1,721,009 research outputs found
How to continue measuring horn growth after capture in Alpine ibex
No full textAccurate measurement of secondary sexual characters are fundamental for understanding life history strategies and mating systems. Ibex horns grow continuously through life and thus provide insights on individual life history. Horn growth can also refl ect changes in
environment and resources availability. Horn length is usually measured by hand on skulls of dead animals during live captures or with the use of two parallel lasers with a known distance pointed on the horns of the animal. Here we propose a simple method to measure
horn growth of marked Alpine ibex ( Capra ibex ) in the years following capture. We took pictures of marked animals when the side of the horn was perpendicular to the lens of the camera and we analysed pictures using the 4th annulus measured during captures as a reference unit to estimate the length of the other annuli. We compared the annuli length estimated with this method with the length of the same annuli measured by hand. Our results show that the error of the estimate is very small and that there is a high repeat of annulus length estimate using pictures
Genetic evidence of a hybrid swarm between Alpine ibex (Capra ibex) and domestic goat (C. hircus)
Full text linkImproving the understanding of the causes and effects of anthropogenic hybridization is fundamental to ensure species conservation, particularly in the case of hybridization between wild species and their domestic relatives. Knowledge is missing for many species also because of a lack of appropriate tools for hybrid identification. Here, coupling genotype and phenotype analysis, we carried out an extensive investigation of ongoing hybridization in Alpine ibex Capra ibex, a mountain ungulate of conservation concern from a genetic perspective. By genotyping 63 diagnostic and 465 neutral SNPs, 20 suspected hybrids and 126 Alpine ibex without suspicious phenotype, representing 8 populations across a major part of the species distribution, we found evidence for ongoing hybridization between Alpine ibex and domestic goat. We identified different levels of hybridization including backcrosses into both Alpine ibex and domestic goat. Our results suggest a lack of reproductive barriers between the two species and good survival and reproductive success of the hybrids. Hybridization was locally intense, like a hybrid swarm, but not spread across the rest of the species distribution. Most of the hybrids were discovered in two locations in the north‐west of Italy, while random sampling of individuals from different areas did not provide evidence of recent hybridization. Our method, based on amplicon sequencing of 63 diagnostic SNPs specifically developed for this purpose, allowed us to identify hybrids and backcrosses up to the fourth to fifth generations and was suitable for genetic samples of different quality, although with varying levels of certainty regarding the exact number of generations passed since hybridization. Based on the paired analysis of genotype and phenotype, we provide guidelines for the first identification of hybrids in the field and suggest a procedure for the reliable identification of hybrids
Diversity-oriented Synthesis of Benzoxazepinones through Coupling the Ugi Multicomponent Reaction with a Mitsunobu Cyclization
No full textAssessing the effects of helicopter disturbance in a mountain ungulate on different time scales
No full textNoisy human activities such as helicopter traffic may affect physiology and behaviour of wild animals. Since chronic behavioural modifications can ultimately alter reproductive success and population dynamics, studying the response of different taxa and species to human-induced disturbance in different habitats is paramount. The present study analysed data collected from 10 male Alpine ibex (Capra ibex) monitored with GPS collars to assess their response to disturbance caused by helicopter overflights. We compared ibex activity levels in the hours before and after 34 helicopter overflights during the summer of 2013 in Gran Paradiso National Park (Italy), a protected area that is essential for the conservation of Alpine ibex. The behaviour of Alpine ibex was affected both during and after helicopter overflights: compared to the average activity levels in the hours before the disturbance event, activity increased during the disturbance and decreased during the hour following the overflights. The reduction in activity persisted over the whole day of the helicopter disturbance and finally went back to normal levels during the following day. There was no evidence of habituation to the disturbance throughout the study period. The prolonged behavioural response to the disturbance suggests that frequent helicopter overflights may ultimately affect the ibex’s body conditions, as well as the life-history traits of a population. These findings highlight the importance of considering medium and long-term behavioural responses in assessing disturbance-related effects on wildlife populations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Dietary differences in males and females of a strongly sexually dimorphic ungulate
Full text linkDetailed knowledge of dietary preferences in wild species are important both for understanding evolutionary processes as well as for their conservation. By means of DNA metabarcoding analysis of faecal samples, we investigated the diet of Alpine ibex (Capra ibex), a mountain ungulate characterised by strong sexual dimorphism and segregation, and analysed differences between male and female diet. Despite a low level of selectivity, we found differences in the diet of males and females that consumed different plant in different quantities. Differences were maintained during both spring and summer. Males tended to feed more on plants richer in fibres (i.e., grasses and sedges) and showed stronger seasonal differences while females consumed more digestible plant families (i.e., forbs). Differences in diet between male and female Alpine ibex are compatible with the strong sexual dimorphism and segregation typical of the species and with female reproductive constraints. These results also show that conservation actions have to take into account different ecological needs of males and females in species characterized by sexual dimorphism and segregation
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Heterozygosity-fitness correlation at the major histocompatibility complex despite low variation in Alpine ibex (Capra ibex)
Full text linkCrucial for the long‐term survival of wild populations is their ability to fight diseases. Disease outbreaks can lead to severe population size reductions, which makes endangered and reintroduced species especially vulnerable. In vertebrates, the major histocompatibility complex (MHC) plays an important role in determining the immune response. Species that went through severe bottlenecks often show very low levels of genetic diversity at the MHC. Due to the known link between the MHC and immune response, such species are expected to be at particular risk in case of disease outbreaks. However, so far, only few studies have shown that low MHC diversity is correlated with increased disease susceptibility in species after severe bottlenecks. We investigated genetic variation at the MHC and its correlations with disease resistance and other fitness‐related traits in Alpine ibex (Capra ibex), a wild goat species that underwent a strong bottleneck in the last century and that is known to have extremely low genetic variability, both genome‐wide and at the MHC. We studied MHC variation in male ibex of Gran Paradiso National Park, the population used as a source for all postbottleneck reintroductions. We found that individual MHC heterozygosity (based on six microsatellites) was not correlated with genome‐wide neutral heterozygosity. MHC heterozygosity, but not genome‐wide heterozygosity, was positively correlated with resistance to infectious keratoconjunctivitis and with body mass. Our results show that genetic variation at the MHC plays an important role in disease resistance and, hence, should be taken into account for successfully managing species conservation
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