Responses of Australian wading birds to a novel toxic prey type, the invasive cane toad Rhinella marina

The impact of invasive predators on native prey has attracted considerable scientific attention, whereas the reverse situation (invasive species being eaten by native predators) has been less frequently studied. Such interactions might affect invasion success; an invader that is readily consumed by native species may be less likely to flourish in its new range than one that is ignored by those taxa. Invasive cane toads (Rhinella marina) in Australia have fatally poisoned many native predators (e.g., marsupials, crocodiles, lizards) that attempt to ingest the toxic anurans, but birds are more resistant to toad toxins. We quantified prey preferences of four species of wading birds (Nankeen night heron, purple swamphen, pied heron, little egret) in the wild, by offering cane toads and alternative native prey items (total of 279 trays offered, 14 different combinations of prey types). All bird species tested preferred the native prey, avoiding both tadpole and metamorph cane toads. Avoidance of toads was strong enough to reduce foraging on native prey presented in combination with the toads, suggesting that the presence of cane toads could affect predator foraging tactics, and reduce the intensity of predation on native prey species found in association with toads.

Does the rate of foraging attempts predict ingestion rate for young-of-the-year brook trout (Salvelinus fontinalis) in the field?

To assess the costs and benefits of young fish adopting different behavioural tactics, field studies of juvenile salmonines have assumed that (but did not test whether) the rate of foraging attempts predicts ingestion rate. We tested this assumption by quantifying capture, ingestion, and rejection rates of potential prey items for individual young-of-the-year brook trout (Salvelinus fontinalis) in a lake. Overall, capture rate (a conservative estimate of the rate of foraging attempts) was only a fair predictor of overall ingestion rate (Kendall's 1 = 0.54) and only 46% of captured items (number/minute) were ingested. Surface capture rate was a poor predictor of surface ingestion rate (T = 0.27) and only 1% of captured items were ingested. In contrast, subsurface capture rate was an excellent predictor of subsurface ingestion rate (T = 0.75) and 93% of captured items were ingested. No benthic prey captures were observed. Fish that ingested a low proportion of captured items spent a greater proportion of time moving, moved faster, and pursued prey further than fish that ingested a higher proportion of captured items. Rejection of captured items can represent a significant and little appreciated component of the foraging cycle for young salmonid fishes.

The central-place territorial model does not apply to space-use by juvenile brook charr Salvelinus fontinalis in lakes

1. Territoriality is widely accepted as the mechanism responsible for density-dependent mortality, emigration, and 'self-thinning' of populations of juvenile salmonine fishes in streams. Numerous studies have focused on territoriality exclusively in stream (lotic) environments and thus have fostered a stereotyped view of juvenile salmonines as sedentary and territorial. We term this behavioural paradigm the central-place territorial model (CPTM).

2. We tested predictions characterizing the CPTM for young-of-the-year (YOY) brook charr (Salvelinus fontinalis) in two Canadian lakes to determine if territoriality may also potentially limit space and population size of brook charr in lakes.

3. Our findings were not consistent with the CPTM. Fish in both lakes were not central-place forages. Maximum displacement distance did not increase with body length as predicted by the general salmonine model of Grant and Kramer (1990). Net displacement distanced increased with the proportion of time spent moving. Aggressive frequency was greatest for fish which spent large proportions of time moving and did not defend from a central-place.

4. Fish in both lakes were rarely aggressive, highly active, and often moved back over the same areas. However, lake fish which migrated to a tributary stream had no net displacement (central-place foraging) illustrating the immediate effects of current on foraging tactics and space-use.

5. The effect of hydrodynamic environment (flowing vs. still water) on fish behaviour needs to be explicitly considered in future models of salmonine behaviour.

Social and professional participation of individuals who are deaf : utilizing the psychosocial potential maximization framework

This article documents a strength-based understanding of how individuals who are deaf maximize their social and professional potential. This exploratory study was conducted with 49 adult participants who are deaf (n ¼ 30) and who have typical hearing (n ¼ 19) residing in America, Australia, England, and South Africa. The findings support a systematic and comprehensive framework of proactive psychosocial attributes and tactics. Statistical analysis showed no significant differences between the groups across four variables of psychosocial competencies. Qualitative data further suggests that participants who are deaf maximize their potential using two types of proactive psychosocial attributes and tactics: 1) skills that individuals with typical hearing use and 2) specialized skills for identifying, circumventing, or mastering deafness-related difficulties. These findings contribute to understandings of how individuals who are deaf can achieve social and professional success.

