Keywords: acoustic communication arousal Capra hircus positive emotions ungulates valence vocal analysisEmotions are important because they enable the selection of appropriate behavioural decisions in response to external or internal events. Techniques for understanding and assessing animal emotions, and particularly positive ones, are lacking. Emotions can be characterized by two dimensions: their arousal (bodily excitation) and their valence (negative or positive). Both dimensions can affect emotions in different ways. It is thus crucial to assess their effects on biological parameters simultaneously, so that accurate indicators of arousal and valence can be identified. To find convenient and noninvasive tools to assess emotions in goats, Capra hircus, we measured physiological, behavioural and vocal responses of goats in four situations: (1) control (no external stimulus, neutral); (2) anticipation of a food reward (positive); (3) food-related frustration (negative); (4) isolation away from conspecifics (negative). These situations were characterized by different levels of arousal, assessed a posteriori by heart rates measured during the tests. We found several clear, reliable indicators of arousal and valence. During situations of higher arousal, goats had lower heart rate variability and higher respiration rates. They displayed more head movements, moved more, had their ears pointed forwards more often and on the side (horizontal) less often and produced more calls. They also produced calls with higher fundamental frequencies and higher energy distribution. In positive situations, goats had their ears oriented backwards less often and spent more time with their tails up than in negative situations. Furthermore, they produced calls in which the fundamental frequencies were less variable. Our methods for assessing the effects of emotional arousal and valence on biological parameters could lead to more effective monitoring and understanding of animal emotions, as well as to a better understanding of the evolution of emotions through cross-species comparisons.

Activity rhythms play an important role in the ecological relations of a species and form part of its evolutionary adaptation. Such rhythms are strongly synchronised with the annual cyclic changes by environmental stimuli, the so-called zeitgebers. Animals’ reliance on environmental stimuli is highly species-specific and allows behavioural adjustments to be made in preparation for the conditions expected in each season. We investigated daily and annual activity rhythms of Alpine chamois (Rupicapra rupicapra) by analysing high-resolution data of animals monitored with GPS collars. This first detailed field study of chamois activity showed that this species exhibited clear daily and annual activity rhythms entrained to the light-dark cycle. Chamois were more active during spring-summer and less active during winter, likely in response to the variation in the availability of food resources: both sexes appeared to maximise energy intake during the season offering the highest amount of food resources to compensate for poor food supply during winter. Daily activity was influenced by the climatic factors considered. We showed a negative correlation between daily activity and adverse climatic conditions (i.e. precipitation and, during winter, snow depth). As activity was strongly influenced by the interplay between temperature and wind throughout the year and by radiation and wind in winter, we conjectured that it was critically dependent upon animals’ thermal balance. In conclusion, our study highlighted that chamois is well adapted to the Alpine environment and seasonality but also raised questions about its ability to adapt to future climate change. Significance statement: In this study, we investigated the effects of ecological factors on Alpine chamois activity. Thanks to radio collars with accelerometers, we obtained highly detailed information on activity levels of wild animals. We found that chamois were more active during spring-summer (i.e. the seasons with the highest quality and quantity of food) and less active during winter. Our results showed that chamois activity was strongly influenced by such climatic factors as temperature, precipitation and wind speed. In winter time, chamois activity increased during the days with high solar radiation and decreased with high snow depth. Given their wide distribution in the Alps, chamois can be considered as a sentinel species of Alpine habitats. Thus, our results on the current relationship between climate and chamois behaviour may shed light on the animals’ ability to track and adapt to climate change

Different species exhibit individual daily and annual activity patterns, in response to a range of intrinsic and extrinsic drivers. Historically, research on the activity budgets of large wild animals focused on daylight hours due to the logistical difficulties of observing animals at night. Thanks to recent advances in animal-attached technology, however, research can nowadays be extended to a 24-hour timeframe. Taking advantage of GPS collars with activity sensors collecting a large amount of data per hour, we separately studied diurnal and nocturnal activity patterns of Alpine chamois (Rupicapra rupicapra), in order to identify the factors affecting them and the correlation between them. From March 2010 to November 2013, we collected data on 17 chamois in the Swiss National Park, a strict Alpine nature reserve where human management was forbidden and human harassment quite rare. Environmental factors were found to significantly influence both diurnal and nocturnal activity rhythms, with temperature and seasonality playing a pivotal role.Surprisingly, we detected a stable peak of activity in the first part of the night which varied only slightly over the year. In summer, the nocturnal activity of males was inversely correlated to diurnal activity, potentially to compensate for the scarce diurnal food intake. Conversely, winter nocturnal activity was positively related to the diurnal one and served as a cumulative opportunity for energy intake. Chamois showed a weak lunarphilia, with a slight increase in activity levels during moonlit nights, in particular during the mating season. In conclusion, our findings denote chamois as a cathemeral species able to adapt its behavioural patterns to match varying environmental conditions.

Although numerous studies have reported reproductive senescence in wild animal populations, we still know very little on inter-individual differences in rates of ageing and on the factors accounting for these differences. To investigate age-related variation in breeding success in a natural population of Alpine chamois (Rupicapra rupicapra), we used 15 years of data obtained by monitoring individual ear-tagged females. Analyses at the population level confirmed the occurrence of a decline in female breeding success, which is most noticeable from 9 years of age onward. Using an age-reverse approach, we showed that senescence in female breeding success occurs at the same age, since only very old individuals (older than 16 years) showed a decline in breeding success in the years preceding death. Interestingly, we also found evidence that 'success comes from success', as females that gave birth in a given year were more likely to procreate again in the following year. Moreover, results showed that discrepancies between successful and unsuccessful individuals tend to become more relevant in the oldest age classes. There was no evidence of a terminal allocation. These results emphasize the importance of age-dependent effects and individual quality in shaping reproductive senescence in a wild long-lived ungulate.

The influence of aerosols on climate is highly dependent on the particle size distribution, concentration, and composition. In particular, the latter influences their ability to act as cloud condensation nuclei, whereby they impact cloud coverage and precipitation. Here, we simultaneously measured the concentration of aerosols from sea spray over the North Atlantic on board the exhaust-free solar-powered vessel “PlanetSolar”, and the sea surface physico-chemical parameters. We identified organic-bearing particles based on individual particle fluorescence spectra. Organic-bearing aerosols display specific spatio-temporal distributions as compared to total aerosols. We propose an empirical parameterization of the organic-bearing particle concentration, with a dependence on water salinity and sea-surface temperature only. We also show that a very rich mixture of organic aerosols is emitted from the sea surface. Such data will certainly contribute to providing further insight into the influence of aerosols on cloud formation, and be used as input for the improved modeling of aerosols and their role in global climate processes.