THE LG OSPREY GABFEST FOR MARCH 2015

Unknown said:

C Ringer - I agree with your answer to "Male Intentions"

This is a very interesting paper I keep and follows much of what you report.

I co authored a paper that included some of this research that was published in 2008 in the Journal of Raptor Research. As our population of Ospreys has increased, I am seeing more extra pair copulations and divorces. Hard for me to understand why anyone still believes they are monogamous! But it takes long term study, good field work, with banded birds to prove these behaviors. I am certain it occurs more than we think among unbanded birds.

Firstly, apologies for 'butchering' your most interesting prose - if I had kept all the text in we would be using almost a whole page in  replying!

What you said in the first part comes as no surprise. Again referring to Ollie (where we had the volunteers making notes 24/7) in one year his 'usual' mate was late, he readily accepted a new female and mated with her, but then his regular female turned up and he joined forces with her to drive away the 'new' female. I think the point here is that the new female had not laid eggs. A few years later exactly the same thing happened, but this time he and the new female drove of the 'old' female. The difference, in my humble opinion :-) , was that the new female was on eggs when the old one arrived - he had already 'invested in his future.' Incidentally the new female was the 'famous' one that got tangled in fishing line when the chicks were very young and disappeared leaving Ollie to fish and feed the chicks alone. He was successful.

I think the point you make about both males and females moving nests, but only following a year of failure is a sound observation - very similar observations have been made with Red Kites.

You have mainly discussed EPCs when perhaps a bird has been late arriving. This to me is understandable. What particularly interests me is where a male attempts an EPC when the resident bird has returned, but is not on territory. I have little doubt that most Ospreys know the whereabouts of most other nests, certainly within their foraging range, which we know can be considerable. Surely they must be aware, if they visit these nests after their female has laid, if the resident male has returned and yet it appears they are undeterred in their visits, presumably in the 'hope' that the resident male will be away and the female on the nest receptive.

Taking this a stage further - we know that there are variations in individual Osprey's abilities to catch fish. If you are a good fisher, then it is in your interests to make these visits once your female is on eggs in the hope that the nest you visit has a 'poor fisher' who is likely to be away for some time. In which case the female is likely to be hungry and thus perhaps more receptive to the advances of a male with a nice fat trout. This then poses the question - would it be in the female's interests to be receptive to this interloping male? - her eggs then would hold the genes of the best fisher!! Fish (sorry food) for thought.  

Apologies for the 'in depth' thoughts which I know must be boring to many who frequent these pages. They just add to my fascination of this species in particular.

CRINGER - No Apologies for your in depth answer to my question regarding Males Intentions.

I have found these observations so interesting that I have extracted all three posts and added them to my study papers under your name C Ringer - Your Honour:)

One thing may I ask and not sure if you have already done so - Can I share these with Venessa Greene who I have contact with under your name C Ringer as this is part of her studies. She published a report in the Journal of Raptors along with many other reports during her 20 year of observations around Minneapolis - "Extra Pair Copulation in an increased osprey population.

Unknown said:

CRINGER - No Apologies for your in depth answer to my question regarding Males Intentions.

One thing may I ask and not sure if you have already done so - Can I share these with Venessa Greene who I have contact with under your name C Ringer as this is part of her studies. She published a report in the Journal of Raptors along with many other reports during her 20 year of observations around Minneapolis - "Extra Pair Copulation in an increased osprey population.

Not a problem at all. The stats referred to in the earlier post in relation to forage time pre and post egg laying are in an unpublished undergraduate thesis. Let me know if you / she requires any further information.

Good afternoon all CRinger not boring at all, on the contrary Im finding this discussion very interesting! (Im sure most of us who post on here would agree)

Agreed, willow - fascinating to read. To see our shared observations more scientifically summarized clarifies and explains what we likely only feel to be true.

The best discussion THE GABFEST has had for many a month is NOT BORING!

Hope you won't be a stranger here at the Gabfest, CRINGER.   You & Keith are just what this thread needs. Together you make    a brilliant team. Separately you could really keep us on our toes; remind everyone that the Gabfest is indeed an osprey thread, 

COUNTDOWN FOR  LOCH GARTEN NEST

4 days till  EJ'S RETURN  on    Wed March 25th @ 3;30 pm

10 days till ODIN'S RETURN  on Wed March 31st

Unknown said:

The best discussion THE GABFEST has had for many a month is NOT BORING!

Hope you won't be a stranger here at the Gabfest, Cringer. you are just what we need

Thanks so much June. Unfortunately I have a pressing appointment with a surgeon on Monday and hope to make it out of hospital about 2 weeks later - so if I don't reply to something please don't hold it against me. My thoughts will be with the community and all Ospreys.

And my prayers will be with you, CRinger.  May everything go better than planned!