Female song in the Cyprus Wheatear Oenanthe cypriaca

Female song is widespread across bird species yet rarely reported. Here, we report the first observations and description of female song in the Cyprus Wheatear Oenanthe cypriaca and compare it to male song through the breeding season. Twenty-five percent of colour-ringed females were observed singing at least once, predominantly in April, compared to 71% of males that continued singing through the breeding period. We suggest that female song may have multiple functions in this species, but it may be especially important in territorial defence and mate acquisition.

Fundamental Motives Illuminate a Broad Range of Individual and Cultural Variations in Thought and Behavior

An article published in Current Directions a decade ago introduced the fundamental-motives framework and reviewed initial promising findings using this general approach. According to this framework, a recurring set of challenges and opportunities during human evolution gave rise to overarching motivational systems in the domains of self-protection, disease avoidance, social affiliation, status seeking, mate acquisition, mate retention, and kin care. When activated, fundamental motives influence psychological processes by directing cognition and behavior in distinct and functionally relevant ways. In the intervening years, the approach has been expanded to a broader range of motives, individual and cultural variations in those motives, and the physiological correlates of activating different motives. In this article, we review a decade of research applying the fundamental-motives framework and point to promising new research directions.

Family Still Matters: Human Social Motivation during a Global Pandemic

How have people’s fundamental social motives changed during the COVID-19 pandemic? In data collected from 32 countries before the onset of the pandemic, we saw that a) people prioritized family-related motives (romantic relationship maintenance and kin care) over mate-acquisition motives (mate-seeking and breakup concern), and b) family-related motives were positively associated, whereas mate-acquisition motives were negatively associated, with subjective well-being (Ko et al., 2020). The pandemic involved massive changes in social arrangements – separation from friends and coworkers, and often enforced close contact with immediate family members. Did those changes in people’s social lives affect the relative priority of family-related motives and their relationship with well-being? Data collected from 28 countries during the pandemic shows that people’s disease avoidance motivation has increased as expected, but a) the relative prioritization of family-related motives over mate-acquisition motives remains unchanged, and b) family-related motives remain positively associated with well-being and mate-acquisition motives remain negatively associated. Given that human beings have, throughout history, relied on family bonds during recurring social upheavals, sometimes caused by infectious diseases, it may be unsurprising that the powerful motivations associated with family relationships have persisted even in the face of this historically unique disruption.

Do Females in a Unisexual-Bisexual Species Complex Differ in Their Behavioral Syndromes and Cortisol Production?

Studies of suites of correlated behavioral traits (i.e., behavioral syndromes) aid in understanding the adaptive importance of behavioral evolution. Behavioral syndromes may be evolutionarily constrained, preventing behaviors from evolving independently, or they may be an adaptive result of selection on the correlation itself. We tested these hypotheses by characterizing the behavioral syndromes in two sympatric, closely related species and testing for differences between the species. We studied the unisexual Amazon molly (Poecilia formosa) and one of its bisexual, parent species, the sailfin molly (P. latipinna). Sympatric female sailfin and Amazon mollies compete for mating which could affect the behavioral syndromes found in each species. We identified a behavioral syndrome between exploration and activity in both species that did not differ between species. Additionally, we explored the relationship between a stress response hormone, cortisol, and behavioral type, and did not detect a relationship. However, P. formosa differed from P. latipinna in their cortisol release rates. Behavioral syndromes may be constrained in this complex, aiding in mate acquisition for P. formosa by virtue of having a similar behavioral type to P. latipinna. The difference between the females in cortisol release rates may be a useful mate identification cue for males to offset higher mating mistakes associated with the similar behavioral types.

