Une nouvelle espèce de prédateurs

En principe, nous n’avons pas, en Europe, du coyote. Quoique… Par contre, c’est le chacal doré qui semble être observé un peu partout. Mais, silence, ce n’est pas vrai, comme il était faux de dire qu’il y avait des loups hybrides dans la nature avant 1992 et très probablement après.

Ces animaux hybrides se reproduisent beaucoup plus vite que le loup gris pur. Ils se propagent à grande vitesse…. Mais, ce n’est pas, officiellement, possible puisque, en France, ce n’est pas vrai. Nous avons de la race pure. Nous sommes les meilleurs… surtout meilleurs qu’en Italie dont on dit, depuis plus de 20 ans, que nos loups sont originaires.

Mensonges? Manipulation? Tout ceci ressemble étrangement au cochonglier (1000 + individus dans Berlin) s'adaptant à tout - surtout à l'homme. La joie à nos portes!

Nos "campagnes", ou ce qu'il en restera, ainsi que nos villes et nos jardins seront peuplés de ces nouvelles "espèces": Le cochonglier et le chaclouchien. Le béton deviendra le refuge des humains tandis que tout le reste sera transformé en zones sauvage. C’est d’ailleurs les objectifs de l’UICN - WWF: le rewilding

Bel avenir!

• Une nouvelle espèce se développe sous nos yeux - issue du mélange loups, coyotes (chacals en Europe et en Afrique) et chiens particulièrement réussi
• A new species is evolving right before our eyes — an ultra-successful mix of wolves, coyotes and dogs
• Greater than the sum of its parts

- Une nouvelle espèce se développe sous nos yeux - issue du mélange loups, coyotes (chacals en Europe et en Afrique) et chiens particulièrement réussi

Une nouvelle espèce issue du croisement loups, coyotes et chiens se développe devant les yeux des scientifiques dans l'Est des États-Unis.

Les loups confrontés à une baisse du nombre de partenaires potentiels diminuent leurs prétentions et s'accouplent avec d'autres espèces similaires, rapporte The Economist.

Le métissage a commencé il y a 200 ans, lorsque les colons européens poussés dans le sud de l'Ontario ont fait disparaître l'habitat de l'animal au profit de l'agriculture et tué un grand nombre de loups qui y vivaient.

Un fait qui a permis aux coyotes de se propager dans les Prairies, au moment où les fermiers blancs ont apporté les chiens dans la région.

Au fil du temps, les loups ont commencé à s'accoupler avec leurs nouveaux voisins génétiquement semblables.

La progéniture résultante - qui a été appelé le coyote de l'Est ou, pour certains, le "coywolf" - se monte à des millions d'individus, selon des chercheurs de l'Université d'État de Caroline du Nord.

En général, les individus issus de croisement sont moins vigoureux que leurs parents, lorsque la progéniture arrive à survivre, selon The Economist.

Ce n'est pas du tout le cas de l'hybride loup-coyote-chien, qui a développé en une espèce supérieure à ses ascendants.

Pesant environ 55 livres, l'animal hybride est environ deux fois plus lourd qu'un coyote normal, et ses grandes mâchoires, ses jambes plus rapides et son corps musclé lui permettent d'attaquer des petits cerfs et même de chasser des groupes d'élans, car l'animal est habile à la chasse aussi bien dans les terrains découverts que dans les forêts denses.

L'analyse effectuée sur 437 animaux hybrides a montré que l'ADN du coyote domine dans leur patrimoine génétique, qu'ils comprennent environ un dixième de l'ADN du chien, généralement des grands chiens tels que les Doberman Pinscher et les bergers allemands, et enfin un quart d'ADN des loups.

Le cri de l'animal commence comme le hurlement aigu et profond du loup et se transforme en yipping plus aigu - comme celui du coyote.

- L'ADN du chien offre un avantage supplémentaire.

Certains scientifiques pensent que l'animal hybride est ainsi capable de s'adapter à la vie de la ville parce que son ascendance chien lui permet de tolérer les gens et le bruit - ce que ni les coyotes ni les loups n'ont réussi à faire de leur propre chef.

Les coywolves se sont propagés dans certaines des plus grandes villes du pays - y compris New York, Boston et Washington par les voies ferrées.

Le métissage permet à l'animal de diversifier son alimentation et de manger des aliments jetés dans les poubelles, des rongeurs et des petits mammifères - y compris des chats dont les coywolves mangent tout y compris le crâne - et de devenir nocturnes pour éviter les humains.

