Infanticide and infant defence by males--modelling the conditions in primate multi-male groups

Infanticide by primate males was considered rare if groups contain more than one adult male because, owing to lower paternity certainty, a male should be less likely to benefit from infanticide. Guided by recent evidence for strong variation of infanticide in primate multi-male groups, we modelled the conditions for when infanticide should occur for a group with a resident and an immigrant male. Setting the parameters (e.g. infant mortality, reduction of interbirth interval, life-time reproductive success, genetic representation) to fit the conditions most commonly found in nature, we develop a game-theoretic model to explore the influence of age and dominance on the occurrence of infanticide and infant defence. Male age strongly impacts the likelihood of an attack which is modified by the father's defence. If the new male is dominant he is likely to attack under most circumstances whereas a subordinate male will only attack if the father does not defend. These model scenarios fit the conditions under which infanticide is known to occur in primate multi-male groups and offer an explanation why infanticide is common in some multi-male groups and rare in others. Overall, the benefits for infanticidal males are strongly governed by a reduced interbirth interval while advantages via improved genetic representation in the gene pool contribute but a minor fraction

Punishing Infanticide in the Irish Free State

This article explores sentencing of women convicted of infanticide offences at the Central Criminal Court between 1922 and 1949. A sample of 124 cases involving women who had been convicted of manslaughter, concealment of birth, or child abandonment/child cruelty, after appearing at the Central Criminal Court on a charge of murdering their newly or recently born infant, is examined. The sentences imposed in this sample mainly include short prison terms, suspended prison sentences, and conditional discharges/probation. It will be argued that the limited use of imprisonment, particularly in cases involving manslaughter convictions, indicates that Irish judges took a lenient approach to sentencing in cases of maternal infanticide. The court records show that a notable aspect of sentencing practice in these Irish infanticide cases is the use of non-penal religious institutions, mostly convents, as an alternative to traditional custody. The impact of patriarchal ideologies and pragmatic considerations on sentencing practice in cases of infanticide is explored, particularly in regard to the use of religious institutions. One of the questions considered is whether the approach to sentencing women convicted of infanticide offences was a unique product of the patriarchal, conservative, catholic, and nationalist philosophies of the Irish Free State, or whether sentencing practice in these cases reflects wider trends in the response to female criminality which have been identified elsewhere

Are male orangutans a threat to infants? Evidence of mother-offspring counter strategies to infanticide in Bornean orangutans (Pongo pygmaeus wurmbii)

Sexually selected infanticide by males is widespread in primates. Female primates employ a variety of strategies to reduce infanticide risk. While infanticide has never been directly observed in wild orangutans (Pongo spp.), their slow life history makes infants vulnerable to infanticide. The mating strategies of female orangutans include polyandrous and postconceptive mating that may serve to increase paternity confusion, an infanticide avoidance strategy. Here, we investigate whether female orangutans alter their social interactions with males as another infanticide avoidance strategy. We hypothesize that females with younger offspring avoid males and that the distance between mother and offspring decreases in the presence of males. We use long-term behavioral data collected between 1994 and 2016 from Bornean orangutans (Pongo pygmaeus wurmbii) in Gunung Palung National Park, Indonesia, to test whether the sexual selection hypothesis for infanticide helps explain aspects of orangutan social behavior. We found that mothers with offspring 6 yr. old and females without offspring. In addition, the distance between a mother–offspring dyad showed a statistically significant decrease in the presence of males, but not females. Our results are consistent with the hypothesis that female orangutans employ strategies to reduce infanticide risk in their social interactions. Because orangutans have a high fission–fusion dynamic, they have flexibility in manipulating social interactions as a counter-infanticide strategy. Our results suggest that infanticide by males is a selective pressure shaping female orangutan social behavior.Accepted manuscrip

Possible male infanticide in wild orangutans and a re-evaluation of infanticide risk

Infanticide as a male reproductive tactic is widespread across mammals, and is particularly prevalent in catarrhine primates. While it has never been observed in wild orangutans, infanticide by non-sire males has been predicted to occur due to their extremely long inter-birth intervals, semi-solitary social structure, and the presence of female counter-tactics to infanticide. Here, we report on the disappearance of a healthy four-month-old infant, along with a serious foot injury suffered by the primiparous mother. No other cases of infant mortality have been observed at this site in 30 years of study. Using photographic measurements of the injury, and information on the behavior and bite size of potential predators, we evaluate the possible causes of this injury. The context, including the behavior of the female and the presence of a new male at the time of the injury, lead us to conclude that the most likely cause of the infant loss and maternal injury was male infanticide. We suggest that in orangutans, and other species where nulliparous females are not preferred mates, these females may be less successful at using paternity confusion as an infanticide avoidance tactic, thus increasing the likelihood of infanticide of their first-born infants.Published versio

"The mad", "the bad", "the victim":gendered constructions of women who kill within the criminal justice system

