Studies identifying interspecific competition require the investigation of negative long‐term effects between sympatric species showing overlap in resource use. A potential for competition exists ...between red deer Cervus elaphus and chamois Rupicapra spp., as revealed by the high dietary overlap observed throughout the range where the species co‐occur. Furthermore, some studies have recently reported negative demographic consequences on chamois populations living in sympatry with red deer. Using time series of counts spanning 35 years between 1984 and 2018 in the Stelvio National Park (Central Italian Alps), we tested for density dependence using state‐space models and explored the evidence of competitive interaction through Ricker‐like models on the growth rate of both species. We contrasted alternative hypotheses for the processes explaining the trends of (decreasing) chamois and (increasing) red deer populations. We expected chamois dynamics to be negatively affected by increasing deer abundance, while deer dynamics should be primarily affected by climate forcing and density dependence. We found evidence that resources were limiting for both species. In particular, growth rates were negatively affected by the synergistic effect of winter weather conditions and density dependence. The most important variable limiting the chamois population, however, was the increase in red deer numbers. The dynamics of this species was unaffected by chamois numbers. While causality cannot be inferred from the data, these results are consistent with the hypothesis of a negative effect of red deer on chamois dynamics, thus supporting the occurrence of interference or exploitation competition between sympatric mountain‐dwelling ungulates. Understanding the processes underlying temporal dynamics is pivotal for informed management of wildlife. Consequences of interspecific competition should be carefully evaluated where the populations of the weaker competitor are of conservation concern, especially in the light of the negative effects of anthropogenic environmental change on animal populations.
We used long‐term count series to contrast alternative process hypotheses to explain the couple dynamics of chamois and red deer in the Italian Alps. We found evidence that the most important variable limiting the chamois population was the numeric increase in red deer, whose dynamics was independent of chamois. These results are consistent with the hypothesis of a negative effect of red deer on chamois demography.
Alternative mating tactics (AMTs) may show different trade-offs between current reproduction and survival; however, the proximate mechanisms underlying this pattern remain unclear. Among them, the ...relationship between reproductive effort and parasite resistance mediated by hormonal secretion has received increasing attention. We monitored 19 marked adult male chamois, Rupicapra rupicapra, within the Gran Paradiso National Park (Italy) between the pre- and postrut 2011, to investigate the trade-off between mating effort and parasites associated with AMTs, and the underlying physiological mechanism. Territorial males sharply increased mating effort, faecal androgen and cortisol metabolites, and parasite levels during the rut, whereas nonterritorial ones displayed a similar pattern only for androgen metabolite levels. During the rut, territorial males invested more in rutting activities, while having higher levels of hormone metabolites and greater faecal counts of parasites than nonterritorial males. Before and after the rut, differences between male types (territorial and nonterritorial males) were smaller. Our analysis suggests that a trade-off between mating effort and parasitism exists, and that the proximate mechanism underlying this pattern may be found in the secretion of androgen metabolites. The greater investment in rutting activities, which territorial males make, suggests potentially high mating benefits. However, mating benefits could be counterbalanced by greater risk of injuries, consumption of fat reserves and higher hormone levels, which might favour the suppression of immunological defence and the subsequent decrease in parasite resistance.
► Alternative mating tactics (AMTs) may entail differential fitness payoffs. ► We explore possible costs associated with AMTs in rutting male chamois. ► Greater mating effort in territorial males linked to greater parasitism. ► Androgens mediate the trade-off between reproductive effort and immune response. ► These results hint at potential life history trade-offs between AMTs in chamois.
In long-lived mammals, costs of reproduction may vary with age. The terminal investment hypothesis predicts greater reproductive effort as females approach the end of their life expectancy. We ...monitored 97 individually marked female Alpine chamois (Rupicapra rupicapra (L., 1758)) between 2007 and 2013 to determine how age-specific reproduction affected body mass and subsequent reproductive success. We captured and weighed females between April and August and monitored reproductive success from April to October through mother–kid associations. Reproductive success was strongly age-dependent and peaked at 70% for prime-aged females (4–7 years). Reproductive senescence began at 8 years, earlier than reported by other studies of ungulates. There was no clear evidence of reproductive costs in any age class. Reproductive success was very heterogeneous for old females, suggesting variability in the onset of senescence. Old females were less likely to reproduce in poor years despite being heavier than prime-aged females, suggesting reproductive restraint in late life rather than terminal investment. Female mass remained stable from May to August with no effect of lactation. Our results suggest that chamois reproductive strategy becomes increasingly conservative with age, resulting in no detectable costs of reproduction.
