Lancs Eagle Owls (1 Viewer)

[Amarillo]

I find it hard to accept that natural colonisation may have happened because (a) Relatively large numbers of EOs are kept in captivity (over 400 license applications per year) (b) Significant numbers of captive birds of prey escape or are released each year (I've seen a figure of 25% going missing in their first year quoted). (c) Wild EOs if they occur here at all (remember no accepted records, no ringing recoveries showing sea crossings) are likely to be in such low numbers that colonisation by wild birds is unlikely at the moment. If you look at the available evidence, then it seems to me that the balance of probability is heavily weighted in favour of current breeding etc records being almost entirely due to escaped or released birds or their offspring.

I agree! No-one is disputing that almost all eagle owls occuring here are as a result of escapes!

I was disputing those people who refuse to accept the possibility (however small) that some birds get here naturally. You clearly accept that possibility.

One thing for those who demand proof to consider is: How can it ever be proven that an eagle owl has flown across the sea from the continent if every eagle owl seen here is automatically assumed to be an escape?

 

[KnockerNorton]

>Poecile - So; not a comparitive control for a rare vagrant then.

well if it was a rare vagrant then it wouldn't feature and it was never a native bird then? So end of debate??

>Is that likely?

one would assume so, judging by their density in othe rparts of their range, and the fact that they shae similar diet, nesting sites and trophic level to eagles, yes. And, apparently, they're ever so common on the near continent that they're literally falling off it and into England!

>Your second point regarding Owls in art; unprovable and my understanding >subesequent to my study of history, pre-history and our interpretations of >history lead me to disagree with your conclusion.

can you tell us why you disagree, and why large predators like WTE and wolf would be so prevalent in art and folklore and organic remains, yet EO is totally absent?

>Your third point regarding the probabilities of Vagrant colonisation and
>breeding, unlikely is not the same as impossible,

yet again, someone who doesn't grasp the significance between 'possible' and 'probable'. It's possible that EO are being flown in by Glen Miller and Amy Johnson. But is it probable?

>we still don't know (with regard to European Eagle Owls) definitively.

we still don't know that Glen Miller is dead. What do you think, though? Definitively.

>I'm sorry, I fail to understand your comment regarding a failure of Little Owls

becasue it took an introduction for them to colonise, despite them being common on the adjacent continent and probably rare vagrants cf Scops Owl. I thought it was rather a good example, showing how just because an owl is common nearby, it doesn't mean that it can or will colonise without people shipping them over in crates. And LO has a much more restricted diet and lower trophic level than EO, so that old hoary chestnut is irrelevant (diet mainly insects and worms).

>I'm concerned that you appear to see eradication as the only solution to an
>essentially unproven case.

but the case against introductions (essentially or literally) of predators, especially top predators and into island ecosystems, has been proved time and time again. It's basic ecology.

>It is not proven that Eagle Owls, in low vagrant densities and possibly even
>as a rare breeder are incompatible with or do not belong within UK ecologies.

but that's not what we're talking about. We're talking about an established, permanant, expanding population. If it was just a couple of pairs and coastal wanderers, like Snowy Owls, that's different. But when it's widespread breeding leading to a relatively large feral population, that's different and significant. I'm saying that we cannot hope that they will not spread and increase, so they should be removed now. You've already accepted that the majority of them (at least) are feral, so do you think they wont expand or something? They're either 'low density vagrants' or largely increasing feral breeders. Which is it? One doesn't really matter, the other will matter.

>The control is; a study of the impacts of similar density species of similarly
>vagrant or rare species in similar habitats and ecologies or identical species >at similar densities in other areas with similar habitats and ecologies.

But we're not talking about now, when they are still rare. we're talking about when they are more abundant and therefore have the potential to have an impact once they are established. Again, this is why i want them removed now, BEFORE they can spread and have that impact. Secondly, trawl back through this thread and you will find studies looking at the impact of EO in other parts of their range. Finally, we will never have that info for the Uk until it happens, so we have to make a judgement about the risks and benefits and make some value calls as to whether to take action.

