San Jose Nest Diary 2009:
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Beginning on April first, ALIYAH KOVNER, an intern with the Predatory Bird Research Group at UC Santa Cruz, has contributed the nest diaries. We are grateful for her help! Note that diary entries list most recent events first.
June 12, 2009: Fledging began on Monday June 1st with Veer and Ilahay fledging in the midst of the excitement resulting from parent birds vocalizing and stooping at individuals on an exterior stairwell that they perceived as a threat to their young. Both fledglings made acceptable flights and fairly acceptable landings that allowed them to remain above ground level. In the coming days, the remaining females fledged with Tierra spending a night on the glass roof of the rotunda beneath the bars that form a shade for the glass roof. She weathered the experience and eventually made her way to perches on the City Hall tower. Just one San Jose fledgling, Kya, needed an elevator ride to the roof for a second chance at fledging. These birds fly well but land poorly and we all observed many instances during the first 3-5 days of flight where youngsters just barely “stuck” their landings. By Sunday June 7th, all of the San Jose fledglings had flown from and returned to the nest ledge. Today, they are putting on a spectacular flight show in the sky above downtown San Jose.
May 22: San Jose:
The SJ brood has received their names! Sent in to the Mayor, the suggestions came from elementary school children learning about the falcons, and there were more than 200 great suggestions. The three females are: Ilahay, meaning 'angel' in Persian; Kya, an African name meaning 'diamond in the sky'; and Tierra, Spanish for 'earth'.
The one male has been dubbed Veer, a Hindi word for 'brave'. Now that the four eyasses have grown stronger and spend less time sleeping and more exploring, it is often difficult to see more than one or two at a time through the camera. They seem to enjoy crouching between the nest box and the cement building ledge, and they can often be seem huddled there for companionship with one another.
May 15: San Jose
This morning at about 7:30 am the San Jose chicks were banded successfully. Each chick receives an ID band so that researchers and public observers can identify who is who, and a silver Fish and Wildlife Service band on the other leg. The final, approved names of they eyasses have not yet been decided, but it was confirmed that there are three females and one male. The process was very smooth this morning, taking only about twenty-five minutes for the whole banding procedure. Although it distresses the chicks and parents temporarily, they soon recover and go back to their normal routine. The eyasses at San Jose were more calm with the researchers than the SF brood, and they instinctively held onto the glove of bander Glenn Stewart. Only hours later the parents were back at the nest, feeding the young. Fledging will happen very soon at both nests, as they become more experimental with their growing wings. As they flap and stretch them, a breeze will catch under the feathers and give them a slight lift. In about a week, the Eureka! Moment will occur when they first become airborne.
May 11, San Jose: The four eyasses are now nearly as large as their parents. Their bodies will soon begin to appear more streamlined as flight feathers develop and cover their coat of down over the next two weeks. Already, dark patches may be seen through the white down as true feather shafts grow.
By now, the chicks have mastered their balance and amble around the nest curiously. When Clara or Esteban bring food, the chicks eat as much as possible and soon become drowsy and immobile. This is why the chicks are often huddled together asleep for long periods throughout the day. After they have had a chance to digest, they become alert once more and soon the cycle repeats itself. Due to their rapid growth, they need all of this food as their bodies immediately convert in into muscle and bone and other tissues. Clara will sit at the edge of the scrape, watching as they rest.
May 3, San Jose: In most species that have multiple young in a brood, there tends to be an alpha – the dominant and most aggressive of the young. Of the four in San Jose, one chick seems to have taken this title. Though the sex is still unclear, he or she grabs at the food enthusiastically, and before Clara can give it to another of the chicks. Sometimes he or she even tries to go straight at the food itself, before the mother can give it an appropriate sized piece. During a recent feeding, two chicks got most of the food from Clara, one was laying down and seemed unable to get up for the feeding—possibly too much food at a previous feeding! All of the eyasses appear to be healthy and each must each be getting sufficient food, as they have grown to about four times their size at hatching. They are still covered with white down, but in about a week, true feather shafts will begin to emerge. They are still awkward, but the muscles in their legs have developed significantly, so they can balance well enough to remain upright. (Though still inclined to tumble over.)
April 26: San Jose: Esteban was seen standing over the nest a few days after hatching, getting a good look at his newly arrived brood. His visits are brief however, as he spends most of his days away from the nest perhaps hunting for food. When the young are about two weeks of age, Clara will join the hunt for food, but as for now, her time away from the babies has been very short. After the surprising late hatching of the fourth egg, the large brood is healthy and growing quickly. A comparison of the chicks today to their pictures at hatching reveals a remarkable difference.
