The extirpation of eagles from Scotland (windfarms again) (1 Viewer)

[Sandy Martin]

Give us more details, please. This would be news to me. - Or is it the usual desinformation technique: spreading rumours?
.

If David and myself are aware of it, it is a great surprise that you are unaware of it.
One cannot say that all oil companies are supporting one side or another but it does show that a holier than thou attitude is a risky business.
Sandy

 

[nirofo]

nirofo,

The latest survey information (http://www.rspb.org.uk/scotland/action/goldeneaglesurvey.asp) I can find states that there were 431 pairs in 2003. Now this may perhaps be a slightly high count taking account of annual variation, though note that it is entirely consistent with the figure of 422 pairs in 1993, and with the figure that Moore uses. There were more pairs (147) on the Hebrides than the total you state for the entire country! Where did your total of 123 come from?

I'm intrigued by the comment that "the figures [33] are as accurate as they need to be"... to do what? Do you stand by this count as an accurate indicator of average fledged Golden Eagles per year for the entire UK?

Tim has provided eagle breeding success rates from a quoted source - if you accept these, and are willing to believe the RSPB endorsed survey count, then 210 fledged eagles a year is reasonably accurate, isn't it?

Hi dbradnum

The figure of 123 is the number of actual pairs recorded breeding or attempted breeding in Scotland, as was stated, 2005 was an exceptionally poor breeding year. As I said the 33 reported successfully fledged young was from a published reliable source mentioned in my earlier post. I have no reason to doubt the accuracy of the published data.

The average of 0.5 young fledged per breeding pair per annum is not based on the total number of breeding pairs in the country all breeding at the same time, but is based on the recorded fledging success of the actual number of pairs breeding for any one year. This figure could be anything from one to 430+ breeding. So the figure of 123 breeding pairs attempting, or actually breeding in 2005, would be about right given that it was a poor breeding season!

The RSPB receive their data in general from the various Raptor Study Groups, SNH, their own employed field recorders and records from individual dedicated amateurs, the figure of 147 pairs in the Hebrides is not disputed, it is part of the total of 420 - 440 pairs resident in Scotland!

The figure of 210 young fledged Eagles per year is unrealistic as an annual figure and is unlikely to be sustained on a regular basis, the results for 2005 are a case in point. The fledging results are very variable depending on weather conditions, prey availability, persecution etc.

The last full Golden Eagle Survey (Census) took place in 2003, (I was involved in it), nearly every territory known for more than 100 years was checked, (over 600) along with other areas where birds may have bred or attempted to breed. 435 Occupied territories were located in what proved to be a good breeding year, good weather at the right time helps a lot, of course not all the birds bred or were successfull as is usual.

nirofo

 

[nirofo]

Here's an interesting web link, shows what our birds of prey have to contend with and that's without the windfarms!

http://www.bloodybusiness.com/news/commercial_shooting/bloody_businesses/year_round_slaughter.htm

nirofo.

 

[dbradnum]

Thanks nirofo - exactly the kind of useful stuff that this thread ought to support more often. Sorry to keep chasing you with questions!
:clap:

Hi dbradnum

The figure of 123 is the number of actual pairs recorded breeding or attempted breeding in Scotland, as was stated, 2005 was an exceptionally poor breeding year. As I said the 33 reported successfully fledged young was from a published reliable source mentioned in my earlier post. I have no reason to doubt the accuracy of the published data.

The average of 0.5 young fledged per breeding pair per annum is not based on the total number of breeding pairs in the country all breeding at the same time, but is based on the recorded fledging success of the actual number of pairs breeding for any one year. This figure could be anything from one to 430+ breeding. So the figure of 123 breeding pairs attempting, or actually breeding in 2005, would be about right given that it was a poor breeding season!

The RSPB receive their data in general from the various Raptor Study Groups, SNH, their own employed field recorders and records from individual dedicated amateurs, the figure of 147 pairs in the Hebrides is not disputed, it is part of the total of 420 - 440 pairs resident in Scotland!

