Genetic Integrity. (1 Viewer)

[Anthony Morton]

QUOTE=birdman

So, next question, would the relative dearth of "wild" perlins doom the hybrid to failure?


Hi Birdman,

I'm beginning to wish I was a geneticist - but sadly I'm not!

As I see it (and I'm open to correction of course!) so long as there is at least one male and one female 'perlin' living in the wild, then it is statistically possible for the two of them to eventually meet, pair up and breed successfully - although I imagine that would be stretching the odds of possibility/probabitity to the absolute limit.

If I understand Suricates earlier posting correctly, he is confirming that an unknown number of assorted hybrids, including 'perlins', are already living wild in the UK. Therefore I assume the chance of two wild 'perlins' meeting and getting it together would increase in direct proportion to their total population.

But this is only half of the problem. What if just one 'perlin' took a fancy to a peregrine falcon, or another 'perlin' set its heart on a merlin for a mate? In each case any resulting young would all carry a percentage of impure blood, which they in turn would then pass on from generation to generation.

I spoke in an earlier posting of eventually breeding the 'impure' blood out, but with the benefit of hindsight that cannot happen, as it doesn't matter how many times the blood is diluted, in DNA terms it will always contain a measurable trace of the blood from the original hybrid pairing.

So if only one 'perlin' is living in the wild it still has the potential to leave its DNA mark simply by breeding with a bird from an otherwise pure species, or even a different hybrid. This was the point I was making when I suggested that the genetic integrity of Britain's raptors is in danger of being compromised for all time by these 'man-made' hybrids.

 

[birdman]

To be fair, Anthony, I never really addressed your original comment, that you have repeated again in you last post.

I suppose it is sadly true that genetic integrity must be "breached" by the introduction of man-made cross-breeds into the wild.

And as you have said, once a given blood-line is compromised, then technically you can never get purity back.

But then, I suppose, there is purity and there is purity. If one accepts Evolutionary Theory, then there must be some time in history when peregrines and merlins were both one and the same ancestral species. Somehow, through the process of natural selection, the populations of this archaic raptor separated to produce peregrines, merlins and all other raptor species.

Whilst I understand from another thread there are 35 sub-species of Barn Owl, and therefore these are sufficiently different from one another to be separated by whatever techniques mankind has developed, there must come a time after a relatively few (?) generations when any hybridisation that does not produce a wholly different "species" or at least "sub-species", will be indiscernible from pure, even using the most sophisticated DNA analysis.

Mind you, I am certainly not suggesting this is any defence against releasing non-native raptors (or any other species for that matter) into the wild.

Also, and this like the above, is based purely on my thoughts rather than any empirical data, we have thousands upon thousands of ducks in this country.

Whilst hybrids obviously occur, and some common hybridisations in sufficient numbers to be reasonably well studied, we're not exactly knee-deep in mixtures!

For the most part it seems, without human intervention at least, ducks tend to breed within their species. Pochards with Pochards, Tufties with Tufties, Teal with Teal. Even Mallards, who seems to have a reputation for trying it on with anything with a bill, generally choose other Mallards.

I don't see any reason why things should be different with raptors.

 

[Suricate]

QUOTE=birdman

So, next question, would the relative dearth of "wild" perlins doom the hybrid to failure?


Hi Birdman,

I'm beginning to wish I was a geneticist - but sadly I'm not!

As I see it (and I'm open to correction of course!) so long as there is at least one male and one female 'perlin' living in the wild, then it is statistically possible for the two of them to eventually meet, pair up and breed successfully - although I imagine that would be stretching the odds of possibility/probabitity to the absolute limit.

If I understand Suricates earlier posting correctly, he is confirming that an unknown number of assorted hybrids, including 'perlins', are already living wild in the UK. Therefore I assume the chance of two wild 'perlins' meeting and getting it together would increase in direct proportion to their total population.

But this is only half of the problem. What if just one 'perlin' took a fancy to a peregrine falcon, or another 'perlin' set its heart on a merlin for a mate? In each case any resulting young would all carry a percentage of impure blood, which they in turn would then pass on from generation to generation.

