A handful of species practice it, like the chin-strap penguin, the long-eared owl, the mantis shrimp, a few termites and the black vulture.
Circumstantial evidence has accumulated for the hypothesis that many animal species practice self-medication, yet in most cases definitive tests are lacking [6], [7], [13].
Although there are other bird species that prey on the parental skills of their feathered neighbors by laying eggs in their nests, only birds of those two species practice obligate parasitism in North America, placing them among approximately one percent of avian species worldwide.
Selection silvicultural practices, as currently applied, do not ensure regeneration of desirable species; practices might require modifications in general (e.g., increasing gap size) and to match them to regionally varying factors like deer density.
We humans are used to hearing about even the kinkiest of our own species' practices, but for the fifteen species in the slideshow below, mating is a whole different game plan.
In my model of morality, our dual dispositional nature of good and evil arose from our evolutionary history as a social primate species practicing within-group amity and between-group enmity.
Four significant changes towards genitalia concealment among species practicing direct coercive mating seem to fit this idea.
However, in contrast to Sattler's observations [20], Arnqvist's thorough review [3] of all available information on mating behaviors of water striders resulted in classifying A. najas as a species practicing direct coercion, presumably in a manner similar to A. remigis [2], [24].
Although theory predicts that inbreeding depression in many species is likely to be purged through substantial selfing (Lande and Schemske 1985; Charlesworth et al. 1990), several species practicing mixed mating or even high degrees of selfing are known to maintain significant levels of inbreeding depression (examples in Husband and Schemske 1996; Routley et al. 1999; Goodwillie et al. 2005).
But the prairie vole, a tiny, gray two-ounce rodent, is among the fewer than 5% of mammal species that practice monogamy.
Similarly, if there are many species (in practice, there are many more species (>1000) than those used in our simulation), there would be more edges in the graph, which also leads to many small components.
