Taxon-Specific Pair Bonding in Gibbons (Hylobatidae)

This study provides the first statistically significant evidence that the mechanisms of how pair bonds are created or maintained differ between gibbon taxa. We examine the pair bond in captive pairs of three genera of gibbons (Hylobatidae): siamangs (Symphalangus, N = 17 pairs), crested gibbons (Nomascus, N = 7 pairs), and pileated gibbons (Hylobates pileatus, N = 9 pairs). In the first part of this study, we determine three generally-accepted indicators of pair-bond strength (mutual grooming, behavioral synchronization and partner distance). A pairwise comparison of our samples reveals a difference in relative partner distances between siamangs and pileated gibbons, suggesting that siamangs may have a stronger pair bond than pileated gibbons. No difference among the three taxa was found in other variables believed to indicate pair bond strength. In the second part we examine the amount of partner-directed grooming in each sex. In siamangs, males invest significantly more into pair bonds than females, whereas the opposite is true in crested and pileated gibbons. Our results for siamangs correspond to predictions derived from the ‘mate-defense hypothesis’ for the evolution of pair bonds, whereas our results for crested gibbons and pileated gibbons correspond to predictions derived from the ‘male-services hypothesis’.

Download Full-text

Mate Attentiveness, Seasonal Timing of Breeding and Long-term Pair Bonding in the House Finch (Carpodacus mexicanus)

Behaviour ◽

10.1163/156853904772746565 ◽

2004 ◽

Vol 141 (1) ◽

pp. 1-13 ◽

Cited By ~ 7

Author(s):

Geoffrey Hill ◽

Kevin McGraw

Keyword(s):

Pair Bond ◽

Egg Laying ◽

Carpodacus Mexicanus ◽

Timing Of Breeding ◽

Pair Bonding ◽

House Finches ◽

Breeding Date ◽

Pair Bonds ◽

Term Pair

AbstractIn seasonally breeding birds, natural selection favors individuals that begin breeding earlier in a year because they produce more or higher quality offspring than those that begin breeding later. Among the factors that influence the timing of breeding, which include the age, health, competitive ability, or mate quality of individuals, is the longevity of the pair bond, with birds that remain mated across years initiating breeding earlier in the season than newly formed pairs. The behavioural interactions between pair members that may facilitate long-term pair bonding and early breeding onset have infrequently been studied, however. Here we report the relationship between male-female affiliative behaviour, pair-bond duration, and breeding date in house finches (Carpodacus mexicanus), a short-lived, socially monogamous passerine species in which the duration of pair bonds is highly variable within and among seasons. Finches that initiated breeding earliest in the season were those that had bred with one another in previous years. Early breeding males from returning pairs maintained significantly closer contact with their mate during the first egg-laying period of the year than did males from late-breeding, newly formed pairs. Similarly, early-breeding females from returning pairs followed their mate more closely in nest-vicinity flights during the fertile period than females from late-breeding, newly formed pairs. These results suggest that attributes of and interactions between both pair members may help to maintain stable breeding pairs and influence the timing of breeding in seasonally nesting, short-lived songbirds. Rather than advertising for or seeking extra-pair fertilization opportunities, high-quality pairs of finches may invest heavily in their mate to secure the pair bond and ensure high intrapair reproductive success.

Download Full-text

Prolonged partner separation erodes nucleus accumbens transcriptional signatures of pair bonding in male prairie voles

10.1101/2021.07.14.452355 ◽

2021 ◽

Author(s):

Julie M Sadino ◽

Xander G Bradeen ◽

Conor J Kelly ◽

Deena M Walker ◽

Zoe R Donaldson

Keyword(s):

