Artificial ornaments manipulate intrinsic male quality in wild-caught zebra finches (Taeniopygia guttata)

The addition of red and green color bands is a commonly used method for manipulating male attractiveness in the zebra finch (Taeniopygia guttata), providing insight into the study of maternal investment and sexual selection. The addition of artificial ornaments has been assumed to manipulate a females’ perception of the male, rather than affecting intrinsic qualities of the male himself. Here, however, we reveal that the artificial band color worn by a male changes his body mass, condition, and courtship display rate. Males wearing red color bands in aviaries prior to mate-choice trials had a significantly higher song rate during trials than those wearing green color bands, alongside a significant increase in mass change and condition. Male song rate was found to significantly correlate with female preference alongside a female preference for red-banded males. However, male song rate in turn increased when female response was positive, suggesting a social feedback between the interacting birds. Our data suggest the presence of socially mediated feedback mechanisms whereby the artificial increase in attractiveness or dominance of a male directly affects other aspects of his attractiveness. Therefore, housing birds in social groups while manipulating attractiveness can directly influence other male qualities and should be accounted for by future studies.

Retracted: Experimental evidence that maternal corticosterone controls adaptive offspring sex ratios

1. Sex allocation theory has received considerable attention, yet the mechanism(s) by which mothers skew offspring sex ratios remain unknown. In birds, females are the heterogametic sex, which potentially gives them control of whether gametes will be male or female. How females might control the sex of the gamete is unclear, but one possibility is that variation in steroid hormones may mediate this process. 2. We experimentally altered circulating levels of corticosterone in female Gouldian finches (Erythrura gouldiae), a species that demonstrates both extreme stress responses and extreme offspring sex ratio biases when breeding with a low-quality (genetically incompatible) partner. 3. During egg production, individual females received both corticosterone and metyrapone (a corticosterone-synthesis inhibitor) implants, in random order, to induce both high and low levels of circulating stress hormones (within physiological limits). 4. We found that females with elevated corticosterone levels produced male-biased sex ratios, but when the same females were treated with metyrapone they produced female-biased offspring sex ratios. 5. These stress responses are adaptive because females constrained to breeding with low-quality males can substantially increase their fitness by overproducing sons. Changes in maternal corticosterone levels during stressful situations, such as the quality of a breeding partner, may provide an endocrine mechanism that can be exploited for strategic sex allocation.

Female body condition affects foetal growth in a capital breeding mysticete

1.Sex allocation theory has received considerable attention, yet the mechanism(s) by which mothers skew offspring sex ratios remain unknown. In birds, females are the heterogametic sex, which potentially gives them control of whether gametes will be male or female. How females might control the sex of the gamete is unclear, but one possibility is that variation in steroid hormones may mediate this process. 2.We experimentally altered circulating levels of corticosterone in female Gouldian finches (Erythrura gouldiae), a species that demonstrates both extreme stress responses and extreme offspring sex ratio biases when breeding with a low-quality (genetically incompatible) partner. 3.During egg production, individual females received both corticosterone and metyrapone (a corticosterone-synthesis inhibitor) implants, in random order, to induce both high and low levels of circulating stress hormones (within physiological limits). 4.We found that females with elevated corticosterone levels produced male-biased sex ratios, but when the same females were treated with metyrapone they produced female-biased offspring sex ratios. 5.These stress responses are adaptive because females constrained to breeding with low-quality males can substantially increase their fitness by overproducing sons. Changes in maternal corticosterone levels during stressful situations, such as the quality of a breeding partner, may provide an endocrine mechanism that can be exploited for strategic sex allocation.

Causes of male sexual trait divergence in introduced populations of guppies

Males from different populations of the same species often differ in their sexually selected traits. Variation in sexually selected traits can be attributed to sexual selection if phenotypic divergence matches the direction of sexual selection gradients among populations. However, phenotypic divergence of sexually selected traits may also be influenced by other factors, such as natural selection and genetic constraints. Here, we document differences in male sexual traits among six introduced Australian populations of guppies and untangle the forces driving divergence in these sexually selected traits. Using an experimental approach, we found that male size, area of orange coloration, number of sperm per ejaculate and linear sexual selection gradients for male traits differed among populations. Within populations, a large mismatch between the direction of selection and male traits suggests that constraints may be important in preventing male traits from evolving in the direction of selection. Among populations, however, variation in sexual selection explained more than half of the differences in trait variation, suggesting that, despite within-population constraints, sexual selection has contributed to population divergence of male traits. Differences in sexual traits were also associated with predation risk and neutral genetic distance. Our study highlights the importance of sexual selection in trait divergence in introduced populations, despite the presence of constraining factors such as predation risk and evolutionary history.