>If that's the best data that we have then it is incomplete data. I personally
>would not wish to adopt an eradication programme based upon incomplete
>data, I would prefer to accumulate enough data to enable a valid
>assessment first.

But, yet again, by then it will too late to do much about it, except at enormous cost and once damage has already been done. So all we can do is look at what we do know- that introductions of non-natives are bad (especially predators); that EO eat disproportionate numbers of raptors and owls and that these groups are already threatened in the UK and have had vast resources expended on their conservation; that EO have a wide diet and are capable of taking any native UK bird and most native UK mammals and that we do not know what impact this may have (localised or national); that EO will attack livestock (esp lambs) and can be significant predators of game (hares, grouse) and these are already sensitive flashpoints for conflict between conservationsists and landowners and a tightrope that we all have to walk if we want wldlife conservation to continue on our uplands and raptor persecution to be discouraged. On the plus side, EO look really pretty. I can't think of any more plusses to seeing them breeding in the UK.

>What known negative impacts are Eagle Owls currently proven to be >causing within UK ecologies?

none yet, because they are still in the pioneer stage. But that will only last for so long, just like it did with muntjac, mink, coypu, ruddy duck, himalayan balsam, grey squirrel, canadian pondweed...................................again, the lesson is that introductions are usually bad news for native ecology. That's why there are laws against it!

 

[KnockerNorton]

I agree! No-one is disputing that almost all eagle owls occuring here are as a result of escapes!

I was disputing those people who refuse to accept the possibility (however small) that some birds get here naturally. You clearly accept that possibility.

I don't think anybody is denying it's possible, mate. But at the end of the day it doesn't matter if 1, 5, 10, 50 have made it over the past 100 years. It doesn't represent a colonisation and it doesn't mean to say they've stayed. What's happening now is nothing to do with vagrants. It's the same as with Little Owl - they were rare vagrants before they were introduced, but nobody in their right mind would suggest that the establishment of that species in this country had anything whatsoever to do with any vagrants.

 

[PaulD]

One thing for those who demand proof to consider is: How can it ever be proven that an eagle owl has flown across the sea from the continent if every eagle owl seen here is automatically assumed to be an escape?

I would accept a ringing recovery as proof, and I suspect that a significant number of the offspring of the Eagle Owls on the near Continent are rung (there are quite a few birdwatchers in Belgium, Holland etc), so the chances of a wild Eagle Owl in Britain having a continental ring are probably fairly reasonable.

Isotope testing of feathers might well be another possibility, but I don't know enough about that to be sure.

You're right I do accept the possibility that Eagle Owls could get here naturally, but I think the probability of colonisation via that avenue is so small that it would be unwise for it to heavily influence our thinking.

 

[nirofo]

Does anyone here realistically believe that the gamekeepers will leave them alone long enough for them to become widespread and a threat to our wildlife! If they can't leave the Harriers alone what chance the Eagle Owl?

nirofo.

 

[dave123]

Does anyone here realistically believe that the gamekeepers will leave them alone long enough for them to become widespread and a threat to our wildlife! If they can't leave the Harriers alone what chance the Eagle Owl?

nirofo.

you are definately right on the mark there

 

[Big Phil]

Don't you find it staggering that, in the face of all that, that bronze-age to medieval people would have totally ignored EO and left absolutely nothing? No carvings, no legends, no bones, no nothing. And if EO were here naturally, then why would they be at low numbers? Even if they were, their habit of nesting in caves etc would make them even easier to find traces of, as they'd be preserved in there along with the wolves and bears and eagles.

I think this is a bit over confident!. It's notoriously difficult to deduce the status of any British Bird historically due to poor or stylised drawings and inconsistent use of names etc. Even with a diurnal bird as blindingly obvious as the Little Egret we are left grasping as to whether it ever bred here before the recent colonisation - it has even been confused with Lapwing(!) when interpreting old texts. Wild Eagle Owls can be incredibly hard to find even when known to be nesting in an area and I find it easy to believe that a low density presence in our wild places could go unrecorded up until relatively recent times. I don't think comparing to an obvious diurnal bird like an eagle is valid.

