[QUOTE=spoke-]
Feral cattle quickly develop formidable weaponry. They can also develop a leaner, rangier build. No reason they couldn’t coexist with predators, particularly since (as you noted, Stranger) many of North America’s big predators have been exterminated.
Moreover, predators don’t normally hunt their prey to extinction. A balance would be found, likely resulting in a lot of yellow dogs, herds of rangy and long-horned cattle, tabby cats, razorbacks, mustangs, wild goats and feral chickens.
[/QUOTE]
You’re conflating the idea of feral populations of domestic animals which are in closed ecosystems with marginal or no predation with an open system in which an ill-adapted domestic species is in competition both against predation and with native species for the same resources. The expansion of predators introduced into a new system or a system in which constraints have been removed is rapid, and yes, this does sometimes result in the endangerment or extinction of prey species; trophic cascades and extinction catastrophes are common problems that result from a rapid change in environmental pressures. The speed at which this can occur is often far more so than can be accomodated by natural selective pressures, and highly domesticated species that have been substantially altered from their ancesteral capabilities simple aren’t going to survive long enough to breed for many generations to develop more aggressive instincts and defensive capabilities.
Domestic cattle, Yorkshire- and Landrace- type hogs, show breeds of dogs, domestic fowl, et cetera, neither have the capabilities nor the canniness to survive predation, while native, if currently endangered, native or migrated apex predators will expand as rapidly as breeding permits. I’m not sure where the notion that domesticated, neotenic species will somehow redevelop the speed, agility, or defensive phenotypes that will make them equivilent to wild ancestor species, but barring some kind of Lamarckian-type acquisition of such characteristics there just isn’t sufficient expression in most domestic species to make much of a difference. Cross-breeding with existing wild species will offer some advantages (and in some cases in both directions, as with the more aggressive wolf-dog and coyote-dog crosses) but then those aren’t members of a domestic species but hybrids.
Certain domestic species are more likely to survive, particularly those which are mesopredators that can evade predation by apex predators. Dogs, as you note, have demonstrated effectiveness in feral populations and currently exist in characteristics sufficiently close to wild species of Canis that they can compete and/or merge with existing populations of cursoral hunters. The Domestic Cat will probably also endure as it is adaptable and being not substantially different than wild cousin species. Some breeds of Domestic Goat are not far removed from the Wild Goat in capability, and could conceivably survive in an unconstrained feral lifestyle, but most feral goat populations that are geographically isolated from broad predation. Domestic herd animals and fowl, on the other hand, won’t stand much of a chance.
All of this again refers to open systems with pre-existing apex predators that have been held at bay by the presence of human populations, i.e. North America, Eurasia, Africa. Populations of domestic animals that are geographically isolated from potential predators may survive and adapt indefinitely, as evidenced by the natural evolution of flightless birds and island gigantism among herbivores.
Stranger