April 22: This just in: Egg #4 has hatched! Happy Earth Day
21: After thirty-three days of patient incubation, the first
of Clara's brood hatched, on schedule, late Monday evening. By
that night two more had broken free of their shells, totaling
a brood of three. Like the San Francisco nest, it appears that
one unhatched egg remains. Though this may be a disappointing
sight, Clara and Esteban will still be very busy caring for their
three healthy chicks.
Though it is hard to see through a web cam, the eggs start to move as they get ready to break from the egg. At this stage of development, the chicks are not getting enough oxygen, so their bodies convulse to break into the air sac at the large end of the egg. About two days after this event, the baby convulses again to create small cracks in the shell for the exchange of fresh air. With the egg partially broken, the chick's task of slowly breaking its way out begins.
The mother can sense these movements, and in the days and hours leading up to chick's emergence, Clara was anxious. She shifted frequently and watched the eggs carefully. She could be seen making small calls, perhaps in response to the muted chirping emerging from the clutch. Finally, on Friday, the wait was over and the chicks made their way out. Though they emerge pink, squirming and looking more like aliens than baby birds, they soon dried out to reveal the fluffy white down of healthy eyasses. Though they retain parts of the yolk in their abdomen for nourishment, the chicks are already hungry!
The mother kept the vulnerable chicks under her body to keep the pair warm, though they could be seen squirming under her protective form.
She left the three for small periods of time, to fetch food from Esteban, during which they swayed unsteadily by the still unhatched egg. Returning every few hours with a pigeon or other small bird, Clara carefully fed each hungry chick small morsels. Their appetite can be explained, as these birds go from helpless down fluffballs to fledging adolescents in just 42 days. They have a lot of growing to do, and exciting milestones await as we watch these amazing creatures mature!
April 1: Incubation continues. Here, our tiercel Esteban, prepares to take his turn on the eggs while Clara takes some time off to stretch, preen, and eat away from her incubation duties. Approximately 20 days of incubation remain before hatching occurs. Some observers have difficulty differentiating between the members of this pair. Clara has an outline of white feathers around the top and sides of her beak. That marking is absent in this photo so we know that we are seeing Esteban on the nest.
March 19: Clara’s clutch was completed today with a 4th egg that arrived during the afternoon. She and her mate have been sitting tight on the nest for a little over a day now indicating that incubation is now underway. We can look forward to about 33 days of incubation (start counting with today’s date), then hatching, and then about 42 days to fledging. The pair will exchange incubation duties but the female will do most of it with the male providing food for her. The male will come in to the nest box to incubate while the female is eating or taking a break. Breaks generally occur every three or four hours during the day.
March 15: A second egg was visible at first light on Sunday morning, March 15. The female falcon, known as “Clara,” is on and off the eggs at this point and has not begun incubation. Typically, incubation begins soon after the third egg is laid. And also typical of Peregrine Falcons, a fourth egg is usually laid to complete the clutch. That egg will hatch a day or two after the others because it got a later start. The younger baby soon catches up with its siblings and becomes indistinguishable from the others by the time they are all about ten days old.
March 12: Just one day short of her 2008 laying date, “Clara” laid her first egg of the year in her nest box high on a south ledge of the San Jose City Hall building. It was early afternoon and viewers were able to watch, live, as the egg appeared. Peregrine Falcons lay their clutch of eggs at intervals of about 60 hours and there are usually 4 eggs in a clutch. The first two eggs are laid and left in the nest scrape without incubation. “Hard” (i.e. continuous) incubation begins after the third egg is laid. A fourth egg usually arrives after incubation has already begun and so it hatches one or two days after the first three.
On February 19, 2009, a new male Peregrine Falcon appeared at the San Jose City Hall nest site to court Clara. Soon, he was named “Esteban Colbert” by avid falcon observers at City Hall. We formally announce the opening of the falcon camera-viewing season on Valentines Day because February 14th generally coincides with initial courtship behaviors such as “cliff-racing” (demonstrations of male flight ability and prowess), and visits to the nest ledge where both the male and female walk in the gravel and appear to talk over just where the eggs will be laid (vocalizations sound like, “eee-chup”). Soon members of the pair begin to form a depression, egg-cup, or scrape, in the gravel where the eggs will eventually be deposited and incubated.