A lioness may have her cubs destroyed if the pride's males are overthrown.

For the practice among humans, see infanticide.

In the animal kingdom, infanticide involves the killing of young offspring by a mature animal of its own species, and is studied in zoology, specifically in the field of ethology. Ovicide is the analogous destruction of eggs. Although human infanticide has been widely studied, the practice has been observed in many other species throughout the animal kingdom since it was first seriously treated by Sugiyama.^[1] These include microscopic rotifers, insects, fish, amphibians, birds and mammals.^[2] Infanticide can be practiced by both males and females. In sociology and biology, infanticide is the practice of intentionally causing the death of an infant of a given species, by members of the same species - often by the mother. ... Look up killing in Wiktionary, the free dictionary. ... In biology, offspring are the product of reproduction, a new organism produced by one or more parents. ... In biology, a species is one of the basic units of biodiversity. ... Zoology (rarely spelled zoölogy) is the biological discipline which involves the study of non-human animals. ... This article or section does not adequately cite its references or sources. ... In most birds and reptiles, an egg (Latin ovum) is the zygote, resulting from fertilization of the ovum. ... In sociology and biology, infanticide is the practice of intentionally causing the death of an infant of a given species, by members of the same species - often by the mother. ... For other uses, see Animal (disambiguation). ... Classes Monogononta Digononta The rotifers make up a phylum of microscopic and near-microscopic pseudocoelomate animals. ... Insects (Class Insecta) are a major group of arthropods and the most diverse group of animals on the Earth, with over a million described species—more than all other animal groups combined. ... A giant grouper at the Georgia Aquarium Fish are aquatic vertebrates that are typically cold-blooded, covered with scales, and equipped with two sets of paired fins and several unpaired fins. ... For other uses, see Amphibian (disambiguation). ... “Aves” redirects here. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in... The shield and spear of the Roman god Mars, which is also the alchemical symbol for iron, represents the male sex. ... This article does not cite any references or sources. ...

Infanticide based on sexual competition has the general theme of the killer (often male) becoming the new sexual partner of the victim's parent which would otherwise be unavailable to it. This represents a gain in fitness by the killer, and a loss in fitness by the parent of the offspring killed. This is a form of sexual conflict and is a type of evolutionary struggle between the two sexes, in which the victim sex may have its own counter-adaptations which reduce the success of this practice. It may also occur due to non-sexual competition, such as the struggle for food between females. In this case individuals may even kill closely related offspring. Sexual reproduction is a union that results in increasing genetic diversity of the offspring. ... Fitness (often denoted in population genetics models) is a central concept in evolutionary theory. ... A parent is a father or mother; one who begets or one who gives birth to or nurtures and raises a child; a relative who plays the role of guardian // Mother This article or section does not cite its references or sources. ... Sexual conflict is a form of evolutionary conflict where males and females share different interests. ... An evolutionary arms race is an evolutionary struggle between a predator species and its prey (including parasitism) that is said to resemble an arms race. ...

Filial infanticide occurs when a parent kills its own offspring. This often involves consumption of the young themselves, which is termed filial cannibalism. The behavior is widespread in fishes, and is seen in many terrestrial animals as well, including pigs, where it can be costly to farmers. Human infanticide has been recorded in almost every culture. A unique aspect of human infanticide is selection of individuals based on their gender. Three Mormon crickets eating a fourth Mormon cricket In zoology, cannibalism is a common ecological interaction in the animal kingdom and has been recorded for more than 1500 species (this estimate is from 1981, and likely a gross underestimation). ... Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: wise man or knowing man) in the family Hominidae (the great apes). ... Sex-selective abortion is the practice of aborting a fetus after a determination (usually by ultrasound but also rarely by amniocentesis or another procedure) that the fetus is an undesired sex, typically female. ...

Sexual competition infanticide

This form of infanticide represents a struggle between the sexes, where one sex tries to exploit the other, much to the latter's disadvantage.

Male killing of female-guarded offspring

Semnopithecus hypoleucos, a species of gray langur.