Nucleus Accumbens ◽

Pair Bond ◽

Pair Bonding ◽

Partner Preference ◽

Same Sex ◽

Prairie Voles ◽

Pair Bonds ◽

Transcriptional Changes ◽

Opposite Sex ◽

Over Time

The loss of a spouse is often cited as the most traumatic event in a person's life. However, for most people, the severity of grief and its maladaptive effects subside over time via an understudied adaptive process. Like humans, socially monogamous prairie voles (Microtus ochrogaster) form opposite-sex pair bonds, and upon partner separation, show behavioral and neuroendocrine stress phenotypes that diminish over time. Eventually, they can form a new bond, a key indicator of adapting to the loss of their partner. Thus, prairie voles provide an ethologically-relevant model for examining neuromolecular changes that emerge following partner separation for adapting to loss. Here, we test the hypothesis that extended partner separation diminishes pair bond-associated behaviors (partner preference and selective aggression) and causes pair bond transcriptional signatures to erode. Pairs were cohoused for 2 weeks and then either remained paired or were separated for 48hrs or 4wks before collecting fresh nucleus accumbens tissue for RNAseq. In a separate cohort, we assessed partner preference and selective aggression at these time points. Surprisingly, pair bond-associated behaviors persist despite prolonged separation and are similar between same-sex and opposite-sex paired voles. In contrast, we found that opposite-sex pair bonding, as compared with same-sex pairing, led to changes in accumbal transcription that were stably maintained as long as animals remained paired but eroded following prolonged partner separation. Eroded genes are primarily associated with gliogenesis and myelination, suggesting a previously undescribed role for glia in maintaining pair bonds and adapting to partner loss. We further reasoned that relevant neuronal transcriptional changes may have been masked by the prominent transcriptional signals associated with glia. Thus, we pioneered neuron-specific translating ribosomal affinity purification in voles. Neuronally-enriched transcriptional changes revealed dopaminergic-, mitochondrial-, and steroid hormone signaling-associated gene clusters whose expression patterns are sensitive to acute pair bond disruption and loss adaptation. Together, our results suggest that partner separation results in erosion of transcriptomic signatures of pair bonding despite core behavioral features of the bond remaining intact, revealing potential molecular processes central to priming a vole to be able to form a new bond.

Download Full-text

What makes a pair bond in a Neotropical primate: female and male contributions

Royal Society Open Science ◽

10.1098/rsos.191489 ◽

2020 ◽

Vol 7 (1) ◽

pp. 191489 ◽

Cited By ~ 4

Author(s):

Sofya Dolotovskaya ◽

Sarah Walker ◽

Eckhard W. Heymann

Keyword(s):

Pair Bond ◽

The Other ◽

Pair Bonding ◽

Neotropical Primate ◽

Other Hand ◽

Pair Bonds ◽

Titi Monkeys ◽

Male Care ◽

Intergroup Encounters ◽

Peruvian Amazonia

Pair living and pair bonding are rare in mammals, and the mechanisms of their maintenance remain a puzzle. Titi monkeys, a ‘textbook example’ for ‘monogamous’ primates, have strong pair bonds and extensive male care. To investigate mechanisms of pair-bond maintenance, we studied seven wild groups of red titis ( Plecturocebus cupreus ) in Peruvian Amazonia over a period of 14 months. We analysed pair bonds by measuring proximity, grooming and approaches/leaves within pairs, and collected data on intergroup encounters. Females contributed to grooming more than males, especially during infant dependency, when most of the grooming within pairs was done by females. Females were also more active in controlling proximity between pair mates, making most of the approaches and leaves. Males, on the other hand, invested more in territorial defences. They participated in more intergroup encounters than females and were more active during these encounters. Our data is most consistent with the ‘male-services’ hypothesis for pair-bond maintenance, where a female contributes more to the proximity and affiliation maintenance while a male provides beneficial services.

Download Full-text

Sex differences in parental response to offspring begging are associated with pair bond strength across birds

10.1101/2021.10.14.464423 ◽

2021 ◽

Author(s):

Shana M Caro ◽

Karleen Wu ◽

Hans A Hofmann

Keyword(s):

