Interspecies hybrids are not just pieces of literature or science fiction. Such a phenomenon also occurs in nature and is not as rare as it seems, and its effect can be the creation of new species. One of the most interesting crossword puzzles is: show – a combination of bison with domestic cattle.
- Hybrids in the animal world
- The history of the creation of the bison
- What does the bison look like?
- Who is behind all this?
- Żubroń – where does the name come from?
- Żubroń, ie a utility animal
Hybrids in the animal world
Interspecies hybrids are most often observed with. So far, about 10% of over 10,000 species have been found to be crossed with other species, with ducks being the most common (Anatidae) and geese (Anserinae† The best known naturally formed hybrids (so-called hybrids) include: squawk (grouse and capercaillie), water frog (black-headed frog and lake frog), hybrids of little eagle and great spotted eagle, white-necked and mourning flycatcher, and European bison. Yes, the European bison appears to be a hybrid of an extinct male primitive bison (prażubra) with an aurochs cow, an ancestor of domesticated cattle, which was born 120,000 years ago. In fact, scientists suggest that it is thanks to this phenomenon that this species has survived to this day, because it was better adapted to the changing climatic conditions that brought about the end of the ice age (interglacial), which led to the occupation of new areas by forests. and entailed strong pressure from human hunters. It is very likely that people drove the bison to the forest. Because, as the latest research on their diet shows, they are more associated with open spaces. Herbaceous plants and grasses form the basis of their food throughout the year, and the proportion of trees and shrubs usually does not exceed 10%. Now let’s move on to the hybrids that are man-made, because there are a lot of them too. Humans have contributed to the creation of, for example, mule (horse mare and domesticated donkey stallion), pig (wild boar and domestic pig), ligris (lion and tigress), and beefalo (bison and domestic cattle), and the list goes on for much longer.
The history of the creation of the bison
What once happened to the bison in nature was repeated much later, this time entirely by man. This should come as no surprise, because even in artificial conditions, breeding these animals is quite difficult. In the jungle of Białowieża, where bison and cows slowly grazed in forests and clearings, they lived together for decades and never crossed each other. For this to happen, specially selected young bison bulls are used, which are more likely to cover domesticated livestock than the older ones. However, they are not always interested in cows of different types. It is worth explaining here why the following system of parent stock is most commonly used when crossing bison and cows: the father is a bison and the mother is a cow, although the opposite is also possible. This is due to a very practical reason – universal access to domestic livestock, which can be fertilized by one bison. If conception occurs, the delivery of bison calves is quite complicated and requires the participation of a veterinarian and often the use of cesarean section, especially when bulls are born whose body weight can exceed 50 kg. They are initially quite sensitive and often die of respiratory or cardiovascular failure. Although they are generally characterized by high resistance to adverse weather conditions, which do not require winter shelter, and are extremely healthy, being resistant to most diseases that plague domestic cattle.
Currently, there is no large-scale breeding of bison in Poland. Source: shutterstock
What does the bison look like?
As you can guess, the appearance of the bison is a mixture of the guild of both species. The offspring of bison and domestic cattle have a huge silhouette typical of sires, but more proportional, without so much difference between the front part and the rump, and the head is usually similar in circumference to dams with smaller horns typical of them . Color quite variable, but usually black brown, black or fawn red, usually with narrow black longitudinal stripes on the back and sides of the body. However, bison are much larger and more massive than the original forms, as they can weigh up to 1030 kg in the case of bulls (bison up to 920 kg) and 880 kg in the case of cows (bison up to 640 kg).
Who is behind all this?
The experience of crossing a bison bull and cattle cows began in the mid-nineteenth century by a Pole, Leopold Walicki, at his estate in Wilanowo near Grodno. His goal was to create high-performance cattle, characterized by significant gains in muscle mass (a characteristic of domestic cattle), even with very poor quality feed (a characteristic of a bison).