The figure of 210 young fledged Eagles per year is unrealistic as an annual figure and is unlikely to be sustained on a regular basis, the results for 2005 are a case in point. The fledging results are very variable depending on weather conditions, prey availability, persecution etc.

The last full Golden Eagle Survey (Census) took place in 2003, (I was involved in it), nearly every territory known for more than 100 years was checked, (over 600) along with other areas where birds may have bred or attempted to breed. 435 Occupied territories were located in what proved to be a good breeding year, good weather at the right time helps a lot, of course not all the birds bred or were successfull as is usual.

nirofo

 

[David]

Here's an interesting web link, shows what our birds of prey have to contend with and that's without the windfarms!

http://www.bloodybusiness.com/news/commercial_shooting/bloody_businesses/year_round_slaughter.htm

nirofo.

For me the moral of this story is that the landowners should be punished for what their employees do. The question of proof of personal involvement (issuing orders) is difficult; but the burden of responsibility clear. What gamekeeper would kill protected birds of prey against the wishes/orders of his boss? At the very least names should be named in such cases and be published prominently on - say - a Most Wanted (Britains most callous bird killers) list. We could make a start here.

 

[Mark Duchamp]

If David and myself are aware of it, it is a great surprise that you are unaware of it.
One cannot say that all oil companies are supporting one side or another but it does show that a holier than thou attitude is a risky business.
Sandy

If you guys would find the name or the email of that lawyer who offers his services for free, be sure to let me know: I know a lot of potential clients among people trying to save German bird life from the choppers.
.

 

[Mark Duchamp]

For me the moral of this story is that the landowners should be punished for what their employees do. The question of proof of personal involvement (issuing orders) is difficult; but the burden of responsibility clear. What gamekeeper would kill protected birds of prey against the wishes/orders of his boss? At the very least names should be named in such cases and be published prominently on - say - a Most Wanted (Britains most callous bird killers) list. We could make a start here.

It is an important subject on its own, well worth a separate thread.
.

 

[David]

If you guys would find the name or the email of that lawyer who offers his services for free, be sure to let me know: I know a lot of potential clients among people trying to save German bird life from the choppers.
.

I don't know if I have it filed Mark. It last came up in Brandenburg when discussing wind turbine threats to Otis tarda habitat.

I'll research when I have time.

David

 

[David]

It is an important subject on its own, well worth a separate thread.
.

I'm happy to start a MOST WANTED (for services against birdlife) thread in this forum if people want it. I will then need info to post. The story will do - I can work up a precis.

David

 

[Mark Duchamp]

Hi dbradnum

The figure of 123 is the number of actual pairs recorded breeding or attempted breeding in Scotland, as was stated, 2005 was an exceptionally poor breeding year. As I said the 33 reported successfully fledged young was from a published reliable source mentioned in my earlier post. I have no reason to doubt the accuracy of the published data.

The average of 0.5 young fledged per breeding pair per annum is not based on the total number of breeding pairs in the country all breeding at the same time, but is based on the recorded fledging success of the actual number of pairs breeding for any one year. This figure could be anything from one to 430+ breeding. So the figure of 123 breeding pairs attempting, or actually breeding in 2005, would be about right given that it was a poor breeding season!

The RSPB receive their data in general from the various Raptor Study Groups, SNH, their own employed field recorders and records from individual dedicated amateurs, the figure of 147 pairs in the Hebrides is not disputed, it is part of the total of 420 - 440 pairs resident in Scotland!

The figure of 210 young fledged Eagles per year is unrealistic as an annual figure and is unlikely to be sustained on a regular basis, the results for 2005 are a case in point. The fledging results are very variable depending on weather conditions, prey availability, persecution etc.

