Topic
Capra ibex
About: Capra ibex is a research topic. Over the lifetime, 255 publications have been published within this topic receiving 5774 citations.
Papers published on a yearly basis
Papers
TL;DR: The results suggest that attempts to forecast how warmer winters and springs will affect animal population dynamics and life histories in alpine environments should consider factors influencing the rate of changes in primary production during green-up and the timing of vegetation onset.
Abstract: Seasonal patterns of climate and vegetation growth are expected to be altered by global warming. In alpine environments, the reproduction of birds and mammals is tightly linked to seasonality; therefore such alterations may have strong repercussions on recruitment. We used the normalized difference vegetation index (NDVI), a satellite-based measurement that correlates strongly with aboveground net primary productivity, to explore how annual variations in the timing of vegetation onset and in the rate of change in primary production during green-up affected juvenile growth and survival of bighorn sheep (Ovis canadensis), Alpine ibex (Capra ibex), and mountain goats (Oreamnos americanus) in four different populations in two continents. We indexed timing of onset of vegetation growth by the integrated NDVI (INDVI) in May. The rate of change in primary production during green-up (early May to early July) was estimated as (1) the maximal slope between any two successive bimonthly NDVI values during this period and (2) the slope in NDVI between early May and early July. The maximal slope in NDVI was negatively correlated with lamb growth and survival in both populations of bighorn sheep, growth of mountain goat kids, and survival of Alpine ibex kids, but not with survival of mountain goat kids. There was no effect of INDVI in May and of the slope in NDVI between early May and early July on juvenile growth and survival for any species. Although rapid changes in NDVI during the green-up period could translate into higher plant productivity, they may also lead to a shorter period of availability of high-quality forage over a large spatial scale, decreasing the opportunity for mountain ungulates to exploit high-quality forage. Our results suggest that attempts to forecast how warmer winters and springs will affect animal population dynamics and life histories in alpine environments should consider factors influencing the rate of changes in primary production during green-up and the timing of vegetation onset.
313 citations
TL;DR: Analysis of a range of caprines indicated that the sequence changes occurred between the divergence of the Himalayan tahr (Hemitragus jemlahicus) and the ibex and that the proposed goat marker is diagnostic of all Capra species and breeds.
286 citations
TL;DR: In this article, the authors examined correlations between multilocus heterozygosity (MLH) and trait value and found that MLH was more strongly associated with trait variation than individual inbreeding coefficients.
Abstract: Secondary sexual traits, such as horns in ungulates, may be good indicators of genetic quality because they are costly to develop. Genetic effects on such traits may be revealed by examining correlations between multilocus heterozygosity (MLH) and trait value. Correlations between MLH and fitness traits, termed heterozygosity–fitness correlations (HFC), may reflect inbreeding depression or associative overdominance of neutral microsatellite loci with loci directly affecting fitness traits. We investigated HFCs for horn growth, body mass and faecal counts of nematode eggs in wild Alpine ibex ( Capra ibex ). We also tested if individual inbreeding coefficients ( f′′ ) estimated from microsatellite data were more strongly correlated with fitness traits than MLH. MLH was more strongly associated with trait variation than f′′ . We found HFC for horn growth but not for body mass or faecal counts of nematode eggs. The effect of MLH on horn growth was age-specific. The slope of the correlation between MLH and yearly horn growth changed from negative to positive as males aged, in accordance with the mutation accumulation theory of the evolution of senescence. Our results suggest that the horns of ibex males are an honest signal of genetic quality.
278 citations
TL;DR: It is shown that genetic variability in ibex populations (HE ≈ 0.13) is among the lowest reported from microsatellites in mammal species, and that the Alpi Marittime–Mercantour population has suffered from a severe genetic bottleneck associated with its reintroduction.
Abstract: We evaluated the usefulness of microsatellites and recently developed statistical methods for the conservation management of fragmented and reintroduced populations, using the alpine ibex (Capra ibex) as a model species. First, we assessed the effects of past reintroduction programmes on genetic diversity and population differentiation considering different population sizes and histories. We show that genetic variability in ibex populations (H-E approximate to 0.13) is among the lowest reported from microsatellites in mammal species, and that the Alpi Marittime-Mercantour population has suffered from a severe genetic bottleneck associated with its reintroduction. Second, using a computer-simulation approach, we provide examples and rough guidelines for translocation programmes concerning the number and origin of individuals for future reintroductions and for the reinforcement of populations with low genetic variability. Finally, we use the ibex microsatellite data to assess the usefulness of several published statistical tests for detecting population bottlenecks and assigning individuals to their population of origin. This study illustrates that microsatellites allow: M evaluation of alternative translocation scenarios by simulating different numbers and origins of 'migrants'; (ii) identification of bottlenecked. populations (especially using the Wilcoxon signed-ranks test); and (iii) population assignment with a high certainty (P < 0.001) of almost 100% of the individuals (or trophies or carcasses) from two distant populations (especially using STUCTURE or WHICHRUN software).
246 citations
TL;DR: In this paper, the authors examined a 45-year time series of annual censuses of Alpine ibex (Capra ibex) in the Gran Paradiso National Park in northwestern Italy.
Abstract: Population models in ecology are rarely validated by comparing their pre- dictions to long-term observations of changes in population size. We have used a variety of analytical tools to examine a 45-year time series of annual censuses of Alpine ibex (Capra ibex) in the Gran Paradiso National Park in northwestern Italy. This ibex population grew from about 3300 to almost 5000 individuals in the 1980s during a decade of anom- alously mild winters, and then began to decline in the 1990s. By 1997, the population size had returned to previous levels. Adult survival apparently increased and adult sex ratio may have changed to slightly favor males during the increase in population density. Yearly changes in total population were correlated with seasonal average snow depth and population density over the 39 years for which climate data were available. Our results show that the ibex population size was limited by both density dependence and deep snow. A model based on these factors fit to the first 19 years of data was used to forecast subsequent changes in total population based on initial population size and yearly snow depth. The model was able to predict the increase and subsequent decline in total population size over the final 20 years of the study but failed to reproduce population levels after the eruption. Our results suggest that the 1980s episode of population growth was primarily driven by increased adult survival, rather than increased recruitment.
199 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 12 |
| 2020 | 10 |
| 2019 | 9 |
| 2018 | 9 |
| 2017 | 7 |
| 2016 | 2 |