الفهرس | Only 14 pages are availabe for public view |
Abstract In the present study, two different locations were studied, one of them is a group of houses in Haradia Village, and the other is an agricultural field, about 50 m away from the Village. Both of them belong to El Maragha District which is about 25 km away from Sohag, City. This study has paid attention to identify the species of rodents in houses and field habitats, their density, population structure, outbreak, monthly changes over the two successive years 2013 and 2014, and their effects on agricultural crops in the field area. This study has proved that there were four species in houses area, these were: (1) Rattus rattus frugivorus. (2) Rattus rattus alexandrinus. (3) Arvicanthis niloticus. (4) Rattus norvegicus. And three species in the field area: 1. Rattus rattus frugivorus. 2. Rattus rattus alexandrinus 3. Arvicanthis niloticus. In the present study, the body length, tail length and the ratio between the body length and tail length and abdomen colour were used to distinguish between the different species. The ratio between the body length and tail length was the most important classification character that separates the different species. Summary 130 Also, the study has proved that the most common species at houses area was Rattus rattus frugivorus then Rattus rattus alexandrinus while the two species: Arvicanthis niloticus and Rattus norvegicus were the less common. In the field area the most common species was Arvicanthis niloticus followed by Rattus rattus frugivorus and the less common was Rattus rattus alexandrinus and Rattus norvegicus was not recorded in this area. The study proved also that, in big species, tail length was longer than body length. So, the body length to tail length ratio was less than ”One”. In the Rattus rattus frugivorus species it was about 0.85 and in Rattus rattus alexandrinus species it was about 0.95. In Arvicanthis niloticus species the body length was longer than the tail length and the ratio was more than ”one” and about 1.5. The study also showed an alternate temporal relationship between Rattus rattus frugivorus and Rattus rattus alexandrinus. The species Rattus rattus frugivorus was common in autumn and winter but the species Rattus rattus alexandrinus was common in summer and spring. The species Arvicanthis niloticus didn’t appear except in the beginning of summer and disappeared in the other months of the year. In the field area (Rattus rattus frugivorus) was most common in summer and spring and less in autumn and winter. Rattus rattus alexandrinus was common at the end of summer and beginning of autumn, the end of winter and the beginning of spring. The species (Arvicanthis niloticus) appeared Summary 131 in spring and the beginning of summer. (Rattus norvegicus) didn’t appear at all in the field area. The study also, proved that in all months, almost all species have two generations, a young and an older one. But due to the small collected numbers and absence of the new recruits, the analysis of study was difficult and needs more information. The study paid attention to the effect of the present species in field area on two kinds of economic crops: The wheat and maize. The study has proved that the damage in wheat crop was about 24.3% to 50% in 2013, and 30.6% to 36.8% in 2014. The percentage of damage was increasing near to the irrigation cannal and far away from the main road. The percentage of damage in maize crop was about 4% to 5.8% in 2013 and 5.2% to 5.8% in 2014. The percentage of damage was high near the irrigation canal and decreases away from it, and it was less near to the main road and increased away from it. The study showed that the moving ability and wandering of the present species in the field area |