Artificial Light at Night (ALAN) has been identified as a primary driver of environmental change in the 21st century with key impacts on ecosystems. At the same time, developments of LED lighting ...systems with adjustable parameters—such as color temperature and light intensity—may provide an opportunity to mitigate the negative effects of ALAN. To test the potential effects of LED properties, we conducted a comprehensive field study over two summers at three forest sites in Switzerland. We investigated the impact of three key attributes of LED lights (color temperature, brightness, and luminaire shape) on the abundance and community structure of ground-dwelling invertebrate functional groups (predators, omnivores, and detritivores). We found a significantly increased nocturnal attraction of omnivores (+275%) and predators (+70%), but not detritivores, to ALAN, altering arthropod community composition and trophic interactions in forests. LED color temperature and luminaire shape showed minimal effects on all three functional groups, while reducing light level from 100% to 50% attracted fewer individuals in all groups with a significant effect in omnivores (−57%). In addition, we observed significant interactions of color temperatures and luminaire shapes with light intensity, with a decrease in numbers when dimming the light to 50% intensity combined with a color temperature of 3700 K for predators (−53%), with diffusing luminaire shapes for omnivores (−77%) and with standard luminaire shape for detritivores (−27%). The predator-detritivore ratio showed a significant color temperature – light level interaction, with increased numbers of predators around streetlights with 3700 K and 100% intensity, resulting in an elevated top-down pressure on detritivores. These results suggest the importance of considering combined light characteristics in future outdoor lighting designs.
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•Assessing the effects of interacting LED light characteristics.•Predators and omnivores are strongly attracted to artificial light at night.•Artificial light at night can increased top-down effects on lower trophic levels.•Light color and luminaire shape show significant interactions with light intensity.
Zusammenfassung
Hintergrund und Ziel der Studie
Der Transport von Früh und Neugeborenen mit respiratorischem Versagen ist mit einem hohen Transportrisiko assoziiert und stellt höchste Anforderungen ...an medizinisches Personal und technische Ausrüstung. Eine kontinuierliche Überprüfung der Qualität ist daher unumgänglich. Ziel dieser monozentrischen retrospektiven Analyse ist es, die Mortalität transportierter Neugeborener mit respiratorischem Versagen mithilfe eines Outcomescores, Transport Risk index of Physiologic Stability, Version II, (TRIPS-II-Score) und im Vergleich zu bereits publizierter Literatur zu analysieren.
Methodik
Es wurden 79 Intensivtransporte von Früh- und Neugeborenen mit hochgradigem respiratorischem Versagen retrospektiv analysiert. Zur Einschätzung des Transportrisikos und der Transportqualität wurde der TRIPS-II-Score erhoben und mit der Literatur verglichen.
Ergebnisse
Insgesamt wurden 77 Patienten luft- (
n
= 56, 73 %) oder bodengebunden (
n
= 21, 27 %) transportiert. Zwei Patienten verstarben vor dem Transport. Kein Patient verstarb während des Transports. Alle Patienten mussten invasiv beatmet werden, davon 22 (29 %) mit Hochfrequenzoszillation (HFOV) und 55 (71 %) erhielten inhalatives Stickoxid (iNO). Der mittlere Oxygenierungsindex (OI) betrug 33 4-100, min.-max. Insgesamt mussten 24 Patienten (31 %) nach Aufnahme einer ECMO-Therapie unterzogen werden. Insgesamt verstarben 20 (26 %) Neugeborene, 7 davon in der ECMO-Therapie-Gruppe.
Schlussfolgerung
Transporte von Neugeborenen mit schwerem Lungenversagen können durch den Einsatz eines spezialisierten Teams mit Sonderequipment meist komplikationslos durchgeführt werden. Die scheinbar sehr hohe Mortalität ist mit Daten der internationalen Literatur vergleichbar.