Not without significance was the fact that the mongrels reach enormous dimensions, significantly exceeding the original forms (cattle and bison). Walicki obtained the first bison in 1847, and in 1859 managed to breed a total of 15 individuals. In addition to this success, he had another, which was the creation of the first fertile male in the first generation, which is extremely rare (usually such bulls are sterile). However, the information about this is considered unreliable by modern researchers. The experiment was interrupted by political changes, as a result of which Walicki’s property was taken over by the Russian authorities and he himself was arrested. It is not known what the fate of his farm’s bison was.
Żubroń – where does the name come from?
Not from the beginning, the hybrids of domesticated cattle bison were called bison. This happened only in 1969, after the biweekly Przekrój announced a competition for a name for hybrids of both species. Readers submitted hundreds of suggestions, but the name “żubroń” won. This contributed to the introduction of a more precise nomenclature in the breeding of these animals. The offspring of the first generation (F1) were called ubronie, regardless of which species was the father or the mother. The same name is also given to individuals after crossing a domestic bull with a bison mother (retrograde cross, F2 generation). However, if the father is a bison and the mother is a cow a bison, then such offspring are called bison (F2).
Żubroń, ie a utility animal
Professor August Dehnel, founder and head of the Mammal Research Institute of the Polish Academy of Sciences in Białowieża, returned in 1958 to create a new usable cattle breed, a cross between a bison and a cattle. The main aim was to investigate the mechanisms of inheritance, hybrid fertility and the abundance of hybrid traits (heterosis). This was to improve the breeding of animals that would provide meat at a low cost and labor to meet the needs of the population during the time of the Polish People’s Republic. For this purpose, further commercial breeding of these animals was started in several centers in the country: PGR Rzepin, PGR Łękno and the State Animal Insemination Plant in Myśliborzyce. Bison bulls and Polish red and lowland black and white cows were used to make the bison. In 1984 almost 550 animals of different generations were obtained, including 253 of the first generation (F1). Obtaining this large number of animals was possible through the development of an effective method of insemination, of which Edward Sumiński was the creator. Not only did he use a special diet to make bison bulls sexually active all year round (in nature there is a decrease in winter hair production), but he also started collecting semen from fertilized cows to have material for insemination. His method proved so effective that the Germans, Italians, Swedes and Russians took an interest in it. The latter even tried to learn this method from the creator himself, but failed. Again, the systemic changes saw that in the early 1990s the experiment was terminated and 56 first-generation heifers were sold to the research station in Popielno, which is currently owned by the Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences. in Olsztyn. The fate of the remaining individuals is unknown, but most likely they were massacred.
The subject of making bison came back in 2005 in Wielkopolska in Gospodararstwo Rolnym Karolew Sp. zo o. The president, Henryk Ordanik, formerly associated with PGR Łękno, and Edward Sumiński, who created a small herd of bison, were involved in this process. An interesting fact is that the father of the first bull born on this farm, Leo, was a bison who died 30 years earlier. It was possible thanks to Sumiński’s preservation of his sperm.
Until now, however, there is no possibility to raise bison on a larger scale. Each of the attempts made ended with his liquidation. Although bison have great potential as meat animals, due to the high gains in poor feed and their meat is lower in fat than beef, it seems that today’s domesticated cattle breeds are more attractive to breeders. While they require no infrastructure other than fenced pastures, there is no evidence that they are anything more than a curiosity. That’s a good thing, of course, because the uncontrolled formation of hybrids can pose a major threat to the purity of the species. Such a phenomenon was confirmed in the case of the bison herd at Custer State Park, where genetic studies confirmed the mixing of genes in domestic livestock. Most likely, among the pure animals of the original herd was a retrograde hybrid, which outwardly was indistinguishable from genetically pure bison.
Ekologia.pl (Adam Zbyryt)
- Krasińska M. 1988.; “Bison and domestic bovine hybrids.”; PAN ZBS Ossolineum.;
- Krasińska M., Krasiński ZA 2017.; “Sensible. Nature monograph. Second edition, updated and expanded.”; Chyra.pl, Bialowieża;
- Szklarska-Meller A. 2015; “In Karolewo everything is wrong. And yet … it grows. “; Głos Wielkopolski, June 16;