Sex Differences ◽

Bond Strength ◽

Meta Analysis ◽

Bird Species ◽

Pair Bond ◽

Strongly Correlated ◽

Costs And Benefits ◽

Burden Of Care ◽

Parental Response ◽

Pair Bonds

Mothers, fathers, and offspring regularly clash over how much care offspring receive. Offspring beg to solicit for more resources--but how much begging is rewarded can depend on who is listening. While both parents benefit from provisioning offspring, each would benefit from their partner shouldering more of the burden of care, leading to sexual conflict. Additionally, if the costs and benefits of provisioning differ by sex, parent-offspring conflict should vary by sex. How these evolutionary conflicts influence sex differences in parent-offspring communication is unknown. To determine whether the sexes differ in their response to offspring signals, we conducted a meta-analysis on 30 bird species, comparing responsiveness to social and physiological traits affecting conflict. We found that a species' typical pair bond strength predicts whether males or females respond more to offspring begging. In species with stable and/or monogamous bonds, and thus lower sexual and paternal-offspring conflict, males' provisioning effort is more strongly correlated with offspring begging than females'. The opposite holds for species with weak pair bonds: females respond more to begging, perhaps compensating for males' lower responsiveness. These results demonstrate that sex differences in parental care can arise via sex differences in parent-offspring communication, driven by evolutionary conflicts.

Download Full-text

Promiscuity in an evolved pair-bonding system: Mating within and outside the Pleistocene box

Behavioral and Brain Sciences ◽

10.1017/s0140525x05370051 ◽

2005 ◽

Vol 28 (2) ◽

pp. 290-291 ◽

Cited By ~ 8

Author(s):

Lynn Carol Miller ◽

William C. Pedersen ◽

Anila Putcha-Bhagavatula

Keyword(s):

Pair Bonding ◽

Hunter Gatherers ◽

Early Menarche ◽

Bonding System ◽

Pair Bonds ◽

Bonding Mechanisms ◽

Similar Pair

Across mammals, when fathers matter, as they did for hunter-gatherers, sex-similar pair-bonding mechanisms evolve. Attachment fertility theory can explain Schmitt's and other findings as resulting from a system of mechanisms affording pair-bonding in which promiscuous seeking is part. Departures from hunter-gatherer environments (e.g., early menarche, delayed marriage) can alter dating trajectories, thereby impacting mating outside of pair-bonds.

Download Full-text

Comparison of Shear Bond Strength and Microleakage of Various Bulk-fill Bioactive Dentin substitutes: An in vitro Study

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-1970 ◽

2016 ◽

Vol 17 (12) ◽

pp. 997-1002 ◽

Cited By ~ 6

Author(s):

Fahad I Alkhudhairy ◽

Zeeshan H Ahmad

Keyword(s):

Bond Strength ◽

Shear Bond Strength ◽

Physical And Mechanical Properties ◽

Pairwise Comparison ◽

In Vitro Study ◽

Composite Resins ◽

Intergroup Comparison ◽

Significant Difference ◽

Tukey Honestly Significant Difference

ABSTRACT Introduction Various bulk-fill materials depending on their composition, viscosity, and flow ability have different physical and mechanical properties. The aim of this in vitro study was to determine and compare the shear bond strength and microleakage properties of activa restorative with other bulk-fill restorative materials surefil (SDR), Biodentine, ever X posterior. Materials and methods Forty permanent premolars were selected for shear bond strength, and 20 permanent premolars were selected with class II cavities on mesial and distal side for microleakage. Universal testing device was used to assess the shear bond strength. Microleakage was checked using dye penetration method under a stereomicroscope. Mean and standard deviation values were calculated from the recorded values. Intergroup comparison was done by one-way analysis of variance (ANOVA) followed by pairwise comparison using Tukey honestly significant difference (HSD) post hoc test. Results The mean shear bond strength was highest for SDR surefil followed by Ever X posterior, Bioactive restorative, and Biodentine respectively. In this study, SDR (surefil) showed better shear bond strength and better microleakage properties compared with the other test materials (F = 186.7157, p < 0.05). Conclusion The result of this study showed that flowable and fiber-reinforced composites have better shear bond strength and microleakage properties. Clinical significance Flowable bulk-fill composite resins can be used as dentin substitutes because of its superior properties. How to cite this article Alkhudhairy FI, Ahmad ZH. Comparison of Shear Bond Strength and Microleakage of Various Bulk-fill Bioactive Dentin substitutes: An in vitro study. J Contemp Dent Pract 2016;17(12):997-1002.

