Variation in reproductive investment increases body temperature amplitude in a temperate passerine

Many birds and mammals show substantial circadian variation in body temperature, which has been attributed to fluctuations in ambient temperature and energy reserves. However, to fully understand the variation in body temperature over the course of the day, we also need to consider effects of variation in work rate. We made use of a dataset on body temperature during the resting and active periods in female marsh tits (Poecile palustris) that bred in a temperate area and were subjected to experimental changes in reproductive investment through brood size manipulations. Furthermore, the amplitude increased with daytime, but were unaffected by nighttime, ambient temperature. Amplitudes in females with manipulated broods were 44% above predictions based on inter-specific allometric relationships. In extreme cases, amplitudes were > 100% above predicted values. However, no individual female realised the maximum potential amplitude (8.5 °C, i.e. the difference between the highest and lowest body temperature within the population) but seemed to prioritise either a reduction in body temperature at night or an increase in body temperature in the day. This suggests that body temperature amplitude might be constrained by costs that preclude extensive use of both low nighttime and high daytime body temperatures within the same individual. Amplitudes in the range found here (0.5–6.7 °C) have previously mostly been reported from sub-tropical and/or arid habitats. We show that comparable values can also be found amongst birds in relatively cool, temperate regions, partly due to a pronounced increase in body temperature during periods with high work rate

A whole blood approach improves speed and accuracy when measuring mitochondrial respiration in intact avian blood cells

Understanding mitochondrial biology and pathology is key to understanding the evolution of animal form and function. However, mitochondrial measurement often involves invasive, or even terminal, sampling, which can be difficult to reconcile in wild models or longitudinal studies. Non-mammal vertebrates contain mitochondria in their red blood cells, which can be exploited for minimally invasive mitochondrial measurement. Several recent bird studies have measured mitochondrial function using isolated blood cells. Isolation adds time in the laboratory and might be associated with physiological complications. We developed and validated a protocol to measure mitochondrial respiration in bird whole blood. Endogenous respiration was comparable between isolated blood cells and whole blood. However, respiration towards oxidative phosphorylation was higher in whole blood, and whole blood mitochondria were better coupled and had higher maximum working capacity. Whole blood measurement was also more reproducible than measurement on isolated cells for all traits considered. Measurements were feasible over a 10-fold range of sample volumes, although both small and large volumes were associated with changes to respiratory traits. The protocol was compatible with long-term storage: after 24 h at 5°C without agitation, all respiration traits but maximum working capacity remained unchanged, the latter decreasing by 14%. Our study suggests that whole blood measurement provides faster, more reproducible, and more biologically and physiologically relevant (mitochondrial integrity) assessment of mitochondrial respiration. We recommend future studies to take a whole blood approach unless specific circumstances require the use of isolated blood cells

Naturresursfällan och exportdiversifiering: En empirisk studie om hur naturresursfällan påverkar exportdiversifiering

The purpose with this study is to examine if a higher level of natural resources hinders export diversification in less developed countries. This is important as low export diversification might affect a country negatively in several aspects that might lead to lower economic growth. Successful management of natural resources is of principle interest for an economist since it affects the direction a country takes. An econometric survey is made with help from panel data regressions. For the issue “the resource curse and export diversification in less developed countries. A contradiction?” the conclusion has been reached that yes, it is a contradiction. Less developed countries get a lowered diversification when their profits from the natural resource sector increases, they get stuck in the resource curse

Klarspråk i nätinteraktionTrevlighet, trafikordningsplaner och undringar om döda rådjur i ett kommunalt e-serviceforum

I det svenska klarspråksarbetet har råd och riktlinjer för språket hittills varit anpassade för olika typer av traditionellt skriftspråkliga och monologiska texter, såsom informationstexter och beslutsbrev. Den nya typ av skriftlig kommunikation i olika digitala forum som börjar bli vanlig ställer krav på nya typer av råd och rekommendationer. För att veta mer om vilka råd och rekommendationer som ska utformas behöver vi dock veta mer om vad som faktiskt försiggår i sådana forum, och vilka kommunikationsproblem som kan uppstå. Artikeln bygger på en undersökning av interaktionen i ett internetforum på en svensk kommuns hemsida. Analysen visar att kommunikationen kännetecknas av en stark betoning av den relationella funktionen från kommunföreträdarnas sida, och denna ”trevlighet” fungerar av allt att döma väl. En utmaning verkar dock vara konflikten mellan vardagsvärld – här och nu – och regelstyrd myndighetsvärld, men analysen visar också att det inte nödvändigtvis är så enkelt att enskilda endast vill veta vad som gäller ”här och nu”.Summary In the ‘Plain Swedish’ effort, advice and guidelines have mostly focused on traditional written and monologic texts. This paper presents some results from a survey of the interactions between government employees and citizens in a Swedish municipality’s online forum, where citizens are invited to ask questions and seek advice. The findings represent a first step towards developing advice for written communication in the digital forums that are used by authorities to provide citizen services. The analysis shows that communication in the forums was characterised by a strong emphasis on the relational function or, in other words, on the relationship between the communicators manning the forum and the citizens. Seemingly, a focus on ‘niceness’ enabled the interactions to run relatively smoothly. One challenge, however, arose from the conflict between citizens’ life-world perspective and the rule-controlled government world. Citizens wish to find practical solutions to their problems in the here and now, and conflicts may occur when a specific question or request is simply answered by quoting the relevant regulation. The analysis, however, also shows that citizens were, in some cases, interested in knowing the underlying rules and regulations. This paper concludes by discussing the actual advantages of online forums for government-citizen interactions where repair in communications is possible

