1,721,016 research outputs found
Analysis of ecological factors able to affect horn size in yearling Alpine chamois: the role of the geological substrate in affecting horn growth.
No full textBehavioural response of two alpine ungulates after the recolonisation of the same predator.
No full textAlternative mating strategies and reproduction in Alpine ibex (Capra ibex): consequences of snowy winters.
No full textHabitat selection in adult males of Alpine ibex,Capra ibex ibex
Full text linkHabitat use and selection of 14 Alpine ibex males were studied in the Gran
Paradiso National Park. Alpine meadows were always overused and positively selected, because
this habitat constituted an important food resource for the ibex. Even if rocks (30%) and stone
ravines (22%) were the most frequented habitats in the study area, their use was lower than their
availability because they offered few trophic resources. Pastures were used only in spring when
the ibexes were looking for those sites just free from snow and with fresh vegetation. Stone
ravines, where the ibexes rested in the hottest days, were most used in summer. Rocks were most
used in winter: rock-faces are the only sites where the risk of avalanches is low and where it is
still possible to find snow-free patches. Larch woods were especially used in winter and spring
when it was still possible to find snow-free patches. The home range sizes proved to be
influenced by the amount of Alpine meadows and rocks
The role of geological substrate for horn growth in ungulates: a case study on Alpine chamois
No full text""Ecological factors such as environmental and climatic conditions affect the growth of ornaments in ungulates. Studies about their influence can reveal key information on individual life histories and detect the events that can have important evolutionary consequences. Among the ecological factors commonly thought to play a role in such ecological processes, researches have so far neglected the possible influence of the geological feature which may either promote or restrain the early investment in horn growth. This study takes into consideration a broad range of ecological factors that are expected to affect horn growth and analyses how the substrate (calcareous versus siliceous) could modify the horn size in 1,685 yearling Alpine chamois (Rupicapra rupicapra) which were legally shot during 5 consecutive years in Central-Eastern Italian Alps. Interestingly, we found shorter horns in chamois shot on siliceous than on calcareous substrate, irrespective of the sex, showing how the substrate (and related ecological conditions) may affect horn growth. The substrate interacted with two ecological factors in shaping the horn size, i.e. aspect and snow cover. Differences between horn lengths recorded for chamois shot on these two substrates were less pronounced where South-facing slopes prevailed. During an average winter (about 100 days with more than 10 cm of snow on the ground) chamois horns were longer in individuals using calcareous areas, although the increase of number of days with more than 10 cm of snow on the ground had a stronger impact in reducing horn length in calcareous environment. We demonstrated that substrate, and related ecological conditions, influence horn growth. In ungulate species where ornament size is related to reproductive success, environmental factors, such as geological feature, can thus cause evolutionary consequences in the expression of ornaments and individual fitness."
Consequences of snowy winters on male mating strategies and reproduction in a mountain ungulate
No full text"Alternative mating tactics (AMTs) are intrasexual variants in mating behaviour of several species ranging from arthropods to mammals. Male AMTs coexist between and within populations. In particular, male ungulates rarely adopt just one tactic throughout their lifetime. Tactics commonly change according to internal factors (age, body size, condition) and external conditions (weather, resources, predation, animal density). However, the influence of weather has not yet been investigated in upper vertebrates. Such influence may be relevant in species whose rutting period occurs late in fall or in winter, when environmental conditions and the snow cover in particular may vary considerably. We detected two AMTs in Alpine ibex (Capra ibex) males: older and full-grown males mainly adopted the tending tactic, while younger males usually pursued an alternative one (coursing tactic). Weather was found to influence the use of AMTs by males: in snowy mating seasons, the coursing tactic was no longer used due to difficulties in moving through deep snow. In snowy rutting periods, males appeared to delay or even avoid mating activities and a decrease of births was reported in the second part of the following birth season. Snow cover may have a negative effect on population dynamics by reducing the recruitment and on population genetic variability, as a consequence of poorer mating opportunities. Studies on factors affecting mating behaviour and leading to a reduced availability of mates and a decrease in female productivity are especially relevant in species, like Alpine ibex, whose genetic variability is low.
The mouflon: A problematic species or a species in trouble? Different perspectives from the Alps and from Sardinia.
No full textHunting seasons in relation to biological breeding seasons and the implications for the control or regulation of ungulate populations
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