Jonathan Farmer
Well-known member
What is meant by "FIRST CY"
Thanks in advance
JF
Thanks in advance
JF
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Cy?? (1 Viewer)
- Thread starter Jonathan Farmer
- Start date
StuartReeves
Local rarity
In the context of ageing an individual bird it refers to 'Calendar Year', i.e. a 1CY is in its first calendar year, so a bird that was fledged in 2009 would currently be in its first calendar year.
Jonathan Farmer
Well-known member
Thanks Stuart.
Colin
Axeman (Retired)
Everything said above is spot on. However, don't forget that species which breed almost throughout the year such as Woodpigeon (in the UK) could have a brood quite late, say October. When the young get to 1st Jan 2010, they start their 2nd calendar year even though they are not much more than 2 months old. Compare that to the young of the early nesting corvids which might have hatched in February 2009. When they start their 2nd calendar year they will nearly be a year old (about 11 months).
Colin, I agree. This is one of the reasons that CY is not an ideal way to describe the age of birds, but as far as I can see, there are disadvantages to every system I have come across so far. Especially when you think about both northern and southern hemispheres being off with ½ year, and tropical birds breeding whenever the situation is right no matter what the month say.
Niels
Niels
Colin
Axeman (Retired)
I also agree that all of the systems have their faults. Another oddball is that say a bird is hatched in June/July/August. A few months later, it enters its first winter and the following summer when it is about a year old it is its first summer because it is its first FULL summer. I expect that you know this but many people think that the first summer is the summer in which it hatched. These labels generally refer to plumage.
Yes, that was one of the not logical ones I was thinking of :-O Even worse, there are two usages of that one, one of which equates "First Summer" to "First Adult Summer", which means that first summer can become the plumage of a bird in its fifth year.
Using basic and alternate at least does not have summer or winter included in the name, and it is a little easier to figure out that first alternate does not have to happen in the first year of a birds life. On the other hand, first alternate as the plumage of a gull in its second calendar year long before it reaches its full adult plumage may not be that logical either.
Niels
