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1.
The habitat use and seasonal migratory pattern of birds in Ethiopia is less explored as compared to diversity studies. To this end, this study aimed at investigating the patterns of distribution related to seasonality and the effect of habitat characteristics (elevation, slope, and average vegetation height) on habitat use of birds of Wondo Genet Forest Patch. A stratified random sampling design was used to assess the avian fauna across the four dominant habitat types found in the study area: natural forest, wooded grassland, grassland, and agroforestry land. A point transect count was employed to investigate avian species richness and abundance per habitat type per season. Ancillary data, such as elevation above sea level, latitude and longitude, average vegetation height, and percent slope inclination, were recorded with a GPS and clinometers per plot. A total of 33 migratory bird species were recorded from the area, of which 20 species were northern (Palearctic) migrants while 13 were inter‐African migrants. There was a significant difference in the mean abundance of migratory bird species between dry and wet seasons (t = 2.13, p = .038, df = 44). The variation in mean abundance per plot between the dry and wet seasons in the grassland habitat was significant (t = 2.35, p = .051, df = 7). In most habitat types during both dry and wet seasons, omnivore birds were the most abundant. While slope was a good predictor for bird species abundance in the dry season, altitude and average vegetation height accounted more in the wet season. The patch of forest and its surrounding is an important bird area for migratory, endemic, and global threatened species. Hence, it is conservation priority area, and the study suggests that conservation coupled with ecotourism development is needed for its sustainability.  相似文献   

2.
An investigation of population structure and ecology of the African buffalo (Syncerus caffer Sparrman, 1779) was carried out in the Chebera Churchura National Park, Ethiopia during the wet and dry seasons of 2005–2006. Sample counts of African buffaloes were carried out in an area of 1,215 km2. The estimated population of buffalo was 2,617 individuals. Males comprised 35.0%, while females 52.8% of the population. The remaining 12% of the population was young of both sexes and of all ages of unknown sex. It was difficult to categorize the young into male and female in the field, as their primary sexual characteristics were not easily visible. Male to female sex ratio was 1.00 : 1.51. Age structure was dominated by adults, which constituted 72.06% of the total population. Subadults comprised 22.02%, and young accounted for 5.9% of the population. Larger herds of up to 27 individuals were observed during the wet season and smaller herds of eight individuals during the dry season. The mean herd size during wet and dry seasons was 24.81 and 7.77, respectively. The African buffaloes were distributed in four habitat types such as grasslands, woodlands, montane forests and riverine habitat in the study area. They were observed more in the riverine vegetation types during the dry season. Relative abundance of food resources, green vegetation cover and water availability in the area were the major factors governing their distribution in the present study area. They spent a greater proportion of the time in feeding and resting/ruminating activities. On the average, 49.7% of the daytime was spent in feeding, and 38.75% of the day on resting (lying down and standing). Morning and the late afternoon activity peaks were more pronounced during the dry season than the wet season.  相似文献   

3.
This study was undertaken to determine the current population size, structure and habitat preference of Soemmerring's gazelle [Nanger soemmerringii (Cretzschmar 1828)] in the Alledeghi Wildlife Reserve, NE Ethiopia. Animals were counted, both during dry and wet seasons, along 12 line transects each in three habitat types (grassland, tree‐scattered grassland and bushland) in 2015/16. Habitat type had nonsignificant effect on mean population density of Soemmerring's gazelle, but wet season mean density was significantly higher than dry season mean density. Estimated weighted mean (±95% CI) population density of the species in the reserve was 1.90 (±0.17) and 5.99 (±0.370) individuals/km2 during the dry and wet seasons, respectively. Total population size of the species in the Alledeghi Wildlife Reserve was estimated at 826 ± 77 and 2,562 ± 158 individuals during the dry and wet seasons, respectively. Over half of the total population of Soemmerring's gazelle was represented by adult females during both seasons. Seasonal habitat preference of Soemmerring's gazelle was statistically significant, with greater preference for grassland habitat during wet season and for bushland habitat during dry season. In conclusion, this study has provided valuable data that will be used as a baseline for future population monitoring.  相似文献   

4.
The African wild ass (Equus africanus) is the most endangered wild equid in the world and is listed as a Critically Endangered (CR) on the IUCN Red list. Today, only relict populations remain in Ethiopia and Eritrea. The current Ethiopian population persists in the Danakil Desert at a very low density. Wildlife managers need to identify the extent of the remaining suitable habitat and understand human–wildlife interactions for appropriate conservation strategies. This study employed the maximum entropy model (Maxent) to determine suitable habitat and seasonal distribution of African wild ass in the Danakil Desert of Ethiopia. Field surveys were conducted four times annually, twice during the wet season and twice during the dry season, for 2 years. Field data and predictor variables were separated into the dry and wet seasons, and models were generated for each season independently. Distance from water, distance from settlements, herbaceous cover and slope were the best predictors of suitable habitat for both dry and wet seasons. Evaluations of model performances were high with area under the curve (AUC) values of 0.94 and 0.95 for the dry and wet seasons, respectively. Our results will be critical for identifying the available suitable habitat that should be conserved to safeguard this species from extinction.  相似文献   