De första svenska fynden av parköronvivel Otiorhynchus crataegi Germar, 1824 (Coleoptera: Curculionidae)

crataegi Germar, 1824. The first specimen was found in the city of Malmö in the southernmost province of Sweden in the beginning of October 2020, where one individual had taken shelter from a heavy morning rain on a house wall, together with several other beetle species. The species was subsequently sought after during late autumn and winter by sifting litter beneath putative host plants, but it could not be relocated until May 2021 when a large, but local, population was found in a scarlet firethorn (Pyracantha coccinea) hedge some hundred metres from the original location. The species has since then been observed in the same hedge on numerous occasions, suggesting that O. crataegi might be established in southernmost Sweden. Its sudden appearance in Sweden seems to be the result of an unintentional introduction with ornamental hedging plants from continental Europe rather than of a natural range expansion from nearby Denmark

Age differences in night-time metabolic rate and body temperature in a small passerine

Spending the winter in northern climes with short days and cold ambient temperatures (Ta) can be energetically challenging for small birds that have high metabolic and heat loss rates. Hence, maintaining body temperature (Tb) in Ta below thermoneutrality can be energetically costly for a small bird. We still know little about how increased heat production below thermoneutrality affects the level at which Tb is maintained, and if these patterns are age specific. To test this, we measured subcutaneous body temperature (Ts) and resting metabolic rate (RMR) simultaneously in blue tits (Cyanistes caeruleus) during winter nights in Ta’s ranging from 25 to − 15 °C. RMR increased below the lower critical temperature (LCT, estimated at 14 °C) and was 6% higher in young (birds in their first winter) compared to old birds (birds in their second winter or older). The higher RMR was also mirrored in higher Ts and thermal conductance (C) in young birds, which we suggest could be caused by age differences in plumage quality, likely driven by time constraints during moult. Reduction in nightly predicted Tb was modest and increased again at the coldest ambient temperatures, suggesting that either heat retention or heat production (or both) improved when Ta reached levels which are cold by the standards of birds in our population. Our results show that levels of heat production and Tb can be age specific. Further studies should address age-specific differences on quality, structure, and thermal conductivity of plumage more explicitly, to investigate the role of variation in insulation in age-linked metabolic phenotypes

The Impact of Weather on the Behavior and Ecology of Birds

Weather conditions affect animals in many different ways. Variation in temperature, rainfall, wind, and other environmental variables can have an impact at a range of temporal and spatial scales and at every level from individual behavior to species distributions. The interactions between these variables may be particularly important but are often overlooked. Hence, understanding how animals respond to weather conditions is a fundamental topic in evolution, ecology, and conservation, especially in a time of major environmental change.Birds are an ideal group in which to investigate these relationships because they occur in almost every ecosystem across the globe, exploit a wide variety of food resources and often move between vastly different environments during their annual life cycle. Most recent research has focused on the impact of climate change and extreme weather events, but even small-scale variation in weather conditions may influence avian behavior, life history, physiology, and morphology. Assessing how birds respond to variation in weather, and the fitness consequences this brings, therefore plays a crucial role in a number of active research areas, including:(1) identifying the selective pressures that may have led to trait evolution;(2) predicting how birds will respond to environmental change; and(3) developing successful conservation measures for threatened species.This timely Research Topic builds on the symposium The Effects of Weather on Birds held at the 2019 European Ornithologists’ Union Congress at Cluj-Napoca, Romania. It will bring together articles from a range of disciplines to offer valuable and synthesized insights into the relationship between weather and birds. In doing so, it will link together broader themes such as adaptation, phenotypic plasticity, life history evolution, population dynamics, and migration, while also increasing our knowledge on the potential impacts of climate change.We welcome contributions on any aspect of the weather and how it affects the behavior or ecology of birds. Articles may be original research papers, comparative analyses, reviews or perspectives

Effects of the urban environment on oxidative stress in early life: insights from a cross-fostering experiment

