nesting falcons - live web cam

Aylesbury Vale have peregrine falcons nesting on their platform and a live webcam:  http://www.aylesburyvaledc.gov.uk/leisure-culture/biodiversity-wildlife-conservation/peregrine-falcons-nesting/  

I have seen 3 eggs when they changed over this morning, but I would love to know if it is possible to tell which is the female and which is the male.  I have seen them change over during the day and I couldn't honestly say that one of them sits more than the other and it's difficult to tell size when they're all fluffed up.  The only difference between them that I have seen is that one of them has one lighter feather on the back of his / her head. 

Hi secretduckling and welcome to the forum.

Nice clear pictures from the webcam.

I think the adult birds have very similar markings but the female is somewhat larger than the male. Of course unless you see them together it would be tricky to tell them apart - I don't think I would be able to. However, there are some folk on this forum who know birds of prey very well who may be able to give some pointers.

Hello secretduckling, and welcome from me.

They are excellent clear pictures.

I have no idea how to tell the sexes apart, but as TJ says, there are some bird of prey experts on the forum who may be able to help.

The male of any falcon, refered to as the tiercel is one third smaller than the female. Perigrines

are very simlar markings in both sexes.

I read on t'interweb that the female is usually the one who incubates during the day, but they both look the same size when fluffed up against this horrible weather.  My youngest said "I bet those eggs are warm and cosy" before he left for school this morning. :)

change over time!

Just looked in on the happy couple and it looks like they're going to have a sleep over tonight.  The female (I think) is perched on the edge of the platform and the male (?) is still sitting.  Normally one has flown away by now for the night.  

I have spotted a chick this evening and he/she is really cute.  Just a little ball of white fluff.  I took a screen shot but can't work out how to post it here.

Hi secretduckling

To post it under my post click the "use rich formatting" link and you will see an insert image icon in the info bar

Cute babies!

Female Peregrines often have slightly browner plumage tones and heavier markings than males but the differences are subtle, subject to individual variation, and even then are difficult to see unless you see both birds together. Size-wise females are typically only a little larger in terms of body and wing lengths than males, but considerably heavier. Again, hard to see unless the pair is together. Measurements show most females are 12-18% longer than typical males but 40-70% heavier on average but sometimes more. The difference between the sexes is much less marked in some other falcon species eg Hobby (females 3-5% longer and 30% heavier) and Kestrel (females 4-5% longer and up to 20% heavier). Figures from Raptors of the World (Ferguson-Lees & Christie).

Beat me to it aiki.

Although female falcons are invariably larger than the males the exact ratios vary. The name tiercel might be a reference to the weight difference but some sources refer to the ancient belief that only every third egg produces a male.  The size difference between Peregrine genders can be quite noticeable when the pair are flying together.

Thank you so much for these.  I have studied both birds for days and there is no real noticeable difference between the two even when they're side by side.  Maybe it's because they are so puffed up in this weather.  Does one spend longer sitting than the other or does one stay more during the day than the other?  The only reason that I ask is that one of the adults has a couple of rogue white feathers on their back so I could work it out this way.

Normally the female will spend more time on the nest than the male, especially at night. Being bigger she is more efficient at passing on her body heat to eggs/small chicks, and she's also a more fearsome nest defender than he is.