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| [Note Guidelines] Photographer's Note |
A Hybrid Goose at RSPB Freiston Shore nature reserve.
This picture will end my series representing Goose species in the wild. (I promise no Geese until next year!)
This individual was mingling with a flock of Canada Geese. Although it looks so different to Canada Geese it could be part of the family. I could not identify this bird. It has features of Greylag Goose and possibly White-fronted Goose. So I sent the picture to Birdguides and received a comment from the administrator: "Looks like a hybrid to me. Probably some domestic (Greylag) goose, with possibly White-fronted and Canada in there too."
Here is some information about hybrids:
Hybrid (biology)
From Wikipedia, the free encyclopedia
In biology, hybrid has two meanings. The first meaning is the result of interbreeding between two animals or plants of different taxa. Hybrids between different species within the same genus are sometimes known as interspecific hybrids or crosses. Hybrids between different sub-species within a species are known as intra-specific hybrids. Hybrids between different genera are sometimes known as intergeneric hybrids. Extremely rare interfamilial hybrids have been known to occur (such as the guineafowl hybrids). The second type of hybrid consists of crosses between populations, breeds or cultivars within a single species. This second meaning is often used in plant and animal breeding. In plant and animal breeding, hybrids are commonly produced and selected because they have desirable characteristics not found or inconsistently present in the parent individuals or populations. This rearranging of the genetic material between populations or races is often called hybridization.
Types of hybrids
Depending on the parents, there are a number of different types of hybrids;
Single cross hybrids - result from the cross between two pure bred lines and produces an F1 generation called an F1 hybrid (F1 is short for Filial 1, meaning "first offspring). The cross between two different homozygous lines produces an F1 hybrid that is heterozygous; having two alleles, one contributed by each parent and typically one is dominant and the other recessive. The F1 generation is also homogeneous, producing offspring that are all similar to each other.
Double cross hybrids - result from the cross between two different F1 hybrids.
Three-way cross hybrids - result from the cross between one parent that is an F1 hybrid and the other is from an inbred line.
Triple cross hybrids - result from the crossing of two different three-way cross hybrids.
Population hybrids - result from the crossing of plants or animals in a population with another population. These include crosses between organisms such as interspecific hybrids or crosses between difference races.
Interspecific hybrids
Interspecific hybrids are bred by mating two species, normally from within the same genus. The offspring display traits and characteristics of both parents. The offspring of an interspecific cross very often are sterile; thus, hybrid sterility prevents the movement of genes from one species to the other, keeping both species distinct. Sterility is often attributed to the different number of chromosomes the two species have, for example donkeys have 62 chromosomes, while horses have 64 chromosomes, and mules and hinnies have 63 chromosomes. Mules, hinnies, and other normally sterile interspecific hybrids cannot produce viable gametes because the extra chromosome cannot make a homologous pair at meiosis, meiosis is disrupted, and viable sperm and eggs are not formed. However, fertility in female mules has been reported with a donkey as the father. Most often other mechanisms are used by plants and animals to keep gametic isolation and species distinction. Species often have different mating or courtship patterns or behaviors, the breeding seasons may be distinct and even if mating does occur antigenic reactions to the sperm of other species prevent fertilization or embryo development. The Lonicera fly is the first known animal species that resulted from natural hybridization. Until the discovery of the Lonicera fly, this process was known to occur in nature only among plants.
While it is possible to predict the genetic composition of a backcross on average, it is not possible to accurately predict the composition of a particular backcrossed individual, due to random segregation of chromosomes. In a species with two pairs of chromosomes, a twice backcrossed individual would be predicted to contain 12.5% of one species' genome (say, species A). However, it may, in fact, still be a 50% hybrid if the chromosomes from species A were lucky in two successive segregations, and meiotic crossovers happened near the telomeres. The chance of this is fairly high, 1/2^(2×2)=1/16 (where the "two times two" comes about from two rounds of meiosis with two chromosomes); however, this probability declines markedly with chromosome number and so the actual composition of a hybrid will be increasingly closer to the predicted composition.
