Breeders and Scientists - Chances of Natural Hybrids?

[Little Joe]

I'd like to know what the chances are of natural hybrids occurring in the wild. Examples could be Barbary x Brookei in the Atlas mountains, or Gyr x Sakers in the Altai range. But feel free to bring in whatever examples you are aware of.

I am not a breeder or expert on reproduction cycles or raptors, so I'd really appreciate some input from those who are.

In my "philosophical" opinion natural hybrids do occur and breeding clocks are not cast in stone. Even if they are, it just takes a few anomalies in a billion to produce a decent number of natural hybrids.

[Brian Sullivan]

I'd like to know what the chances are of natural hybrids occurring in the wild. Examples could be Barbary x Brookei in the Atlas mountains, or Gyr x Sakers in the Altai range. But feel free to bring in whatever examples you are aware of.

I am not a breeder or expert on reproduction cycles or raptors, so I'd really appreciate some input from those who are.

In my "philosophical" opinion natural hybrids do occur and breeding clocks are not cast in stone. Even if they are, it just takes a few anomalies in a billion to produce a decent number of natural hybrids.

Just sample the bird watcher reports in the US and you will be amazed how many natural hybrid avian's are listed on these reports.

[Little Joe]

Just sample the bird watcher reports in the US and you will be amazed how many natural hybrid avian's are listed on these reports.

Hi Brian, I see you started falconry the year I was born. I am humbled...:-|

Would you care to touch on the subject of breeding cycles please? How do two species overcome the difference in timing when their natural breeding clocks click in? An example on another thread was the hybridization between Barbaries and Brookei's where there is a 30 day or so difference between their breeding times.

Regards,
Jannes

[Hatchero]

i think there are some cases of peregrines and prairies hooking up in the wild. i had sort of thought that black gyrs are really a peregrine hybrid however far removed. i might be wrong but i think there are some regions where gyrs and sakers show some sign of mixing(besides every breeding chamber in Britain). i know that some years ago there was a pairing of a European goshawk and american goshawk in the northern sierras that pair was around for a few years as i recall. i would expect that given a large time span hybridization is rather normal. in the case of plants, hybrid swarms are a sign of active speciation.
jim

[Tacatanach]

There have been a few documented peregrine x prairies.

Hawkwise, Swainsons x Rough-legged Hawk has been found, the paper (Clark and Witt 2005)says this is the first confirmed wild Buteo hybridizaiton where a specimen has been collected. Here's their intro paragraph of other documented hybridizations:
Few documented cases of hybridization exist between any 2 of the 27 or so species in the genus Buteo. Hybrid combinations have been reported for Long-legged Buzzard (B. rufinus) and Upland Buzzard (B. hemilasius) in Asia (Pfander and Schmigalew 2001), Common Buzzard (B. buteo) and Long-legged Buzzard in Europe (Dudás et al. 1999), and Red-shouldered Hawk (B. lineatus) and Gray Hawk (Asturina nitidus) in North America (Lasley 1989). Additionally, an adult Swainson's Hawk (B. swainsoni) bred for more than 8 years with a presumably escaped South American Red-backed Hawk (Red-backed Buzzard, B. polyosoma) in Colorado, USA, and produced offspring in some years (Allen 1988, Wheeler 1988); a Red-tailed Hawk (B. jamaicensis) that escaped from a falconer bred with a Common Buzzard in Scotland (Murray 1970).

More recently Hull et all (2007) also documented 3 Swainsons x red tails

Both the Hull et al and Clark and Witt used molecular tecniques to demonstrate hybridization.

[Little Joe]

Thanks for the info so far. Very interesting.

How do these odd pairs overcome the natural inhibitors. Different species evolved different courtship rituals, different fitness indicators, different biological "clocks". Without human intervention, how are these overcome?

I'm particularly interested in the different timings of breeding cycles as mentioned before. Anyone with a hypothesis or some observed info?

[John Beaumont]

Something similar seems to have come up yesterday.

Here's what I have on my desk:

Eastham and Nicholls, J Raptor Res 39 (4) 386-393, Morphometric Analysis of Large Falco Species and their Hybrids with implications for Conservation.

In its references section you'll find some others of interest.

There was a recent discussion on the Raptor Conservation forum over Common buzzard and Harris hawk hybrids in Britain.

Good luck.

[ReluctantTwitcher]

Just thought I'd chime in with a couple of other examples of natural hybrid pairings. The first ones concern Black Kites & Red Kites in Scania (southernmost Sweden), where at least two mixed pairs have bred succesfully. Interestingly enough, some of the hybrid offspring have later been documented as to go on and breed successfully with Red Kites themselves. The theory is that the Black kites paired up with Red Kites due to a lack of suitable partners, since Black Kites are normally only vagrants/migrants here in Scania, whereas Red Kites breed in large numbers. Why the Red kites decided to go along with it, with so many potential same species partners available, I have no idea. Just goes to show that species imprinting is not always set in stone.

