Fishing activities in Gendwuha, Guang, Shinfa and Ayima rivers in Tekeze and Abbay basins, Ethiopia: preliminary study

水位的洪枯变化通过江湖连通影响泛滥平原湖泊鱼类的组成和分布，因而江湖过渡带是反映泛滥平原生态系统鱼类交流和多样性变动的关键区域.尽管如此，针对江湖过渡带鱼类群落随水位洪枯变化的研究十分匮乏.本研究以菜子湖江湖过渡带为例，分别在洪水和枯水期选取包括静水和流水生境的样点对鱼类群落进行系统的调查采样，探讨水位洪枯变化对菜子湖江湖过渡带鱼类物种和功能多样性的影响.共采集到鱼类6目12科37属52种，其中，洪水期和枯水期物种数差异显著，分别采集到鱼类50和42种，而静水生境和流水生境物种数差异不明显，分别采集到鱼类47和48种.与洪水期相比，枯水期山溪河流性鱼类的物种数、重量、尾数和优势度百分比分别减少了7.3%、6.3%、14.4%和12.0%；与静水生境相比，流水生境山溪河流性鱼类的物种数、重量、尾数和优势度百分比分别增加了5.3%、14.6%、18.0%和22.3%.SIMPER分析结果显示，麦穗鱼（Pseudorasbora parva）、蛇鮈（Saurogobio dabryi）、（Hemiculter leucisculus）、鲤（Cyprinus carpio）、鲫（Carassius auratus）、短颌鲚（Coilia brachygnathus）、似鳊（Pseudobrama simoni）、翘嘴鲌（Culter ilishaeformis）、达氏鲌（Culter dabryi）、光唇蛇鮈（Saurogobio gymnocheilus）和无须鱊（Acheilognathus gracilis）是引起水位洪枯变化以及不同生境类型鱼类群落结构差异的主要物种.优势度分析结果表明枯水期和静水生境的优势种鱼类相似，重要值较高的优势种鱼类为鲤、鲫、和似鳊；而洪水期和流水生境的优势种鱼类同样相似，重要值较高的优势种鱼类为麦穗鱼、蛇鮈、光唇蛇鮈和短颌鲚.通过双因素方差分析解析了水位洪枯变化和不同生境类型对鱼类物种和功能多样性的影响.发现洪枯水位变化仅对物种多样性指数中的物种数（Richness）产生显著差异，而对功能多样性的3个指数（功能丰富度指数（FRic）、功能离散指数（FDiv）和功能分散指数（FDis））均有显著影响.洪水期鱼类的Richness、FRic、FDiv和FDis指数均显著高于枯水期.同时，静水生境条件下的FRic指数要显著高于流水生境.本研究发现，与传统的物种多样性相比，基于功能性状的功能多样性对水位的洪枯变动更为敏感，河流周期性洪泛是泛滥平原生态系统中鱼类功能补充的重要方式.;Water level fluctuations between wet and dry seasons, assisting by lateral connectivity, play a fundamental role in underpinning the composition and distribution of fish fauna in floodplain lakes. The ecotone floodplains between the floodplain rivers and lakes are generally considered as the key areas where witness the exchange of fish species and the variations of biodiversity. However, the study of changes in taxonomic and functional diversity of fish communities in the ecotone floodplain in response to water level fluctuations is limited. Here we address this issue by measuring temporal (dry and wet seasons) and spatial (lotic and lentic habitat patches) changes in taxonomic and functional diversity of fish communities in the ecotone floodplain between the Yangtze River and Lake Caizi. A total of 52 species belonging to 37 genera, 12 families and 6 orders were collected in our study. Among them, there were significant differences in species number between wet and dry seasons, with 50 species and 42 species collected respectively. On the other hand, there was no significant difference in the number of species between lentic and lotic habitat patches, with 47 species and 48 species collected respectively. In comparison with wet season, the species richness, weight, abundance and importance value percentage of riverine species decreased by 7.3%, 6.3%, 14.4% and 12.0% in dry season. In comparison with lentic habitat patches, the species richness, weight, abundance and importance value percentage of riverine species increased by 5.3%, 14.6%, 18.0% and 22.3%. The fish fauna differences between seasons (dry and wet) and habitat patches (lentic and lotic) were determined by the abundance of Pseudorasbora parva, Saurogobio dabryi, Hemiculter leucisculus, Cyprinus carpio, Carassius auratus, Coilia brachygnathus, Pseudobrama simony, Culter ilishaeformis, Culter dabryi, Saurogobio gymnocheilus and Acheilognathus gracilis. Important value analysis showed that the dominant species of fish in lentic habitat patches and dry season were similar, and the dominant species of fish in lotic habitat patches and wet season were similar as well. The dominant species in wet season and lotic habitat patches were P. parva, S. dabryi, S. gymnocheilus and C. brachygnathus, while the dominant species in dry season and lentic habitat patches were C. carpio, C. auratus, H. leucisculus and P. simoni. Two-way ANOVA analysis indicated that one taxonomic diversity indices (Richness) and three functional diversity indices (FRic, FDiv and FDis) significantly differed between wet and dry seasons. Taxonomic richness, functional richness, functional divergence and functional dispersion were significantly higher in wet season than in dry season. Meanwhile, the functional richness was significantly higher in lentic than in lotic habitat patches. Functional diversity exhibited higher sensitivity than the traditional taxonomic diversity, since three functional diversity indices showed significant variations between wet and dry seasons. Meanwhile, our study highlight important functional recruitments of fish assemblages triggered by seasonal flood pulses.