I spoke in an earlier posting of eventually breeding the 'impure' blood out, but with the benefit of hindsight that cannot happen, as it doesn't matter how many times the blood is diluted, in DNA terms it will always contain a measurable trace of the blood from the original hybrid pairing.

So if only one 'perlin' is living in the wild it still has the potential to leave its DNA mark simply by breeding with a bird from an otherwise pure species, or even a different hybrid. This was the point I was making when I suggested that the genetic integrity of Britain's raptors is in danger of being compromised for all time by these 'man-made' hybrids.

Hi Anthony,
I think I am right in stating that there are no precise numbers in regard to hybrid raptors.
Many falconry birds are identi rung by the IBR ( Independant bird register ) and they have a web site that lists many falconry issues and a lost / stolen page which does at times seem full!!!
The implications of your thread re genetic integrety must be taken seriously as the threat is there, Falconry does seem to be the area that hybridation is mainly worked in, trying for some ridiculous reason to improve on nature.
The list of hybrids is extensive but it does not stop there how about "tribrids".
Most of the hybrids are of the falco genus as other genus are not possible, not desirable or not worth it. There are over 15 hybrid species in the UK and at some point a percentage , perhaps minute will breed with wild species.
Suricate

 

[Joern Lehmhus]

Hi all,

maybe this is of some interst here (sorry, it is in German)

http://nrw.nabu.de/m05/m05_01/

The important thing is that there was a pairing of a hybrid with a Peregrine in Northrhine-Westfalia in 2000 (the 2 young were taken from the wild and brought into a Raptor centre; the hybrid tiercelwas later caught and it was found it belonged to a Raptor dealer in Bavaria); and in 2001 2 pairings that involved a hybrid were found in whole Germany.

If this increases, it will become a problem (more than I thought previously); also because some of the hybrids seme to be very difficult to distinguish from pure birds even at close distance. The tiercel in Northrhine -westfalia was only recognized as a hybrid when the ringers found the young differed from pure peregrines.

Jörn

 

[Jane Turner]

I really worry about the forced captive hybidisation of raptors and would lobby strongly to have it stopped.

I've seen one monstrous hybrid Saker/Gyr sized thing in the wild, an all black Peregrine and what was either a fem Barbary falcon or a Peregrine X Prairie type thing...

I would have expected that the young of hybrid falcons to be infertile!

 

[Edward woodwood]

seconded Jane

 

[Joern Lehmhus]

Hi Jane,
Doesn´t seem to be so-at least not with Peregrine X Gyr/Peregrine or Saker/Peregrine hybrids.

I red somewhere that Peregrines probably evolved from the steppe/tundra inhabiting Gyr/saker group; as an adaptation to less open country the special hunting behaviour of the peregrine developed (stoops from high in the air on prey flying above tree canopy in wooded areas), but the peregrine also still has the low flying technique of gyr or saker in open biotopes.
Don´t know if that is true , though it seemed quite plausible to me. And it might also explain why these hybrids can be fertile
(but I don´t know how this is with merlin/Peregrine hybrids or hybrids with prairie falcon?)

Jörn

 

[Jane Turner]

I was basing it more on the supposed lack of fertility of F1 hybrids of full species rather than on habit

 

[Anthony Morton]

QUOTE=Joern Lehmhus

If this increases, it will become a problem (more than I thought previously); also because some of the hybrids seme to be very difficult to distinguish from pure birds even at close distance. The tiercel in Northrhine -westfalia was only recognized as a hybrid when the ringers found the young differed from pure peregrines.

Jörn

Hi Joern,

Thank you for an excellent contribution!

This is exactly the point I am making - that 'IF' the number of lost hybrids is allowed to increase unchecked, then what might, or might not, have happened by a natural evolutionary process over possibly thousands of years will be forced upon the species involved (in this case raptors) in very short order due to man playing God and meddling with genetics.

And once the genie is out of the bottle (which it may already be don't forget!) the damage becomes irrevocable, because we will have hybrids which are virtually impossible to identify by any means other than DNA sample. Personally I much preferred it when nature was allowed to get on with things in its own time - but then, I'm old fashioned!