It has long been recognized that the patterning of social interactions within a group can give rise to a social structure that holds very different places for different individuals. Such within-group ...variation in sociality correlates with fitness proxies in fish, birds, and mammals. Broader integration of this research has been hampered by the lack of agreement on how to integrate information from a plethora of dyadic interactions into individual-level metrics. As a step towards standardization, we collected comparative data on affinitive and affiliative interactions from multiple groups each of five species of primates to assess whether the same aspects of sociality are measured by different metrics and indices. We calculated 16 different sociality metrics used in previous research and thought to represent three different sociality concepts. We assessed covariation of metrics within groups and then summarized covariation patterns across all 15 study groups, which varied in size from 5 to 41 adults. With some methodological and conceptual caveats, we found that the number of weak ties individuals formed within their groups represented a dimension of sociality that was largely independent from the overall number of ties as well as from the number and strength of the strong ties they formed. Metrics quantifying indirect connectedness exhibited strong covariation with strong tie metrics and thus failed to capture a third aspect of sociality. Future research linking affiliation and affinity to fitness or other individual level outcomes should quantify inter-individual variation in three aspects: the overall number of ties, the number of weak ties, and the number or strength of strong ties individuals form, after taking into account effects of social network density.
Significance statement
In recent years, long-term studies of individually known animals have revealed strong correlations between individual social bonds and social integration, on the one hand, and reproductive success and survival on the other hand, suggesting strong natural selection on affiliative and affinitive behavior within groups. It proved difficult to generalize from these studies because they all measured sociality in slightly different ways. Analyzing covariation between 16 previously used metrics identified only three rather independent dimensions of variation. Thus, different studies have tapped into the same biological phenomenon. How individuals are weakly connected within their group needs further attention.
Intense reproductive competition and social instability are assumed to increase concentrations of glucocorticoids and androgens in vertebrates, as a means of coping with these challenges. In ...seasonally breeding redfronted lemurs (Eulemur fulvus rufus), the mating and the birth season and the associated increased male competition are predicted to pose such reproductive challenges. In this paper, we investigate seasonal variation in hormone excretion in male redfronted lemurs, and examine whether this variation is associated with social or ecological factors. Although dominance status has been shown to affect individual stress levels across many taxa, we predicted no rank-related differences in glucocorticoids for redfronted lemurs because relatively equal costs are associated with both high and low rank positions (based on patterns of rank acquisition/maintenance and threats toward subordinates). Over a 14-month period, we collected behavioral data (1843 focal hours) and 617 fecal samples from 13 redfronted lemur males in Kirindy Forest/Madagascar. We found no general rank-related pattern of testosterone or glucocorticoid excretion in this species. Both hormones were excreted at significantly higher levels during the mating and the birth season, despite social stability during both periods. The elevated mating season levels may be explained by increased within-group reproductive competition during this time and are in line with previous studies of other seasonally reproducing primates. For the birth season increase, we propose that the predictable risk of infanticide in this highly seasonal species affects male gonadal and adrenal endocrine activity. We evaluate alternative social and ecological factors influencing the production of both hormone classes and conclude based on our preliminary investigations that none of them can account for the observed pattern.
Maintenance of group cohesion is of vital importance for group-living species. Individuals therefore need to coordinate their potentially divergent interests to maintain group cohesion. We studied ...behavioural aspects and mechanisms of coordinated group movements in Verreaux's sifakas (Propithecus verreauxi), an arboreal Malagasy primate living in small groups. During a field study in Kirindy forest, western Madagascar, we studied the initiation and course of group movements, as well as vocalisations used in this context, in three social groups. We found that both sexes initiated group movements, but females did so more often, lead groups further and enlisted more followers than males. Sex of the leader had no effect on the probability that a group would feed or rest after a successful movement, however. Grumble vocalisations were emitted by both leaders and followers at high rates, both before and during group progressions, but Grumbles uttered just before an individual moved were characterised by a significantly steeper frequency modulation at the beginning of the call and higher call frequencies in both females and males. The results of this study indicated that sifakas, which evolved group-living independently from other primates, converge with many other group-living primates in several fundamental proximate aspects of group coordination and cohesion. In contrast to many other primates, however, sifakas did not use a particular call or other signals to initiate or control group movements.