As regards remains, recent or fossilised, these represent tiny glimpses into the past with various possible interpretations rather then representing any sort of undeniable or full record, and should be treated as such.

 

[Himalaya]

somethings are just hard to prove but it does nt mean it did nt happen. in a way im excited that they are here bt their effects on other species need to be minitored of course on the hen harrier who i think must be the first priority for the bowland area. if eagle owls got here naturally still they could breed elsewhere. there more habitat for them than for hen harriers.

in a way the fact that egle owls would prey on foxes, corvids, ravens, other birds of prey, rabbits, and even young deer are in a way plus points.

as eagle owls do prey on other birds of prey - dont goshawks do the same? i hae read goshawks do prey on other smaller birds of prey and ave taken large ones as big as buzzards too and there fore are athreat to hen harriers and peregrines right?

arent other birds of prey such as buzzards and goshawks and hen harriers able to defend themselves from eagle owls?

Like the Goshawks?

All the evidence painstaking presented by several knowledgeable posters throughout this and previous threads suggests that the Eagle Owls at large in this country are escapes or descendants of escapes. No credible evidence of natural colonisation has been provided. Why is that so hard for people to accept?

Graham

 

[DGRW]

Poecile -

well if it was a rare vagrant then it wouldn't feature and it was never a native bird then?

I'm not arguing that it was a "native bird", I'm arguing that it may belong here as a rare vagrant and possible occasional breeder. You seem to be completely dismissing that possibility out of hand with no evidence for your proposal other than an absence of evidence.

one would assume so, judging by their density in othe rparts of their range

The Eagle Owls European range is not such that birds can simply hop across the Channel is it? It is such that it may appear as an occasional vagrant though, isn't it?

can you tell us why you disagree, and why large predators like WTE and wolf would be so prevalent in art and folklore and organic remains, yet EO is totally absent?

In this context Poecile your use of the words 'so prevalent' can only be viewed in relative terms: 'so prevalent' in comparison to what? We're not exactly tripping over the pre-historic images that you describe, though they exist they are still quite rare in UK ancient art, they're the cream of the archaeological crop, those subject species were also common species, the Eagle Owl, as we all agree, has never been a common species. Why therefore do you assume that their prevalence in ancient UK art must be a forgone conclusion and why do you assume that we have interpreted Owls in ancient UK art correctly? I see little point in repeating myself further on this principle as you seem to be convinced that our current interpretations of history and historic art are the only possible interpretations when any historian will tell you that they may be open to revised interpretation subsequent to new finds, new discoveries and subsequent new knowledge. In short, in most cases, it is as impossible to prove that an image of an Owl in ancient art is not an EO as it is impossible to prove that it is, we don't know. Any "Horned Owl" in ancient UK art may be an Eagle Owl, we just don't know.

yet again, someone who doesn't grasp the significance between 'possible' and 'probable'.

Touche, the irony.

Thank you for clarifying your point regarding colonising Little Owls. Whilst agree entirely that your principle may apply to released or introduced species I would point out that you again appear to be dismissing out of hand even the possibility that EO's may arrive in this country as vagrants, that seems to be what this discussion is currently about. I don't refute your views on introduced/released EO's at all but I do refute your views regarding the possibility that natural vagrants may occur.

but the case against introductions (essentially or literally) of predators, especially top predators and into island ecosystems, has been proved time and time again. It's basic ecology.

I absolutely agree with youand I accept fully, as I have already stated, that there may be a case for controls on released birds. My problem with your eradication proposal is that it fails to take into account entirely the possibility that EO's may appear naturally in the UK as vagrants and they may equally have a small role in UK ecologies as such.

but that's not what we're talking about. We're talking about an established, permanant, expanding population. If it was just a couple of pairs and coastal wanderers

Again; I take your point entirely and again my problem is your apparent complete failure to recognise that these birds may also arrive in the UK as natural vagrants. I've seen Eagle Owls in the North of Scotland, such isolated birds do not represent the same ecological impact that other well known populations such as the Lancashire birds represent, my problem with your proposal is that complete eradication means exactly that and makes no allowance whatsoever for other possibilities in terms of possible means of arrival.