Download Full-text

Behavioral and Endocrine Alterations to Partner Interactions and Offspring Care during Periods of Conflict

Integrative Organismal Biology ◽

10.1093/iob/obaa002 ◽

2020 ◽

Vol 2 (1) ◽

Author(s):

Timothy Paciorek ◽

Leese Joseph

Keyword(s):

Pair Bond ◽

Biparental Care ◽

Resident Male ◽

Male And Female ◽

Pair Bonds ◽

Convict Cichlids ◽

Before And After ◽

Males And Females ◽

Cortisol Levels ◽

Endocrine Alterations

Abstract Biparental care has evolved to ensure successful rearing of offspring. However, separation during periods of care can lead to conflicts that might negatively impact pair bonds and offspring care. In this study, pair-bonded convict cichlids (Amatitlania nigrofasciata) were observed for changes in behavior toward their partners and offspring before and after a period of separation. Males and females were designated either as a Resident (remain with offspring) or Removed (separated from partner and offspring for 5 days) individual. Behaviors between partners and toward offspring were measured before and after separation, and compared to the levels of behavior of control pairs (never separated), as well as individuals introduced to a novel partner instead. Cortisol levels of Resident male and female A. nigrofasciata were assayed using water-borne hormone collection before and after separation. Aggression between pair bond members did increase following reintroduction, but did not lead to the termination of pair bonds. Resident females showed more aggression to novel partners than Resident males. Offspring care decreased in both Resident and Removed females. Experimental pairs decreased the amount of time spent interacting with intruders. Cortisol levels were significantly higher among experimental pairs compared with control pairs that did not experience a separation. Females (both control and experimental) showed small, yet significant increases in cortisol levels, while both control and experimental males did not. These results suggest that while pair bonds appear resilient, prolonged separations influence pair bond and parental care dynamics, both behaviorally and hormonally, and require pairs to re-establish roles, resulting in less time caring for offspring.

Download Full-text

Interpersonal Neural Synchronization during Interpersonal Touch Underlies Affiliative Pair Bonding between Romantic Couples

Cerebral Cortex ◽

10.1093/cercor/bhaa316 ◽

2020 ◽

Author(s):

Yuhang Long ◽

Lifen Zheng ◽

Hui Zhao ◽

Siyuan Zhou ◽

Yu Zhai ◽

...

Keyword(s):

Near Infrared ◽

Vocal Communication ◽

Romantic Love ◽

Pair Bonding ◽

Romantic Couples ◽

Functional Near Infrared Spectroscopy ◽

Neural Synchronization ◽

Interpersonal Touch ◽

Pair Bonds ◽

Opposite Sex

Abstract Interpersonal touch plays a key role in creating and maintaining affiliative pair bonds in romantic love. However, the neurocognitive mechanism of interpersonal touch in affiliative pair bonding remains unclear. Here, we hypothesized that interpersonal neural synchronization (INS) during interpersonal touch underlies affiliative pair bonding between romantic couples. To test this hypothesis, INS between heterosexual romantic couples and between opposite-sex friends was measured using functional near-infrared spectroscopy-based hyperscanning, while the pairs of participants touched or vocally communicated with each other. The results showed significantly greater INS between the mentalizing and sensorimotor neural systems of two members of a pair during interpersonal touch than during vocal communication between romantic couples but not between friends. Moreover, touch-induced INS was significantly correlated with the self-reported strength of romantic love. Finally, the results also showed that men’s empathy positively modulated the association between touch-induced INS increase and the strength of romantic love. These findings support the idea that INS during interpersonal touch underlies affiliative pair bonding between romantic couples and suggest that empathy plays a modulatory role in the neurocognitive mechanism of interpersonal touch in affiliative pair bonding.