 

[Suricate]

QUOTE=Joern Lehmhus

If this increases, it will become a problem (more than I thought previously); also because some of the hybrids seme to be very difficult to distinguish from pure birds even at close distance. The tiercel in Northrhine -westfalia was only recognized as a hybrid when the ringers found the young differed from pure peregrines.

Jörn

Hi Joern,

Thank you for an excellent contribution!

This is exactly the point I am making - that 'IF' the number of lost hybrids is allowed to increase unchecked, then what might, or might not, have happened by a natural evolutionary process over possibly thousands of years will be forced upon the species involved (in this case raptors) in very short order due to man playing God and meddling with genetics.

And once the genie is out of the bottle (which it may already be don't forget!) the damage becomes irrevocable, because we will have hybrids which are virtually impossible to identify by any means other than DNA sample. Personally I much preferred it when nature was allowed to get on with things in its own time - but then, I'm old fashioned!

Hi Anthony,
In regard to the fertility of hybrids raised by someone earlier on the thread, there is evidence to prove that hybrids and tribrids are able to reproduce., This is obviously because all successful hybrids in regard to birds of prey ( Raptors ) is due to the falco genus only being used.
This hybrid problem will be forwarded in the consultation from DEFRA regarding the guidelines set down for non indigenous species.
Falconry should perhaps have stronger guidelines ?
Suricate

 

[Andrew Rowlands]

'IF' the number of lost hybrids is allowed to increase unchecked, then what might, or might not, have happened by a natural evolutionary process over possibly thousands of years will be forced upon the species involved (in this case raptors) in very short order due to man playing God and meddling with genetics.

"FORCED"!!!!! If, as has been suggested, the population is at saturation point, then the F1 hybrids etc., would be at a disadvantage and possibly never get a chance to breed!

Andy.

Still waiting for your references from your earlier post!

 

[Jane Turner]

It is of course an interesting itellectual argument to discuss if any "meddling" in species itegrity is acceptable. How about selective breeding?

 

[Ranger James]

QUOTE=Joern Lehmhus

If this increases, it will become a problem (more than I thought previously); also because some of the hybrids seme to be very difficult to distinguish from pure birds even at close distance. The tiercel in Northrhine -westfalia was only recognized as a hybrid when the ringers found the young differed from pure peregrines.

Jörn

Hi Joern,

Thank you for an excellent contribution!

This is exactly the point I am making - that 'IF' the number of lost hybrids is allowed to increase unchecked, then what might, or might not, have happened by a natural evolutionary process over possibly thousands of years will be forced upon the species involved (in this case raptors) in very short order due to man playing God and meddling with genetics.

And once the genie is out of the bottle (which it may already be don't forget!) the damage becomes irrevocable, because we will have hybrids which are virtually impossible to identify by any means other than DNA sample. Personally I much preferred it when nature was allowed to get on with things in its own time - but then, I'm old fashioned!

That's very old fasioned Anthony, seeing as man has been meddling in genetics for many thousands of years.

This is a worrying prospect however, and I think Suricate has a good point suggesting much stricter codes regulating falconry. It is illegal to 'release' any non-native in this country, so perhaps the legeslative effects of the CROW act should be called into play in these situations.

 

[Anthony Morton]

QUOTE = Ranger James

This is a worrying prospect however, and I think Suricate has a good point suggesting much stricter codes regulating falconry. It is illegal to 'release' any non-native in this country, so perhaps the legeslative effects of the CROW act should be called into play in these situations.

Hi James,

Perhaps one way of illustrating the hypocricy of this, is that while I could release and lose a Peregrine/Lanner x Lugger/Gyr hybrid (if such a 'beast' exists, but you'll get my drift) without penalty, while you could be prosecuted for deliberately releasing a Budgerigar!

Daft, or what? Perhaps Mr Bumble was right, and "... the law is a ass - a idiot."

Anthony

 

[Joern Lehmhus]

Hi all,
I think the situation with peregrines and hybrids shows some similarities to the ruddy duck-whiteheaded duck problem.
I wouldn´t think a few hybrids breeding with the pure species cause any problems, but if hybrid numbers and escapes are increasing, the genepool of the species may in the end be strongly altered.
This could have effects on populations and species on different levels and even affect the peregrines long-term survival as á species.