Which is it? One doesn't really matter, the other will matter.

My point entirely, so why eradicate them all?

Regarding the rest of your response to me; Please tell me what negative impacts the Lancashire population is proven to be having on local ecologies. When I see some evidence that this population does result in negative impacts then I shall be far more sympathetic to your proposal. The Lancashire population is the ideal initial study target for your proposal isn't it? so by all means use it, then make an informed decision, then take appropriate action. I would simply prefer that we have a better understanding of the situation before we take drastic (eradication) action, there is still time to do that effectively so use that time.

It may well turn out that eradication or severe control is the answer but I would prefer that we KNOW that before that action is taken. Otherwise, every time this impressive bird arrives in the UK as a natural vagrant, some bright spark will shoot it. Many birds ranges are changing at the moment, how do you KNOW that EO's are not one of those species?

 

[Brian Stone]

I agree! No-one is disputing that almost all eagle owls occuring here are as a result of escapes!

I was disputing those people who refuse to accept the possibility (however small) that some birds get here naturally. You clearly accept that possibility.

One thing for those who demand proof to consider is: How can it ever be proven that an eagle owl has flown across the sea from the continent if every eagle owl seen here is automatically assumed to be an escape?

Not sure how this helps. I can't see how anyone could deny there is a possibility some birds get here naturally. But that surely doesn't mean that it's Ok to release large numbers of any actual or potential vagrant into the wild and let them breed to established numbers while waiting to see what will happen.

 

[Edward woodwood]

arent other birds of prey such as buzzards and goshawks and hen harriers able to defend themselves from eagle owls?

they attack roosting birds (by surprise, therefore)

please no more cod philosophy - the IBWO thread weas bediviled with 'evidence of absence' circular gibberish

Many things are possible. We can't live our lives as if these have happened but we can't prove it. 'Burden of proof' is a very important and real concept.

 

[KnockerNorton]

I think this is a bit over confident!. It's notoriously difficult to deduce the status of any British Bird historically due to poor or stylised drawings and inconsistent use of names etc. Even with a diurnal bird as blindingly obvious as the Little Egret we are left grasping as to whether it ever bred here before the recent colonisation - it has even been confused with Lapwing(!) when interpreting old texts. Wild Eagle Owls can be incredibly hard to find even when known to be nesting in an area and I find it easy to believe that a low density presence in our wild places could go unrecorded up until relatively recent times. I don't think comparing to an obvious diurnal bird like an eagle is valid.

As regards remains, recent or fossilised, these represent tiny glimpses into the past with various possible interpretations rather then representing any sort of undeniable or full record, and should be treated as such.

well yes, to a point, but my point is that there isn't apparently anything even suggestive of eagle owl. And as they are such bird mysterious birds, like eagles, then remains would have been concentrated at human settlements, as they'd have been sought after (just as the eagles etc were), so we WOULD have found them if they existed.

 

[KnockerNorton]

Poecile -

I'm not arguing that it was a "native bird", I'm arguing that it may belong here as a rare vagrant and possible occasional breeder. You seem to be completely dismissing that possibility out of hand with no evidence for your proposal other than an absence of evidence. The Eagle Owls European range is not such that birds can simply hop across the Channel is it? It is such that it may appear as an occasional vagrant though, isn't it? In this context Poecile your use of the words 'so prevalent' can only be viewed in relative terms: 'so prevalent' in comparison to what? We're not exactly tripping over the pre-historic images that you describe, though they exist they are still quite rare in UK ancient art, they're the cream of the archaeological crop, those subject species were also common species, the Eagle Owl, as we all agree, has never been a common species. Why therefore do you assume that their prevalence in ancient UK art must be a forgone conclusion and why do you assume that we have interpreted Owls in ancient UK art correctly? I see little point in repeating myself further on this principle as you seem to be convinced that our current interpretations of history and historic art are the only possible interpretations when any historian will tell you that they may be open to revised interpretation subsequent to new finds, new discoveries and subsequent new knowledge. In short, in most cases, it is as impossible to prove that an image of an Owl in ancient art is not an EO as it is impossible to prove that it is, we don't know. Any "Horned Owl" in ancient UK art may be an Eagle Owl, we just don't know. Touche, the irony.