Harm reduction as anarchist practice : a user’s guide to capitalism and addiction in North America

In spite of its origins as an illegal, clandestine, grassroots activity that took place either outside or in defiant opposition to state and legal authority, there is growing evidence to suggest that harm reduction in North America has become sanitized and depoliticized in its institutionalization as public health policy. Harm reduction remains the most contested and controversial aspect of drug policy on both sides of the Canada–US border, yet the institutionalization of harm reduction in each national context demonstrates a series of stark contrasts. Drawing from regional case study examples in Canada and the US, this article historically traces and politically re-maps the uneasy relationship between the autonomous political origins of harm reduction, contemporary public health policy, and the adoption of the biomedical model for addiction research and treatment in North America. Situated within a broader theoretical interrogation of the etiology of addiction, this study culminates in a politically engaged critique of traditional addiction research and drug/service user autonomy. Arguing that the founding philosophy and spirit of the harm reduction movement represents a fundamentally anarchist-inspired form of practice, this article concludes by considering tactics for reclaiming and re-politicizing the future of harm reduction in North America.

Strategies for agent-based negotiation in e-trade

£-negotiation handles negotiation over the Internet without human supervision and has shown effectiveness in concluding verifiable and more favorable agreements in a reasonably short time. In this chapter, the authors discuss the negotiation 5ystem and its components with particular emphasis on negotiation strategies. A negotiation strategy defines strategic tactics, which advise on the proper action to select from a set of possible actions that optimizes negotiation outcomes. A strategy should integrate negotiation goals and reactive attitudes. Usually, a fixed strategy is implemented during the course of negotiation regardless ofsignificant decision-makingfactors including market status, opponent :S profile, or eagerness for a negotiated goods/service. The chapter presents the main negotiation strategies and outlines the different decision-makingfactors that should be considered. A strategy uses a utility function to evaluate the offer of an opponent and advises on the generation of a counter offer or the best interaction. The authors finally discuss different utility functions presented in the literature.

Testing dynamic variance-sensitive foraging using individual differences in basal metabolic rates of zebra finches

Social foragers can alternate between searching for food (producer tactic), and searching for other individuals that have located food in order to join them (scrounger tactic). Both tactics yield equal rewards on average, but the rewards generated by producer are more variable. A dynamic variance-sensitive foraging model predicts that social foragers should increase their use of scrounger with increasing energy requirements and/or decreased food availability early in the foraging period. We tested whether natural variation in minimum energy requirements (basal metabolic rate or BMR) is associated with differences in the use of producer–scrounger foraging tactics in female zebra finches Taeniopygia guttata. As predicted by the dynamic variance-sensitive model, high BMR individuals had significantly greater use of the scrounger tactic compared with low BMR individuals. However, we observed no effect of food availability on tactic use, indicating that female zebra finches were not variance-sensitive foragers under our experimental conditions. This study is the first to report that variation in BMR within a species is associated with differences in foraging behaviour. BMR-related differences in scrounger tactic use are consistent with phenotype-dependent tactic use decisions. We suggest that BMR is correlated with another phenotypic trait which itself influences tactic use decisions.

The elimination race in track cycling : patterns and predictors of performance

The track cycling Omnium is a multi-event competition that has recently been expanded to include the Elimination Race (ER), which presents a unique set of physical and tactical demands. The purpose of this research was to characterise the performance attributes of successful and unsuccessful cyclists in the ER, that are also predictive of performance. Video recordings of four international level ERs were analysed. The performance attributes measured related to the cyclists’ velocity and two dimensional position in the peloton. The average velocity of the peloton up to lap 30 (of 50) was relatively high and consistent (52.2±1.5 km/h). After lap 30, there was a significant (p<0.001) change in velocity (49.9±2.4 km/h), characterised by more fluctuations in lap-to-lap velocity. Successful ER cyclists adopted a tactic of remaining in the middle of the peloton, in the lower lanes of the velodrome, thus avoiding the risk of elimination at the rear and the extra effort required to remain on the front of the peloton. Unsuccessful cyclists tended to reside in the rear and upper (higher) portions of the peloton, risking elimination more often and having to ride faster than those in the lower lanes of the velodrome. The physiological demands of the Elimination Race that are determined by velocity, vary throughout the Elimination Race and the pattern of movement within the peloton is different for successful and unsuccessful cyclists. The findings of the present study may confirm some aspects of race tactics that are currently thought to be optimal, but they also reveal novel information that is useful to coaches and cyclists who compete in the Elimination Race.

Australasia

Public relations (PR) in Australia has strong governmental roots from the 19th century, and it expanded along this route until the end of World War II when influences from the  US and then globalization led to expansion in practice, PR organizations and education. The vast distances in Australia between colonies and later, States of the federation, reinforced state and national governments’ roles in applying public information-style communication to reach the widespread population. This development was not in imitation of British models but of the need to inform convince and persuade the widely spread population.' Some scholars trace the development of New Zealand's public relations industry to the wartime and post-war efforts of military personnel. However, the use of strategies and tactics that are now recognized as part of a PR 'toolkit' occurred much earlier. They can be traced back to indigenous Maori culture and to the promotional techniques used in the mid-19th century to attract settlers to the new colony. Post-war. Public relations has developed along Anglo- merican lines with an emphasis on media relations and corporate communications.  