5.
Lemur catta's ability to consume a wide variety of plant foods is a key to this species' survival in a time of ecological crisis across its geographic range. We examined seasonal diet variability of L. catta groups inhabiting two rocky outcrop fragments in south‐central Madagascar: Anja Reserve and Tsaranoro Valley forest. Leaves and fruit of Melia azedarach were a keystone resource for Anja lemurs in wet and dry seasons. At Tsaranoro, L. catta relied on M. azedarach and Ficus spp. in dry season, but during the wet season, neither was a dominant food resource. Top food species at both sites differed markedly from those consumed by L. catta in other habitats. At Tsaranoro, a greater proportion of lemurs engaged in feeding during the dry season compared with wet season. We attribute this to resource scarcity during dry season, when greater feeding effort is needed to maintain energy requirements. Because M. azedarach is ubiquitous throughout Anja Reserve, producing fruit and leaves year‐round, Anja lemurs can meet energy requirements with little seasonal adjustment in feeding activity. L. catta's IUCN status has been upgraded to Endangered, thus, greater insight into its diet flexibility and ability to survive on introduced plant species, can inform conservation plans in remaining wild habitats and ex situ programs.  相似文献   

6.
One of the fundamental questions in animal ecology concerns the activity pattern of animals and the environmental and intrinsic factors that influence such dynamics. This study tested the hypotheses that activity time budgets of the African buffalo appeared to vary by season and times of day and predicted that buffalo would express unequal proportion of time for different activity patterns during the wet and dry seasons in Chebera Churchura National Park (CCNP). An investigation on the diurnal activity budget of the African buffalo was carried out during the wet and dry seasons of 2012–2014 in the Chebera Churchura National Park, Ethiopia, using focal‐animal sampling method. Buffalo spent a greater proportion of the time in feeding and resting/ruminating activities in both the wet and dry seasons. Feeding and resting (lying down and standing) were the predominant activities (87.14% of the diurnal active period), 48.95% time spent feeding during the dry season and 44.91% during the wet season. There was a significant decrease in feeding and an increase in resting from dry seasons to wet seasons. Daytime grazing and resting periods during the wet season were estimated to be 5.39 h and 4.98 h, respectively. Morning and the late afternoon activity peaks were more pronounced during the dry season than the wet season. Therefore, feeding and resting time was influenced by the time of day and the seasons. But there were no significant difference in time allocation for other activities in both the wet and dry seasons. The study has implications for understanding animal activity budget across species, particularly relationships between temperature and season.  相似文献   

7.
To understand habitat preferences, seasonal abundance and diets of rodents in wet and dry season surveys were conducted in Alage, Southern Ethiopia. Sherman and snap traps were used to capture rodents from the four habitats: bushland, Acacia woodland, maize and wheat farmlands. A total of 3312 trap nights, from the four trapping habitats, yielded 776 individuals that represented 11 species of rodents. The distribution of rodents varied between habitats and seasons. Wet season rodent abundance was 52.3% while in the dry season it was 47.7%. Seasonal differences in species abundance were insignificant. Bushland habitat had high wet and dry season abundances with 137 and 211 individuals, respectively. Abundance was low in maize farm (57 individuals) in the wet season and wheat farm (10 individuals) in the dry season. Stomach content composition analysis of snap‐trapped rodents from different habitats showed differences between species and across seasons. Six rodent species were recorded as pests on the farmlands in this study area. In conclusion, variation in habitat preferences and diet of rodents in different habitats and across seasons might be due to the role of ground cover and food sources.  相似文献   

8.
To avoid unnecessary waste of limited resources and to help prioritize areas for conservation efforts, this study aimed to provide information on habitat use by elephants between the wet and dry seasons in the Mole National Park (MNP) of Ghana. We compiled coordinates of 516 locations of elephants’ encounters, 256 for dry season and 260 for wet season. Using nine predictor variables, we modeled the probability of elephant's distribution in MNP. We threshold the models to “suitable” and “nonsuitable” regions of habitat use using the equal training sensitivity and specificity values of 0.177 and 0.181 for the dry and wet seasons, respectively. Accuracy assessment of our models revealed a sensitivity score of 0.909 and 0.974, and a specificity of 0.579 and 0.753 for the dry and wet seasons, respectively. A TSS of 0.488 was also recorded for the dry season and 0.727 for the wet season indicating a good model agreement. Our model predicts habitat use to be confined to the southern portion of MNP due to elevation difference and a relatively steep slope that separates the northern regions of the park from the south. Regions of habitat use for the wet season were 856 km2 and reduced significantly to 547.68 km2 in the dry season. We observed significant overlap (327.24 km2) in habitat use regions between the wet and dry seasons (Schoener's D = 0.922 and Hellinger's‐based I = 0.991). DEM, proximity to waterholes, and saltlicks were identified as the key variables that contributed to the prediction. We recommend construction of temporal camps in regions of habitat use that are far from the headquarters area for effective management of elephants. Also, an increase in water point's density around the headquarters areas and selected dry areas of the park will further decrease elephant's range and hence a relatively less resource use in monitoring and patrols.  相似文献   

