Appio and Vergine 2011

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Warbler
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Appio and Vergine 2011

Messaggioda Warbler » ven apr 15, 2011 8:11 pm

We know that many of you have been following tragic events at this nest and probably wonder what has been going on.

After an initially good start, there were suddenly problems with a lack of continuity and constancy in incubating and many of us here were very concerned about the likely effect on the eggs. Much to our surprise, all three eggs hatched this week but, as you have probably realised, none of the chicks has survived. This is my translation of Giac's long post recounting the details of yesterday and giving some theories about what may have caused this situation. It can also be found in the thread for Appio and Vergine on the BCAW site:

Unfortunately, the second chick (the one removed from the nest) died last night.
During the first visit in the morning I ascertained the death of one of the chicks (probably the one which hatched first) and the very serious condition of the other two. The three chicks hatched after an incubation which had been discontinuous at times and had lasted a long time. One of the four eggs laid by the female disappeared from the nest in the final stage of incubation (probably eaten by the adults) and, once we'd gone past 45 days from the date the first egg was laid, we didn't think the eggs would hatch.. But, to everyone's great surprise, the first chick hatched a few days ago and the other two a short while later. The chicks seemed weak right from the start and the female didn't seem able or capable of giving them food. Despite this, all three seemed vital until the last images broadcast by the cam on Wednesday evening. It should be said that, in the very first days after hatching, chicks can still count on the nutritional reserves of the yolk and so survive, even without food from the parents, as long as they're kept warm...
Yesterday morning, the bodies of the two surviving chicks were infested by parasites
(Carnus haemapterus, a dipteron that sucks blood from very young chicks which are unable to remove them with their beaks) and covered with clots of blood under the wings. The chicks were very weak and their weight was only 25 gm (consider that a newly laid egg weighs around 45 gm and about 37 at hatching!, imagine how undernourished they were - effectively, they'd not been fed by their parents...). We removed as many parasites as we could (hundreds) with our fingers and pincers, we gave the chicks a little food and put them back into the nest where the female immediately took them back under her wings to brood them.
We were on the other side of the wall separating the nest (on the left in the picture from the cam) and we watched the parents' behaviour, ready to remove the chicks if they weren't accepted back immediately. However, the female returned to the nest in 5 minutes and we thought that, with a full stomach and the warm protection of the mother, the chicks could have gained some energy. The intention was to have them regain strength and then they may have become more convincing in asking the parents for food (begging). We planned to make a second visit to the nest in the late afternoon to make a definitive elimination of the parasites and check on the condition of the two chicks left, giving them more food so that they could get through the night.
When we went back, we found one of the chicks in an even worse condition compared to the morning, with scratches and scabs on its back. It was laying on its back in the nest (it was probably the one 'ill-treated' by the male). We decided to remove it from the nest to try a recovery in a more comfortable place - I took it home, put it under a solar lamp with a hot-water bottle at 37°C and fed it with tiny bits of food, but it slowly gave up and died a short time ago...)
We left the one that seemed stronger in the nest after feeding it. We watched to see whether the female would take it back, ready to take it away if she didn't. After about 12 minutes, she came back and put it back under her wings and so we left it with her, thinking that the warmth of the mother would be enough to get it through the night. Tomorrow morning, we'll find out whether we made the right choice but, at this point, we mustn't delude ourselves....

The pair Appio and Vergine (we've called them with these names but they may not be the same pair as last year) have behaved strangely during this breeding season, the male, in particular, seems to have no experience at all or, perhaps, as someone suggested, if he's not the natural father of the chicks, he may have more interest in removing them than raising them... For the moment, these are only speculations but we may be able to make and check some hypotheses later. For example, comparing the DNA of the chicks of this year and last year to see if they are related or the parents have changed..
The observations through the cam are unveiling unexpected behaviour in these birds. The comparison between the various pairs shows that there are characters and personalities in them, just as in humans. The attention of Vento towards his partner and the chicks, the way he takes turns in incubation, his constant, yet discreet, attendance are reflected in reproductive success which is repeated regularly while the confused and 'crazy' behaviour of Appio is having tragic consequences for the survival of the chicks. It may be that balanced behaviour and collaboration with the female are acquired with 'maturity' and reproductive experience, and this may help a pair to face difficulties like scarcity of food or storms. However, there may be other factors, like environmental disturbances and pollution, which may be felt by the falcons differently from how we humans perceive them and that the behaviour we interpret as 'aberrant' or unexplicable are merely adaptations to these changes. For example, we should reflect on the fact that, 3 of the 4 pairs of falcons nesting in boxes in Roma (Appio & Vergine, Aloha & Falcao and Alice & Virgilio) have lost an egg shortly before hatching. An analysis of the pictures recorded (all our cams record images on the PC every 5 minutes as well as sending pictures onto the web) shows that the only explanation could be for all cases that the female has eaten or 'cannibalised' the egg. Some of you may remember there was a similar episode during the reproduction of Aria & Vento in 2005. In that case, the cannibalism was well documented with a series of 'strong' photos (requests were received at the time to remove the photos from the forum so that younger visitors were not shocked) and this aroused scientific interest with many hypotheses about the behaviour. Cannibalism, that we may judge as crazy may be to enable the reproductive investment and parental efforts to be optimised with a view to a period of limited resources, which the birds are in some way able to predict. In other words, if I lay 4 eggs thinking I can raise all of them but then after starting incubation I realise that there isn't enough food for all of them in the environment, or the weather conditions are getting worse (wind and cold = less prey to hunt), it's better to sacrifice an egg straightaway, when the investment in reproduction is at the beginning, rather than risk losing the chicks later, when there has been greater investment in reproduction... Last year, our colleague Stefania Casagrande noted 4 episodes of cannibalism of the eggs out of 11 nests among the kestrels, and the explanations for this behaviour may be the same as for the peregrine falcons.
We'll wait and watch over the coming weeks to try to understand how to connect what happens inside the nests to what's happening in the environment...
The cams enable us to have a front seat in discovering and seeing what has always happened in Nature. It may seem ruthless, we have emotional reactions but it's an honest contribution to the increase in our knowledge of the reality of the world and the animals living around us.
warbler

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Nigno84
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Re: Appio and Vergine 2011

Messaggioda Nigno84 » sab apr 16, 2011 9:17 am

Non trovo il post di giac x favore mi indichi il link. grazie
Giovanni

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Passera
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Re: Appio and Vergine 2011

Messaggioda Passera » sab apr 16, 2011 9:22 am

album fotografico di appio e vergine
viewtopic.php?f=56&t=5189&start=765#p100236
Alla zampa di ogni uccello che vola e' legato il filo dell'infinito.(victor hugo)

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Nigno84
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Re: Appio and Vergine 2011

Messaggioda Nigno84 » sab apr 16, 2011 9:34 am

Grazie passera :) :)
Giovanni


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