Carnivore Conservation and Human-Carnivore Conflict Some carnivores come into conflict with humans, who destroy habitat, compete for the prey of carnivores, and hunt the carnivores themselves for meat or skins. Humans also kill carnivores to retaliate against real and perceived threats to human life and to livestock. For example, over a seventy-three year period in the twentieth century, Ugandan lions, leopards, and hyenas injured or killed 373 men, women, and children. Over the same period, thousands of lions and leopards were killed in retaliation for livestock attacks or for the trade in skins. Cheetahs and hyenas were driven extinct in Uganda by human eradication campaigns. Generally, large carnivores are subject to the most intense human persecution, but even mustelids may face trapping and lethal retaliation for raiding poultry. Wolves present the best documented history of human-carnivore conflict.Wolves were once distributed widely throughout Eurasia and North America, until humans began raising domestic livestock. Then wolves would occasionally attack these tame, relatively defenseless prey. In turn, humans became ingenious in trapping, poisoning, and killing wolves. Wholesale decimation of wolves did not begin until the invention of firearms, but then it proceeded rapidly and without mercy.Wolves were virtually eliminated from most of the world. Now, fewer than 500,000 remain across the globe, and only a small fraction of these are legally protected. More recently, public attitudes have changed, and respect for the wolf as a noble animal, coupled with awareness of the wolf's role in ecosystem function, have allowed the wolf to recover slightly in some countries.
Fathers Extraordinaire Because mothers are the single parent in most single-parent species, those species in which the father does most of the parenting are referred to as sex-role-reversed. Typical of role-reversed species is a cluster of sex differences that are reversed in many ways other than just parenting: Females tend to be larger, more aggressive, and more flashy than the males, and they may be the more "promiscuous" sex, mating with a series of stay-at-home fathers in a mating system called polygyny. Polygyny and exclusive paternal care have been best studied in birds. Other types of animals, however, also provide examples of exclusive paternal care. In several species of invertebrates, fish, and amphibians, females lay their eggs and leave, while males remain to guard the eggs after they have been fertilized, protecting them against the vagaries of weather, water currents, and predation. Even after the eggs hatch the male may continue to guard the young or to transport them: Some tiny Amazonian frogs carry their tadpole offspring on their back if the small pool of water where they hatched starts to dry up. In other species, males carry fertilized eggs on their back, in their mouth, or in a specialized pouch. In the case of pipefish, seahorses, and some frogs, the male's tissue actually provides nutrients to the developing embryos. In these rare creatures, one could truly say that it is the male that becomes pregnant.