Les animaux sont aussi assez intelligents pour regarder des deux côtés avant de traverser les routes.

Tous les chercheurs ne s'accordent pas à voir dans cet animal une espèce à part, estimant qu'une espèce ne se croise pas avec une autre - même si l'existence de l'hybride soulève en premier lieu la question de savoir si les loups et les coyotes sont des espèces distinctes.

Mais les scientifiques qui ont étudié l'animal disent que le mélange des gènes a été beaucoup plus rapide, approfondi et transformationnel qu'on avait pu le remarquer jusqu'à présent.

"Cette étonnante histoire de l'évolution contemporaine se déroule juste sous notre nez", a déclaré Roland Kays, chercheur à l'État de Caroline du Nord.

Un nouveau prédateur hybride dans la ville, New York et le Bronx. A quand dans les villes françaises. Pourquoi ce silence face à ce que de nombreux éleveurs dénoncent sans se faire entendre?

Auteur: Travis Gettys
Source: Raw Story du 30 octobre 2015

• Le loup en France et... ailleurs
• Le chacal doré

- A new species is evolving right before our eyes — an ultra-successful mix of wolves, coyotes and dogs

New species combining wolves, coyotes and dogs is evolving before scientists’ eyes in the eastern United States.

Wolves faced with a diminishing number of potential mates are lowering their standards and mating with other, similar species, reported The Economist.

The interbreeding began up to 200 years ago, as European settlers pushed into southern Ontario and cleared the animal’s habitat for farming and killed a large number of the wolves that lived there.

That also allowed coyotes to spread from the prairies, and the white farmers brought dogs into the region.

Over time, wolves began mating with their new, genetically similar neighbors.

The resulting offspring — which has been called the eastern coyote or, to some, the “coywolf” — now number in the millions, according to researchers at North Carolina State University.

Interspecies-bred animals are typically less vigorous than their parents, The Economist reported — if the offspring survive at all.

That’s not the case at all with the wolf-coyote-dog hybrid, which has developed into a sum greater than the whole of its parts.

At about 55 pounds, the hybrid animal is about twice as heavy as a standard coyote, and its large jaws, faster legs and muscular body allows it to take down small deer and even hunt moose in packs, and the animal is skilled at hunting in both open terrain and dense woodland.

An analysis of 437 hybrid animals found that coyote DNA dominates its genetic makeup, with about one-tenth of its DNA from dogs, usually larger dogs such as Doberman pinschers and German shepherds, and a quarter from wolves.

The animal’s cry starts out as a deep-pitched wolf howl that morphs into higher-pitched yipping — like a coyote.

Its dog DNA may carry an additional advantage.

Some scientists think the hybrid animal is able to adapt to city life — which neither coyotes or wolves have managed to do on their own — because its dog ancestry allows it to tolerate people and noise.

The coywolves has spread into some of the nation’s largest cities — including New York, Boston and Washington — using railway corridors.

The interbreeding allows the animal to diversify its diet and eat discarded food, along with rodents and smaller mammals — including cats, which coywolves eat skull and all — and they have evolved to become nocturnal to avoid humans.

The animals are also smart enough to learn to look both ways before crossing roads.

Not all researchers agree the animal is a distinct species, arguing that one species does not interbreed with another — although the hybrid’s existence raises the question of whether wolves and coyotes are distinct species in the first place.

But scientists who have studied the animal say the mixing of genes has been much faster, extensive and transformational than anyone had noticed until fairly recently.

“(This) amazing contemporary evolution story (is) happening right underneath our nose,” said Roland Kays, a researcher at North Carolina State.

Auteur: Travis Gettys
Source: Raw Story du 30 octobre 2015

- Greater than the sum of its parts

It is rare for a new animal species to emerge in front of scientists’ eyes. But this seems to be happening in eastern North America

Like some people who might rather not admit it, wolves faced with a scarcity of potential sexual partners are not beneath lowering their standards. It was desperation of this sort, biologists reckon, that led dwindling wolf populations in southern Ontario to begin, a century or two ago, breeding widely with dogs and coyotes. The clearance of forests for farming, together with the deliberate persecution which wolves often suffer at the hand of man, had made life tough for the species. That same forest clearance, though, both permitted coyotes to spread from their prairie homeland into areas hitherto exclusively lupine, and brought the dogs that accompanied the farmers into the mix.