Diversity, relative abundance and some biological aspect of fishes in Gilgel Abay and Andassa Rivers were studied from September 2010 to June 2011 by using gillnets of mesh sizes 6 cm, 8 cm, 10 cm and 12 cm, monofilaments of different mesh sizes, cast net, hook and lines. Fish species identification was done by using literature and specimen deposited in the laboratory. Abiotic parameters such as temperature, conductivity, pH, total dissolved solids and transparency of the rivers were also taken, using multi-meters. The analysis of independent ttest showed that there was significant deference in pH and transparency between seasons in Andassa River (p<0.05). In Gilgel Abay River, there was significant difference in temperature and transparency (p<0.05) between seasons. Totally 939 fish specimens were collected from Gilgel Abay and Andassa Rivers. Three families and thirteen species of fishes were identified from Andassa and Gilgel Abay Rivers. Labeobarbus intermedius, Varicorhinus beso, L. nedgia and Clarias gariepinus were the most dominant fish species found in both Rivers. Index of Relative Importance (IRI) and Shannon Diversity Index (H') were used to evaluate the abundance and diversity of fish species. Andassa River had higher diversity (H'=4.06) than Gilgel Abay River (H'=4.05) in dry season but lower than Gilgel Abay in wet season which was (H'=3.32) and 4.35, respectively. In wet season, the most abundant species in Andassa River were L. intermedius, V. beso, C. gariepinus and L. crassibarbis. L. intermedius, L. nedgia and C. gariepinus were the most abundance species in Gilgel Abay during wet season. In both seasons, L. intermedius was the most important species at Andassa and Gilgel Abay Rivers. In Gilgel Abay River, the most important fish species in wet and dry seasons were L. intermedius, L. nedgia and C. gariepinus. The sex ratio analysis showed that there was significant deviation from unity (p<0.05).

AimTropical forests are vertically complex, and offer unique niche opportunities in the form of climate, habitat and resource gradients from ground to canopy. Rainforest species organize within this vertical spatial gradient and recent macroecological research suggests that the highest levels of vertical stratification occur in structurally complex and climatically stable tropical rainforests. However, although the classical view of the tropics is that of aseasonality, particularly in temperature, there is strong seasonality in rainfall. Thus, we predict considerable variation in vertical stratification in time, characterized by a seasonal restructuring of communities across vertical space.LocationSierra Llorona, Colón Province, Panama.TaxonAmphibians.MethodsWe performed 121 ground‐to‐canopy surveys across the wet and dry seasons for amphibians. Using a bootstrap simulation method we calculated species‐specific and community‐wide vertical height and abundance shifts between seasons. Separately, we tested the importance of vertical height and season on the vertical distribution of species using a redundancy analysis, and employed linear models to explore turnover in species composition across vertical height between seasons.ResultsOur results show a clear downward shift of 5 m in height in amphibian communities from the wet season to dry season. We also observe significant changes in species composition across vertical strata in both seasons, driven primarily by nestedness in the dry season (loss of species over height) and genuine turnover in the wet season (loss and addition of species over height).Main conclusionsThe exploitation of canopy microhabitats and resources in the wet season resulted in complex patterns of stratification, whereas drying flattened the distribution and simplified the composition of arboreal communities. As such, pattern and process in the vertical dimension is not static in time but rather exists as a dichotomy with inverse patterns between wet and dry seasons. Complex, multidimensional distributions of diverse rainforest communities can be simplified by climatic constraints – an important consideration as anthropogenic climate change increases the magnitude of seasonal swings in temperature and precipitation.