Conceptual developments in sperm competition: a very brief synopsis

The past half century has seen the development of the field of post-ejaculatory sexual selection, the sequel to sexual selection for mate-acquisition (pre-ejaculatory) described by Darwin. In richness and diversity of adaptations, post-ejaculatory selection rivals that of pre-ejaculatory sexual selection. Anisogamy—and hence two sexes—likely arose by primeval gamete competition, and sperm competition remains a major force maintaining high sperm numbers. The post-ejaculatory equivalent of male–male competition for matings, sperm competition was an intense ancestral form of sexual selection, typically weakening as mobility and internal fertilization developed in many taxa, when some expenditure became diverted into pre-ejaculatory competition. Sperm competition theory has been relatively successful in explaining variation in relative testes size and sperm numbers per ejaculate and is becoming more successful in explaining variation in sperm phenotype. Sperm competition has generated many other male adaptations such as seminal fluid proteins that variously modify female reproduction towards male interests, and copulatory plugs, prolonged copulations and post-ejaculatory guarding behaviour that reduce female remating probability, many of which result in sexual conflict. This short survey of conceptual developments is intended as a broad overview, mainly as a primer for new researchers. This article is part of the theme issue ‘Fifty years of sperm competition'.

Mating pattern, duration and multiple mating in Chondromorpha severini Silvestri (Diplopoda: Polydesmida)

Mating behaviour of Chondromorpha severini, a polydesmid millipede was studied in the field and in the laboratory condition. Copulating pair follows the general rule of love play before actual act of coitus. Mating duration varied from one to 25 minute with an average of eight minute. Mating frequency was maximum in early and late hours of day. In the multiple mate preference experiment, 10 pairs of male and female were used to calculate preference index (Pi) of individual sex. Preference index varies from 0.65 to 0.91. The implication of multiple mating has been discussed in detail. The study confirmed that i) the species belongs to polygynandrous mating system where males are the pursuers and females are the accomplishers ii) short and long duration mating is related to mate acquisition and mate guarding respectively

Relations between self-esteem dimensions and fundamental social motives

The article presents the concept of fundamental social motives, which is novel for Polish readers, and its relations with self-esteem. The studies conducted so far suggest that there may be significant correlations between various dimensions of self-esteem and fundamental motives focused on interpersonal relations (affiliation motives and mate acquisition/retention motives). Data was collected from a sample of N = 363 subjects in order to find predictors for the level and stability of self-esteem. The results include correlations between 11 scales measuring fundamental motives and self-esteem dimensions: its level and instability. Multiple regression analyses with self-esteem measures as explained variables and motives related to sociometer theory as explanatory variables were also conducted. The article presents a detailed discussion of regression analysis results for male and female samples. Limitations and future research directions are also discussed.

Do metrics of sexual selection conform to Bateman's principles in a wind-pollinated plant?

Bateman's principles posit that male fitness varies more, and relies more on mate acquisition, than female fitness. While Bateman's principles should apply to any organism producing gametes of variable sizes, their application to plants is potentially complicated by the high levels of polyandry suspected for plants, and by variation in the spatial distribution of prospective mates. Here we quantify the intensity of sexual selection by classical Bateman metrics using two common gardens of the wind-pollinated dioecious plant Mercurialis annua . Consistent with Bateman's principles, males displayed significantly positive Bateman gradients (a regression of fitness on mate number), whereas the reproductive success of females was independent of their ability to access mates. A large part of male fitness was explained by their mate number, which in turn was associated with males' abilities to disperse pollen. Our results suggest that sexual selection can act in plant species in much the same way as in many animals, increasing the number of mates through traits that promote pollen dispersal.

5. Sexual selection after mating

Darwin viewed sexual selection as a process that ended with mate acquisition, assuming that females are fundamentally monogamous, mating with just one male. ‘Sexual selection after mating’, however, shows this assumption to be false. Sexual selection continues long after the physical act of mating is over, as sperm compete inside a female’s reproductive tract and females bias the paternity of their young by selectively using sperm from particular males. Multiple mating by females has turned out to be ubiquitous across animal taxa. The far-reaching evolutionary consequences of sperm competition and cryptic female choice for the evolution of reproductive traits are examined, from the gametes themselves to the adult organisms producing them.