1,720,978 research outputs found
L’esercizio site visit 2007–2008. Metodologia della ricerca, elaborazione ed analisi dei dati
No full textThe analysis of sexual segregation in fallow deer (Dama dama) on different time and space scales
No full textLong-term influence of human presence on spatial sexual segregation in fallow deer (Dama dama).
No full textThe present work investigates how a fallow deer (Dama dama) population in central Italy might have been affected from 1984 to 2003 by the increase of human access to the study site, where humans were the main deer predators. By using deer census data, possible correlations were analyzed between the increase in human presence and the response of. each age and sex class. The numbers of different age and sex classes of deer recorded inside and outside the sector affected by human presence throughout the 20-year period of study were compared. A differential response was recorded among classes. Adult females and juveniles left this area (reducing their presence from 37% of all deer observed to 11% for adult females and from 19% to 3% for juveniles) when human pressure became higher, whereas the opposite result was true for males older than 24 months (adult males) that remained inside the disturbed sector (from 27% to 50% of deer observed). Intermediate values were recorded for yearling males, because they can be associated with both groups of females and groups of males. Results Of this long-term study are best explained with the reproductive strategy hypothesis, because the increase of predation risk evoked a marked spatial Sexual segregation in the fallow deer population. Females and juveniles used relatively predator-safe habitats, whereas males used habitats with higher predation risk but better food quality. Furthermore, as females increased their presence outside the disturbed sector, males gradually abandoned the undisturbed area, increased use of the disturbed sector, and maximized foraging opportunities by going to areas where indirect competition with females was probably reduced
Fallow deer lekking and alternative mating strategies in San Rossore, Italy: Insights from a long term study
No full textStudio delle strategie riproduttive adottate dai maschi di daino (Dama dama) nella Tenuta di San Rossore (Pisa): analisi dei fattori che influenzano l’adozione di una strategia di successo
No full textAnalisi delle marcature effettuate dai maschi adulti di daino (Dama dama) in prossimità di un lek durante il periodo riproduttivo
No full textHabitat selection in adult male of Alpine ibex, Capra ibex ibex
No full textHabitat 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
Habitat selection in adult male of Alpine ibex, Capra ibex ibex
No full textHabitat 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
Laterality in roe deer embryos implantation
Full text linkFemale reproductive success is one of the most important life-history traits to be monitored when determining population dynamics in free-ranging ungulates. Several studies have described how phenotypic characteristics of the mother, climatic conditions, population status, and habitat can impact on potential reproductive output in wild ungulates. However, little is known regarding the internal, physiological factors, that may account for differences in implantation rates. The present study investigated the differences in implantation rates and site on the basis of site and number of ovulations through the examination of about 3000 intact uteri collected from pregnant roe deer does (Capreolus capreolus). Although ovulation occurs with the same frequency in the left and right ovary, we revealed a higher frequency of embryos implantation in the left uterine horn in odd litter size, demonstrating that embryos can migrate between the uterine horns. In our study, a greater proportion of reproductive wastage was associated to females with three and four corpora lutea and interestingly, in relation to the site of ovulation, the percentage of corpora lutea that did not correspond to a fetus was higher in the right ovary than in the left one (73.2% vs. 26.8%). Our research described for the first time the absence of laterality in ovulation and the presence of laterality in implantation in roe deer, thus laying the foundations for in-depth studies about the functionality of this uterine side and for comparisons with populations located in other geographical areas to understand whether it is a widespread phenomenon or a local adaptation
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