Women commit significantly fewer murders than men and are perceived to be less violent. This belief about women’s non-violence reflects the discourses surrounding gender, all of which assume that women possess certain inherent essential characteristics such as passivity and gentleness. When women commit murder the fundamental social structures based on appropriate feminine gendered behaviour are contradicted and subsequently challenged. This article will explore the gendered constructions of women who kill within the criminal justice system. These women are labelled as either mad, bad or a victim, by both the criminal justice system and society, depending on the construction of their crime, their gender and their sexuality. Symbiotic to labelling women who kill in this way is the denial of their agency. That is to say that labelling these women denies the recognition of their ability to make a semi-autonomous decision to act in a particular way. It is submitted that denying the agency of these women raises a number of issues, including, but not limited to, maintaining the current gendered status quo within the criminal law and criminal justice system, and justice both being done, and being seen to be done, for these women and their victims

Gretchen's infanticide

In the scene At The Well, Gretchen herself describes the sequence of events best and in all their fateful simplicity. It is the progress from "sin" to "shame", that is to public disgrace as soon as her private transgression becomes "visible" as pregnancy. Already here the painful confusion over her private perception ("good, dear love", lines 3585/6) and public judgment ("slut", line 3753) which will eventually drive her mad is obvious. In her derangement and despair she will destroy the evidence against her, that is, drown her child

Infanticide in Chimpanzees: Taphonomic Case Studies from Gombe

Objectives We present a study of skeletal damage to four chimpanzee (Pan troglodytes) infanticide victims from Gombe National Park, Tanzania. Skeletal analysis may provide insight into the adaptive significance of infanticide by examining whether nutritional benefits sufficiently explain infanticidal behavior. The nutritional hypothesis would be supported if bone survivorship rates and skeletal damage patterns are comparable to those of monkey prey. If not, other explanations, such as the resource competition hypothesis, should be considered. Methods Taphonomic assessment of two chimpanzee infants included description of breakage and surface modification, data on MNE, %MNE, and bone survivorship. Two additional infants were assessed qualitatively. The data were compared to published information on monkey prey. We also undertook a review of published infanticide cases. Results The cases were intercommunity infanticides (one male and three female infants) committed by males. Attackers partially consumed two of the victims. Damage to all four infants included puncture marks and compression fractures to the cranium, crenulated breaks to long bones, and incipient fractures on ribs. Compared to monkey prey, the chimpanzee infants had an abundance of vertebrae and hand/foot bones. Conclusions The cases described here suggest that chimpanzees may not always completely consume infanticide victims, while reports on chimpanzee predation indicated that complete consumption of monkey prey usually occurred. Infanticidal chimpanzees undoubtedly gain nutritional benefits when they consume dead infants, but this benefit may not sufficiently explain infanticide in this species. Continued study of infanticidal and hunting behavior, including skeletal analysis, is likely to be of interest

Of apples and oranges? The evolution of “monogamy” in non-human primates

Behavioral ecologists, evolutionary biologists, and anthropologists have been long fascinated by the existence of “monogamy” in the animal kingdom. Multiple studies have explored the factors underlying its evolution and maintenance, sometimes with contradicting and contentious conclusions. These studies have been plagued by a persistent use of fuzzy terminology that often leads to researchers comparing “apples with oranges” (e.g., comparing a grouping pattern or social organization with a sexual or genetic mating system). In this review, we provide an overview of research on “monogamy” in mammals generally and primates in particular, and we discuss a number of problems that complicate comparative attempts to understand this issue. We first highlight why the muddled terminology has hindered our understanding of both a rare social organization and a rare mating system. Then, following a short overview of the main hypotheses explaining the evolution of pair-living and sexualmonogamy, we critically discuss various claims about the principal drivers of “monogamy” that have been made in several recent comparative studies.We stress the importance of using only high quality and comparable data. We then propose that a productive way to frame and dissect the different components of pair-living and sexual or genetic monogamy is by considering the behavioral and evolutionary implications of those components from the perspectives of all participants in a species’ social system. In particular, we highlight the importance of integrating the perspective of “floater” individuals and considering their impacts on local operational sex ratios, competition, and variance in reproductive success across a population. We stress that pair-living need not imply a reduced importance of intrasexual mate competition, a situation that may have implications for the sexual selection potential that have not yet been fully explored. Finally, we note that there is no reason to assume that different taxa and lineages, even within the same radiation, should follow the same pathway to or share a unifying evolutionary explanation for “monogamy”. The study of the evolution of pair-living, sexual monogamy, and genetic monogamy remains a challenging and exciting area of research.Fieldwork related to the data discussed and presented here was supported through grants awarded to AD, EF-D, and their students by the Wenner-Gren Foundation, the L.S.B. Leakey Foundation, the J. William Fulbright Scholar Program, Primate conservation, Inc., Idea Wild, the National Geographic Society, as well by the New York Consortium in Evolutionary Primatology, New York University, the Zoological Society of San Diego, the University of Pennsylvania, the University of Texas at Austin, and Yale University, as well as through grants awarded to Eckhard W. Heyman and MH by the Deutsche Forschungsgesellschaft (HE 1870/10-1,2,3, HU1746-2/1). The Owl Monkey Project of Argentina was supported through the following grants to EFD: NSF-BCS-0621020, 1232349, 1503753 and 1848954; NSF-REU 0837921, 0924352 and 1026991; NSFRAPID-1219368; NIA- P30 AG012836-19, and NICHD R24 HD-044964-11