Hanuman langurs (or gray langurs) are an Old World monkey found in India. They are a social animal, living in groups. Each group is generally dominated by a single male, with many females, though the male must struggle for control of the group with other males. When a male tries to take over a group, there is a violent struggle with the existing male. If successful in overthrowing the previous male, infants of the females are then killed.^[3] This infanticidal period is limited to the window just after the group is taken over. Cannibalism has not been observed in this species, however. Binomial name Semnopithecus hypoleucos The Black-footed Gray Langur (Semnopithecus hypoleucos) is an Old World monkey, one of the species of langurs. ... Species Semnopithecus schistaceus Semnopithecus ajax Semnopithecus hector Semnopithecus entellus Semnopithecus hypoleucos Semnopithecus dussumieri Semnopithecus priam The gray langurs are a group of Old World monkeys and make up the entirety of the genus Semnopithecus. ... Subfamilies Cercopithecinae - 11 genera Colobinae - 10 genera The Old World monkeys or Cercopithecidae are a group of primates, falling in the superfamily Cercopithecoidea in the clade Catarrhini. ... In biology, psychology and sociology social behavior is behavior directed towards, or taking place between, members of the same species. ... Violence is a general term to describe actions, usually deliberate, that cause or intend to cause injury to people, animals, or non-living objects. ...

This behavior not only reduces intraspecific competition between the incumbent's offspring and those of other males and increases the parental investment afforded to their own young, but also allows females to become sexually receptive sooner. This is because females of this species, as well as many other mammals, do not ovulate during the period in which they produce milk. It then becomes easier to see how this behavior could have evolved. If a male kills a female's young, they stop lactating and are able to become pregnant again. As males are in a constant struggle to protect their group, those that express infanticidal behavior will contribute a larger portion to future gene pools (see natural selection). Intraspecific competition is the interaction between members of the same species that vie for the same resource in an ecosystem (e. ... Robert Trivers theory of parental investment predicts that the sex making the largest investment in lactation, nurturing and protecting offspring will be more discriminating in mating and that the sex that invests less in offspring will compete for access to the higher investing sex. ... A glass of cows milk. ... A breastfeeding infant Breastfeeding is the practice of a woman feeding an infant (or sometimes a toddler or a young child) with milk produced from her mammary glands, usually directly from the nipples. ... A pregnant woman Pregnancy is the process by which a mammalian female carries a live offspring from conception until it develops to the point where the offspring is capable of living outside the womb. ... The gene pool of a species or a population is the complete set of unique alleles that would be found by inspecting the genetic material of every living member of that species or population. ... Darwins illustrations of beak variation in the finches of the Galápagos Islands, which hold 13 closely related species that differ most markedly in the shape of their beaks. ...

Similar behavior is also seen in male lions, among other species, who also kill young cubs, allowing them to impregnate the females. Unlike langurs, male lions live in small groups, which cooperate to take control of a pride from an existing group.^[4] They will attempt to kill any cubs that are roughly 9 months old or less, though as in other species, the female will attempt to defend their cubs viciously. Males have, on average, only a two year window in which to pass on their genes, and female lions only give birth once every two years, so the selective pressure from them to behave like this is strong. In fact it is estimated that a quarter of cubs dying in the first year of their life are victims of infanticide.^[4] Binomial name (Linnaeus, 1758) Distribution of Lions in Africa Synonyms Felis leo (Linnaeus, 1758) The lion (Panthera leo) is a member of the family Felidae and one of four big cats in the genus Panthera. ... For a non-technical introduction to the topic, see Introduction to Genetics. ... This article or section does not cite any references or sources. ...

Male mice show great variation in behavior over time. After fertilizing a female, they become aggressive towards mouse pups for three weeks, killing any they come across. After this period however, their behavior changes dramatically, and they become paternal, caring for their own offspring. This lasts for almost two months, but afterwards they become infanticidal once more. It is no coincidence here that the female gestation period is three weeks as well, or that it takes roughly two months for pups to become fully weaned and leave their nest. The proximate mechanism that allows for the correct timing of these periods involves circadian rhythms (see chronobiology), each day and night cycle affecting the mouse's internal neural physiology, and disturbances in the duration of these cycles results in different periods of time between behaviors.^[5] The adaptive value of this behavior switching is two-fold; infanticide removes competitors for when the mouse does have offspring, and allows the female victims to be impregnated earlier than if they continued to care for their young, as mentioned above. Mice may refer to: An abbreviation of Meetings, Incentives, Conferencing, Exhibitions. ... A father is the male parent of a child. ... A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. ... Chronobiology is a field of science that examines periodic (cyclic) phenomena in living organisms. ... The nervous system of an animal coordinates the activity of the muscles, monitors the organs, constructs and processes input from the senses, and initiates actions. ...

