[9] It is also seen in Chinook salmon (Oncorhynchus tshawytscha),[6] red-spotted newts (Notophthalmus viridescens), and seed-eating true bugs (Neacoryphus spp.).
[12] Wild chimpanzees can charge at females, shake branches, hit, slap, kick, pound, drag, and bite them.
Bornean orangutans (Pongo pygmaeus) exhibited aggression in almost 90 percent of their copulations, including when the females were not resisting.
[13] A possible explanation for aggressive behaviors in primates is that it is a way for males to train females to be afraid of them and be more likely to surrender to future sexual advances.
Therefore, males intimidate females into mating by attracting predators; they tap on the water's surface and create ripples that catch the attention of predatory fish.
[14][15] Another indirect form of sexual coercion occurs in red-sided garter snakes, Thamnophis sirtalis parietalis.
While some males have evolved different types of modifications to aid in grasping, others just grab females and attempt to force copulation.
In addition to aiding penetration, these spines promote the passage of seminal fluids, and act as an anchor to keep the female from fleeing.
[17] Another type of modification is found in male diving beetles (of the family Dytiscidae), who are equipped with suction cup structures on their front legs.
Unable to get air, female diving beetles submit to the male's advances in order to avoid drowning (and they lose the energy to resist).
Most birds mate with the males balancing on top of the females and touching cloacas in a “cloacal kiss”; this makes forceful insemination very difficult.
The phallus that male waterfowl have evolved everts out of their bodies (in a clockwise coil) and aids in inseminating females without their cooperation.
In dogs, the male has a knot in his penis that gets engorged with blood and ties the female, locking them together during copulation, until the act is complete.
Coercive mating is very common in water striders (Gerridae) because in most of the species, the female genitalia are often exposed and easily accessible to males.
In pigs and boars, males grab females and maneuver the pelvis to lift the vaginal opening and facilitate copulation.
Grasping and/or grappling mating situations have also been documented in Calopteryx haemorrhoidalis haemorrhoidalis (Odonata),[23] fallow deer (Dama dama),[6] wild orangutans (Smuts 1993), wild chimpanzees,[1] water voles (semi-aquatic rats) Arvicola amphibius,[22] feral fowl,[24] mallard (Anas platyrhynchos),[25] hamadryas baboons[26] and many other primates,[1] coho salmon (Oncorhynchus kisutch),[6] and others.
[1] In the newt species Notophthalmus viridescens, the males rub off hormonal secretions onto the skin of the females they are courting.
[18] Guarding also occurs in water striders where, once males complete their sperm transfer, they often remain on top of the females.
These chemicals may also serve to increase the female's reproductive success, but at the cost of decreased longevity and immune response.
[6] Male seed beetles (Coleoptera: Bruchidae) have sclerotized spines on their genitalia, which penetrate the female and leave melanized scars.
Also, semen transferred from the males can contain pathogens and fecal matter, which can lead to disease and decrease female fitness.
[22] Other species in which the females (and/or their offspring) are injured or even killed include lions, rodents, farm cats, crabeater seals, grey seals,[27] sea lions,[1] bottle-nosed dolphins (Tursiops truncatus),[9] red-sided garter snakes (Thamnophis sirtalis parietalis),[16] and newts (N.
For example, female water striders, Gerridae,[21] and marine snails of the genus Littorina have to carry the males on their backs while they mate.
Harassment can lead to stress, which can result in weight loss, decreased immune function and energy stores, and less feeding, which has been seen in red-spotted newts.
[28] This also happens in species where herding males sometimes do not permit females to join their family in different groups, like in hamadryad baboons.
[3] Females of some species, such as the water striders, developed morphological shields to protect their genitalia from males that want to forcefully copulate.
As a response, females have developed vaginal structures called dead end sacs and clockwise coils to protect themselves from forceful intromission.
A similar phenomenon occurs in elephants, bighorn sheep, and fallow deer, where the females stay close to dominant males for protection.
[14] Females of some species of water striders have evolved protection from forceful insemination, such as abdominal spines and downward-bent abdomens to make it harder for males to mate.
In diving beetle species family Dytiscidae, an intersexual arms race occurs between males and females.