As urban areas expand rapidly worldwide, wildlife is exposed to a wide range of novel environmental stressors, such as increased air pollution and artificial light at night. Birds in highly polluted and/or urbanized habitats have been found to have increased antioxidant protection, which is likely important to avoid accumulation of oxidative damage, which can have negative fitness consequences. Yet, the current knowledge about the ontogeny of antioxidant protection in urban areas is limited; i.e., is the capacity to up-regulate the antioxidant defences already established during pre-natal development, or does it manifest itself during post-natal development? We cross-fostered great tit (Parus major) nestlings within and between urban and rural habitats, to determine if oxidative stress (measured as non-enzymatic total antioxidant capacity, superoxide dismutase (SOD), and plasma lipid peroxidation) is affected by habitat of origin and/or by habitat of rearing. The results demonstrate that being reared in the urban environment triggers an increase in SOD (an intracellular, enzymatic antioxidant) independent of natal habitat. Oxidative damage increased with hatching date in urban-reared nestlings, but there was little seasonal change in rural-reared nestlings. Total antioxidant capacity was neither affected by habitat of rearing or habitat of origin, but we observed a decline with hatching date in both rearing habitats. Taken together, our results support the growing evidence that the urban environment induces a direct plastic adjustment in antioxidant protection, but that up-regulation is not sufficient to avoid increased oxidative damage in late-hatched broods. Future studies should explore the underlying causes for this effect in late-hatched broods and whether it has any negative long-term implications, both at the individual- and the population level

Avian Behavioral and Physiological Responses to Challenging Thermal Environments and Extreme Weather Events

Birds occupy habitats ranging from Antarctic ice shelves and Arctic tundra to low-latitude deserts and lowland rainforests, and so are exposed to the full range of climates present on Earth. Cold, hot, or variable (on a variety of temporal scales) thermal conditions can present significant thermoregulatory challenges to birds, which typically must maintain body temperatures within narrow physiological tolerance limits. Such challenges may occur in all stages of the annual cycle and in all life stages of birds, so the ability to adjust to these conditions is required to maintain stable populations through time. For this Research Topic, we broadly define a challenging thermal environment as one necessitating behavioral or physiological adjustments to maintain body temperatures at levels appropriate for continued physiological function.Avian abilities to respond to extreme cold and heat are defined by thermoregulatory capacities for heat production or dissipation, respectively. Behavioral responses to temperature challenges can reduce the necessity for and magnitude of physiological adjustments, so together, physiological capacities and behavioral responses determine the probability of survival in thermally challenging situations. Moreover, thermal conditions experienced during reproduction can affect parental investment in the nesting effort and, independently, alter the course of nestling development, with potentially long-term consequences. Behavioral responses to these conditions as well as physiological responses at multiple levels of organization, from organisms to molecules, allow birds to tolerate thermal challenges. Our knowledge of the mechanisms by which birds respond, the time course for such responses, and the impacts on fitness, however, remain incompletely understood. Studies examining behavioral and physiological responses of birds to extreme and/or seasonally variable climates have been a research focus for decades, but recent advances in methods of measurement and analyses of physiological and behavioral traits have led to novel findings regarding the patterns and mechanisms by which birds adjust to challenging thermal environments.This Research Topic examines how thermal conditions in the environment pose challenges to birds and the physiological and behavioral adjustments that birds employ to meet them. Articles for this Research Topic may be original research papers, reviews, or perspectives. Specific themes that we believe are suitable for this Research Topic include, but are not limited to:• Integrative mechanisms underlying bird thermoregulatory capacities contributing to a tolerance of challenging thermal environments and their links to fitness• Influence of thermal conditions during reproduction on parental investment or nestling development• Behavioral responses to challenging thermal conditions and their mechanistic underpinnings• Time courses for physiological adjustments to environmental temperature variation• Physiological and behavioral flexibility associated with daily or seasonal temperature variation• Physiological and behavioral responses and tolerance limits during extreme weather events• Body temperature regulation under challenging thermal conditions and energy or water restrictions, including real-time field measurements and thermal imaging• Body temperature regulation and environmental or ecological drivers of hypometabolic strategies• Physiological consequences of exceeding thermoregulatory capacitie

Experimental facilitation of heat loss affects work rate and innate immune function in a breeding passerine bird

The capacity to get rid of excess heat produced during hard work is a possible constraint on parental effort during reproduction [heat dissipation limit (HDL) theory]. We released hard-working blue tits (Cyanistes caeruleus) from this constraint by experimentally removing ventral plumage. We then assessed whether this changed their reproductive effort (feeding rate and nestling size) and levels of self-maintenance (change in body mass and innate immune function). Feather-clipped females reduced the number of feeding visits and increased levels of constitutive innate immunity compared with unclipped females but did not fledge smaller nestlings. Thus, they increased self-maintenance without compromising current reproductive output. In contrast, feather clipping did not affect the number of feeding visits or innate immune function in males, despite increased heat loss rate. Our results show that analyses of physiological parameters, such as constitutive innate immune function, can be important when trying to understand sources of variation in investment in self-maintenance versus reproductive effort and that risk of overheating can influence innate immune function during reproduction