The last full Golden Eagle Survey (Census) took place in 2003, (I was involved in it), nearly every territory known for more than 100 years was checked, (over 600) along with other areas where birds may have bred or attempted to breed. 435 Occupied territories were located in what proved to be a good breeding year, good weather at the right time helps a lot, of course not all the birds bred or were successfull as is usual.

nirofo

Very informative, Nirofo, thank you. So the example given by Stan Moore of 210 young fledged annually is distant from reality.

Then, out of these 33 fledglings in 2005 (a bad year, you said) how many do you reckon would survive till they are in age of breeding successfully? (before taking into account windfarm mortality, which will take effect in the years ahead of us).
.

 

[Osprey_watcher]

Here's an interesting web link, shows what our birds of prey have to contend with and that's without the windfarms!

http://www.bloodybusiness.com/news/commercial_shooting/bloody_businesses/year_round_slaughter.htm

nirofo.

That's a truly shocking report. Is there no way these people can be educated?
Custodial sentences of at least 1 year for the keepers and owners who allow it should be mandatory! (My opinion only)

 

[nirofo]

Very informative, Nirofo, thank you. So the example given by Stan Moore of 210 young fledged annually is distant from reality.

Then, out of these 33 fledglings in 2005 (a bad year, you said) how many do you reckon would survive till they are in age of breeding successfully? (before taking into account windfarm mortality, which will take effect in the years ahead of us).
.

Hi Mark

Usually if the young survive the first year then they have a very good chance of surviving at least into breeding age, (3 to 5 years old). After that as I stated in an earlier post, they could go on to live for 30 years or more, persecution, food availability etc., will determine. There is no way of determining whether they will go on to breed in their lifetime however, this still depends on the availability of suitable territories and mates being available to them.

nirofo.

 

[Osprey_watcher]

Hi Mark

Usually if the young survive the first year then they have a very good chance of surviving at least into breeding age, (3 to 5 years old). After that as I stated in an earlier post, they could go on to live for 30 years or more, persecution, food availability etc., will determine. There is no way of determining whether they will go on to breed in their lifetime however, this still depends on the availability of suitable territories and mates being available to them.

nirofo.

Hi Nirofo,
Just curious and you sound like you know your eagles, where do the adults who can't establish a territory go to live/feed etc. Or are they nomadic i.e. travelling about in other eagles territiries until chased off then moving to the next one?

 

[nirofo]

Hi Nirofo,
Just curious and you sound like you know your eagles, where do the adults who can't establish a territory go to live/feed etc. Or are they nomadic i.e. travelling about in other eagles territiries until chased off then moving to the next one?[/QUOTE]

Hi Osprey_watcher

They are generally tolerated as free hunters outside the breeding season, even then they are tolerated to a certain extent providing they make no approaches to the actual nesting site or the mate of the resident bird. Young birds probably up to 3 or 4 yeras old are quite often seen flying with the resident adults, I've seen as many as 5 birds in the air at once, 2 ads and 3 young still showing plenty of white, soaring over an actual eyrie still containing unfledged young.

nirofo.

 

[Osprey_watcher]

Hi Osprey_watcher

They are generally tolerated as free hunters outside the breeding season, even then they are tolerated to a certain extent providing they make no approaches to the actual nesting site or the mate of the resident bird. Young birds probably up to 3 or 4 yeras old are quite often seen flying with the resident adults, I've seen as many as 5 birds in the air at once, 2 ads and 3 young still showing plenty of white, soaring over an actual eyrie still containing unfledged young.

nirofo.

Thanks for that, never too old to learn.
Must be a magnificent sight, I've only ever seen one in the wild and that was 20 years ago in the Lake District.

 

[Jos Stratford]

Tim has provided eagle breeding success rates from a quoted source - if you accept these, and are willing to believe the RSPB endorsed survey count, then 210 fledged eagles a year is reasonably accurate, isn't it?

