It works together with the chorion to exchange gasses between the embryo and the outside environment. The egg shell is porous and thus allows oxygen and carbon dioxide to pass freely back and forth from the environment to the inside of the egg.
The chorio-allantoic membrane is also responsible for drawing calcium from the egg shell and carrying it back to the chick. Calcium is needed to carry on general metabolism and make bone ( ossification) . For the first 15 days the chick can absorb a sufficient amount of calcium from the yolk. But at around day 15, the formation of bones begins to accelerate and the embryo must draw calcium from the egg shell. The allantois also stores wastes (urine) once the embryonic kidneys begin to function. When the chick hatches, the chorio- allantoic membrane remains attached to the egg shell and is therefore discarded with it.

It is an amazing journey to see what is happening inside the egg. And a true miracle of life

illustration by Janet Sinn-Hanlon

Embryo: the first 4 days

The Mystery of the beginning of life

The beginning

The age of the embryo when the egg is laid varies. Peregrines tend to lay eggs during the night or early morning or in the evening.; if the egg is not complete until later in the day, it will probably not be laid until the next day. The rate of development of the embryo once the egg is laid also varies. If the eggs are cooled after laying, development of the embryo ceases until the temperature rises again. Development can resume even after the eggs have been cooled for several days. The temperature of eggs incubated by their mother is 106 degrees Fahrenheit The temperature of course will vary when the peregrine leaves the eggs to eat, etc. All of this affects the rate at which the embryo develops and, therefore, how long it takes for the chick to hatch.

The first 4 days are essential. A lot is going on in those 4 days. Let's have a closer look inside the eggshell. It is a magic journey through the universe of the dawning of life itself.

First Day: The Journey Begins

Before the Egg is Laid:

* The egg is fertilized.
* The zygote divides and begins to grow.
* The cells segregate into groups of specialized function.
* The embryo nearly stops growing between laying and incubation.




During Incubation:

* The area pellucida and area opaca of the blastoderm develop.

MAJOR EVENTS

Second day:

*27 hours: The alimentary tract appears.
*28 hours: The brain crease begins to form.
*29 hours: Somites appear.
*31 hours: The brain and nervous system begin to form.
*32 hours: The head fold begins to form.
*34 hours: Blood islands appear.
*35 hours: The eyes begin to form.
*37 hours: The heart begins to form.

Third day

*52 hours: The ears begin to form.
*58 hours: The heart starts to beat


Fourth Day

Yolk in the 4th day

*76 hours: head turns to the left
*78 hours: Amnion has enclosed the embryo
*80 hours: Allantois begins to form
*88 hours: The beak begins to form.
*92 hours: The leg begins to form.
*94 hours: The wings begin to form

Alcoa : day 5

The incubation is on it's way. The eggs are being turned every hour!.
That is necessary to prevent the embryo to stick to the membranes.

The estimated date of hatching is October 4!