Abundance and fish species composition of both Gerado and Drima Rivers were studied in dry and wet seasons from February to November 2014. The objectives of the study were to assess fish species composition, relative abundance and recommend sustainable fishery management to help biodiversity conservation in aquatic ecosystem. Gillnet with mesh size of 6-10 cm were used to catch the fish species, sensitive balance was used to measure weight of the fish in gm and Ruler was used to measure total length of the fish species in cm . Shannon diversity index was used to compare species diversity in both rivers between season.Univarate analysis and t test were used to test species composition and abundance difference in both rivers between sites and season through application of SPSS Version 16.The number of fish species collected from Gerado River was more (8) than from Dirma River(6).In both rivers, abundance and fish species composition were more in dry season than wet season. The Shannon diversity index(H') value were 1.78 and 1.66 in dry and wet season respectively for Gerado river and 1.61 and 1.41 in dry and wet seasons, respectively, for Dirma River. The dominant fish species in Dirma and Gerado Rivers in dry season was Varcorhinus beso with total number of specimens of 128 and 129, respectively. The dominant fish species in wet season in Dirma River was Labeobarbus intermedius (40) whereas Varcorhinus beso was dominant in Gerado River (25). The total fish species composition of Dirma River was more (6) in dry season than wet season (5). The total fish specimens collected in Drima River was more in dry season (236) than wet season (77). The species composition of Gerado River was higher (8) in dry season than wet season (6). The total fish specimen collected in Gerado River was higher (199) in dry season than wet season (37). There was significant difference in abundance of fish specimens between season and site (P&lt;0.05) unlike the non significant variation in Shannon diversity index value (P&gt;0.05) between rivers.

The study about species composition, relative abundance and habitat association of avian fauna in Zegie Peninsula forest patches and associated wetlands was carried out from August 2018 to March 2019, covering both the wet and dry seasons. Forest, shrub, lakeshore and wetland were habitats. Data were collected using point count and line transect methods, for 24 days. A total of 96 species of birds were identified. Out of the total, 40 species were observed during the wet season; 13 during dry and 43 species in both seasons. There was statistically significance variation of species distribution among habitats (χ2=11.89, df=3, p=0.008). During the wet season, the highest species diversity was recorded in the wetland habitat (H’=3.3) followed by forest habitat (H’= 2.9). During the dry season, avian diversity was highest in lakeshore (H’=2.58) followed by wetland (H’=2.51). Highest evenness was observed in the shrub land (E=0.87) and (E=0.84) during the wet and dry seasons, respectively .During the wet season, the highest species similarity was recorded between wetland and lakeshore habitat (SI=0.39) and during the dry season the highest species similarity was recorded between forest and shrub habitats (SI= 0.6). 64(66.66%) of the avian species were uncommon. Currently, however, the species diversity in the area decreases. This might be due to various anthropogenic activities such as deforestation of trees for timber and cutting tree for fire wood. Therefore, awareness creation should be given to the local community to reduce habitat destruction. Keywords/Phrases: Bird diversity, relative abundance, wetlands, Zegie Peninsula, DOI: 10.7176/JBAH/12-11-01 Publication date: June 30 th 2022

