Seeking temporal refugia to heat stress: increasing nocturnal activity despite predation risk

Flexibility in activity timing may enable organisms to quickly adapt to environmental changes. Under global warming, diurnally adapted endotherms may achieve a better energy balance by shifting their activity towards cooler nocturnal hours. However, this shift may expose animals to new or increased environmental challenges (e.g. increased predation risk, reduced foraging efficiency). We analysed a large dataset of activity data from 47 ibex (Capra ibex) in two protected areas, characterized by varying levels of predation risk (presence versus absence of the wolf-Canis lupus). We found that ibex increased nocturnal activity following warmer days and during brighter nights. Despite the considerable sexual dimorphism typical of this species and the consequent different predation-risk perception, males and females demonstrated consistent responses to heat in both predator-present and predator-absent areas. This supports the hypothesis that shifting activity towards nighttime may be a common strategy adopted by diurnal endotherms in response to global warming. As nowadays different pressures are pushing mammals towards nocturnality, our findings emphasize the urgent need to integrate knowledge of temporal behavioural modifications into management and conservation planning.

Behavioural heat-stress compensation in a cold-adapted ungulate: Forage-mediated responses to warming Alpine summers

Alpine large herbivores have developed physiological and behavioural mechanisms to cope with fluctuations in climate and resource availability that may become maladaptive under climate warming. We tested this hypothesis in female Alpine ibex (Capra ibex) by modelling annual and daily movement and activity patterns in relation to temperature, vegetation productivity and reproductive status based on bio‐logging data and climate change projections. In summer, ibex moved upslope, tracking the green wave. Ibex decreased diel activity sharply above a threshold temperature of 13–14°C, indicating thermal stress, but compensated behaviourally by foraging both earlier and later in the day, and by moving further upslope than on cooler days, especially reproductive females. This critical temperature will be exceeded three times as often under climate change projections. Under such scenarios, the altitudinal extent of the area will limit the available habitat providing thermal shelter, potentially impacting performance and population distribution of this emblematic mountain ungulate.

Bronchopulmonary Nematodes in Alpine Ibex: Shedding of First Stage Larvae Analyzed at the Individual Host Level

Pneumonia is the most frequent cause of death for Alpine ibex (Capra ibex) in Gran Paradiso National Park, (Italy). The etiology of this form of pneumonia is currently unknown and the identification of the primary etiological agent remains difficult due to biological and logistic constraints. Uncovering individual differences in Protostrongylid prevalence and intensity is important to further investigate the epidemiology of respiratory diseases and their relationship to heterozygosity and inbreeding in a once almost extinct population like C. ibex. In a group of 21 individually recognizable adult male we monitored monthly prevalence and intensity of Protostrongylid first-stage larvae using Baerman's technique from June to September 2019. First-stage larvae of 5 genera were detected. Muellerius (P = 100%, CI_95% = 84–100) and Protostrongylus (P = 86%, CI_95%:71–100) were two dominant genera according to Bush's importance index. Neostrongylus (P = 38%,CI_95%: 17–59), Cystocaulus (P = 33%,CI_95% = 13–53) were classified as co-dominant genera while Dictyocaulus filaria (P = 0.05%, CI_95% = 0.04–0.13) was detected, for the first time in Alpine ibex, in one subject. Protostrongylidae larval excretion varied significantly over time, with minimum L1 excretion in July. Individual median larval intensity ranged from 4.4 lpg to 82.2 lpg with Poulin's discrepancy index showing highly aggregated distribution patterns for Muellerius spp. (D = 0.283, CI_95% = 0.760–0.895) and Protostrongylus spp. (D = 0.635, CI_95% = 0.580–0.705). Presented data provide the necessary base point to further investigate how lungworm infection account for the different rates of progression of pneumonia in C. ibex. Individual aggregation of larval intensity must be further evaluated to determine whether these differences mirror different levels of parasitic infection related to individual differences in immune response, hormonal-states or genetic fitness.

Identification and Characterization of Mycoplasma feriruminatoris sp. nov. Strains Isolated from Alpine Ibex: A 4th Species in the Mycoplasma mycoides Cluster Hosted by Non-domesticated Ruminants?

The genus Mycoplasma, a group of free-living, wall-less prokaryotes includes more than 100 species of which dozens are primary pathogens of humans and domesticated animals. Mycoplasma species isolated from wildlife are rarely investigated but could provide a fuller picture of the evolutionary history and diversity of this genus. In 2013 several isolates from wild Caprinae were tentatively assigned to a new species, Mycoplasma (M.) feriruminatoris sp. nov., characterized by an unusually rapid growth in vitro and close genetic proximity to ruminant pathogenic species. We suspected that atypical isolates recently collected from Alpine ibex in France belonged to this new species. The present study was undertaken to verify this hypothesis and to further characterize the French ibex isolates. Phylogenetic analyses were performed to identify the isolates and position them in trees containing several other mycoplasma species pathogenic to domesticated ruminants. Population diversity was characterized by genomic macrorestriction and by examining the capacity of different strains to produce capsular polysaccharides, a feature now known to vary amongst mycoplasma species pathogenic to ruminants. This is the first report of M. feriruminatoris isolation from Alpine ibex in France. Phylogenetic analyses further suggested that M. feriruminatoris might constitute a 4th species in a genetic cluster that so far contains only important ruminant pathogens, the so-called Mycoplasma mycoides cluster. A PCR assay for specific identification is proposed. These French isolates were not clonal, despite being collected in a restricted region of the Alps, which signifies a considerable diversity of the new species. Strains were able to concomitantly produce two types of capsular polysaccharides, β-(1→6)-galactan and β-(1→6)-glucan, with variation in their respective ratio, a feature never before described in mycoplasmas.

Neanderthal exploitation of ibex and chamois in southwestern Europe

There is increasing evidence that Neanderthals had a diverse and flexible diet. They exploited a wide range of resources from large proboscideans to small animals like turtles, rabbits, and marine species. Here, we discuss the importance of ibex and chamois in Neanderthal hunting strategies. The exploitation of both animals has traditionally been regarded as typical of Homo sapiens hunting behavior but was not a feature of Neanderthal behavior, which was thought to have focused on other kinds of game like deer, horses or large bovids. Our analysis of an extensive sample of Middle Paleolithic sites with faunal remains in the Iberian Peninsula reveals that Iberian ibex and chamois were frequently present throughout this period. Statistical analyses allowed us to assess the conditions that might have favored the presence or absence of these animals in the sites, while the taphonomic analyses enabled us to address the issue of whether ibex and chamois were indeed hunted by Neanderthals in the Iberian Peninsula. Our results indicate a better representation of both species in rocky and mountainous areas. The taphonomy of some sites reveals that chamois and ibex were hunted by Neanderthals, who showed great adaptive capacities to a wide variety of environments, including mountainous habitats. In contrast, other sites with favorable ecological conditions for ibex and chamois where these animals were not exploited by Neanderthals, who chose to hunt other species like deer, horses or aurochs, suggest behavioral complexity and large versatility.