Experimentally elevated plasma testosterone levels do not influence singing behaviour of male blue tits (Parus caeruleus) during the early breeding season

Sexual selection theory suggests that females might prefer males on the basis of testosterone (T)-dependent secondary sexual traits such as song. Correlational studies have linked high plasma T-levels to high diurnal song output. This has been confirmed in experiments where T-levels were kept high at times when natural T-levels have decreased. However, surprisingly little is known about the relation between T-levels during the early breeding season and song. In many passerine birds males sing at a high rate at dawn early in the breeding season, referred to as the dawn chorus. In blue tits (Parus caeruleus), the dawn chorus coincides with the fertile period of the female, whereas diurnal song occurs throughout the breeding season. Previous studies on blue tits showed that characteristics of the dawn chorus correlate with male reproductive success. We experimentally elevated plasma T-levels in male blue tits during the pre-fertile and fertile period. Our aim was to test whether increased plasma T-levels affect dawn song characteristics and increase the amount of diurnal song. Although T-implants successfully raised circulating T-levels, we did not find any difference between T- and control males in temporal performance measures of dawn song or in diurnal song output. Our results suggest that either there is no direct causal link between song output or quality and individual T-levels, or experimental manipulations of T-levels using implants do not permit detection of such effects during the early breeding season. Although we cannot exclude that individual T-levels are causally linked to other (e.g. structural) song parameters, our results cast doubt on T-dependence as the mechanisms that enforces honesty on song as a sexually selected trait.

The natural plasma testosterone profile of male blue tits during the breeding season and its relation to song output

In male birds, the gonadal hormone testosterone (T) is known to influence territorial and mating behaviour. Plasma levels of T show seasonal fluctuations which vary in relation to mating system and social instability. First, we determined the natural T profile of male blue tits Parus caeruleus during the breeding season. We found that plasma levels of T increased at the onset of nest building. Thus, the increase in circulating T was not associated with territory establishment, nor with the fertile period of the males' mates. In most individuals, T levels dropped to values close to zero during the period of chick feeding. Second, we investigated the relationship between plasma levels of T and male age, size, and singing behaviour. During the mating period, T levels did not differ between 1 yr old and older males and did not correlate with body size or condition. However, song output during the dawn chorus tended to be positively correlated with T levels. Therefore, if high T levels are costly, song output might be an honest indicator of male quality in blue tits. Finally, we show that plasma levels of T are significantly higher during the night than during the day. This pattern has also been observed in captive non-passerine birds, but its functional significance remains unknown.

Validating the use of intrinsic markers in body feathers to identify inter‑individual differences in non‑breeding areas of northern fulmars

Many wildlife studies use chemical analyses to explore spatio-temporal variation in diet, migratory patterns and contaminant exposure. Intrinsic markers are particularly valuable for studying non-breeding marine predators, when direct methods of investigation are rarely feasible. However, any inferences regarding foraging ecology are dependent upon the time scale over which tissues such as feathers are formed. In this study, we validate the use of body feathers for studying non-breeding foraging patterns in a pelagic seabird, the northern fulmar. Analysis of carcasses of successfully breeding adult fulmars indicated that body feathers moulted between September and March, whereas analyses of carcasses and activity patterns suggested that wing feather and tail feather moult occurred during more restricted periods (September to October and September to January, respectively). By randomly sampling relevant body feathers, average values for individual birds were shown to be consistent. We also integrated chemical analyses of body feather with geolocation tracking data to demonstrate that analyses of δ13C and δ15N values successfully assigned 88 % of birds to one of two broad wintering regions used by breeding adult fulmars from a Scottish study colony. These data provide strong support for the use of body feathers as a tool for exploring non-breeding foraging patterns and diet in wide-ranging, pelagic seabirds.

Merely Birds of Passage: Lady Hariot Dufferin's Travel Writings and Medical Work in India, 1884-88

This article examines the travel writings and medical work in India of Lady Hariot Dufferin, Vicereine of India between 1884 and 1888. Lady Dufferin accompanied her husband, the Viceroy Lord Dufferin, through various social and political engagements in India, and carved her own niche in colonial and postcolonial history as a pioneer in the medical training of women in India. The article examines her travel writings on India and explores the nature of her complicity in the Raj, as well as the gendered nature of the separate public role she created for herself in relation to her 'zenana work' in providing medical care for the women of India. The author suggests that, through her work, Lady Dufferin challenges and extends the theoretical paradigms of postcolonialist and feminist critiques of empire.