Introduction. Ethiopia is one of the most avifauna rich countries in Africa. Avifaunal surveys are required to inform conservation decisions and enhance land management for biodiversity. Avifaunal surveys from Ethiopia are lacking. This study examines species composition, relative abundance, and habitat association of avian fauna in Zegie Peninsula forest patches and associated wetlands from surveys carried out from August 2018 to March 2019, covering both the wet and dry seasons. Data Collection. Forest, shrub, lakeshore, and wetland habitats were identified as ecologically relevant habitats in the study area for data collection. Data were collected using point count and line transect methods, for 24 days in total for both seasons in the morning and afternoon. Results. A total of 96 species of birds were identified during the whole study period. Out of the total, 40 species were observed during the wet season, 13 during dry and 43 species in both seasons. There was significant variation of species distribution among habitats. During the wet season, the highest species diversity was recorded in the wetland habitat followed by forest habitat. During the dry season, avian diversity was the highest in the lakeshore followed by wetlands. The highest evenness was observed in the shrubland during both the wet and dry seasons. During the wet season, the highest species similarity was recorded between wetland and lakeshore habitats, and during the dry season, the highest species similarity was recorded between forest and shrub habitats. Based on encounter rate data, 64 (66.66%) of the avian species were uncommon. Conclusions. Compared to previous studies conducted in the study area, species diversity was lower. This might be due to various anthropogenic activities such as deforestation of trees for timber and cutting trees for firewood. Therefore, awareness creation should be given to the local community to reduce habitat destruction due to various human-induced factors.

Biotic and abiotic properties most closely associated with subtropical forest soil respiration differ in wet and dry seasons: A 10-year in situ study

The southwestern mountains of Hainan Island are the southernmost region with tropical karst landform in China. The frequent alternation of dry and wet seasons leads to the loss of the mineral nutrients of limestone, creating karst fissure habitats. Plants living in karst fissure habitats for long periods of time have developed local adaptation mechanisms correspondingly. In the paper, hydrogen–oxygen stable isotope technology was applied to determine the water-use sources of Impatiens hainanensis in the dry and wet seasons, hoping to expound the adaptation mechanism of I. hainanensis in karst fissure habitats to the moisture dynamics in the wet and dry seasons. In the wet season (May to October, 2018), the air humidity is relatively high in the I. hainanensis habitat; in the dry season (November 2018 to April 2019), there is a degree of evaporation. In the wet season, fine-root biomass increases with soil depths, while coarse-root biomass decreases with soil depths; in the dry season, fine-root biomass is lower and coarse-root biomass is higher compared with the wet season. It was found that the average rainfall reached 1523 mm and the main water-use sources were shallow (0–5 cm) and middle (5–10 cm) soil water, epikarst water, and shallow karst fissure water during the wet season; the average rainfall reached 528 mm, and the deep (10–15 cm) soil water and shallow karst fissure water were the main water-use sources during the dry season. Fog water has a partial complementary effect in the dry season. The differences in the distribution of root biomass and each source of water in the wet and dry seasons of I. hainanensis also reflect the different water-use strategies of I. hainanensis in the wet and dry seasons. In both dry and wet seasons, I. hainanensis formed a water-use pattern dominated by soil water and shallow fissure water (0–15 cm) under the influence of the “fissure-soil-plant” system in the karst region.