9.
An investigation into the population status and distribution of the African buffalo (Syncerus caffer Sparrman, 1779) in Chebera Churchura National Park, Ethiopia, was carried out during the wet and dry seasons of 2012–2015. This study tested the hypothesis that buffalo would demonstrate seasonal habitat preferences and changes in population density. Sample counts were carried out in an area of 1215 km2. The estimated buffalo population was 5193 individuals, with the population density of 4.3/km2. The population showed an increase from 2617 to 5194 individuals during 2006–2015. Males comprised 42.6%, while females 46.7% of the population. Age structure was dominated by adults, which constituted 52.5% of the total population. Subadults comprised 24.3% and young 12.4% of the population. Larger herds of up to 30 individuals were observed during the wet season, and smaller herds of a minimum of four individuals were seen during the dry season. The mean herd sizes during the wet and dry seasons were 29.59 and 16.95, respectively. They were observed more in the riverine vegetation types during the dry season. Of the total, 57.6% utilized riverine habitat during the dry season, whereas 39.8% used this habitat during the wet season. Relative abundance of food sources, green vegetation cover and availability of water were the major factors governing their distribution in the present study area.  相似文献   

10.
Trees that maintain some leaves throughout dry seasons become important ruminant browse depending on nutritive and antinutritive values. Leaves from seven tree species that maintained some leaves during the dry season were collected during dry and wet seasons and analysed for nutritive and antinutritive values. Neutral detergent fibre of leaves was either not different or less (≤ 0.05) during the dry season as compared to the wet season depending on species. Acid detergent fibre was either not different or greater (≤ 0.05) during the dry season as compared to the wet season. Crude protein and condensed tannins (CT) were either not different or less (≤ 0.05) during the dry season than during the wet season for the seven species. The biological activity (protein‐binding ability; PB) of the CT was highly species specific and was either not different between seasons, more bioactive during the wet season, or more bioactive during the dry season depending on the species. Based on combinations of low fibre, high protein and potentially beneficial levels of bioactive CT, Senegalia caffra, Vachellia karoo and Searsia lancea may be the most promising dry‐season browse of the species studied.  相似文献   

11.
Land‐cover change can alter the spatiotemporal distribution of water inputs to mountain ecosystems, an important control on land‐surface and land‐atmosphere hydrologic fluxes. In eastern Mexico, we examined the influence of three widespread land‐cover types, montane cloud forest, coffee agroforestry, and cleared areas, on total and net water inputs to soil. Stand structural characteristics, as well as rain, fog, stemflow, and throughfall (water that falls through the canopy) water fluxes were measured across 11 sites during wet and dry seasons from 2005 to 2008. Land‐cover type had a significant effect on annual and seasonal net throughfall (NTF <0=canopy water retention plus canopy evaporation; NTF >0=fog water deposition). Forest canopies retained and/or lost to evaporation (i.e. NTF<0) five‐ to 11‐fold more water than coffee agroforests. Moreover, stemflow was fourfold higher under coffee shade than forest trees. Precipitation seasonality and phenological patterns determined the magnitude of these land‐cover differences, as well as their implications for the hydrologic cycle. Significant negative relationships were found between NTF and tree leaf area index (R2=0.38, P<0.002), NTF and stand basal area (R2=0.664, P<0.002), and stemflow and epiphyte loading (R2=0.414, P<0.001). These findings indicate that leaf and epiphyte surface area reductions associated with forest conversion decrease canopy water retention/evaporation, thereby increasing throughfall and stemflow inputs to soil. Interannual precipitation variability also altered patterns of water redistribution across this landscape. Storms and hurricanes resulted in little difference in forest‐coffee wet season NTF, while El Niño Southern Oscillation was associated with a twofold increase in dry season rain and fog throughfall water deposition. In montane headwater regions, changes in water delivery to canopies and soils may affect infiltration, runoff, and evapotranspiration, with implications for provisioning (e.g. water supply) and regulating (e.g. flood mitigation) ecosystem services.  相似文献   

