Pagina 12 di 43
Inviato: mar mar 30, 2010 3:38 pm
da Giovanna
Inviato: mar mar 30, 2010 3:42 pm
da Gabbiano
bellissima notizia :D
Inviato: gio apr 01, 2010 6:26 pm
da Giovanna
Anche una notizia dello scorso anno aveva localizzato Treasure a Port Colborne, Ontario, Canada.
Great news about one of the Terminal Tower juvies from 2007:
June 17, 2009 - Port Colborne - ADM Mill
Doug Garbutt Reports:
Thanks to Carol Phillips our friend in Rochester N.Y. the new falcon here has been ID’d. M/82, black/green is Treasure (female) hatched at the Terminal Tower Cleveland Ohio Apr. 27 2007. We’re not sure if she has taken over the nest box but has been here for a week or so that we know of and could be more. Falcon activity here is abound, however not producing young ones which is very discouraging. We are keeping a close eye to see if Millie is still in the picture. Next year is another year & hopefully we have a dominant pair that can have a successfull brood. All I know is that every falcon we see here is impressive & special.
Doug Garbutt
Ma l'ultima è decisamente molto meglio! :D :D :D
Inviato: gio apr 01, 2010 6:49 pm
da Giovanna
Le ipotesi su che cosa sia veramente accaduto a una delle uova di SW&Ranger sono varie e, alla fine, non possono spiegare il vero motivo per il quale SW (sicuramente c'era lei sulle uova in quei 7 minuti) con ogni probabilità se lo sia mangiato, almeno il guscio.
Tuttavia le spiegazioni di Harvey Webster sono molto interessanti, oltre che scientificamente fondate e chiaramente esposte da quell'ottimo biologo naturalista che è il Direttore del CMNH.
Le riporto qui per chi avesse la pazienza di leggerle nell'originale
Dalla home page.
The Case of the Missing Egg.
A mystery unfolded on Monday, 5/29/2010 at the nest on the terminal tower’s 12th floor. 4 eggs in a tight clutch at 12:05 pm. One minute later SW moves over the eggs in an awkward pose as if she is turning the eggs. Ranger shows up at the right side of the nest platform but SW stays in the same pose for the next seven minutes. She finally settles down over the eggs. At the next shift change when the eggs are visible at 3:42 pm, there are only three eggs and no sign of the fourth, no eggshells, nada. What gives?
First, it is not without precedent for SW to lose an egg. It happened in 2007. She laid her first egg, then her second. A day later the second egg broke. She followed with a third and fourth egg. The first egg was covered with the egg whites and yolk from the broken second egg and she avoided incubating the egg for a time. Only the third and fourth eggs hatched that year giving us Erie and Treasure. Erie died at the Terminal later that summer. Treasure is part of a pair at Port Colbourne in Ontario.
So what might have caused the egg to break? Possibly disturbance at the nest site might have caused either S/W or Ranger to accidentally break the egg. We know Peregrines to be very careful and effective parents. However, this is Ranger’s first experience as an incubating adult and he could have been clumsy when attending the eggs. That being said, there is no evidence from the Falconcam archives at the time to suggest that anything was amiss with SW or Ranger. Quite the contrary, everything appeared normal.
Another possibility is that there was an inherent structural deformity in the egg. The formation of the egg in the oviduct of the female is an extremely complicated and resource intensive process. All of the ingredients needed to cook up one new peregrine falcon chick have to be assembled and neatly packaged in a supremely well-designed calcium carbonate container. And this packaging is accomplished in roughly 24 hours. Disturbance to the female at this time or internal challenges, such as pesticides, disease, poor quality diet, or age could compromise the process of forming the shell. The resulting egg lacks the necessary structural integrity and collapses under the weight of the female as she attempts to incubate.
Do any of these attributes apply to S/W? Disease – no, she seems to be very fit and active. Diet - no, she is dining on the finest selection of pigeons, songbirds, woodcock and other birds that a Peregrine Falcon could hope for.
Pesticides or other environmental contaminants are always a possibility with Peregrines. After all it was DDT and other organochlorine pesticides that endangered Peregrine Falcons in the first place. Though DDT was banned over 30 years ago, it is still present in the environment although not at levels that threaten Peregrines. Other toxins like PCBs are a constant threat. New threats are cropping up. For example, polybrominated diphenyl ethers (PBDE), chemicals widely used as flame retardants, have been identified in Peregrine Falcon eggs in Sweden, Greenland and elsewhere, far from the original source or use of the chemical. What effect these contaminants might have on Peregrines is not well understood.