A cross-sectional study was conducted to determine the species, prevalence, and seasonal variation of ticks on cattle in central Oromia. In addition, questionnaire survey was used to assess the control practices of ticks in central Oromia. During the study period from August 2008 through April 2009, a total of 10,440 adult ixodid ticks were collected from a total of 918 cattle (153 cattle during dry and wet seasons from each of three agroecologies) in three agroecological zones during wet and dry seasons. A total of seven species of ixodid ticks belonging to four genera were identified during the wet period, whereas similar numbers of genera but six species of ixodid ticks were recorded during the dry season. Amblyomma, Boophilus, Rhipicephalus, and Hyalomma tick genera were identified during the two seasons. Five different species of ticks were identified from the highland altitude. Significantly (p < 0.05) higher proportion of Boophilus decoloratus (88.2 %) was identified during the wet season, Hyalomma truncatum (1.5 %) was with the least proportion. Rhipicephalus evertsi evertsi (50.8 %) was the most abundant during the dry period, whereas Hyalomma marginatum rufipes (5 %) was with smallest proportion. In the midland, a total of six species of ticks were identified. Significantly (p < 0.05) higher proportion of Amblyomma variegatum (76.6 %) than the other species was recorded during the wet season in the midland. But Rhipicephalus pulchellus (0.05 %) was collected with the lowest proportion. R. e. evertsi (46.3 %) was the most abundant tick species during the dry season, whereas R. pulchellus (0 %) was with lowest proportion. In the lowland, a total of seven species of ticks during the wet and six during the dry season were identified. A significantly (p < 0.05) higher proportion of A. variegatum (30.3 %) was recorded during the wet season, whereas R. pulchellus (1.4 %) was identified with the lowest proportion in the lowland. R. e. evertsi (24.8 %) was the most abundant tick species during the dry season in the lowland, but R. pulchellus (0 %) was with the lowest proportion during the same season in the lowland. Results of the study revealed that the highest mean total tick burden was recorded during the early rainy season than the dry season from the end of March to April. And the lowest mean tick count was recorded during the early dry and the late dry season during December and February, respectively. The overall tick count across seasons showed significant variation (F = 114 and p = 0.000). The questionnaire survey on the tick control practices has revealed that (90 %) diazinon and (57.3 %) cypermethrin were the commonly used acaricides with a frequency of one to three times per year during the peak of tick infestation. In conclusion, this study demonstrated that ixodid ticks occur with high prevalence and burden and still play major roles in reducing productivity of cattle and cause health problems of cattle in central Oromia. Further studies on the role of ticks in the transmission of pathogens to cattle, other animals, and zoonotic pathogens to man in Oromia are urgently needed.

The study analysed the spatial and temporal contamination levels of fresh water resources by saline intrusion in the Douala coastal area. Water samples were collected from 19 stations. 3 stations were selected from the mangrove area and 16 stations were selected from the rest of the area partitioned into four transects (coastal transect, inner transect 1, inner transect 2 and inner transect 3). Sampling was done repeatedly during the wet and dry seasons. They were analyzed for physico-chemical parameters according to the American Public Health Association methods. Geostatistical analysis was used in mapping the water properties. Considerable levels of actual electrical conductivity values (208.91 to 660.63 and 45 to 7540 μS/cm for the wet and dry seasons, respectively); calcium (0.06 to 85 and 4 to 256 mg/L for the wet and dry seasons, respectively); sulphate (0 to 103 and 0 to 99 mg/L for the wet and dry seasons) and total dissolved solids (15.79 to 1467 and 20 to 3750 mg/L for the wet and dry seasons, respectively) were observed for ground water in the study area based on spatio-temporal assessment. From the output grid, it could be deduced that the south eastern region had a hint of salt water intrusion (SWI) contamination of fresh water resources with actual value highs of electrical conductivity (1790 and 820 μS/cm) for the dry and wet seasons, respectively. Calcium highs (140 and 16 mg/L) for the dry and wet seasons were obtained at the central part of the study area. The spatial distribution of calcium highs extends from the central zone of the study area in the dry season and the south eastern zone in the wet season. The southern region is more vulnerable to contamination by calcium ions during this season. An up to date scope for surveillance monitoring and forecasting regarding the deterioration of coastal aquifers is recommended. Modelling of aquifers shifts for the coastal zone should be instituted as a means of ensuring efficient fresh water resources evaluation and utilization. An indepth study of the geochemical characteristics of ground water of the coastal zone could determine factors that most significantly impact on fresh water resource quality.