Assortative mating as a mechanism for rapid evolution of a migratory divide.

There have been numerous recent observations of changes in the behavior and dynamics of migratory bird populations, but the plasticity of the migratory trait and our inability to track small animals over large distances have hindered investigation of the mechanisms behind migratory change. We used habitat-specific stable isotope signatures to show that recently evolved allopatric wintering populations of European blackcaps Sylvia atricapilla pair assortatively on their sympatric breeding grounds. Birds wintering further north also produce larger clutches and fledge more young. These findings describe an important process in the evolution of migratory divides, new migration routes, and wintering quarters. Temporal segregation of breeding is a way in which subpopulations of vertebrates may become isolated in sympatry.

Caged birds and cloning machines: how student imagery 'speaks' to us about cultures of schooling and student participation

With the advent of the United Nations Convention on the Rights of the Child (CRC), there is an increasing requirement that schools ensure children and young people's views are voiced, listened to and taken seriously on matters of significance. Encouraging these shifts by law is one thing; changing the culture in schools is another. For a significant proportion of schools, actively engaging students' voices on how they experience education poses a significant challenge and crucial gaps may exist between the rhetoric espoused and a school's readiness for genuine student involvement. This ethnographic study illuminates tensions that persist between headteachers' espoused views of how students are valued and students' creative images of their actual post-primary schooling experience. If cultures of schooling are to nurture the true spirit of democratic pupil participation implied by changes in the law, there is a need to develop genuine processes of student engagement in which students and staff can collaborate towards greater shared understandings of a school's priorities.

Two Birds, One Stone: Combining Student Assessment and Socio-Legal Research

We describe here a method of assessment for students. A number of short-comings of traditional assessment methods, especially essays and examinations, are discussed and an alternative assessment method, the student project, is suggested. The method aims not just to overcome the short-comings of more traditional methods, but also to provide over-worked and under-resourced academics with viable primary data for socio-legal research work. Limitations to the method are discussed, with proposals for minimising the impact of these limitations. The whole �student project� approach is also discussed with reference to the Quality Assurance Agency benchmark standards for law degrees, standards which are expected of all institutions in the UK.

The energetics of lactation in cooperatively breeding meerkats Suricata suricatta

Species may become obligate cooperative breeders when parents are unable to raise their offspring unassisted. We measured the daily energy expenditure of mothers, helpers and offspring during peak lactation in cooperatively breeding meerkats Suricata suricatta using the doubly labelled water technique. Lactating mothers expended more energy per day than allo-lactating subordinate females, non-lactating females or suckling offspring. Metabolizable energy intakes of lactating mothers were calculated from isotope-based estimates of offspring milk energy intake, and were not significantly different from the previously suggested maximal limit for mammals. Allo-lactating females were the only category of animals that lost weight during the period of study, probably because they spent more time babysitting than non-lactating females. Daily energy expenditure (DEE) of lactating mothers increased with litter size but decreased with the number of helpers. Calculations show that for every 10 helpers, even in the absence of allo-lactators, mothers are able to reduce their DEE during peak lactation by an amount equivalent to the energy cost of one pup. These results indicate that helpers have beneficial energetic consequences for lactating mothers in an obligate cooperatively breeding mammal.

Early birds are sexy: male age, dawn song and extrapair paternity in blue tits, Cyanistes (formerly Parus) caeruleus

