title: Environmental influences on Adelie penguin breeding schedules, endocrinology, and chick survival

authors: Ninnes, Calum Edward

subjects: Adelie penguin

abstract: To understand how the social and physical environment influences behaviour, reproduction and survival, studies of underlying hormonal processes are crucial; in particular, interactions between stress and reproductive responses may have critical influences on breeding schedules. Several authors have examined the timing of breeding in relation to environmental stimuli, while others have independently described endocrine profiles. However, few studies have simultaneously measured endocrine profiles, breeding behaviour, and offspring survival across seasons. We measured sex and stress hormone concentrations (oestrogens, testosterone, and corticosterone), timing of breeding, and chick survival, in Adelie penguins (Pygoscelis adeliae) at two colonies in two different years. Clutch initiation at Cape Bird South (CBS; year 1, 14,000 pairs) occurred later than at Cape Crozier East (CCE; year 2, 25,000 pairs); however, breeding was more synchronous at CBS. This pattern was probably generated by the persistence of extensive sea ice at CBS (year 1). Higher corticosterone metabolite and lower sex hormone concentrations at CBS correlated with later breeding and lower chick survival compared to at CCE – again, a likely consequence of sea ice conditions. Within colonies, sub-colony size (S, 50–100; M, 200–300; L, 500–600; XL, >1000 pairs) did not influence the onset or synchrony of breeding, chick survival, or hormone concentrations. We showed that the endocrine profiles of breeding Adelie penguins can differ markedly between years and/or colonies, and that combining measures of endocrinology, behaviour, and offspring survival can reveal the mechanisms and consequences that different environmental conditions can have on breeding ecology.

text: Environmental influences on Adelie penguin breeding schedules, endocrinology, and chick survival To understand how the social and physical environment influences behaviour, reproduction and survival, studies of underlying hormonal processes are crucial; in particular, interactions between stress and reproductive responses may have critical influences on breeding schedules. Several authors have examined the timing of breeding in relation to environmental stimuli, while others have independently described endocrine profiles. However, few studies have simultaneously measured endocrine profiles, breeding behaviour, and offspring survival across seasons. We measured sex and stress hormone concentrations (oestrogens, testosterone, and corticosterone), timing of breeding, and chick survival, in Adelie penguins (Pygoscelis adeliae) at two colonies in two different years. Clutch initiation at Cape Bird South (CBS; year 1, 14,000 pairs) occurred later than at Cape Crozier East (CCE; year 2, 25,000 pairs); however, breeding was more synchronous at CBS. This pattern was probably generated by the persistence of extensive sea ice at CBS (year 1). Higher corticosterone metabolite and lower sex hormone concentrations at CBS correlated with later breeding and lower chick survival compared to at CCE – again, a likely consequence of sea ice conditions. Within colonies, sub-colony size (S, 50–100; M, 200–300; L, 500–600; XL, >1000 pairs) did not influence the onset or synchrony of breeding, chick survival, or hormone concentrations. We showed that the endocrine profiles of breeding Adelie penguins can differ markedly between years and/or colonies, and that combining measures of endocrinology, behaviour, and offspring survival can reveal the mechanisms and consequences that different environmental conditions can have on breeding ecology.

year: 2011

title: Putting the burden of proof in its place: When are differential allocations legitimate?

authors: Dare, Tim

subjects: allocations legitimate

abstract: It is widely assumed that legitimate differential allocations of the burden of proof are ubiquitous: that in all cases in which opposing views are being debated, one side has the responsibility of proving their claim and if they fail, the opposing view wins by default. We argue that the cases in which one party has the burden of proof are exceptions. In general, participants in reasoned discourse are all required to provide reasons for the claims they make. We distinguish between truth-directed and non-truth-directed discourse, argue that the paradigm contexts in which there are legitimate differential allocations of the burden of proof (law and formal debate) are non-truth-directed, and suggest that in truth-directed contexts, except in certain special cases, differential allocation of the burden of proof is not warranted.

text: Putting the burden of proof in its place: When are differential allocations legitimate? It is widely assumed that legitimate differential allocations of the burden of proof are ubiquitous: that in all cases in which opposing views are being debated, one side has the responsibility of proving their claim and if they fail, the opposing view wins by default. We argue that the cases in which one party has the burden of proof are exceptions. In general, participants in reasoned discourse are all required to provide reasons for the claims they make. We distinguish between truth-directed and non-truth-directed discourse, argue that the paradigm contexts in which there are legitimate differential allocations of the burden of proof (law and formal debate) are non-truth-directed, and suggest that in truth-directed contexts, except in certain special cases, differential allocation of the burden of proof is not warranted.

year: 2008

title: Adolescent Māori mothers experiences with social support during pregnancy, birth and motherhood and their participation in education

authors: Rawiri, Casey

subjects: social support

abstract: The purpose of this research was to investigate the role of social support in helping
adolescent Māori mothers cope with pregnancy, birth and motherhood, with a
particular emphasis on its role in enabling them to continue at school. The aim of this
research is to understand and make sense of these experiences and to perhaps identify
gaps within an individual's social network. The analysis and methodology of the
research was underpinned by a community psychology framework.
Nine interviews were conducted with young Māori women who had become pregnant
and continued with their pregnancy, all before the age of 20. The in depth interviews
included questions focusing on the young women learning of pregnancy, the
pregnancy, birth, caring for their child and their experiences with education and future
plans.
Negative experiences were usually those which involved unsupportive people.
Positive interactions were those where support, of all types, was offered and useful to
my participants and their children. Education was highlighted as the most effective
way of providing a better life for adolescent mothers and their children.
The research highlights the importance of social support and the continuation of
education. Combining the efforts of positive social networks and social support
services can improve the lives of adolescent Māori mothers and their children.

text: Adolescent Māori mothers experiences with social support during pregnancy, birth and motherhood and their participation in education The purpose of this research was to investigate the role of social support in helping
adolescent Māori mothers cope with pregnancy, birth and motherhood, with a
particular emphasis on its role in enabling them to continue at school. The aim of this
research is to understand and make sense of these experiences and to perhaps identify
gaps within an individual's social network. The analysis and methodology of the
research was underpinned by a community psychology framework.
Nine interviews were conducted with young Māori women who had become pregnant
and continued with their pregnancy, all before the age of 20. The in depth interviews
included questions focusing on the young women learning of pregnancy, the
pregnancy, birth, caring for their child and their experiences with education and future
plans.
Negative experiences were usually those which involved unsupportive people.
Positive interactions were those where support, of all types, was offered and useful to
my participants and their children. Education was highlighted as the most effective
way of providing a better life for adolescent mothers and their children.
The research highlights the importance of social support and the continuation of
education. Combining the efforts of positive social networks and social support
services can improve the lives of adolescent Māori mothers and their children.

year: 2007