Thank you for clarifying your point regarding colonising Little Owls. Whilst agree entirely that your principle may apply to released or introduced species I would point out that you again appear to be dismissing out of hand even the possibility that EO's may arrive in this country as vagrants, that seems to be what this discussion is currently about. I don't refute your views on introduced/released EO's at all but I do refute your views regarding the possibility that natural vagrants may occur. I absolutely agree with youand I accept fully, as I have already stated, that there may be a case for controls on released birds. My problem with your eradication proposal is that it fails to take into account entirely the possibility that EO's may appear naturally in the UK as vagrants and they may equally have a small role in UK ecologies as such. Again; I take your point entirely and again my problem is your apparent complete failure to recognise that these birds may also arrive in the UK as natural vagrants. I've seen Eagle Owls in the North of Scotland, such isolated birds do not represent the same ecological impact that other well known populations such as the Lancashire birds represent, my problem with your proposal is that complete eradication means exactly that and makes no allowance whatsoever for other possibilities in terms of possible means of arrival. My point entirely, so why eradicate them all?

Regarding the rest of your response to me; Please tell me what negative impacts the Lancashire population is proven to be having on local ecologies. When I see some evidence that this population does result in negative impacts then I shall be far more sympathetic to your proposal. The Lancashire population is the ideal initial study target for your proposal isn't it? so by all means use it, then make an informed decision, then take appropriate action. I would simply prefer that we have a better understanding of the situation before we take drastic (eradication) action, there is still time to do that effectively so use that time.

It may well turn out that eradication or severe control is the answer but I would prefer that we KNOW that before that action is taken. Otherwise, every time this impressive bird arrives in the UK as a natural vagrant, some bright spark will shoot it. Many birds ranges are changing at the moment, how do you KNOW that EO's are not one of those species?

Your main bugbear in htis post seems to be that I do not accept that EO could occur here as a natural vagrant. While this is a side element to the debate (vagrants and a feral population are 2 different things, cf canada goose), I would politely refer you to post 243, which precedes your post here. In that, I fully accept that EO could be a vagrant.

 

[DGRW]

Poecile -

I fully accept that EO could be a vagrant.

So why the insistence on a total eradication programme?

Tim -

bediviled with 'evidence of absence' circular gibberish

This established principle, whilst being now cliche, does not neccessarily have to result in "circular gibberish". With a little thought it can result in an acceptance of "other possibilities" and therefor, equally, other options.

'Burden of proof' is a very important and real concept.

Absolutely and where burden of proof is evident, appropriate action is relevant, however, a total eradication programme for all UK Eagle Owls, inclusive of natural vagrants is not, in my opinion an "appropriate response" whilst a targetted cull may be appropriate.

The burden of proof is most certainly strongly indicated for introduced/released birds but certainly not for natural vagrant birds.

 

[KnockerNorton]

>Poecile - So why the insistence on a total eradication programme?

Because a handful of vagrants means nothing. Rare vagrants do not generally stay to breed, and you have already accepted that the breeding population is feral. So what difference does it make if 3 of them are wild? It's irrelevant, as the feral population is still there so taking those 3 wild birds (which themselves would probabyl be reintroduced birds from the near continent) is a small price to pay in the removal of the feral population - you're ignoring the elephant in the room.

Do we not cull canada geese in case one of them is transatlantic? Are we not eradicating Ruddy Ducks, even though they are perfectly capable of flying here naturally (though never proven, as in EO)?

>a total eradication programme for all UK Eagle Owls, inclusive of natural
>vagrants is not, in my opinion an "appropriate response" whilst a targetted
>cull may be appropriate.

and how, exactly do you tell which is which? How do you even know that any of them ARE vagrants? You're the one wanting proof, so it would be up to you to prove that any of the birds are wild and should not be removed. We do not target the eradication of Ruddy Ducks on the basis that e.g. >1% of them may or not be wild (for which there is no proof). That would be insane. We remove them all, and if a lone vagrant gets caught up in it, then it's not exactly the end of the world (except for the vagrant). It's a risk we accept and a price we decide is worth paying - especially in the total absence of any evidence to the contrary.