Foraging behaviour plays a key role in growth, survival and reproduction. Male ungulates in temperate environments show seasonal fluctuations in uptake and use of energy, with summer accumulation of ...reserves later used to sustain the costs of the mating season. To date, however, very little information is available on the foraging behaviour of individuals adopting alternative reproductive tactics. We investigated the year‐round foraging strategies of nine territorial and 10 non‐territorial male Alpine chamois Rupicapra rupicapra in the Gran Paradiso National Park (Italy), and discussed them in relation to space use and forage quality. Territorial males showed marked seasonal changes in foraging behaviour, with low values of time spent foraging in spring, followed by an increase in summer, a drop in November and a subsequent increase in winter. The foraging rates of non‐territorial males, on the other hand, showed smaller variation, decreasing gradually from spring to autumn, and increasing in winter, but with no significant reduction during the November rut. Although in summer territorial males remained at lower elevations than non‐territorial males, faecal crude protein did not show any significant difference between male types. The effort to establish and defend territories (in spring and in November, respectively) may constrain foraging in territorial males, forcing them to compensate by increasing their energy intake over summer. Different levels of vertical movements in the warm months did not affect forage quality, suggesting that territorial males may be selective in the choice of palatable plants. Our results show that different reproductive tactics imply different foraging strategies over the year, which do not seem to depend on forage quality. Different foraging strategies over summer may possibly lead to different body conditions at the beginning of the mating season, which, in turn, could influence individual capability to cope with the costs of mating.
Foraging efficiency strongly affects individual fitness and is influenced by diverse factors such as food quality and quantity, as well as intra- and inter-specific interactions. We investigated ...whether Alpine chamois (Rupicapra rupicapra (Linnaeus, 1758)) in a protected area in the Swiss Alps adapted their foraging behaviour to forage availability and quality by modeling the bite and step rates of individuals on vegetation nitrogen content, relative plant cover, sex, daytime, air temperature, and slope. Vegetation characteristics were derived using remote sensing data from airborne imaging spectroscopy data sets and feeding locations determined using a theodolite. Chamois increased their bite rates with decreasing forage nitrogen content, decreasing slope, and increasing temperature. Step rates were higher at high temperatures and decreased with increasing relative plant cover. Males showed higher bite rates and lower step rates than females. Daytime had no influence on either bite or step rates. An increase in bite rate may represent a plastic adaptation of foraging behaviour to compensate for lower nutritional quality of the available vegetation. Our results show variability in foraging behaviour according to both vegetation characteristics and physical environment and emphasize the use of remote sensing data to investigate relationships between habitat and subtle behavioural adaptations in ungulates.
Immune system cell subsets in lymph nodes and spleen from alpine chamois (Rupicapra rupicapra subspecies rupicapra) living in the Italian Alps were characterized immunohistochemically. Seven primary ...antibodies (against human CD3, CD79αcy, CD68, or ovine CD4, CD8, CD21 and γδ T-cell receptor TCR epitopes) were tested on tissues fixed either in formalin or in zinc salts (ZS) and cross-reactivity with chamois immune cell epitopes was shown. ZS fixation allowed wider identification of immune cells, without the need for antigen retrieval. CD4+ and CD21+ cells were labelled only in ZS-fixed tissues. Reagents specific for human CD3, CD79 and CD68 antigens successfully detected chamois immune cells, both in ZS-fixed and formalin-fixed tissues. The reactivity and distribution of immune cells in lymph nodes and spleen were similar to those described in other domestic and wild ruminants. Results from this study may allow future investigation of the immune response and pathogenesis of diseases in the chamois.
Characterizing the diet of large herbivores and the determinants of its variation remains a difficult task in wild species. DNA-based techniques have the potential to complement traditional ...time-consuming methods based on the microhistology of plant cuticle fragments in fecal or rumen samples. Recently, it has been shown that a short chloroplast DNA fragment, the P6 loop of the trnL (UAA) intron, can act as a minimalist barcode. Here, we used the trnL approach with high-throughput pyrosequencing to study diet from feces in a wild herbivore, the alpine chamois (Rupicapra rupicapra) and showed that the fine resolution in plant determination obtained with this method allows exploring subtle temporal shifts and inter-individual variability in diet composition. First, we built a DNA barcoding database of 475 plants species. Seventy-two percent of plant species can be unambiguously identified to species level, 79% to genus level and 100% to family level using the P6 loop. Second, we analysed 74 feces collected from October to November. Based on 47,896 P6 loop sequences, we identified a total of 110 taxa, 96 in October and 76 in November, with a clear diet shift between October and November. We recognized four and two clusters of feces composition in October and November, respectively, revealing different diet categories among individuals within each month. DNA-based diet analysis is faster and more taxonomically precise than studies based on microhistology, and opens new possibilities for analysing plant-herbivore interactions in the wild.
