Tuesday, December 27, 2011

Unusual Zebroid and Hardwood Forest Hike

Yesterday I went with my son and his wife, to Jessica's dad's house. On our drive over there, Jonathan told me that we would be passing a farm that had an usual hybrid. Although it rarely occurs in the wild, there are cases where zebras in captivity mate with various types of equines including horses and donkeys.   However, Charles Darwin in his journeys did observe zebroids in the wild. For the most part, though, zebroids did not exist until human's breeding intervention in the 1800s.

Here are a few shots of the zebroid we saw.

Common wisdom states that hybrids only occur when the zebra is the sire, but there are a few known cases where the opposite is true. Two known zebra hinnies have been foaled, but did not survive to adulthood. Genetics determines whether a hybrid is possible. Donkeys and wild equids have different numbers of chromosomes. A donkey has 62 chromosomes; the zebra has between 32 and 46 (depending on species). In spite of this difference, viable hybrids are possible, provided the gene combination in the hybrid allows for embryonic development to birth.  A hybrid has a number of chromosomes somewhere in between the two adult equines. The chromosome difference makes female hybrids poorly fertile and male hybrids generally sterile.

Zebroids physically resemble their nonzebra parent, but are striped like a zebra. The stripes generally do not cover the whole body, and might be confined to the legs or spread onto parts of the body or neck. As you can see in the photos above, the zebroid we saw had stripes on its legs.

Zebroids are preferred over zebra for practical uses, such as riding, because the zebra has a different body shape from a horse or donkey, and consequently it is difficult to ride.  Another issue is that a zebroid is usually more inclined to be temperamental than a purebred horse and can be hard to handle. Zebras, being wild animals, and not domesticated like horses and donkeys, pass on their wild animal traits to their offspring, including zebroids.

In the same field as the zebroid, there were quite a few cows.  When we stopped to take a picture, the cows came running.

It was such a nice day yesterday in southern Michigan.  As you can see below, it was right around 40 degrees.

Here is a shot of Jonathan, Jessica, Sandy, and Jerry on our hike.

Jonathan helped to clear some of the downed trees from the path.

As the sun was going down, we headed back in to have dinner.

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