The other case consists of a Pallid Harrier that supposedly paired up with a Hen Harrier in Finland a few years back, although I have much less information about this one. Maybe some of our Finnish friends have more info on this.

[Pavel Yakimov]

Hi guys,

Very interesting threat! Our colleague Sokoly from Makedonia could give su some tip regarding the eventual natural hybridization between F.c.danubialis and F.b.feldegii on the teritory of Makedonia.

Also it is known of few cases in Germany for hybrids between Aquila pomarina and Aquila clanga.

According to my understanding the last one and some of the natural hybrids could be becasue of habitat lose, nesting area lose, food sources lose and thus it leads to low population of particular species. And if there are some close related by genotype birds of prey, like with the A.pomarina and A.clanga case, here we have a natural hybrid mess. Which in most of the time is our, humans, responsibility for having their destiny.

Even not considering the term hybridisation between subspecies, I could agree that it is not good to have F.p.babylonicus with F.p.pelegrinoides, especialy when the second bird is from the area between Turkmenistan and Afganistan where the birds are very light in colour. I will send some pics soon.


Rgds,

Pavel

[Chabich]

Not wanting to kick off another Hybrid discussion, but as scientific knowlege about the topic stands today, nature 'washes' out hybridization over time - provided the natural breeding stock of the species is large enough. Habitat of the species seems to 'do' the rest of the 'cleaning'. Research e.g. Peregine Fund has shown that even, if you reintroduce subspecies hybrids (e.g. PealesXCalidus) into a specific habitat, after 9-12 generations the stock becomes more and more pure and resembles more or less the original natural breeding stock of the region's species again.
In other words, there wouldn't be a single wild genetically 'unspoilt' duck left in the whole of Europe considering the amount of domesticXwildduck Hybrids occuring.
Funnily enough one never hears anything about these Hybrids (or Deer Hybrids) from the Anti-Hybrid lobby.... wonder why that is ... :idea:


Christian

[Brian Sullivan]

Hi Brian, I see you started falconry the year I was born. I am humbled...:-|

Would you care to touch on the subject of breeding cycles please? How do two species overcome the difference in timing when their natural breeding clocks click in? An example on another thread was the hybridization between Barbaries and Brookei's where there is a 30 day or so difference between their breeding times.

Regards,
Jannes

Hi Jannes,

Overlaping breeding cycles can easly happen. I have an Anatum male paired with a Fijian female that lays eggs in Feb. The male Anatum covers the eggs on both clutches. If in the wild two different subspieces come together and the first clutch is infertile there is very good chance the female will recycle at least once and can even recycle a third time. First recycle can be 10-20 days- average 14 days. You can now see the picture that one female can keep going through the egg laying for sometime. There is many accounts of Peregrines laying up to 16 eggs all in different scrapes. Some will just keep laying no matter what and then might finally start incubating on the last group.

Sometimes there are pairs of Gyrfalcons that seem to have all their first eggs infertile but cover some of the second clutch. This is more because of the male of course. After stripping many many males for semen collection and having many male semen donors you start to see a pattern that some males have semen for long periods of time and others have very little for what ever reason.

One should not be paranoid about Hybrids in birds. This is a very common occurence in the wild and like the the Gentlemen stated from Austria the blood is soon diluted. Otherwise we and all the birders would be seeing more strange birds out there if this was not the case.

If you look at he Homing pigeon that has been bred for over a hundred years. When they go back into a flock of Rock Doves the 100 years of breeding will be compelety diluted in less then 3 generations. The feral Pigeon or Barn pigeon as we Americans call them are very different from well bred Homers. The Rock Dove is design is by its enviroment to be the best for living in the wild.

Something to think about, Brian

[Jerkin]

Just thought I'd chime in with a couple of other examples of natural hybrid pairings. The first ones concern Black Kites & Red Kites in Scania (southernmost Sweden), where at least two mixed pairs have bred succesfully. Interestingly enough, some of the hybrid offspring have later been documented as to go on and breed successfully with Red Kites themselves. The theory is that the Black kites paired up with Red Kites due to a lack of suitable partners, since Black Kites are normally only vagrants/migrants here in Scania, whereas Red Kites breed in large numbers. Why the Red kites decided to go along with it, with so many potential same species partners available, I have no idea. Just goes to show that species imprinting is not always set in stone.

