Hybrids such as mules (horse X donkey)and ligers (lion X tiger) can’t reproduce… but do the females still go into heat? We recently got a mare mule at the rescue I volunteer at and I am just curious.
Also, what about dog/wolf hybrids? Can they reproduce? If I remember correctly, I have seen 3/4 wolf puppies for sale, which would suggest that they can. And if so, what makes them different from other hybrids that cannot reproduce?
Dogs and wolves are more closely related than horses and donkeys.
I’ve read that, on rare occasions, mare mules have reproduced.
The science of hybridization is a little muddy, but, in general, for interspecific hybrids like mules, the two parent species have a different number of chromosomes - horse have 64, donkeys have 62, so most mules have 63. Then, when the mule produces gametes (eggs or sperm), by splitting a cell via meiosis, the chromosomes cannot line up correctly, and the gametes produced are not viable. So no mule foals, except in some very rare cases, where the meiosis produces a viable gamete.
So, yes, female mules (hinnies) will go into estrus like either of the parent species. It’s just the eggs they produce are messed up and usually not fertilizable.
Wolf-dog hybrids are technically inTRAspecific hybrids, since dogs are now classified as Canis lupus familiaris, a subspecies of Canis lupus, which also includes the various wolf species. Dogs and wolves have the same number of chromosomes, so the messed up gametes don’t happen.
Panthera hybrids can, in some cases, reproduce - commonly enough that there are naming conventions for offspring where one of the parents is a hybrid.
They are, in fact, the same species.
All the species in Canis are interfertile. Wolves and coyotes are known to mate on occasion and they produce fertile offspring. It’s thought that the red wolf is a population of wolf/coyote hybrids.
Lots of different species can interbreed and produce fertile offspring. What we call a “species” is just a population that does not usually mate in the wild, even though many can. Female mules can sometimes be fertile.
Yes. The Biological Species Concept requires only that hybridization between two “good” species is rare in nature. It does not require that hybrids, when they occur, be sterile. In fact, many “good” species, including canids and Anas ducks, produce fully fertile hybrids in captivity.
A difference in chromosome number between the parental forms can often produce hybrid sterility due to incorrect chromosome pairing during meiosis. However, it’s also possible for species that differ in chromosome number to produce fully fertile offspring, especially if the difference is due to a single chromosome splitting, or two others fusing, that they are still able to line up correctly with the original chromosome.
A variety of mechanisms can produce hybrid sterility, and it can occur between species with the same chromosome number as well.
what do canid x duck offspring look like? I’m just thinking the logistics of the mating itself are pretty darn severe.
Thanks for the info guys… always great to learn new things! (And a bit of humor is always good too!)
I thought you might like to see this charming zebra/shetland hybrid. Istr a bit more background to the story, that the shetland mum had ended up in the zebra’s field as a result of the restrictions on livestock movement during the foot and mouth crisis. She had belonged to a circus which had to disperse their animals when it was impossible to get them to the usual winter quarters.
Even more remarkable is the cama, a cross between a camel and a llama (or its wild antecedent, the guanaco), especially since the two lineages may have split 25-30 million years ago.
Never heard of the cama… very cute babies! And the zebra/pony foal is adorable!
And here’s another Zebroid or Zorse, with a more striking coat.
I have seen that little pinto girl before and LOVE her! Such a pretty little thing!
The first zorse article claims that the sire must be the species with the lower number of chromosomes, the zebra in this case, yet the second zorse is said to have been sired by the horse and foaled by the zebra. Also I thought mules could come from either pairing, so I’m thinking the first article must be blowing smoke?
Mules CAN come from either pairing, though it’s far more common for the male to be a donkey and the female to be a horse. I always thought that this was because horses are generally larger than donkeys, so if the mother is of the larger species, she’ll be able to carry and give birth much more easily, and produce a larger baby. Since mules are generally produced for work animals, rather than show or pet animals, the larger, the better, up to a certain point. The product of a male horse/female donkey is called a hinny, by the way, and it doesn’t matter which sex the hinny is. I THINK that male mules are called jacks, I know that male donkeys are jacks. I can’t remember what female donkeys and mules are called.
A male mule is called a *john mule *or a horse mule. A female mule is a *molly mule *or a mare mule. A female donkey is a jenny.
Similarly, a john mule’s testes produce testosterone just as effectively as those of a stallion or a donkey jack. John mules should be gelded, since they will otherwise develop the usual range of stallion behaviors without the mitigating benefit of reproductive capability.
Can anyone comment on this? Is it ever easier to have a hybrid with fewer chromosomes on the male side versus the other way around, and why?
That’s where duck-billed platypuses come from!
