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L'Insegnamento della Zoologia a Sassari
Full text linkBreve panoramica sull'insegnamento della Zoologia presso l'Università degli studi di Sassari, caratterizzato da un insieme di approcci che ne garantiscono da un lato la comletezza del processo didattico e nel contempo la possibilità di sviluppare tematiche attuali ed aggiornate di questa diciplina nelle sue diverse accezioni
Relationships between mating systems, spatial behaviour and genetic variability in ungulates, with special reference to European cervids
No full text
Gli Ungulati in Italia: status, gestione e ricerca scientifica
Full text linkUngulates in Italy: status, management and scientific research.
Ungulates in Italy have experienced in the last decade a further increase of their distribution and, possibly, consistence. This trend has been very obvious in the central and northern part of Italy, on the contrary, in south Italy the increase of ungulates populations is quite slow if any. A partial exception is Sardinia where Sardinian red deer (Cervus elaphus corsicanus) has been reintroduced into the four provinces of the island. In this frame the relevance of the increase of ungulates for the increase of wolves (Canis lupus) in Italy must be emphasized. Ungulates management has also experienced a general development in the last decade, even if deep differences between south and central-north Italy still persist. Well conducted reintroductions have allowed to fill many gaps in the species distribution. Ungulates hunting bags size, suggest an increased importance of ungulates in the hunting activities in Italy. Selective hunting with rifles on cervids and bovids was established in wide areas of north and central Italy, mainly as consequence of roe deer (Capreolus capreolus) widespread presence. Wild boar (Sus scrofa) hunting still represents a problem for ungulate management in Italy. Almost 50% of the provinces where wild boar is hunted does not collect hunting bag statistics, and only 35% of them try to roughly estimate the consistence of the populations. The traditional dogs hunting of wild boar has expanded to areas where wild boar was recently and illegally reintroduced, as south Italy and the Alps region, and this is a serious problem for the development of a more rational and correct hunting practices. New possibilities of hunting management of red deer in central Italy, and in the future of alpine ibex (Capra ibex), are to be considered. An increase of the presence of trained wildlife managers in public administrations is suggested, as a further step in the development of a proper management of ungulates and other wildlife. Scientific research on ungulates in Italy was, in the last decade, quite uneven both in the species and in the disciplines chosen. There is a clear opportunistic approach to subjects, that often has no link with the real necessities of wildlife management. The development of long term studies is suggested, together with a more efficient coordination among scientist in the choice of the research subjects. Last but not least a more efficient founding mechanisms is needed in order to avoid money waste and to promote serious research programmes
Successo riproduttivo maschile e caccia di selezione negli Ungulati: l'esempio del daino
No full textEcological sexual segregation in fallow deer (Dama dama): a multi-spatial and multi-temporal approach
No full textWe questioned the different interpretations of ecological sexual segregation from a novel perspective, i.e., by carrying out diverse temporal and spatial scale analyses within a long-term study (1984-2003). Thus we combined spatial (small/large) and temporal (small/large) scale analyses to identify the factors generating sexual segregation in fallow deer in San Rossore, Italy. The study site was divided into an eastern sector characterized by human disturbance (DS) and a western undisturbed sector (US). According to census data, human presence increased in DS from 1984, and while females gradually abandoned it, males remained-thus supporting the predation risk hypothesis (large spatial and temporal scale)-and actually increased their presence in DS, where they seemingly benefited from a lower female density. This supported the indirect competition hypothesis. The analysis of data on a large temporal and small spatial scale confirmed that intersexual competition, in particular for grass, was higher in a crowded pasture in US. Observations by means of radio-telemetry of 23 adult females and 25 adult males (1997-2001, reduced temporal and large spatial scale) showed that large scale segregation was relevant during the day and disappeared at night, when disturbance was absent and also the females reached DS. This also supported the predation risk hypothesis. Moreover, sexes showed different habitat choices inside DS at night, thus supporting the forage selection hypothesis (small spatial and temporal scale). In conclusion, failure to address the whole set of combinations of spatial and temporal scale analyses would have led to monocausal explanations of ecological sexual segregation
Do antlers honestly advertise the phenotypic quality of fallow buck (Dama dama) in a lekking population?
No full textSize and symmetry of secondary sexual traits are supposed to be honest signals of male phenotypic quality in vertebrates. Antler size and symmetry, male quality and mating success have not been fully demonstrated to be correlated in cervids. Such correlations can be particularly intriguing in the case of species adopting costly mating strategies, which imply territorial defence without feeding. In these cases, body condition appears to be crucial at the onset of the rut, and large and symmetrical antlers may be borne by successful males. For these reasons, during four consecutive years, we analysed growth rate, size and symmetry of 26 fallow bucks' antlers in relation to individual mating strategy and success in a lekking population. Territorial (T) males, which gained higher mating success in the lek, showed a faster antler growth (about 10 g/d per antler) than non-territorial (NT) males (3.6-5.2 g/d per antler) during the velvet period, and this was likely because of optimized foraging strategies. At the onset of the rut, when antler growth was completed, T males had larger antlers than NT males. Possibly because of worsened body conditions, NT males showed a pronounced antler directional asymmetry, while T males did not. However, no direct link between antler symmetry and mating success was found, thus confirming the ambiguous role of antler asymmetry as an indicator of fitness. The faster the antler growth, the larger its final size and the higher its beholder's mating success. Our results confirmed that, like groaning and scent marking, antler size reflects social status and dominance in male fallow deer, and therefore represents an honest advertisement of phenotypic quality
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