以艾比湖流域主要入湖河流为研究对象，在5月（丰水期）和8月（枯水期）分别沿博尔塔拉河（博河）和精河进行采样，采用平行因子模型（PARAFAC）和三维荧光区域积分法对水体三维荧光特性进行研究并对其与水质的关系在枯、丰水期下的变化进行探讨.结果表明①河流DOM在枯水期与丰水期都含有C1（240、425 nm） UVC类腐殖质，C2（225、290 nm）紫外区内络氨酸类有机物，C3（230/280、330 nm）蛋白类有机物，C4（265、260 nm）腐殖质类共4种组分.通过对水体三维荧光进行区域积分可以看出DOM荧光成分的占比在不同时期的变化.博河在枯水期时EEM光谱中的区域Ⅲ富里酸含量低于丰水期，枯水期时区域Ⅱ芳香类蛋白质、区域Ⅳ可溶性微生物代谢物以及区域Ⅴ类腐殖质酸高于丰水期；对于精河来说，区域Ⅱ芳香类蛋白质和区域Ⅳ可溶性微生物代谢物在枯水期的含量高于丰水期，区域Ⅲ富里酸和区域Ⅴ类腐殖质酸的含量枯水期低于丰水期，这表明水体腐质化程度较高.②本研究选取了一些常规的荧光指数来描述枯、丰水期水体的荧光指数特性.经研究发现，精河的荧光指数、自生源指数和腐殖化指数在不同时期的变化幅度较小，而博河的变化幅度较大.③将荧光指数与水质参数进行相关性分析并建模，结果表明枯水期自生源指数（BIX）与化学需氧量呈显著正相关，相关系数R=0.688；丰水期时BIX与铵态氮浓度呈显著负相关，相关系数R=-0.493.通过对比分析艾比湖主要入湖河流的三维荧光光谱特性与水质在枯、丰水期时的关系进一步表明水体中DOM的特性以及在枯、丰水期下的差异，为艾比湖流域的治理改善提供一定的理论支持和参考依据.;This study takes the main lakes in Lake Ebinur Watershed as the research object, and samples along the Bortala River and Jing River in May (wet season) and August (dry season). The PARAFAC analysis method and the three-dimensional fluorescence region integration method is used to study the three-dimensional fluorescence characteristics of water and its seasonal variation with water quality. The results show that:1)In both dry and wet seasons, river DOM contains C1 (240, 425 nm) and C4 (265, 260 nm) kind of humus, C2 (225, 290 nm) uranium-like organic matter compounds. It found that fulvic acid is lower, while the aromatic protein, soluble microbial and humic acid were highest in dry season than wet season in Bortala River. The concentration of the aromatic protein and soluble microbial in dry season was higher than in wet season, and the fulvic acid and humic acid in dry season was lower than in the wet season in Jing River, based on fluorescence regional integral (FRI) analysis and the regional standards related to water quality and fluorescence. This indicates that the degree of decomposition in water is relatively high; 2)In this study, some conventional fluorescence indexes were selected to describe the fluorescence index characteristics of water in wet and dry season. It found that the three indexes (FI, BIX, HIX) of the water quality of Jing River and Bortala River in dry and wet seasons showed slight changes, comparing to larger changes in the Bortala River. In general, the change of water quality of Jing River and Bortala River in dry and wet seasons is mainly influenced by microbial activities and human activities; 3) In terms of the correlation coefficients of water quality parameters and fluorescence indexes in different seasons, the results showed that the relationship between BIX and COD concentration was best and a significant positive correlation in dry season(R=0.688, P<0.01). Secondly, there is a significant negative correlation between BIX and ammonium nitrogen concentration in wet season (R=-0.493, P<0.05). The study provides theoretical support and reference basis for the improvement of the governance of Lake Ebinur Watershed, which further proved that exogenous characteristics and the differences in different periods of DOM sources in the water.

