An important proportion of the world's biodiversity is found on oceanic islands. Island endemics frequently have small populations and are known to be sensitive to habitat and community changes, making them prone to extinction. In this paper, we assess the habitat distribution of the terrestrial birds of Pemba, an oceanic island that has been classi®ed has an``Endemic Bird Area''. Most of Pemba has been profoundly altered by human activities and only small patches of natural vegetation remain. However, we found that the six endemic birds (four species and two sub-species) have colonised several of the man-made habitats, including clove plantations and farmland, and remain widespread. Species richness was not reduced in these heavily managed areas when compared to the remnants of tropical forest. Nonetheless, the main strongholds of some endemic species are in habitats which have substantially declined in recent years, and which are likely to be further reduced in area in the medium and long term. For these endemics, particularly the Pemba scops owl (Otus pembaensis), the conversion of areas that were formerly clove plantations to open farmland should be considered a serious threat. #
The antlion larvae are sessile predaceous larvae, which depend on active prey for their food. They dig conical pit in loose fine sand and remain at the bottom of their pits with their long piercing jaws from where they seize and remove the body fluids of the ant and other arthropods that slide into their trap. The effects of hunger and density on the spatial distribution and pit construction by the larvae were studied for the three instar stages in fine and coarse sand textures of particles size of <540 µm and <1200 µm respectively.Twenty four (24) Iron trays of 25cm 2 each filled with sand to the depth of 20cmwere used in the study.The result of the findings reveals that with the increase in density, there was an increased in spatial uniformity and the pits became uniformly distributed. The diameters of the pit were not statistically affected by the changes in the larval density. There was difference between the total number of pits constructed between sand textures and not between the larval instars, in addition, nearest neighbor distance decreases with increase in density and with no effect on pit diameter. Pit diameter increases with hunger level and Antlion move pit to reducedisturbances and to improve food supply. The result analysis showed significant differences in the mean number of pits constructed between densities, sand texture and larval instars at P< 0.01 but none between fed and larval instar.
A study of the impact of developmental activities on the distribution and biodiversity of aquatic macroinvertebrates of Kano River was conducted between June 2014 to May 2016. Six sampling sites from the upstream receiving point to downstream were selected river. Result indicated that the species richness were 2271 and 2844 in first twelve months and preceding respectively, grouped into 19 families and classified into five functional feeding groups. Chironomidae was found to be the dominant family for 24% abundance and 18% abundance in wet and dry seasons of 2014 respectively. Communities were most diverse at Site C (0.94) in 2014 least evenly distributed in the first Twelve month as i However high evenness was observed in Site C (0.99). Sites species composition in degrees of association using Pearson Product Moment Correlation (PPMC) revealed high correlation of (.968) while t in 2015-2016 site E and F showed high correlation of (.995) while moderate correlation wasbetween Site E and A (.611). Results were discussed, concluded and recommendations were made.
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