The other case consists of a Pallid Harrier that supposedly paired up with a Hen Harrier in Finland a few years back, although I have much less information about this one. Maybe some of our Finnish friends have more info on this.
Red kite bred with a vagrant Black Kite in Scotland last year or the year before,not openly publicized by conservationists as they want to use hybrids as a stick to bash the falconry movement

[Little Joe]

Hi Jannes,

Overlaping breeding cycles can easly happen. I have an Anatum male paired with a Fijian female that lays eggs in Feb. The male Anatum covers the eggs on both clutches. If in the wild two different subspieces come together and the first clutch is infertile there is very good chance the female will recycle at least once and can even recycle a third time. First recycle can be 10-20 days- average 14 days. You can now see the picture that one female can keep going through the egg laying for sometime. There is many accounts of Peregrines laying up to 16 eggs all in different scrapes. Some will just keep laying no matter what and then might finally start incubating on the last group.

Sometimes there are pairs of Gyrfalcons that seem to have all their first eggs infertile but cover some of the second clutch. This is more because of the male of course. After stripping many many males for semen collection and having many male semen donors you start to see a pattern that some males have semen for long periods of time and others have very little for what ever reason.

One should not be paranoid about Hybrids in birds. This is a very common occurence in the wild and like the the Gentlemen stated from Austria the blood is soon diluted. Otherwise we and all the birders would be seeing more strange birds out there if this was not the case.

If you look at he Homing pigeon that has been bred for over a hundred years. When they go back into a flock of Rock Doves the 100 years of breeding will be compelety diluted in less then 3 generations. The feral Pigeon or Barn pigeon as we Americans call them are very different from well bred Homers. The Rock Dove is design is by its enviroment to be the best for living in the wild.

Something to think about, Brian

Thanks for sharing your knowledge about the breeding cycle "mystery". It now seems very likely to me that natural hybrids are probably quite common, but because of gene dilution over a few generations, we dont often spot them in the wild.

[HallBeck]

Would i be right in saying that these wild hybrids are actually beneficial? I think i remember reading somewhere that these naturally occuring hybrids are the only way to introduce new genes into a species gene pool.

Surely all species, by definition, have a declining gene poll (just like pedigree dogs) and that the occasional hybrid is an advantage.

[ReluctantTwitcher]

Would i be right in saying that these wild hybrids are actually beneficial? I think i remember reading somewhere that these naturally occuring hybrids are the only way to introduce new genes into a species gene pool.

Surely all species, by definition, have a declining gene poll (just like pedigree dogs) and that the occasional hybrid is an advantage.

Not denying what you're saying, but don't forget the natural mutations that occur within the species' own gene pool. Also, unless numbers are extremely reduced, inbreeding depression is normally counter-acted by the extremely harsh culling mother Nature performs in the wild. A wide genetic "basis" is of course a very good idea when living conditions change (habitat changes, new diseases, etc.), so as to increase the likelihood that at least some individuals survive and are able to re-populate, but there are plenty of examples where populations or even whole species have survived for long periods with extremely limited gene pools.

[HallBeck]

Is a natural mutation as "good" as a bit of natural hybridization?

How come pedigree dogs etc suffer from inbreeding when small populations of wild animals don't? Have often wondered this

[ReluctantTwitcher]

Without being contentious, I would also like to add that instances of breeding between wild and feral birds do not
necessarily constitute hybrid pairings in the true sence of the word. For instance, even though our standard
domestic ducks are quite different from wild mallards, they are still only domesticated versions of the same species,
and as such should not be equalled with hybrids IMO. The same goes for crosses between different sub-species.

[HallBeck]

I was thinking more along the line of the occasional pairing of red/black kites, gyrs/sakers and i believe peregrine/prairie.

I don't really know anything about this subject - i am only asking for interests sake - i hope i don't sound contentious either!:)

[ReluctantTwitcher]

Is a natural mutation as "good" as a bit of natural hybridization?

How come pedigree dogs etc suffer from inbreeding when small populations of wild animals don't? Have often wondered this

Don't know if natural mutations are as good or as fast as natural hybridizations, I just wanted to point out that it is not the only
way gene pools are shall we say rejuvinated.

Regarding the inbreeding, the culling of "weak" genes are just so much more ruthless in the wild, while at the same time selecting for
many more qualities than what we humans usually do with pedigree dogs for instance. By setting a breeding standard that restricts
what size, build, colour, coat and behaviorial traits our dogs are allowed to have, we are also restricting the genetic variability within
that breed. Some of these breeding goals are of course necessary if we want to breed dogs true to type that are specialised enough
and produce more predictable offspring than unplanned mutts. But if we adopted a more "whatever-works-no matter-what-the-looks"
attitude much could probably be won. Just think of how much larger the gene pool would be if we just allowed for more coulours and
coats to surface within many breeds, or out-crossed to closely related breeds on a regular basis (setters to setters, German pointers
to German pointers, etc at the top of my head). Just my two cents - no expert! :wink:

Cheers,
/Magnus

[Little Joe]

Would i be right in saying that these wild hybrids are actually beneficial? I think i remember reading somewhere that these naturally occuring hybrids are the only way to introduce new genes into a species gene pool.