In S/W’s case however, there is nothing in her past history to suggest any difficulty in producing healthy eggs. Quite the contrary, she has been downright prolific.
That leaves age. SW is 12 years old. Falconers that propagate Peregrines in captivity often report that productivity dramatically drops by the 14th year and they usually retire their birds from breeding at that time. The Peregrine Falcons on display at the Cleveland Museum of Natural History, Lou and Jean, were obtained from a breeder who retired them for just this reason. SW is creeping up on that age where you might expect to see some egg failure.
Or in the end, perhaps some physical disturbance, passing trauma or environmental stress occurred just before the laying of that egg that compromised the formation of its eggshell. It was simply a ‘bad egg.’ The egg would not have exploded as some have speculated. It would have simply collapsed.
Whatever the scenario, the absence of eggshell remains is curious. In 2007, the broken eggshell could be seen in the nest box for days after it broke. Peregrines will sometimes consume the eggshell remains after the chicks hatch. Possibly for the seven minutes that SW was in the head tuck posture she was consuming the shell fragments right after the egg broke. It is odd that her abdominal feathers did not appear to be soiled. In 2007 SW’s belly feathers were wet from the liquid contents of the egg. Scott Wright’s photos from Tuesday do show what appears to be albumen from the broken egg adhering to two of the surviving eggs.
Though it is a disappointment that S/W will not have another 4 chick season, this is precisely why Peregrine Falcons have clutches of 3 or 4 eggs. This annual productivity compensates for the inevitable losses that occur with eggs, chicks, fledglings and juveniles. Clutch size is a balance between how many young the adults can successfully parent given available internal and environmental resources and the need to produce adequate numbers to sustain the population.
Will there be some evidence at the nest that might indicate what really happened to the mysterious egg? By now it is doubtful. So we might never know the real story.
Stamane Ranger covava pacificamente come ora sta facendo SW.
Cleveland 25° C!
Inviato: gio apr 01, 2010 8:36 pm
da Nuri945
interessante la spiegazione e tutte le ipotesi, mi è piaciuta molto la seguente frase
".....Non uno qualsiasi di questi attributi si applicano a S / W? Malattia - no, lei sembra essere molto in forma e attiva. Dieta - No, lei mangia la miglior selezione di piccioni, uccelli canori, beccacce e altri uccelli che un falco pellegrino possa sperare. ......." 
Inviato: gio apr 01, 2010 10:05 pm
da Giovanna
Si, anche a me! 
E Harvey spiega con la semplicità di quelle persone cordiali e rare che sanno come non far pesare la propria indubbia preparazione ed esperienza scientifica.
E il giallo dell'uovo scomparso resterà insoluto, uno dei molti misteri di queste creature inconoscibili.
São aves cheias de abismo..
Inviato: ven apr 02, 2010 12:20 am
da Gabbiano
Inviato: sab apr 03, 2010 1:40 pm
da Giovanna
Rolling.
Inviato: lun apr 05, 2010 12:47 pm
da Gabbiano
Inviato: mar apr 06, 2010 4:16 pm
da Gabbiano
Inviato: mar apr 06, 2010 10:25 pm
da Gabbiano
Inviato: mar apr 06, 2010 11:35 pm
da Warbler
Ranger thinks, "Um, why am I sitting on these lumps? Do they do anything? SW, how long do I have to be doing this? I know keeping them warm is what I SHOULD be doing, and I'm doing it well, but I don't know WHY."
SW (off-camera) : "Oh, just wait, dear...Just wait..."
Ranger: "Wait for WHAT?"
SW (smiling): "In late April you'll be surprised - and busy."
Ranger: "HUH???"
At least he won't have diaper duty.
Ho trovato lo scambio qui, postato da Allison sul forum di CMNH, Terminal Tower thread. Grazie Allison :D
Si chiede Ranger: "Perché sono seduto su queste masse? Fanno qualcosa? SW, per quanto tempo devo fare questo? So che mantenerli calde è quello che DOVREI fare, e lo faccio bene, ma non so PERCHE'."
SW (non in vista): "Devi solo aspettare mio caro, solo aspettare."
Ranger: "Aspettare CHE COSA?"
SW: "Alla fine di aprile avrai una sorpresa - e sarai impegnato."
Ranger: "Ehh???"
Almeno non dovrà cambiare i pannolini...
:D :D :D
Inviato: mer apr 07, 2010 12:01 am
da Gabbiano
:D :D :D
quest'anno nidi pieni....quante uova....non sapremo più chi guardare noi ziette :roll:
Inviato: mer apr 07, 2010 3:36 pm
da Gabbiano