Gerbils, on the other hand, no longer commit infanticide once they have paired with a female, but actively kill and eat other offspring when young. The females of this species behave much like male mice, hunting down other litters except when rearing their own.^[6] For other uses, see Gerbil (disambiguation). ...

Prospective infanticide

Prospective infanticide is a subset of sexual competition infanticide in which young born after the arrival of the new male are killed. This is less common than infanticide of existing young, but can still increase fitness in cases where the offspring could not possibly have been fathered by the new mate, i.e. one gestation or fertility period. This is known to occur in lions and langurs, and has also been observed in other species such as house wrens.^[7] In birds, however, the situation is more complex, as female eggs are fertilized one at a time, with a 24-hour delay between each. Males may destroy clutches laid 12 days or more after their arrival, though their investment of around 60 days of parental care is large, so a high level of parental certainty is needed.^[7]

Female killing of male-guarded offspring

Jacana jacana females carry out infanticide.

Females are also known to display infanticidal behavior. This may appear unexpected, as the conditions described above do not apply. Males are not always an unlimited resource though - in some species, males provide parental care to their offspring, and females may compete indirectly with others by killing their offspring, freeing up the limiting resource that the males represent. This has been documented in research by Stephen Emlen and Natalie Demong on wattled jacanas (Jacana jacana), a tropical wading bird.^[8] With the wattled jacana, it is exclusively the male sex which broods, while females defend their territory. In this experiment Demong and Emlen found that removing females from a territory resulted in nearby females attacking the chicks of the male in most cases, evicting them from their nest. The males then fertilized the offending females and cared for their young. It has been suggested that Limiting Factor be merged into this article or section. ... Binomial name Jacana jacana (Linnaeus, 1766) The Wattled Jacana Jacana jacana is a wader which is a resident breeder from western Panama and Trinidad south through most of South America east of the Andes. ... Families Charadridae Jacanidae Rostratulidae Ibidorhynchidae Recurvirostridae Haematopodidae Scolopacidae Dromadidae Burhinidae Glareolidae Thinocoridae Waders, called Shorebirds in North America (where wader is used to refer to long-legged wading birds such as storks and herons), are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. ... Look up Brood in Wiktionary, the free dictionary. ... It has been suggested that intruder be merged into this article or section. ... In the scientific method, an experiment (Latin: ex-+-periri, of (or from) trying), is a set of actions concerning phenomena. ... Categories: Biology stubs ...

Infanticide is also seen in giant water bugs.^[9] Lethocerus deyrollei is a large and nocturnal predatory insect found in still waters near vegetation. In this species the males take care of masses of eggs by keeping them hydrated with water from their bodies. Without a male caring for the eggs like this, they become desiccated and will not hatch. In this species males are a scarce resource which females must sometimes compete for. Those that cannot find a free male will often stab the eggs of a brooding one. As in the above case, males then fertilize this female and care for her eggs. Noritaka Ichikawa has found that males only moisten their eggs during the first 90 seconds or so, after which all of the moisture on their bodies has evaporated. However, they guard the egg masses for as long as several hours at a time, when they could be hunting prey. They do not seem to prevent further evaporation by staying guard, as males that only guarded the nest for short periods were seen to have similar hatching rates in a controlled experiment where there were no females present. It seems rather that males are more successful in avoiding infanticidal females when they are out of the water with their eggs, which might well explain the ultimate cause of this behavior.^[9] Giant water bugs are members of the family Belostomatidae within the order Hemiptera, colloquially known as toe-biters. ... A nocturnal animal is one that sleeps during the day and is active at night - the opposite of the human (diurnal) schedule. ... This snapping turtle is trying to make a meal of a Canada goose, but the goose is too wary. ... Vegetation is a general term for the plant life of a region; it refers to the ground cover provided by plants, and is, by far, the most abundant biotic element of the biosphere. ... Desiccation is the state of extreme dryness, or the process of extreme drying. ... In economics, scarcity is defined as a condition of limited resources, where society does not have sufficient resources to produce enough to fulfill subjective wants. ... This article or section is in need of attention from an expert on the subject. ...