Aside from that there is a problem, if we decide to do something against this situation:

If it is decided to do something about the problem and hybrid birds are allowed to be culled; this would cause heavy effects on the peregrine population, due to the fact that quite a lot of pure birds will be killed also. People would claim to have thought: this must be a hybrid...
A similar problem occured in the Lowlands of Northrhine-Westfalia during the initially successfull Reintroduction of Northern Raven (Corvus corax). The population in that area first increased, then started to decline again allthough habitat was fine. The probable main reason was that birds were shot by people who thought them to be carrion crows (or at least said so; carrion crow shooting not being forbidden). So now this Raven population is again nearly extinct, despite the initial success.

Therefore I agree with Ranger James and Suricate; in the way that a kind of control by law must be found. The release or loosing of a hybrid shouldBut the control of this will be extremely difficult to achieve; so perhaps the possession or production of such hybrids should be made illegal?

Joern

 

[Jane Turner]

I'm with you there.. the problem should be stopped at source...mind you personally, and I stress its a personal view, I'm uncomfortable with falconry...full stop.

I'd still be very very surprised if long-term the hybirds had any serious effect on the natural populations of raptors and left to their own devices thinngs will sort themselves out.

 

[Ranger James]

I'm with you there.. the problem should be stopped at source...mind you personally, and I stress its a personal view, I'm uncomfortable with falconry...full stop.

I'd still be very very surprised if long-term the hybirds had any serious effect on the natural populations of raptors and left to their own devices thinngs will sort themselves out.

I don't want to get too far into the falconry side of things, as I am well aware that this is a wild bird forum, however for this thread it is particularly pertinant.

I belive that the gulf between bad raptor keepers, and good falconers/austringers is as huge as in any animal welfare issue. Some people are capable of keeping an animal well and others do not. If done well, the falcon flies with the falconer, not for them. And at its best the bond between falconer and bird represents one of the most intimate pairings of man and animal. I know many of you will think this utter, utter nonsense, but that's what my (limited) first hand experience has made me feel.

The difference beteen keeping, say, a falcon and a dog in captivity, is that the falcon requires more specialist skill to maintain its wellbeing. The keeping of any bird of prey, in less than perfect conditions is at best undesireable and at worst abhorent. Which is precisely why I am gobsmaked that there are not much tighter regulations in this country governing this persuit.

I also think that by insisting upon the highest level of husbandry for all aspects of falconry, you will almost completely remove the element that this string is following, as systems would be in place for the falconer to report a bird missing as soon as it happens, and all captive bred falcons/hawks/owls being flown free in this country would be accounted for. A mammoth undertaking I grant you. But one that should be done to bring the pursuit up to modern animal welfare standards.

What I do not want to see, (and I'm sure there was no intention by the thread starter to imply this) is this issue cited as a reason for getting rid of some 'undesireable' populations of peregrines, that by some are seen to be getting in the way of songbird numbers; pigeon racing; climbers; can't think of any other user groups that could object to a healthy population of falcons in thier patch?

In an over-simplified nutshell: Don't blame the birds for escaping, make it more difficult to own one in the first place.

Just my thoughts.
James

 

[Anthony Morton]

Re: Posting No 37 by Ranger James.


Hi James,

Absolutely spot on. Very well said indeed.

Anthony

 

[Joern Lehmhus]

Hi Jane,
agreed. The point of concern for me is if there is a high frequency of escape and therefore a constant introgression into the wild population (similar to the situation in wild salmon and farm salmon).

Hi James,
agreed. And I didn´t intend to start a thread on banning falconry or blaming the bird that escapes. But I have seen too many birds in less than perfect conditions (so I would like to have very strict control on falconers and the conditions they keep their animals). This is similar with other birds, especially with many parrots and their keepers-
but I didn´t want to drift away from this threads topic- this would be something for another thread.

 

[Edward woodwood]

Joern...you said
I wouldn´t think a few hybrids breeding with the pure species cause any problems, but if hybrid numbers and escapes are increasing, the genepool of the species may in the end be strongly altered.


have a look at the WWT website page on Ruddy Ducks and proliferation of hybrids...what you say in the second half of your sentence above is happening in Spain....result: no more White-headeds....unless BANG BANG BANG

atb
Tim