The aim of this study was to examine effects of seasonal and social factors on male androgen excretion in a seasonally breeding primate living in multimale-multifemale groups. By combining detailed ...behavioural observations (>2,500 h) on 3 groups of redfronted lemurs living in Kirindy Forest/Madagascar with non-invasive hormone analysis of >800 faecal samples collected concomitantly from the same animals, we tested predictions on: (1) the effect of social status on immunoreactive testosterone (iT) excretion; (2) seasonal variation of iT across reproductive periods; and (3) the relationship between aggression and iT excretion. The study lasted 14 months, covering two mating and one birth season. The results revealed that males fall into two distinct social classes, with one dominant male and several subordinate males in each group. In contrast to our prediction, the behavioural differences between these two classes were not reflected by differences in androgen levels, making physiological suppression of testicular function an unlikely mechanism of male reproductive competition. As expected for a seasonally breeding animal, iT values were elevated during the mating season. Androgen levels tracked the increase in the rate of reproductive aggression during the mating season as predicted by the challenge hypothesis. An increase in aggression due to spontaneous social instability outside the mating season, however, was not linked to a parallel rise of iT. Furthermore, the highest iT levels were obtained during the birth season, which may be part of a male strategy to remain aggressive during this period of high infanticide risk. These findings suggest that redfronted lemurs do not respond with increases in androgens to short-term challenges and that high androgen levels instead correlate with longer-lasting and predictable situations, such as the mating and birth seasons.
Despite their ubiquity, in most cases little is known about the impact of eukaryotic parasites on their mammalian hosts. Comparative approaches provide a powerful method to investigate the impact of ...parasites on host ecology and evolution, though two issues are critical for such efforts: controlling for variation in methods of identifying parasites and incorporating heterogeneity in sampling effort across host species. To address these issues, there is a need for standardized methods to catalogue eukaryotic parasite diversity across broad phylogenetic host ranges. We demonstrate the feasibility of a metabarcoding approach for describing parasite communities by analysing faecal samples from 11 nonhuman primate species representing divergent lineages of the primate phylogeny and the full range of sampling effort (i.e. from no parasites reported in the literature to the best‐studied primates). We detected a number of parasite families and regardless of prior sampling effort, metabarcoding of only ten faecal samples identified parasite families previously undescribed in each host (x̅ = 8.5 new families per species). We found more overlap between parasite families detected with metabarcoding and published literature when more research effort—measured as the number of publications—had been conducted on the host species' parasites. More closely related primates and those from the same continent had more similar parasite communities, highlighting the biological relevance of sampling even a small number of hosts. Collectively, results demonstrate that metabarcoding methods are sensitive and powerful enough to standardize studies of eukaryotic parasite communities across host species, providing essential new tools for macroecological studies of parasitism.
In group-living species, theoretical considerations indicate the existence of a fundamental conflict of interest between the sexes over the adult sex ratio within groups. Females may derive certain ...benefits from living with many males. Males, in contrast, should generally try to monopolize access to a group of females. Which sex ultimately controls adult group sex ratio is poorly known. We examined this conflict between the sexes in redfronted lemurs, Malagasy primates characterized by an unusual lack of female-biased adult sex ratios. Using various demographic and behavioural data from several groups collected over 6 years, we examined (1) the proximate determinants of this unusual sex ratio, (2) the temporal distribution of female fertile phases within groups as a determinant of male monopolization potential, (3) sources of between-group variation in the adult sex ratio, and (4) possible social benefits of the relatively high number of males for both sexes. Birth and mortality rates were not sex biased and males migrated considerably more frequently than females, providing no proximate explanation for the unusual sex ratio. However, certain life history traits (fast maturation, short interbirth intervals) may ultimately play a role because they act to facilitate joint group transfers of male coalitions. Despite a relatively small female group size and an associated high monopolization potential, female oestrous synchrony may prevent the formation of single-male groups. Reduced male group size seems to be the main predictor of take-over rate, and, thus, infanticide risk, suggesting that both sexes may benefit from the high number of coresident males, thereby considerably defusing the conflict of interest between the sexes.
Wie gestaltet sich der Zusammenhang von (ver-)geschlechtlichter Erfahrung, Differenz, Alterität und Anderssein? Wie sind (ver-)geschlechtliches Erleben und der körperliche Leib miteinander ...verschränkt? Und welche Bedeutung haben Unausgesprochenes und Unaussprechbares für die Erfahrung geschlechtlicher Existenzweisen? Die Beiträger*innen widmen sich diesen drei bislang wenig systematisch bearbeiteten Fragen und setzen Erfahrung neu auf die Agenda der Geschlechterforschung. Aus den Perspektiven von Geistes-, Kultur- und Sozialwissenschaften loten sie Erfahrung als Forschungsgegenstand sowie Analysekategorie aus und legen dessen epistemologisches Potential als Grundlage von Kritik und politischer Praxis offen.
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