Auditor industry specialisation, service bundling and partner effects in a mining-dominated city

This study examines auditor industry specialisation effects in Perth, a remote mining town in Australia characterised by a large number of small, homogeneous firms. We consider the impact of leadership by the non-Big 4 auditor BDO Kendalls (BDO) for a sample of 371 mining development stage entities (MDSE's). After controlling for factors known to determine audit fees, we find no evidence of auditor industry leadership fee premiums accruing to (BDO), a result robust to a range of sensitivity tests including the broadening of tests Australia-wide. However, when the dependent variable is redefined to the total 'bundle' of services provided by the audit firm (including audit and non-audit fees), the industry leader is shown to earn a fee premium suggesting BDO uses audits as a conduit to supply higher margin non-audit services. Our findings suggest that strategic pricing by industry leaders may not be confined to Big 4 firms.

Alcohol, masculinity, honour and male barroom aggression in an Australian sample

Introduction and Aims
The link between alcohol and men's aggression is well established, although growing evidence also points to individual and learned social factors. The aim of the present study was to investigate the relationships between male alcohol-related aggression (MARA) among young Australian men and heavy episodic drinking, trait aggression, masculinity, concerns about social honour and expected positive consequences of MARA.

Design and Methods
The total sample comprised 170 men aged 18–25 years who completed an online questionnaire exploring beliefs and attitudes towards MARA.

Results
Those who reported heavy episodic drinking were more likely to be involved in an incident of MARA. In addition, those who were involved in MARA had higher levels of trait aggression, concern for social honour and expected positive consequences of aggression in bars than did those without such involvement. The relationship between socially constructed masculinity factors (a combined variable reflecting masculinity, social honour and expected positive consequences) and MARA was mediated by heavy episodic drinking. Social honour accounted for almost all of the predictive power of masculinity factors. Heavy episodic drinking and trait aggression remained significant predictors of MARA in a multivariate model.

Discussion and Conclusions
The findings from the current study may assist in developing preventative techniques for young men which target masculinity concerns and the consequences of participating in MARA.

Breaker Morant's split personality: Australian male identity through opposing eyes

Breaker Morant was born in a workhouse to a widow. In Australia, he attempted to overcome the stigma associated with the British workhouse system by creating an alternative identity as a gentleman, a soldier and an Australian poet, but he died as a criminal convicted for murdering captured Boers.

New rules, no rules, old rules or our rules : women designing mixed-orientation relationships with bisexual men

This chapter draws from an Australian semi-structured interview project with seventy-eight culturally, sexually and geographically diverse women, aged nineteen to sixty-five, who were in monogamous, open and polyamorous marital and de facto relationships with bisexual men, abbreviated as MOREs (mixed-orientation relationships).
For the purposes of this chapter, I will provide an overview of the shifting subjectivities, agency and resistance of those women and their male partners who stated that, without coercion or repression, they undertook processes of ‘designing’ their long-term MOREs.
I wiIl explore what every woman stated as being an essential component of consensually and creatively entering or being in a relationship with a bisexual man: designing, negotiating and maintaining some “ground rules” and “boundaries”.
There appear to be three overall groups of ‘rules’ within which specific ‘designs’ are created:
1. ‘Old Rules’: Monogamy is considered the only workable or desirable rule, and a partner’s inability to adhere to monogamy would mean the end of the relationship.
2. ‘New Rules’: A range of negotiations and design-specifications establish non-monogamous boundaries and operational strategies.
3. ‘Our Rules or His and Her Rules’: Decisions are made regarding to what extent the rules will be equitable to both, or there are separate regulations for each partner.

Patterns and perceptions of physical activity and sedentary time in male transport drivers working in regional Australia

 Abstract

Objective: To objectively measure physical activity (PA) patterns and sedentary time, and explore perceptions of workplace PA opportunities in regional male transport workers.

Methods: A multi-method study involving 28 drivers (52.4±9.69years) working at a bus company in South-East Queensland, Australia. PA was measured using accelerometers (n=23) to determine the proportion of time spent in sedentary (<150 cpm), light (151–2,689 cpm) and moderate+ (≥2,690 cpm) intensity categories. Paired sample t-tests were used to evaluate differences between categories on a workday/off-workday (n=16), and during work/non-work time (n=15). Interviews were conducted with 28 drivers and six managers to explore perceptions and ideas relating to workplace PA opportunities.

Results: Sedentary time was significantly higher on off-work (64% of wear time) than work (52%) days (p<0.05), while the opposite was the case for light intensity time (off-workday=33%; workday=44%; p<0.05). On workdays, sedentary time was significantly lower when employees were working (44%) than when not working (60%; p<0.05). No significant differences were found for time spent in moderate+ PA. Driver perceptions indicated that PA opportunities (walking club and corporate gym membership) were being adopted by some drivers. However, at this depot, perceived health issues and organisational barriers (shift work and irregular driving routines), tended to preclude some drivers from engaging with these opportunities.

Conclusions: Findings contest the notion that a sedentary occupation such as driving necessitates an inactive work environment.

Implications: This research informs ongoing intervention efforts to target inactive drivers who are struggling to take advantage of existing workplace-related PA opportunities.