THIS IS TIM POSTING NOT JOS!

the number of pairs given by Mr Moore appears rather good, doesn't it?

and if you look at the figures quoted in Newton for breeding success, Mr Moore's figure there aint half bad either.

curious that our resident eagle expert didn't know the published breeding success rates, took me 10 mins max to find em...

all too brief views of Hazel Grouse this afternoon....

Tim

 

[nirofo]

THIS IS TIM POSTING NOT JOS!

the number of pairs given by Mr Moore appears rather good, doesn't it?

and if you look at the figures quoted in Newton for breeding success, Mr Moore's figure there aint half bad either.

curious that our resident eagle expert didn't know the published breeding success rates, took me 10 mins max to find em...

all too brief views of Hazel Grouse this afternoon....

Tim

Hi Jos Stratford

If we accept that 210 young are fledged annually, and we accept that the fledging success rate is a mean of 0.5, then it must be that 420 breeding pairs are needed to successfully rear to fledging 0.5 young annually.

A phenomenal success rate if I may say so!

nirofo.

 

[Jos Stratford]

okay, funny business aside...

does anyone have a handle on breeding pairs and success rate over last ten years. Maybe in selected areas, rather than 'Scotland'?

Tim again...
lovely nutcracker earlier... and two stunning adult WTE. I'll log in as me in a mo to keep the boy Stratford out of trouble...he was looking nervous a few mins ago

 

[dbradnum]

THIS IS TIM POSTING NOT JOS!

the number of pairs given by Mr Moore appears rather good, doesn't it?

and if you look at the figures quoted in Newton for breeding success, Mr Moore's figure there aint half bad either.

curious that our resident eagle expert didn't know the published breeding success rates, took me 10 mins max to find em...

all too brief views of Hazel Grouse this afternoon....

Tim

Tim / Jos / whoever else you might be

I agree that SM's figure of 420 pairs is fine, and that a success rate of 0.5 young per pair is not bad on average either...

However, from what nirofo says (I guess you hadn't got to this bit yet), the possible flaw in SM's logic is that not all of those pairs breed - in 2005 there were only c 120 breeding pairs, perhaps plus a handful more that went unrecorded.

 

[Edward woodwood]

The 2003 golden eagle survey
A UK-wide survey of golden eagles was conducted in 2003, 11 years after the last, as a collaboration between the RSPB, Scottish Natural Heritage and Scottish Raptor Study Groups. Over 670 home ranges were surveyed, by far the most complete coverage achieved in an eagle survey.

Pairs were found in 435 home ranges, up by 13 (3.1%) from 1992, although an alternative criterion for assessing range-occupancy suggests that the total was 443 pairs (not comparable with the 1992 figure).

Higher densities were recorded in the west of Scotland, particularly in Lochaber, Mull and the Outer Hebrides. New ranges have become occupied in the south of the range since 1992, but densities there are still very low given the amount of suitable habitat.



Variation in coverage means that caution has to be used in interpreting trends since the last survey, but it appears that there has been little change in the overall UK golden eagle population. There have, however, been regional changes, with the number of pairs decreasing in the east and south-central Highlands (-19 and -14% respectively) and increasing in the Hebrides (+24%).

Golden eagle productivity is density-dependent, so it is no surprise that productivity was higher east of the Great Glen where eagle density was low (eg 0.69 fledged offspring per pair in east Highlands) than in areas of high density (eg 0.39 in the Hebrides).

That eagle numbers are low in the east and south of the range, despite relatively high productivity, may support recent analyses showing that persecution of raptors is highest in regions such as these with a high prevalence of grouse moors. As well as suppressing the breeding population, this persecution may have an effect beyond these areas, acting as an ecological trap for wandering immature birds from elsewhere in Scotland.

Further reading:

Green RE (1996) Status of the Golden Eagle in Britain in 1992. Bird Study 43: 20-27.

Whitfield DP, McLeod DRA, Watson J, Fielding AH and Haworth PF (2003) The association of grouse moors in Scotland with the illegal use of poisons to control predators. Biological Conservation 114: 157-163.