Interbreeding between animal species usually leads to offspring less vigorous than either parent—if they survive at all. But the combination of wolf, coyote and dog DNA that resulted from this reproductive necessity generated an exception. The consequence has been booming numbers of an extraordinarily fit new animal (see picture) spreading through the eastern part of North America. Some call this creature the eastern coyote. Others, though, have dubbed it the “coywolf”. Whatever name it goes by, Roland Kays of North Carolina State University, in Raleigh, reckons it now numbers in the millions.

The mixing of genes that has created the coywolf has been more rapid, pervasive and transformational than many once thought. Javier Monzón, who worked until recently at Stony Brook University in New York state (he is now at Pepperdine University, in California) studied the genetic make-up of 437 of the animals, in ten north-eastern states plus Ontario. He worked out that, though coyote DNA dominates, a tenth of the average coywolf’s genetic material is dog and a quarter is wolf.

The DNA from both wolves and dogs (the latter mostly large breeds, like Doberman Pinschers and German Shepherds), brings big advantages, says Dr Kays. At 25kg or more, many coywolves have twice the heft of purebred coyotes. With larger jaws, more muscle and faster legs, individual coywolves can take down small deer. A pack of them can even kill a moose.

Coyotes dislike hunting in forests. Wolves prefer it. Interbreeding has produced an animal skilled at catching prey in both open terrain and densely wooded areas, says Dr Kays. And even their cries blend those of their ancestors. The first part of a howl resembles a wolf’s (with a deep pitch), but this then turns into a higher-pitched, coyote-like yipping.

The animal’s range has encompassed America’s entire north-east, urban areas included, for at least a decade, and is continuing to expand in the south-east following coywolves’ arrival there half a century ago. This is astonishing. Purebred coyotes never managed to establish themselves east of the prairies. Wolves were killed off in eastern forests long ago. But by combining their DNA, the two have given rise to an animal that is able to spread into a vast and otherwise uninhabitable territory. Indeed, coywolves are now living even in large cities, like Boston, Washington and New York. According to Chris Nagy of the Gotham Coyote Project, which studies them in New York, the Big Apple already has about 20, and numbers are rising.

Even wilier

Some speculate that this adaptability to city life is because coywolves’ dog DNA has made them more tolerant of people and noise, perhaps counteracting the genetic material from wolves—an animal that dislikes humans. And interbreeding may have helped coywolves urbanise in another way, too, by broadening the animals’ diet. Having versatile tastes is handy for city living. Coywolves eat pumpkins, watermelons and other garden produce, as well as discarded food. They also eat rodents and other smallish mammals. Many lawns and parks are kept clear of thick underbrush, so catching squirrels and pets is easy. Cats are typically eaten skull and all, with clues left only in the droppings.

Thanks to this bounty, an urban coywolf need occupy only half the territory it would require in the countryside. And getting into town is easy. Railways provide corridors that make the trip simple for animals as well as people.

Surviving once there, though, requires a low profile. As well as having small territories, coywolves have adjusted to city life by becoming nocturnal. They have also learned the Highway Code, looking both ways before they cross a road. Dr Kays marvels at this “amazing contemporary evolution story that’s happening right underneath our nose”.

Whether the coywolf actually has evolved into a distinct species is debated. Jonathan Way, who works in Massachusetts for the National Park Service, claims in a forthcoming paper that it has. He thinks its morphological and genetic divergence from its ancestors is sufficient to qualify. But many disagree. One common definition of a species is a population that will not interbreed with outsiders. Since coywolves continue to mate with dogs and wolves, the argument goes, they are therefore not a species. But, given the way coywolves came into existence, that definition would mean wolves and coyotes should not be considered different species either—and that does not even begin to address whether domestic dogs are a species, or just an aberrant form of wolf.

In reality, “species” is a concept invented by human beings. And, as this argument shows, that concept is not clear-cut. What the example of the coywolf does demonstrate, though, is that evolution is not the simple process of one species branching into many that the textbooks might have you believe. Indeed, recent genetic research has discovered that even Homo sapiens is partly a product of hybridisation. Modern Europeans carry Neanderthal genes, and modern East Asians the genes of a newly recognised type of early man called the Denisovans. Exactly how this happened is unclear. But maybe, as with the wolves of southern Ontario, it was the only way that some of the early settlers of those areas could get a date.

From the print edition: Science and technology
Source: The Economist du 31 octobre 2015