>The burden of proof is most certainly strongly indicated for
>introduced/released birds but certainly not for natural vagrant birds

what does that even mean? burden of proof for what? The burden of proof says that this population of EO that we have is feral. It falls heavily against any of them being wild. So what's your point?

 

[DGRW]

Peocile -

So what difference does it make if 3 of them are wild? It's irrelevant, as the feral population is still there so taking those 3 wild birds (which themselves would probabyl be reintroduced birds from the near continent) is a small price to pay in the removal of the feral population

By that token, all vagrant birds would be "fair game". I completely disagree that the presence or vagrants is "irrelevant".

(which themselves would probabyl be reintroduced birds from the near continent)

Again; your apparent inability to accept the possible presence of natural vagrant birds.

you're ignoring the elephant in the room.

whilst you're throwing the baby out with the bathwater (my apologies for the predicability there).

and how, exactly do you tell which is which? How do you even know that any of them ARE vagrants?

As (I assume) a birder, I feel sure that you are able to recognise the likely difference between an isolated rare vagrant and an established feral population, but are others so selective? Can individual EO's be recognised and monitored without ringing? yes they can, so why such a non-selective approach to culling?

You're the one wanting proof, so it would be up to you to prove that any of the birds are wild and should not be removed.

I disagree, I feel that before an animal is killed, there should be a proven good reason for that killing. Can individual EO's be recognised and monitored without ringing? yes they can, so why such a non-selective approach to culling?

>The burden of proof is most certainly strongly indicated for
>introduced/released birds but certainly not for natural vagrant birds

what does that even mean? burden of proof for what? The burden of proof says that this population of EO that we have is feral. It falls heavily against any of them being wild. So what's your point?

As I have just said; the burden of proof does fall very strongly against feral/released/introduced populations but as I have also already said it most certainly does not fall against natural vagrants.

I find it a little difficult to understand your ability to discuss the killing of natural vagrants so casually.

They "don't matter"?

I disagree very strongly and that, I suspect, is a moral argument far too subjective on both sides of the debate to be resolved here.

 

[Brian Stone]

DRGW: accepting this argument would give carte blanche to the introduction of a feral population of any actual or potential vagrant. It just won't wash.

 

[Amarillo]

DRGW: accepting this argument would give carte blanche to the introduction of a feral population of any actual or potential vagrant. It just won't wash.

I would never advocate accepting any feral population of an actual or potential vagrant - in my view each case needs to be looked at individually.

And if you look at other introductions of actual/potential vagrants eg. red-legged partridge and little owl in Britain, there tends to be less of a risk.

Obviously in an ideal world there would be no introductions, but we need to be realistic and concentrate our efforts on those which are likely to be a threat.

 

[Farnboro John]

Yes but I begin to think the alternative of not accepting it means advocating the removal of all feral species regardless of known or unknown consequences. Imagine Britain without assorted parakeets, Little Owls, Canada Geese, Mandarins, Ruddy Ducks, Red-crested Pochards, Red-legged Partridges, Pheasants of all species, Rabbits, Brown Hares, Fallow, Sika, Muntjac and Chinese Water Deer, Brown Rats, Grey Squirrels, Common Voles, Lesser White-toothed Shrews, Marsh Frogs, Wall Lizards...and that's an incomplete list of Chordates, heaven knows what there is in invertebrates.

Sounds almost like carte blanche for the hunting fraternity.

John

 

[Farnboro John]

And if you look at other introductions of actual/potential vagrants eg. red-legged partridge and little owl in Britain, there tends to be less of a risk.

Obviously in an ideal world there would be no introductions, but we need to be realistic and concentrate our efforts on those which are likely to be a threat.

Just re-read this more carefully. Are you really suggesting that there is no connection between the hordes of easy to raise Red-legged Partridges infesting farmland from Farnborough to Speyside and the disappearance of native more difficult to maintain and rarely bred for release Grey Partridges? Define threat!

John