Sexual selection theory predicts that signals reflecting the relative quality of individuals should be used in mate choice. Females could base their choice of copulation partners on male secondary sexual traits that honestly signal male age, as predicted by the age-based indicator mechanism. Studies have shown that female blue tits prefer older males and that aspects of dawn song reflect male quality, but it remains unknown whether dawn song characteristics correlate with male age. We compared dawn song characteristics of second-year (SY) and older (ASY) male blue tits (cross-sectional analysis), and tested for age-related changes within individuals (longitudinal analysis) and differential overwinter survival of SY males. We further investigated the relation between dawn song and paternity gain and loss. We found that ASY male blue tits began to sing earlier relative to sunrise than did SY males. This difference in the onset of dawn singing was due to age-related changes in individual performance rather than differential survival of individuals with varying expression of the trait. Males that began to sing earlier at dawn had more mating partners, and were more likely to gain extrapair paternity. Our findings suggest that the onset of dawn song can provide a simple mechanism for females to assess the relative quality of their mate and of neighbouring males. We propose that females use the onset of singing as a cue for their choice of extrapair partners. (c) 2006 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Seasonal patterns of singing activity vary with time of day in the nightingale (Luscinia megarhynchos)

Seasonal patterns of singing activity of male birds have been thoroughly studied, but little is known about how those patterns vary with time of day. Here, we censused mated and unmated male Nightingales (Luscinia megarhynchos) at four different hours of the day throughout the breeding cycle. In unmated males, singing activity increased until the young hatched in their neighborhood, and the seasonal variation was similar at each of the four hours of the day. In mated males, however, the seasonal patterns of singing activity differed between hours of the day. In morning (about the hour of egg-laying) and during the dusk chorus, the singing activity of mated males was strongly influenced by the females' reproductive state: singing activity was low before egg-laying and during incubation, but high during the egg-laying period. In the dawn chorus, however, singing activity showed a similar seasonal pattern in mated and unmated males and was high until late stages of the breeding cycle. Our results suggest that the social context influences singing behavior to a varying degree across the season, and that this variation also depends on time of day. The hour of data collection thus is an important but often neglected factor when seasonal changes of singing activity are studied.

Foraging ecology, fluctuating food availability and energetics of wintering brent geese

Changing energy requirements and dramatic shifts in food availability are major factors driving behaviour and distribution of herbivores. We investigate this in wintering East Canadian High Arctic light-bellied brent geese Branta bernicla hrota in Northern Ireland. They followed a sequential pattern of habitat use, feeding on intertidal Zostera spp. in autumn and early winter before moving to predominantly saltmarsh and farmland in late winter and early spring. Night-time feeding occurred throughout and made a considerable contribution to the birds' daily energy budget, at times accounting for > 50% of energy intake. Nocturnal feeding, however, is limited to the intertidal, possibly because of predation risk on terrestrial habitat, and increases with moonlight. The amount of Zostera spp., declined dramatically after the arrival of birds, predominantly, but not entirely, due to consumption by the birds. Birds gained fat reserves in the first 2 months but then this was dramatically lost as their major food source collapsed and their daily energy intake declined. Single birds consistently fared worse than paired birds and pairs with juveniles fared better than those without suggesting a benefit of having a family to compete for food. Many birds leave the Lough at this time of reduced Zostera spp. for other sea inlets in Ireland but some remain. Body condition of the latter gradually improved in early spring and reflected a heavy reliance on terrestrial habitats, particularly farmland, to meet the birds' daily energy requirements. However, even in the period immediately before migration to the breeding ground, the birds did not regain the amount of abdominal fatness observed in November. The dramatic changes in available food and requirements of the birds drive the major changes seen in foraging behaviour as the birds evade starvation in the wintering period.

Signals of need in a cooperatively breeding mammal with mobile offspring

In many bird species with biparental care for young in the nest, hungry chicks beg repeatedly and parents adjust their feeding rate to the call rate of young. Repetitive calling also occurs in fledglings and in some mammals where offspring follow provisioners. It is not yet clear whether, in mobile systems with dispersed young where adults cannot compare the vocal behaviour of all young simultaneously, the calls represent a signal of need. We investigated repetitive begging by cooperatively reared meerkat, Suricata suricatta, pups that foraged with the group. Pups produced two types of begging calls: repeat calls over long periods and high-pitched calls mainly confined to feeding events. Food-deprived pups stayed closer to feeders, and begged for longer and more intensely by calling at a higher rate. Hungry pups increased both the rate of repeat calls, which were given continually, and the number of high-pitched bouts, but adults increased their food allocation only in relation to the rate of repeat calls. Our study indicates that hunger may lead to several changes in vocal behaviour, only some of which may be used by adults to assess need.