Primary productivity and herbivory were studied in the Serengeti National Park, Tanzania, and Masai Mara Game Reserve, Kenya, during the annual cycle of 1974—1975, and wet—dry season transitions in 1976—1979. Basic state variables measured were aboveground plant biomass inside permanent and temporary fences, and outside fences. Productivity was calculated as the sum of positive plant biomass increments. Control productivity (cPn) was calculated from biomass dynamics inside permanent fences. Temporary fences were moved in concert with grazing by the region's abundant ungulates to estimate actual aboveground primary productivity (aPn). Primary productivity was highly stochastic with productive periods poorly synchronized even among nearby sites. Short—term productivities could be extremely high, exceeding 30 g°m—2°d—1. Grazing animals adjusted their densities in relation to grassland productivity. The average proportion of annual aPn that was consumed by herbivores was 0.66, with a minimum of 0.15 and a maximum of 0.94. Green forage was available everywhere late in the wet season in May but was available only at high rainfall sites in the northwest late in the dry season in November. By the end of the dry season, the residual plant biomass outside fences averaged only 8% of cPn. Nomadic grazers moved seasonally in response to grassland productivity. The growing season ranged from 76 d in low rainfall areas to virtually continuous in high rainfall areas. Annual cPn was linearly related to rainfall and averaged 357 g°m—2°yr—1 over the year and 1.89 g°m—2°d—1 during the growing season. Actual aPn was substantially greater than cPn at most sites, averaging 664 g°m—2°yr—1. Growing season aPn averaged 3.78 g°m—2°d—1. Grazing stimulated net primary productivity at most locations, with the maximum stimulation at intermediate grazing intensities. Stimulation was dependent upon soil moisture status at the time of grazing. Rain had a diminishing effect on primary productivity as the wet season progressed and plant biomass accumulated. Part of the stimulation of grassland productivity by grazing was due to maintenance of the vegetation in an immature, rapidly growing state similar to that at the beginning of the rainy season. Since grazers overrode rainfall—determined productivity patterns, aPn was more closely related to grazing intensity than to ranfall. Grazing was heavier on grasslands that were intrinsically more productive. Rate of energy flow per unit of plant biomass was much higher in grazed vegetation. Grazers ate green leaves almost exclusively during the wet season, but species composition of the diets of different grazers differed markedly. Diets of nomadic grazers were very different in the wet and dry seasons. Vegetation dried out rapidly at the onset of the dry season and dry plant tissues made up a substantial proportion of ungulate dry season diets. However, green forage commonly was more abundant in diets than in the vegetation. Grazing increased both forage quality and its rate of production. Zebras supplemented a high—bulk diet by eating the seeds of awnless grasses. The foraging patterns of different grazers were differentiated by several vegetation properties, including productivity, structure, and species composition, in a manner suggesting resource partitioning. The relationship between the stability of vegetation functional properties and community species diversity was positive in five of seven tests. Greater species diversity was associated with greater biomass stability through the seasons, greater resistance to grazing by a single species of ungulate in both the wet and dry seasons, and greater resilience after grazing. Species diversity was not associated with greater resistance to grazing by several ungulate species or to plant species extinction. Specific properties of trophic web members were identified that produced greater functional stability in more diverse communities. Fire does not appear to have important effects upon the functional properties of the grasslands except for a weak stimulation of productivity in the wet season immediately following dry season burning. Fire did have an important effect upon structural properties of the vegetation that would tend to regulate ungulate feeding. The ecology of neither the plants nor the animals in the Serengeti ecosystem can be understood in isolation; many traits of both suggest coevolution among trophic web members. The functional dynamics of the trophic web suggest that the acceleration of energy and nutrient flow rates due to intense herbivory has resulted in the development of an entire consumer food web due to additive fluxes rather than mere quasi—parasitic fluxes from plants to animals.

Assessment of medium- and large-sized mammals’ species diversity, abundance, distribution, and habitat association is necessary to promote their conservation measures. The study was conducted in the former Dhidhessa wildlife sanctuary (FDWS), to assess the medium- and large-sized mammals’ composition, distribution, and diversity. Transect lines were used to collect the data. A total of 1,146 ± 91 individuals belonging to 25 species, seven orders, and 14 families were recorded. Among these, 607 ± 186.5 (52.97%) were recorded during the wet season, whereas 539 ± 144.5 (47.03%) during the dry season. The order Carnivora was the most diverse one, followed by Artiodactyla and Primates, respectively, while Rodentia, Hyracoidea, Tubulidentata, and Lagomorpha were the least diverse orders. Olive baboon (Papio anubis) was the most abundant species (19.2%), followed by Hippopotamus (Hippopotamus amphibious) (17.63%) and Vervet monkey (Chlorocebus aethiops) (13.18%). Species diversity was higher in the savanna-wooded than in the riverine forest during both the wet (H’ = 2.72, Fisher’s alpha = 6.33) and dry (H’= 2.79, Fisher’s alpha = 6.26) seasons. Species evenness was higher in the savanna-wooded habitat than in the riverine forest habitat during both the wet (J’ = 0.87 and J’ = 0.77, respectively) and dry (J’ = 0.9 and J’ = 0.80, respectively) seasons. The highest similarity in species composition was between the wet and dry seasons in the riverine forest habitat (SI = 85.58%). The lowest similarity was recorded between the dry and wet seasons of the riverine forest and the wet season of the savanna wooded habitat (SI = 45.46% and SI = 46.49%, respectively). The study suggests that mammals are at risk of anthropogenic factors in the area. So, an urgent conservation measure that involves the participation of the local community has paramount significance for the sustainable conservation of mammals in the former Dhidhessa wildlife sanctuary.

