[neilep (OP)]

Dearest Birdologists,


Take a look at Baaaaaambo !



Baaaaambo just moments ago !!

Baaaaaambo is the offspring between my cousin and an elephant, awwwwwww !!!

We often see cross breeds and mongrels of cats and dogs...but ewe never see two different birdies doing the deed and making a hybrid . I'd love to see the result between an Ostrich and a Robin for instance.


So, why do we never see interbred birdies ?


hugs et les shmishes



mwah mwah mwah

neil
xxxxx




"lets get it on" said the Sparrow to the duck !

Next line not posted !!

[alancalverd]

It's all down to the plasticity of the genome (which is exceptional in dogs) and the arbitrariness of the  definition of "species".

Wild animals tend to select similar mates and oddities don't survive, but the variety of domestic chickens or captive budgerigars is at least comparable with cats, if not dogs.

[evan_au]

The term "species" is a bit arbitrary, but by all measures, all dogs are one species, as are all domestic cats.
- So you can easily get "mongrel dogs" (and most domestic cats are mongrels), because they can all interbreed
- What humans see as "breeds" of dogs and cats have mostly arisen in the last couple of centuries, which is too soon to produce significant genetic divergence between breeds.
- I understand that many of the breed distinctions started after humans documented "official" characteristics of particular dog breeds - and then people bred dogs to go to extremes to meet and exceed these documented  characteristics, so they could win the "best in breed" award at the dog (or cat) show.

One clear species differentiator is the number of chromosomes - it is not possible to produce fertile offspring if there are a different number of chromosomes.
- So you can get offspring of horses and donkeys (mules), or horses and zebras, or lions and tigers, but they aren't normally fertile
- Elephants and sheep have different numbers of chromosomes
- Different bird species have different numbers of chromosomes
- One well-studied case is Darwin's finches, living on the Galapagos Islands. They are officially listed as different species (because they are isolated on different islands), but their separation was fairly recent, so they are still fertile. In fact one new hybrid has been seen recently. Things like song, mating displays, environment, breeding season and coloration affect mate choice, which means that (given a choice), the female bird will select a suitor most like her own father (ie the same species).
- The same can be said of the Galapagos tortoises - people have kept them together, and there are now many hybrids.
https://en.wikipedia.org/wiki/Darwin%27s_finches#Taxonomy

Conclusion: Close genetic "cousins" can produce hybrid populations if they have the same number of chromosomes.
- Somewhat close species can produce hybrids, but they won't be fertile if they have a different number of chromosomes
- Distant species won't have viable hybrids.

[Bored chemist]

I think that Darwin's understanding of evolution was, in part influenced by the fact that he kept pigeons.
https://en.wikipedia.org/wiki/Fancy_pigeon

[Kryptid]

This is a website I found a while back that speaks of certain bird hybrids: http://messybeast.com/genetics/hybrid-birds.htm

[CliffordK]

Hmmm...  "Bird" is awfully broad. 

Looking at Canadian Honkers on Wikipedia:

Kingdom:    Animalia
Phylum:    Chordata
Class:    Aves
Order:    Anseriformes
Family:    Anatidae
Genus:    Branta
Species:    Branta canadensis
Binomial name: Branta canadensis

So, if one pushes up the evolutionary tree to "Genus: Branta", they will interbreed some.  I've seen domestic white geese that have mixed with wild Canadian geese.

Geese and Swans are apparently close enough that they will periodically hybridize.

Looking at chickens:
Kingdom:    Animalia
Phylum:    Chordata
Class:    Aves
Order:    Galliformes
Family:    Phasianidae
Genus:    Gallus
Species:    Gallus gallus
Subspecies:    Gallus gallus domesticus
Trinomial name: Gallus gallus domesticus

Any "chicken" within the Species Gallus gallus would be able to interbreed. 

I have to wonder if even though many birds are migratory, different subspecies will be geographically isolated, but could potentially interbreed if the came into contact with distant cousins. 

Wild and domestic turkeys will also interbreed.

Perhaps one of the more distantly related hybrids is Guineafowl & Chicken hybrids.  Not all offspring are viable, and I believe they are all sterile.

[Bored chemist]

Geese and Swans are apparently close enough that they will periodically hybridize.

Since Goose and Swan are both surnames... I hope that the editor of some local newspaper has had the opportunity to announce "Goose marries Swan".

I have to wonder if even though many birds are migratory, different subspecies will be geographically isolated, but could potentially interbreed if the came into contact with distant cousins. 

It's more weird than that.

https://en.wikipedia.org/wiki/Ring_species