Female killing of female-guarded offspring

The Black-tailed prairie dog (Cynomys ludovicianus)

Black-tailed prairie dogs are colonially-living, harem-polygynous squirrels found mainly in the United States. Their living arrangement involves one male living with four or so females in a territory defended by all individuals, and underground nesting. Black-tails only have one litter per year, and are in estrous for only a single day around the beginning of spring. Binomial name Cynomys ludovicianus (Ord, 1815) The Black-tailed Prairie Dog (Cynomys ludovicianus), is found in the Great Plains of North America from about the USA-Canada border to the USA-Mexico border. ... The term polygyny (Greek: poly many, gynaika woman) is used in related ways in social anthropology and sociobiology. ... Genera Many, see the article Sciuridae. ... It has been suggested that intruder be merged into this article or section. ... Estrus (also spelled œstrus) or heat in female mammals is the period of greatest female sexual responsiveness usually coinciding with ovulation. ... This article does not cite any references or sources. ...

A seven-year natural experiment by John Hoogland and others from the University of Princeton revealed that infanticide is widespread in this species, including infanticide from invading males and immigrant females, as well as occasional cannibalism of an individual's own offspring.^[2] The surprising finding of the study was that by far the most common type of infanticide involved the killing of close kin's offspring. This seems illogical, as kin selection favors behaviors that promote the well-being of closely related individuals. It was postulated that this form of infanticide is more successful than trying to kill young in nearby groups, as the whole group must be bypassed in this case, while within a group only the mother need be evaded. Marauding behavior is evidently adaptive, as infanticidal females had more and healthier young than others, and were heavier themselves as well. This behavior appears to reduce competition with other females for food, and future competition among offspring. A natural experiment is a naturally occurring instance of observable phenomena which approach or duplicate a scientific experiment. ... For other Princetons, see Princeton. ... In evolutionary biology, kin selection refers to changes in gene frequency across generations that are driven at least in part by interactions between related individuals, and this forms much of the conceptual basis of the theory of social evolution. ...

Similar behavior has been reported in the meerkat (Suricata suricatta), including cases of females killing their mother's and daughter's offspring. Infanticidal raids from neighboring groups also occurred.^[10] Binomial name Suricata suricatta (Schreber, 1776) Meerkat range The meerkat or suricate Suricata suricatta is a small mammal and a member of the mongoose family. ...

Costs and defenses

Costs of the behavior

While it may be beneficial for some species to behave this way, infanticide is not without risks to the perpetrator. Having already exhausted energy and perhaps sustained serious wounds in a fight with another male, attacks from females who vigorously defend their offspring may be telling for harem-polygynous males, with a risk of infection. It is also energetically costly to pursue a mother's young, which may try to escape. Superficial bullet wounds In medicine, a wound is a type of physical trauma wherein the skin is torn, cut or punctured (an open wound), or where blunt force trauma causes a contusion (a closed wound). ... An infection is the detrimental colonization of a host organism by a foreign species. ... Cost-benefit analysis is an important technique for project appraisal: the process of weighing the total expected costs against the total expected benefits of one or more actions in order to choose the best or most profitable option. ...

Costs of the behavior described in prairie dogs include the risk to an individual of losing their own young while killing another's, not to mention the fact that they are killing their own relatives. In a species where infanticide is common, perpetrators may well be victims themselves in the future, such that they come out no better off; but as long as an infanticidal individual gains in reproductive output by its behavior, it will tend to become common. Further costs of the behavior in general may be induced by counter-strategies evolved in the other sex, as described below.

As a cost of social behavior

Taking a broader view of the black-tailed prairie dog situation, infanticide can be seen as a cost of social living.^[2] If each female were to have her own private nest away from others, she would be much less likely to have her infants killed when absent. This, and other costs such as increased spread of parasites, must be made up for by other benefits, such as group territory defense and increased awareness of predators. A parasite is an organism that spends a significant portion of its life in or on the living tissue of a host organism and which causes harm to the host without immediately killing it. ...