Home space : youth identification in the Greek diaspora

This article draws on a larger study on schooling and diaspora using the case of the Greek community of Melbourne, Australia to examine processes of identification of young people with access to minority cultures. The Melbourne Greek community is long-standing, diverse, and well-established. Because of this, the young people involved in this study provide insights into cultural processes not related in any direct sense to migration. In most cases, it was their grandparents or great-grandparents who migrated. Many have 1 parent with no ancestral link to Greece. In this context, the motivations for and ways of expressing Greekness have the potential to illustrate identification as ambivalent. This article explores the centrality of “home” in these young people's representations of self. Following de Certeau, the argument is made that their everyday experience can be interpreted as an act of “anti-discipline.” As “users” of the Greekness, they are bequeathed through family, community, and schooling; and they use “tactics” of cultural redeployment that allow creative resistance and reinterpretation of both “Greekness” and “Australianness.”

Activism, reflection and Paulo Freire – an embodied pedagogy

This paper explores the critical pedagogy of activists as they participate in activism on some of the most important human rights issues of our time. I argue the pedagogy of activism is critically cognitive and embodied in a practice that is inherently social. The paper commences with some writing on what I claim is Freire’s own activism, always working towards a struggle for social justice and social change. His educational practices were never removed from sites and movements of struggle and resistance and he encouraged teachers to be political, that their teaching should never be disassociated from a critique of the political and social realities that impact on and create impediments to a democratic education.The paper then outlines empirical research on the learning dimensions of activists conducted in Australia and draws on some of the personal narratives of activists. I explore the reflexivity of activists as they work within and against the state, on issues of indigenous self-determination, racism, religion, homophobia, urban development, climate change, civil liberties, economic inequality and others. I argue for a critically reflexive pedagogy, as Paulo Freire reminds us, activism without purposeful reflection has the potential to become what he termed “naïve activism’’. That is, a focus on the theory and philosophical underpinnings of activism, and the tactics and strategies necessary to instigate social change, can create a pedagogy that is wanting in praxis. Yet the urgency of activism and the desire for significant social change often prevents a critical space for reflection to occur.The paper concludes with some suggestions for how Freire’s writing on praxis, can improve activists important practice.

The expression of pre- and postcopulatory sexually selected traits reflects levels of dietary stress in guppies

Environmental and ecological conditions can shape the evolution of life history traits in many animals. Among such factors, food or nutrition availability can play an important evolutionary role in moderating an animal's life history traits, particularly sexually selected traits. Here, we test whether diet quantity and/or composition in the form of omega-3 long chain polyunsaturated fatty acids (here termed 'n3LC') influence the expression of pre- and postcopulatory traits in the guppy (Poecilia reticulata), a livebearing poeciliid fish. We assigned males haphazardly to one of two experimental diets supplemented with n3LC, and each of these diet treatments was further divided into two diet 'quantity' treatments. Our experimental design therefore explored the main and interacting effects of two factors (n3LC content and diet quantity) on the expression of precopulatory (sexual behaviour and sexual ornamentation, including the size, number and spectral properties of colour spots) and postcopulatory (the velocity, viability, number and length of sperm) sexually selected traits. Our study revealed that diet quantity had significant effects on most of the pre- and postcopulatory traits, while n3LC manipulation had a significant effect on sperm traits and in particular on sperm viability. Our analyses also revealed interacting effects of diet quantity and n3LC levels on courtship displays, and the area of orange and iridescent colour spots in the males' colour patterns. We also confirmed that our dietary manipulations of n3LC resulted in the differential uptake of n3LC in body and testes tissues in the different n3LC groups. This study reveals the effects of diet quantity and n3LC on behavioural, ornamental and ejaculate traits in P. reticulata and underscores the likely role that diet plays in maintaining the high variability in these condition-dependent sexual traits.

Sex, androgens, and whole-organism performance in an Australian lizard

Understanding underlying physiological differences between the sexes in circulating androgens and how hormonal variation affects morphology-performance relationships may help clarify the evolution of sexual dimorphism in diverse taxa. Using a widely distributed Australian lizard (Eulamprus quoyii) with weak sexual dimorphism and no dichromatism, we tested whether circulating androgens differed between the sexes and whether they covaried with morphological and performance traits (bite force, sprint speed, endurance). Males had larger head dimensions, stronger bite force, faster sprint speed, and longer endurance compared to females. We found that the sexes did not differ in androgen concentrations and that androgens were weakly associated with both morphological and performance traits. Interestingly, high circulating androgens showed a nonlinear relationship with bite force in males and not females, with this relationship possibly being related to alternative male reproductive tactics. Our results suggest that androgens are not strongly correlated with most performance and morphological traits, although they may play an important organizational role during the development of morphological traits, which could explain the differences in morphology and thus performance between the sexes. Differences in performance between the sexes suggest differential selection on these functional traits between males and females. © 2014 The Linnean Society of London.