Surely all species, by definition, have a declining gene poll (just like pedigree dogs) and that the occasional hybrid is an advantage.

I would say the odd hybrid entering the wild gene pool can only have beneficial results, but as long as a viable wild population exists (I'm not sure how many interbreeding individuals that should be), its not strictly necessary for new blood to be introduced. When the gene pool is so small to already be in danger of extinction, an introduction of "foreign genes" will be less desirable, as I would imagine it would threaten the integrity of that small gene pool. So one should probably look at each case individually.

[Brian Sullivan]

Here you go a weird one from the Washington State birders report:

Once again, the hybrid NORTHERN SHOVELER X BLUE-WINGED TEAL was at the River
S Unit of Ridgefield NWR. I found it with my scope from the south end of
Rest Lake. When its head was tucked in, it was extremely hard to
distinguish from nearby Cinnamon Teal -- the breast and flanks appeared
almost identical. Fortunately, it popped its head out twice in the 30 or so
minutes I was scanning for it, and the crescent on the face was very
obvious, even at a distance. This bird is very interesting in that it has a
red breast that matches its flanks, and the color is like a Cinnamon Teal, a
green head with a yellow eye that matches a Northern Shoveler, and a face
crescent that matches a Blue-winged Teal.

[OutHawkn]

Funnily enough one never hears anything about these Hybrids (or Deer Hybrids) from the Anti-Hybrid lobby.... wonder why that is ... :idea:


Christian

Good question...............:supz:

[Ben Wallace]

Hybrid Bald Eagle X Stellers Sea Eagle,

http://www.aba.org/birding/v40n4p28.pdf

Seen on Vancouver Island.

I have also heard that some biologist who I will not name,......was funded by the CWS to put young eyass gyrfalcons in wild tundra peregrine eyries to see if later natural hybridization would occur. Apparently it was a total failure,......no kidding.

Wish I could get funding to do such nonsense.

Sincerely,
Ben Wallace.

[neutrino_cannon]

I want to see the markings on that stellers x bald eagle when it grows up. It should be quite striking as an adult.

[neutrino_cannon]

Is a natural mutation as "good" as a bit of natural hybridization?

How come pedigree dogs etc suffer from inbreeding when small populations of wild animals don't? Have often wondered this

What I was taught in school is that most mutations have either negative or no practical impact upon the mutant. If the mutations are negative and recessive, they will just lie dormant and not cause problems until inbreeding occurs and two copies of the gene end up on the same animal. Chances are then, a gene that has been sloshing around a population for a while is a good thing, since it isn't bad enough to have been selected out of existence yet.

Domestic dogs are probably a special case since animals are kept alive that any sane and compassionate owner would have immediately put down. Since show circuit breeders are neither of those things, an animal with extreme hip dysplasia, difficulty breathing and cataracts will not only be allowed to live, but will be bred and bred and bred if it "conforms" to the breed "standard."

[Gozzhawk]

news story today in Scotland

red deer under threat due to alien species interbreeding.

I would reckon theres a lot more 'natural' hybridising than we would like to admit , not just birds.

[AccipiterFreak]

http://books.google.com/books?id=MwInO7z_Y3oC&pg=PA143&dq=bird+hybridization&hl=en&ei=GAQ3TaeSLITAgQe4xLWIBA&sa=X&oi=book_result&ct=result&resnum=1&ved=0CCgQ6AEwAA#v=onepage&q=bird%20hybridization&f=false

[Sokoly]

Natural hybredisation does occur everyhere and there. Especialy with overlaping populations or even in case of migrational routs. For one reason or another not all of the birds get to reach their nesting points and having in mind that there is generaly a lack of safe nesting sites some of those birds will mate where they find good conditions. Natural drive for leaving offspring seems stronger then species imprinting?
For about 4 years I am observing a mixed pair of peregrines Brookei X peregrinus. The eyrie was held by brookeis but one year a young falcon was brought by the tiercel instead of his old love. They did not produce any....First year I could not tell that she was a nominal peregrinus but managed to mark the bird. Next season she was back and they had 3 young in the nest. There it was happening without any human interfearing...

Not to mention the Hierofalco members (Gyr,Saker,Lanner) that at the end might even all be very very close cousins.

I would not be scared a bit about any bad results out of it because nature works in mysterious ways and clean up all the "bad" genes out of the population over a period of time.

[HawkFlyer]

harris X common buzzard last year in devon, red X common buzzard for the last 9years in bridlington.dave