An avian example published in Nature is acorn woodpeckers. Females nest together, possibly because those nesting alone have their eggs constantly destroyed by rivals. Even so, eggs are consistently removed at first by nest partners themselves, until the entire group lays on the same day. They then cooperate and incubate the eggs as a group, but by this time a significant proportion of their eggs have been lost because of this ovicidal behavior.^[11] Nature is one of the most prominent scientific journals, first published on 4 November 1869. ... Binomial name Melanerpes formicivorus (Swainson,, 1827) The Acorn Woodpecker (Melanerpes formicivorus) is a medium-sized woodpecker. ... The word incubate in the context of birds refers to the development of the chick (embryo) within the egg and the constant temperature required for the development of it over a specific period. ...

Counter-strategies

Because this form of infanticide reduces the fitness of the victim by lowering their fecundity, animals have evolved a range of counter-strategies against this behavior. These may be divided into two very different classes - those which tend to prevent infanticide, and those which minimize losses. Fecundity is the potential reproductive capacity of an organism or population, measured by the number of gametes (e. ...

Loss minimization

Some females abort or resorb their own young while they are still in development after a new male takes over; this is known as the Bruce effect.^[12] This may prevent their young from being killed after birth, saving the mother wasted time and energy. However, this strategy also benefits the new male. In mice this can occur by the proximate mechanism of the female smelling the odor of the new male's urine.^[13] The Bruce effect is a form of pregnancy disruption in mammals in which exposure of a female to an unknown male results in pre- (Bruce 1959) or postimplantation failure (e. ... Young boy smelling a flower Olfaction, which is also known as Olfactics is the sense of smell, and the detection of chemicals dissolved in air. ... This article or section is in need of attention from an expert on the subject. ...

Preventative adaptations

Infanticide in burying beetles may have lead to male parental care.^[14] In this species males often cooperate with the female in preparing a piece of carrion, which is buried with the eggs and eaten by the larvae when they hatch. Males may also guard the site alongside the female. It is apparent from experiments that this behavior does not provide their young with any better nourishment, nor does is it of any use in defending against predators. However, other burying bugs may try to take their nesting space. When this occurs, a male-female pair is over twice as successful in nest defense, preventing the ovicide of their offspring.

Female langurs may leave the group with their young alongside the outgoing male, and others may develop a false estrous and allow the male to copulate, deceiving him into thinking she is actually sexually receptive.^[15] Females may also have sexual liasons with other males. This promiscuous behavior is adaptive, because males will not know whether it is their own offspring they are killing or not, and may be more reluctant or invest less effort in infanticide attempts.^[16] Lionesses cooperatively guard against scouting males, and a pair were seen to violently attack a male after it killed one of their young.^[17] Resistance to infanticide is also costly, though: for instance, a female may sustain serious injuries in defending her young. At times it is simply more advantageous to submit than to fight.^[18] Promiscuity is the practice of making relatively unselective, casual and indiscriminate choices. ...

Filial infanticide

Damselfish may eat their own offspring.

Filial infanticide occurs when a parent kills its own offspring. Both male and female parents have been observed to do this. Cocoa damselfish (Stegastes variabilis) from the USGS. File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Cocoa damselfish (Stegastes variabilis) from the USGS. File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

Maternal

Further information: Savaging

Savaging is the cannibalistic infanticide of newborn offspring by their mother. It is prevalent among pigs,^[19] where it affects up to 5% of gilts, but seen in many other animals such as rabbits^[20] and burying beetles.^[21] Proper care of the piglets by a mother gilt depends on sanitary conditions and a comfortable environment. ... Faces of mother and child; detail of sculpture at Soldier Field, Chicago, Illinois, USA. Female mallard duck and ducklings. ... This article needs additional references or sources for verification. ... Genera Pentalagus Bunolagus Nesolagus Romerolagus Brachylagus Sylvilagus Oryctolagus Poelagus Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world. ... Species See text. ...

Paternal

Paternal infanticide—where fathers eat their own offspring—may also occur. When young bass hatch from the spawn, the father guards the area, circling around them and keeping them together, as well as providing protection from would-be predators. After a few days, most of the fish will swim away. At this point the male's behavior changes: instead of defending the stragglers, he treats them as any other small prey, and eats them.^[22] Bass may refer to: Look up bass in Wiktionary, the free dictionary. ... Frog spawn Spawning is the production or depositing of large quantites of eggs in water. ...

