Zoology ()The pronunciation of zoology as is typically regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the anatomy, structure, embryology, evolution, Biological classificat ...
, copulation is animal sexual behavior
in which a male introduces
Sperm is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, "female" reproductive cell and a smaller, "male" one). Animals produce motile sperm with a tail known ...
into the female's body, especially directly into her reproductive tract.
This is an aspect of mating
. Many animals that live in water use external fertilization
, whereas internal fertilization
may have developed from a need to maintain
A gamete ( /ˈɡæmiːt/; from Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the follo ...
s in a liquid medium in the Late Ordovician
epoch. Internal fertilization with many vertebrates (such as
Reptiles are tetrapod
Tetrapods (; from Greek 'four' and 'foot') are four-limbed animals constituting the superclass Tetrapoda . It includes extant and extinct amphibians, reptiles (including dinosaurs and therefore birds), and synapsids ...
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. They form a sister group to the tunicates, together forming the Chordate#Taxonomy, olfactores. Included in this def ...
, and most
Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves , characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a four-c ...
s) occurs via
In animal anatomy, a cloaca (plural cloacae or ) is the posterior orifice that serves as the only opening for the digestive, reproductive, and urinary tracts (if present) of many vertebrate
Vertebrates () comprise all species of animal
l copulation, known as cloacal kiss (see also hemipenis
Mammals (from Latin language, Latin , 'breast') are a group of vertebrate animals constituting the class (biology), class Mammalia (), and characterized by the presence of mammary glands which in Female#Mammalian female, females produce milk ...
In mammals, the vagina is the elastic, muscular part of the female genital tract. In humans, it extends from the vulva to the cervix. The outer vaginal opening is normally partly covered by a membrane called the hymen. At the deep end, the cerv ...
lly, and many basal
Vertebrates () comprise all species of animal
Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic ma ...
s reproduce sexually with external fertilization.
In spiders and insects
Spiders ( order Araneae) are air-breathing arthropod
An arthropod (, (gen. ποδός)) is an invertebrate animal having an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Euar ...
s are often confused with
Insects or Insecta (from Latin
Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power ...
s, but they are not insects; instead, they are arachnids.
Spiders have separate male and female sexes. Before mating and copulation, the male spider spins a small web and ejaculates on to it. He then stores the sperm in reservoirs on his large pedipalps, from which he transfers sperm to the female's genitals. The females can female sperm storage, store sperm indefinitely.
For primitive insects, the male deposits spermatozoon, spermatozoa on the substrate, sometimes stored within a special structure; courtship involves inducing the female to take up the sperm package into her genital opening, but there is no actual copulation.
In groups that have reproduction similar to spiders, such as Dragonfly, dragonflies, males extrude sperm into secondary copulatory structures removed from their genital opening, which are then used to inseminate the female. In dragonflies, it is a set of modified Sternum (arthropod anatomy), sternites on the second abdominal segment.
In advanced groups of insects, the male uses its aedeagus, a structure formed from the terminal segments of the abdomen, to deposit sperm directly (though sometimes in a capsule called a ''spermatophore'') into the female's reproductive tract.
Sexual behavior can be classified into behavioral states associated with reward system, reward motivation ("incentive salience, wanting"), reward consummation aka pleasure ("liking"), and satiety ("inhibition");
these behavioral states are regulated in mammals by reward-based sexual learning, fluctuations in various neurochemicals (i.e., dopamine − sexual desire aka "wanting"; norepinephrine − sexual arousal; oxytocin and melanocortins − sexual attraction), and gonadal hormone cycles and further influenced by sex pheromones and motor reflexes (i.e., lordosis behaviour) in some mammals.
These behavioral states correlate with the phases of the human sexual response cycle: motivation − excitement; consummation − plateau and orgasm; satiety − refraction.
Sexual learning (a form of associative learning) occurs when an animal starts to associate bodily features, personality, contextual cues, and other stimuli with genitally-induced sexual pleasure.
Once formed, these associations in turn impinge upon both sexual wanting and sexual liking.
In most female mammals, the act of copulation is controlled by several innate neurobiological processes, including the motor sexual reflex of lordosis behaviour, lordosis.
[PFAFF Donald W. , SCHWARTZ-GIBLIN Susan, MACCARTHY Margareth M. , KOW Lee-Ming : Cellular and molecular mechanisms of female reproductive behaviors, in KNOBIL Ernest, NEILL Jimmy D. : The physiology of reproduction, Raven Press, 2nd edition, 1994]
In males, the act of copulation is more complex, because some learning is necessary, but the innate processes (retrocontrol of penis intromission in the vagina, rhythmic movement of the pelvis, detection of female pheromones) are specific to copulation. These innate processes direct heterosexual copulation.
[MEISEL Robert L. , SACHS Benjamin D. : The physiology of male sexual behavior. in KNOBIL Ernest, NEILL Jimmy D. The physiology of reproduction, Raven Press, 2nd edition, 1994]
Female lordosis behaviour became secondary in hominidae and is non-functional in humans.
Primate sexuality: Comparative studies of the Prosimians, Monkeys, Apes, and Human Beings
Oxford University Press, 2nd edition, 2012.
Mammals usually copulate in a dorso-ventral posture, though there are some primate species that copulate in a ventro-vental posture.
Most mammals possess a vomeronasal organ that is involved in pheromone detection, including sex pheromones.
Despite the fact that humans do not possess this organ, adult humans appear to be sensitive to certain mammalian pheromones that putative pheromone receptor proteins in the olfactory epithelium are capable of detecting.
While sex pheromones clearly play a role in modifying sexual behavior in some mammals, the capacity for general pheromone detection and the involvement of pheromones in regulating human sexual behavior has not yet been determined.
The duration of copulation varies significantly between mammal species, and may be correlated with body mass, lasting longer in small mammals than in large mammals.
[Stallmann, Robert R., and A. H. Harcourt.]
Size matters: the (negative) allometry of copulatory duration in mammals
" Biological Journal of the Linnean Society 87.2 (2006): 185-193.
* Pelvic thrust
* Møller, A. P., and T. R. Birkhead.Copulation behaviour in mammals: evidence that sperm competition is widespread
" Biological Journal of the Linnean Society 38.2 (1989): 119–131.
* Birkhead, Timothy R., L. Atkin, and A. P. Møller.Copulation behaviour of birds
" Behaviour 101.1 (1987): 101–138.
*Carlson, Debra AReproductive biology of the coyote (Canis latrans): integration of behavior and physiology
Utah State University, 2008.
*Castro, Ana Mafalda Lopes Sardica VelezMexican gray wolf courtship and mating: behavior & basic endocrinology during breeding season
Diss. Universidade de Lisboa. Faculdade de Medicina Veterinária, 2016.
* Szykman, Micaela, et al.Courtship and mating in free-living spotted hyenas.
Behaviour 144.7 (2007): 815–846.
* Dixson, Alan F.Baculum length and copulatory behavior in primates.
American Journal of Primatology 13.1 (1987): 51–60.