Temporal Comparisons of Avifauna in Enashiva Nature Refuge, Tanzania An Examination of Species Richness and Abundance, the Effects of the Onset of the Short Rainy Season, and the Migrant Communities Present

This study examined avian species richness, abundance, distribution, and diversity in relation to seasonal and temporal changes in Enashiva Nature Refuge, Tanzania. Data was collected in using point-counts along pre-established transects in four distinct habitats – wooded grassland, grassland, woodland, and riverine – over an 18-day period from November 6 to November 23, 2011. Transects were comprised of five point-count spots, at which data on avian species an abundance was collected for 30 minutes each. Data was compared to two previous studies conducted in November 2009 and April 2011 with similar methodologies over comparable time frames. Descriptive statistics, community similarity, and Simpson and Shannon-Wiener indices of diversity were used to compare all data sets overall and by habitat. Both seasonal and temporal changes over time were found in the avifauna of Enashiva Nature Refuge. Habitat-specific differences were also noticeable. For all studies, the grassland had the fewest species and individuals, while the most species and individuals fluctuated between other habitats. In this study, the wooded grassland had the most community similarity with other habitats, while the grassland had the least. Between studies, the two fall studies were the most similar, reflecting seasonal changes. All habitats and the overall community of Enashiva ranked with relatively high diversity for both Simpson and Shannon-Weiner indices of diversity, with the overall community being the most diverse and the grassland being the least. Between studies, different habitats were the most diverse, but for all studies the grassland was the least diverse. With the onset of the short rainy season, rain hours increased each day, correlating strongly with an increase in both species identified and individuals seen. Migrant species were also analyzed, with a similar number of migrants found in each study but the most similar migrant community shared between the two fall semesters. With both the expected seasonal changes and the lessexpected changes over time, this study provided evidence of the changing avifauna community due to both seasonal rains and the changing habitats at Enashiva Nature Refuge