Download Full-text

Effects of Mating and Social Exposure on Cell Proliferation in the Adult Male Prairie Vole (Microtus ochrogaster)

Neural Plasticity ◽

10.1155/2020/8869669 ◽

2020 ◽

Vol 2020 ◽

pp. 1-14

Author(s):

A. E. Castro ◽

L. J. Young ◽

F. J. Camacho ◽

R. G. Paredes ◽

N. F. Diaz ◽

...

Keyword(s):

Cell Proliferation ◽

Social Interaction ◽

Bond Formation ◽

Precursor Cells ◽

Pair Bond ◽

Microtus Ochrogaster ◽

Physical Contact ◽

Pair Bonding ◽

Social Exposure ◽

Neuron Precursor

Microtus ochrogaster is a rodent with a monogamous reproductive strategy characterized by strong pair bond formation after 6 h of mating. Here, we determine whether mating-induced pair bonding increases cell proliferation in the subventricular zone (SVZ), rostral migratory stream (RMS), and dentate gyrus (DG) of the hippocampus in male voles. Males were assigned to one of the four groups: (1) control: males were placed alone in a clean cage; (2) social exposure to a female (SE m/f): males that could see, hear, and smell a sexually receptive female but where physical contact was not possible, because the animals were separated by an acrylic screen with small holes; (3) social exposure to a male (SE m/m): same as group 2 but males were exposed to another male without physical contact; and (4) social cohabitation with mating (SCM): males that mated freely with a receptive female for 6 h. This procedure leads to pair bond formation. Groups 2 and 3 were controls for social interaction. Male prairie voles were injected with 5-bromo-2′-deoxyuridine (BrdU) during the behavioral tests and were sacrificed 48 h later. Brains were processed to identify the new cells (BrdU-positive) and neuron precursor cells (neuroblasts). Our principal findings are that in the dorsal region of the SVZ, SCM and SE m/f and m/m increase the percentage of neuron precursor cells. In the anterior region of the RMS, SE m/f decreases the percentage of neuron precursor cells, and in the medial region SE m/f and m/m decrease the number of new cells and neuron precursor cells. In the infrapyramidal blade of the subgranular zone of the DG, SE m/m and SCM increase the number of new neuron precursor cells and SE m/m increases the percentage of these neurons. Our data suggests that social interaction, as well as sexual stimulation, leads to pair bonding in male voles modulating cell proliferation and differentiation to neuronal precursor cells at the SVZ, RMS, and DG.

Download Full-text

Evolution of male strategies with sex-ratio–dependent pay-offs: connecting pair bonds with grandmothering

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2017.0041 ◽

2017 ◽

Vol 372 (1729) ◽

pp. 20170041 ◽

Cited By ~ 10

Author(s):

Sara L. Loo ◽

Kristen Hawkes ◽

Peter S. Kim

Keyword(s):

Life History ◽

Sex Ratio ◽

Human Evolution ◽

Paternal Care ◽

Multiple Mating ◽

Sex Ratios ◽

Mate Guarding ◽

Equation Model ◽

Pair Bonding ◽

Pair Bonds

Men's provisioning of mates and offspring has been central to ideas about human evolution because paternal provisioning is absent in our closest evolutionary cousins, the great apes, and is widely assumed to result in pair bonding, which distinguishes us from them. Yet mathematical modelling has shown that paternal care does not readily spread in populations where competition for multiple mates is the common male strategy. Here we add to models that point to the mating sex ratio as an explanation for pairing as pay-offs to mate guarding rise with a male-biased sex ratio. This is of interest for human evolution because our grandmothering life history shifts the mating sex ratio from female- to male-biased. Using a difference equation model, we explore the relative pay-offs for three competing male strategies (dependant care, multiple mating, mate guarding) in response to changing adult sex ratios. When fertile females are abundant, multiple mating prevails. As they become scarce, mate guarding triumphs. The threshold for this shift depends on guarding efficiency. Combined with mating sex ratios of hunter–gatherer and chimpanzee populations, these results strengthen the hypothesis that the evolution of our grandmothering life history propelled the shift to pair bonding in the human lineage. This article is part of the themed issue ‘Adult sex ratios and reproductive decisions: a critical re-examination of sex differences in human and animal societies’.

Download Full-text