Because of a rapidly changing climate, the need to understand how populations respond to varying climatic conditions has become increasingly important. Using long-term data from an unhunted ...population of Alpine chamois (Rupicapra rupicapra) and autoregressive time series models we investigated the extent to which the population demography was affected by local climate. Because density and weather are likely to operate differently on various sex–age categories, anticipated effects were assumed to vary among categories. Generally, elevated densities in 1 year negatively influenced the subsequent change in population size. Severe snow conditions during late winter negatively affected total population growth, and growth of the male, yearling, and juvenile segments of the population. A lagged effect of early winter snow on the change in animal numbers was demonstrated for females. Winter temperatures positively affected the growth rate of juveniles, whereas they appeared to have negative consequences for male and yearling growth rates. The juvenile–female ratio was negatively affected by the current female density, but did not respond to the various climate variables. Winter survival of juveniles was negatively influenced by the juvenile number during the preceding summer and harsh snow conditions during early winter. Our results indicate that winter climate shapes the demography of Alpine chamois. Particularly, winters with a lot of snow might have long-lasting consequences for the population. Considering the juveniles, lagged effects apparently operate through the body condition of their mothers. The conflicting effects of temperature on the different sex–age categories make the direction of expected population response to global warming difficult to predict.
In mammals, males typically have shorter lives than females. This difference is thought to be due to behavioural traits which enhance competitive abilities, and hence male reproductive success, but ...impair survival. Furthermore, in many species males usually show higher parasite burden than females. Consequently, the intensity of selection for genetic factors which reduce susceptibility to pathogens may differ between sexes. High variability at the major histocompatibility complex (MHC) genes is believed to be advantageous for detecting and combating the range of infectious agents present in the environment. Increased heterozygosity at these immune genes is expected to be important for individual longevity. However, whether males in natural populations benefit more from MHC heterozygosity than females has rarely been investigated. We investigated this question in a long-term study of free-living Alpine chamois (Rupicapra rupicapra), a polygynous mountain ungulate.
Here we show that male chamois survive significantly (P = 0.022) longer if heterozygous at the MHC class II DRB locus, whereas females do not. Improved survival of males was not a result of heterozygote advantage per se, as background heterozygosity (estimated across twelve microsatellite loci) did not change significantly with age. Furthermore, reproductively active males depleted their body fat reserves earlier than females leading to significantly impaired survival rates in this sex (P < 0.008). This sex-difference was even more pronounced in areas affected by scabies, a severe parasitosis, as reproductively active males were less likely to survive than females. However, we did not find evidence for a survival advantage associated with specific MHC alleles in areas affected by scabies.
Increased MHC class II DRB heterozygosity with age in males, suggests that MHC heterozygous males survive longer than homozygotes. Reproductively active males appear to be less likely to survive than females most likely because of the energetic challenge of the winter rut, accompanied by earlier depletion of their body fat stores, and a generally higher parasite burden. This scenario renders the MHC-mediated immune response more important for males than for females, which implies a relatively stronger selection pressure on MHC genes in males than in females.
•This is the first report of an ameloblastic fibroma in a wild ungulate.•Spontaneous odontogenic tumors are rare in humans and in animals.•Histological and immunohistochemical examinations are ...essential for the diagnosis.
Spontaneous odontogenic tumors are neoplasms characterized by a mixed odontogenic ectomesenchymal and odontogenic epithelial origin; they are rare in both humans and animals. A 3-year-old male Alpine Chamois (Rupicapra rupicapra) was found dead in north-west Italy, and was referred for the necropsy to the Department of Veterinary Sciences of the University of Turin (Italy). At the external examination a 10 × 8 cm, exophytic, red-pink, smooth, firm and ulcerated mass was observed on the inferior lip. Histologically the tumor was characterized by spindle shaped cells arranged in bundles in an abundant hyaline matrix. Multifocal and rare chords of odontogenic epithelium mixed with rare melanocytes that penetrate the neoplasia were visible. Immunohistochemistry showed a clear cytokeratin positivity of epithelial clusters. Macroscopical, histological and immunohistochemical findings were consistent with a diagnosis of locally infiltrative ameloblastic fibroma. To our best knowledge, this is the first report of this tumor in a wild ungulate and in Alpine Chamois.
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