Other

In honey bees, Woyke found that 3% of brood were eaten by workers.^[23] Some larva seemed to signal to the workers that they should be eaten by excreting a cannibalism-inducing substance. This seems maladaptive, and would be for a normal animal, but bees are eusocial insects, so kin selection and natural selection are equivalent here - the worker caste cannot reproduce, so their survival depends of the fitness of the hive. This cannibalism could be described as altruistic,^[22] and is similar to bees stinging intruders in that both activities end the bee's life while generally improving the well-being of their queen and hence their own genes (for more on this see selfish gene theory). The honeybee is a colonial insect that is often maintained, fed, and transported by farmers. ... Eusociality is the phenomenon of reproductive specialisation found in some species of animal, whereby a specialised caste carries out reproduction in a colony of non-reproductive animals. ... Altruism refers to both a practice or habit (in the view of many, a virtue) as well as an ethical doctrine. ... A bee A bee sting strictly means a sting from a bee (honeybee, bumblebee, sweat bee etc). ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

Human infanticide

Killing Her Baby in Gulag, drawing by Eufrosinia Kersnovskaya

Main article: Infanticide

Infanticide has been, and still is, practiced by some cultures, groups, or individuals. Often it is the mother who commits the act, but criminology recognizes various forms of non-maternal child murder. In many past societies, certain forms of infanticide were considered permissible, whereas in most modern societies the practice is considered immoral and criminal. Nonetheless, it still takes place — in the Western world usually because of the parent's mental illness or violent behavior, and in some poor countries as a form of population control, sometimes with tacit societal acceptance. Female infanticide, a form of sex-selective infanticide, is more common than the killing of male babies. Gulag ( , Russian: ) was the government body responsible for administering prison camps across the former Soviet Union. ... Eufrosinia Kersnovskaya (Евфросиния Керсновская) (1907— 1994) spent 12 years in Gulag camps and wrote her memoirs in 12 notebooks, 2,200,000 characters, accompanied with 680 pictures. ... In sociology and biology, infanticide is the practice of intentionally causing the death of an infant of a given species, by members of the same species - often by the mother. ... Criminology is the scientific study of crime as an individual and social phenomenon. ... Note: for practices of systematically killing very young children, see infanticide For the killing of ones own children, see filicide. ... Morality is a complex of principles based on cultural, religious, and philosophical concepts and beliefs, by which an individual determines whether his or her actions are right or wrong. ... This article does not cite any references or sources. ... The term Western world, the West or the Occident (Latin occidens -sunset, -west, as distinct from the Orient) [1] can have multiple meanings dependent on its context (e. ... A mental illness or mental disorder refers to one of many mental health conditions characterized by distress, impaired cognitive functioning, atypical behavior, emotional dysregulation, and/or maladaptive behavior. ... This article does not cite any references or sources. ... For the Jamaican reggae band, see Third World (band). ... Population control is the practice of limiting population increase, usually by reducing the birth rate. ... Female infanticide, the prevalent form of sex-selective infanticide is the systematic killing of girls at or soon after birth. ... Sex-selective abortion is the practice of aborting a fetus after a determination (usually by ultrasound but also rarely by amniocentesis or another procedure) that the fetus is an undesired sex, typically female. ...

See also

• Sexual cannibalism
• Sexual selection
• Siblicide

Sexual cannibalism is a special case of cannibalism in which a female organism kills and consumes a conspecific (same species) male before, during, or after copulation. ... Illustration from The Descent of Man and Selection in Relation to Sex by Charles Darwin showing the Tufted Coquette Lophornis ornatus, female on left, ornamented male on right. ...

Further reading

• Hausfater, G. & S. G. , Hrdy (1984) Infanticide: Comparitive and evolutionary perspectives New York, Aldine. ISBN 0202020223
• Parmigiani, S. & F. S. vom Saal (1994) Infanticide and parental care London: Harwood. ISBN 9783718655052
• C. P. van Schaik & C. H. Janson (2000) Infanticide by males and its implications Cambridge University Press. ISBN 0521772958

References