Hybrids are often named by the portmanteau method, combining the names of the two parent species. For example, a zeedonk is a cross between a zebra and a donkey. Since the traits of hybrid offspring often vary depending on which species was mother and which was father, it is traditional to use the father's species as the first half of the portmanteau. For example, a liger is a cross between a male lion and a female tiger, while a tigon is a cross between a male tiger and a female lion.
Examples of hybrid animals
A "Zeedonk", a zebra/donkey hybrid
A "Liger", a Lion/Tiger hybrid
A "Jaglion", a Jaguar/Lion hybrid
Würdemann's Heron, a great blue/white heron hybridDog hybrids are crosses between different breeds and are often bred selectively.
Hybrid Iguana is single cross hybrid, result of natural inbreeding from male marine iguana and female land Iguana since late 2000s.
Equid hybrids
Mule, a cross of female horse and a male donkey.
Hinny, a cross between a female donkey and a male horse. Mule and Hinny are examples of reciprocal hybrids.
Zebroids
Zeedonk or Zonkey, a zebra/donkey cross.
Zorse, a zebra/horse cross
Zony or Zetland, a zebra/pony cross ("zony" is a generic term; "zetland" is specifically a hybrid of the Shetland pony breed with a zebra)
Bovid hybrids
Dzo, zo or yakow; a cross between a domestic cow/bull and a yak.
Beefalo, a cross of an American Bison and a domestic cow. This is a fertile breed; this along with genetic evidence has caused them to be recently reclassified into the same genus, Bos.
Zubron, a hybrid between Wisent (European Bison) and domestic cow.
Sheep-goat hybrids, such as the The Toast of Botswana.
Ursid hybrids, such as the Grizzly-polar bear hybrid, occur between black bears, brown bears, Kodiak and polar bears.
Felid hybrids
Savannah cats are the hybrid cross between an African serval cat and a Domestic cat
A hybrid between a Bengal tiger and a Siberian tiger is an example of an intra-specific hybrid.
Ligers and Tigons (crosses between a Lion and a Tiger) and other Panthera hybrids such as the Lijagulep. Various other wild cat crosses are known involving the Lynx, Bobcat, Leopard, Serval, etc.
Bengal cat, a cross between the Asian Leopard cat and the domestic cat, one of many hybrids between the domestic cat and wild cat species. The domestic cat, African wild cat and European wildcat may be considered variant populations of the same species (Felis silvestris), making such crosses non-hybrids.
Fertile Canid hybrids occur between coyotes, wolves, dingoes, jackals and domestic dogs.
Hybrids between Black Rhinos & White Rhinos have been recognized.
Hybrids between spotted owls and barred owls
Cama, a cross between a Camel and a Llama, also an intergeneric hybrid.
Wolphin, a fertile but very rare cross between a False Killer Whale and a Bottlenose Dolphin.
A fertile cross between an albino King Snake and an albino Corn Snake.
The Wurdmann's heron, a cross of the white heron and the great blue heron.
At Chester Zoo in the United Kingdom, a cross between African elephant (male) and Asian elephant (female). The male calf was named Motty. It died of gut infection after twelve days.
Cagebird breeders sometimes breed hybrids between species of finch, such as Goldfinch x Canary. These birds are known as Mules.
Gamebird hybrids, hybrids between gamebirds and domestic fowl, including Chickens, Guineafowl and Peafowl, interfamilial hybrids.
Numerous Macaw hybrids are also known.
Red Kite x Black Kite: 5 bred unintentionally at a falconry center in England. (It is reported that the black kite (the male) refused female black kites but mated with two female red kites.)
Hybridization between the endemic Cuban Crocodile (Crocodilus rhombifer) and the widely distributed American Crocodile (Crocodilus acutus) is causing conservation problems for the former species as a threat to is genetic integrity.
Blood parrot cichlid, which is probably created by crossing a Gold Severum and a Midas Cichlid or Red Devil Cichlid
Hybrids should not be confused with chimaeras such as the chimera between sheep and goat known as the geep. Wider interspecific hybrids can be made via in vitro fertilization or somatic hybridization, however the resulting cells are not able to develop into a full organism. An example of interspecific hybrid cell lines is the humster (hamster x human) cells. |
Gert-Paassen, jconceicao, jaycee, Jamesp has marked this note useful
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