Hybridization In Animals: The Case Of The Grolar
Hybridization in animals is more common in nature than you might think. However, it is true that some of the best known examples are the product of human intervention.
In general terms, although the best known case of hybridization is the mule, which is the cross between a donkey and a mare, there are many other equally interesting ones. Next, the case of the grolar hybrid will be presented.
Overview of hybridization in animals
The crossing or hybridization between animals (or plants) of close species, from the evolutionary point of view, can give rise to the appearance of a new species. Hybrid offspring are sometimes sterile and the only individuals.
However, the cross between species can generate fertile hybrids, that is, specimens that may have offspring. And if the environmental conditions are favorable, a new species can originate from these hybrids.
However, one of the factors that favors the appearance of a new species is isolation. Darwin observed that isolation, along with a long period of time, supports genetic diversity and differentiation between species. Hence, it is so interesting to study hybridization in animals.
A specific case of hybridization in animals: the Grolar
One of the most curious hybridizations that have occurred in nature has resulted in grolar. Next we will see in more detail more about this incredible animal.
The grolar bear is a hybrid resulting from the cross between a polar bear ( Ursus maritimus ) and an American brown bear ( Ursus arctos horribilis ).
Physical characteristics
Being a hybrid ( Ursus arctos x maritimus ), it shows characteristics of both the polar bear and the brown bear. Their fur tends to be either brown in color, or a mix of brown and white.
Compared to its ancestors, the grolar tends to be intermediate in size. It can reach around 2 meters when standing (2.13 meters) and on all fours it exceeds one meter (1.21 meters).
The grolar bear is a fairly agile animal considering its size. Also these bears are more vigorous and have greater strength, which they use in hunting.
Another curious fact about these bears is that they are capable of exceeding fifty kilometers per hour, without exhausting themselves.
Given the advantages offered by these physical characteristics, these bears have been able to capture prey such as deer or caribou.
While it is true that hybridization can give rise to such interesting specimens as grolar, which have several advantageous characteristics, hybridization also has a number of negative aspects.
For example, if two grolars mate with each other, their offspring will have a higher risk of developing malformations.
Another negative aspect is that their large size prevents them from climbing trees. The latter hinders one of the most common defense reactions in bears to danger.
Grolar behavior
When studying the behavior of this new species of bears, the following conclusions have been reached:
- Their behavior may vary depending on the environment. But this behavior is common in most animals.
- They are very energetic animals, in fact, they have been classified as hyperactive.
- Their temperament is not stable, they are distrustful and very territorial.
- It is difficult for them to adapt to changes, both environmental and social.
- They tend to be solitary animals, only interacting in the breeding season or in regions with abundant food.
- It has also been observed that they are withdrawn animals and can become quite aggressive.
- Normally, they only attack if they feel threatened or if their young are in danger.
Habitat and food
The most common locations in which to observe these specimens are wooded and mountainous areas. In particular, in the northern regions of Asia, Europe or North America, exceeding 1,200 meters in altitude up to 1,700 meters.
However, the largest population has been located in Alaska. It is considered the most widespread species of bear on earth.
Despite being omnivorous animals and good hunters, fish and meat are not in their daily diet. They usually feed on fruits, leaves, roots or vegetables, which they can easily find in the forest.
How did the grolar appear?
Hybridization between the polar bear and the brown bear is one of the cases in which humans have not intervened. The person responsible for its appearance has been nature itself.
Its appearance is believed to have been influenced by climate change. The polar bear had to explore other territories in search of food and reached the rivers where the brown bears hunted fish.
Thus, the grolar bear is a fertile hybrid whose emergence has been motivated by climate change. At first it was more common to find them in zoos, but today there are wild populations in protected territories.