BackgroundDisentangling the relative importance of environmental variables and interspecific interaction in modulating co-occurrence patterns of sympatric species is essential for understanding the mechanisms of community assembly and biodiversity. For the two sympatric Galliformes, Silver Pheasants (Lophura nycthemera) and White-necklaced Partridges (Arborophila gingica), we know little about the role of habitat use and interspecific interactions in modulating their coexistence.MethodsWe adopted a probabilistic approach incorporating habitat preference and interspecific interaction using occupancy model to account for imperfect detection, and used daily activity pattern analysis to investigate the co-occurrence pattern of these two sympatric Galliformes in wet and dry seasons.ResultsWe found that the detection probability of Silver Pheasant and White-necklaced Partridge were related to habitat variables and interspecific interaction. The presence of Silver Pheasant increases the detection probability of White-necklaced Partridge in both the wet and dry season. However, the presence of White-necklaced Partridges increases the detection probability of Silver Pheasants in the wet season, but decreases the probability in the dry season. Further, Silver Pheasants were detected frequently in the sites of high values of enhanced vegetable index (EVI) in both the wet and dry season, and in sites away from human residential settlement in the wet season. White-necklaced partridges were mainly detected in low EVI sites. The site use probabilities of two Galliformes were best explained by habitat variables, Silver Pheasants and White-necklaced Partridges preferred steeper areas during the wet and dry season. Both species mainly occurred in low EVI areas during the wet season and occupied sites away from the resident settlement during the dry season. Moreover, the site use probabilities of two species had opposite relationships with forest canopy coverage. Silver Pheasants preferred areas with high forest canopy coverage whereas White-necklaced Partridges preferred low forest canopy coverage in the dry season, and vice versa in the wet season. Species interaction factor (SIF) corroborated weak evidence of the dependence of the site use of one species on that of the other in the either dry or wet season. Temporally, high overlapping of daily activity pattern indicated no significantly temporal niche differentiation between sympatric Galliformes in both wet and dry seasons.ConclusionsOur results demonstrated that the presence of two species influenced the detection probability interactively and there was no temporal partitioning in activity time between Silver Pheasants and White-necklaced Partridges in the wet and dry seasons. The site use probability of two Galliformes was best explained by habitat variables, especially the forest canopy coverage. Therefore, environmental variables and interspecific interaction are the leading drivers regulating the detection and site use probability and promoting co-occurrence of Silver Pheasants and White-necklaced Partridges.

Mole National Park is the largest and the oldest national park in Ghana and an important bird area, yet its waterbird fauna is poorly documented because it is situated in the northern ecological zone far away from the coast of Ghana. Information on the seasonal variation in the park’s bird abundance and diversity is generally patchy but necessary for effective birdwatching planning and management of the park’s birds. Therefore, as a guide to potential ecotourists interested in waterbirds, this study described the seasonal variation in waterbird species diversity and abundance at Mole National Park. As waterbirds mostly congregate around open wetlands and their abundance is more appropriately determined by counting all individuals in the congregant, data were collected using the total area count of waterbirds from August 2015 to October 2015 (the wet season) and from December 2015 to February 2016 (the dry season). Secondary data on arrival of tourists in the park were also analysed. The park’s waterbird species richness was 29 in the dry season compared to 18 in the wet season. There was significant difference (p &lt; 0.05) in the abundance of waterbirds in the dry season in which 4014 waterbirds were encountered compared to 646 in the wet season. The yearly tourist arrival data at Mole National Park shows an increasing trend with peak visitation period occurring during the wet season. The chances of tourists encountering more species and numbers of waterbirds in the park are higher in the dry season compared to the wet season.Conservation implications: Species richness and abundance of waterbirds in Mole National Park varied according to the wet and dry seasons with both the number of species and abundance higher in the dry season than the wet season. It is therefore indicative that most birdwatchers who visit the park in the wet season miss out on a number of species and numbers of waterbirds. To achieve effective birdwatching, management should schedule birdwatching activities to coincide with the dry season as the chances of encountering more species and numbers of waterbirds are higher.