12.
The study investigated the relationship between topography, seasonal food availability and home range use by a troop of olive baboons (Papio anubis) in a dry savannah environment. Valleys were the most utilized parts of the home range in dry seasons while old boma sites were more frequently used in the wet season. Herb‐layer food biomass decreased significantly in dry seasons. The flowers of both Acacia tortilis and Acacia etbaica were available only in dry seasons with valleys having the highest biomass. The biomass of Acacia nilotica seeds was higher in valleys than on other locations. Leaves of the shrub Lycium europaeum were available on all locations in the wet season but valleys had the highest biomass of this food type. Herb‐layer baboon food biomass at ridge tops, slopes, valleys and old boma sites showed similar trends in productivity between seasons. Baboons tracked food along the soil catenas by feeding at ridge tops and old boma sites where foods were available during the wet season and exploiting food sources at the valleys during the dry seasons. Food availability was related to the catena effect and baboons used the catenas in the home range in a predictable manner.  相似文献   

13.
Seasonality and management are factors that may affect the diet selection of the forest buffalo (Syncerus caffer nanus). Fire is considered a major driving force in savannah systems and prescribed burning is a commonly applied conservation tool in protected areas such as Lopé National Park, Gabon. Prescribed annual fires contribute to the maintenance of open areas and provide high‐quality forage for forest buffalo, a major herbivore in the park. We used microhistological faecal analysis to determine the diet selection of forest buffalo and measured the extent of variation between a dry season, preburn and a wet season, postburn sampling period. The buffalo diet comprised mainly of monocotyledons, primarily grasses (Poaceae) and sedges (Cyperaceae). Intake of open‐area‐associated plant species was higher in the wet season, postburn treatment sampling period (97%) than the dry season, preburn sampling period (87%), which corresponded conversely to a reduction in forest‐associated Marantaceae plants (10% versus 1%). High proportions of grasses and sedges in the diet signify the importance of open areas for forest buffalo. Controlled burning as tool for maintenance of open areas may play a key role in the meta‐population management of the forest buffalo.  相似文献   

14.
Five individuals of four civet species were captured and followed by radiotelemetry in a mosaic of dry tropical forest in Huai Kha Khaeng Wildlife Sanctuary, Thailand. Observations were made on a fifth, arboreal species which was never captured. Radio-collared civets used overall areas ranging from 3.1 to 17 km2 with average monthly ranges from 0.72 to 5.4 km2. Average monthly ranges, home range centre shifts and activity radii showed a linear increase with weight and size of the individual, both within and between species. Despite individual differences, there were similar behavioural responses to extrinsic seasonal changes. Civets had activity levels of 50–55% and displayed nocturnal activity patterns. The four smallest civets used trees as resting sites extensively while the largest civet, Viuerra zibetha , was always located on the ground. Faecal analysis indicated that civets fed on at least 18 fruiting tree species as well as rodents, insects and crabs. At least one of the fruits found in civet faeces, Cassia fistula , was not eaten by other major frugivores in the area. The civets showed a preference for mixed deciduous and dry evergreen forest over dry deciduous dipterocarp forest, which had a lower abundance of known food items. The role that civets play as seed dispersal agents may help in the maintenance and structuring of tropical forest communities.  相似文献   

15.
The Malay civet (Viverra tangalunga) is found throughout Southeast Asia, but there have been very few studies on its natural history and ecology. We present here the results from the first radio telemetry study of this species on Peninsular Malaysia and compared our findings to similar studies on Borneo and Sulawesi. From August 2004 to August 2006, we captured 11 Malay civets in Krau Wildlife Reserve and radio-tracked seven adults (four males and three females). The mean weight of males (6.6 kg) was significantly higher than females (5.8 kg). Both sexes on Peninsular Malaysia were larger than their counterparts on Borneo and Sulawesi. There was no significant difference between the mean sizes of male and female home ranges on Peninsular Malaysia; the mean home range size for both sexes was 143 ha (95% MCP), which was larger than the mean range size recorded on Borneo and Sulawesi. We found that the Malay civet is a solitary, territorial species on Peninsular Malaysia: mean range overlap was 15% for males and 0% for females, and the home range of each male overlapped one or two females. Malay civets were mainly nocturnal, with some periods of rest during the night; daytime rest sites were within dense ground cover. Lowland forest is an essential habitat for this species; although Malay civets were sometimes found in plantations, they did not venture far from forested habitat.  相似文献   

16.
There is an urgent recognized need for conservation of tropical forest deer. In order to identify some environmental factors affecting conservation, we analyzed the seasonal habitat use of two Indonesian deer species, Axis kuhlii in Bawean Island and Muntiacus muntjak in south-western Java Island, in response to several physical, climatic, biological, and anthropogenic variables. Camera trapping was performed in different habitat types during both wet and dry season to record these elusive species. The highest number of photographs was recorded in secondary forest and during the dry season for both Bawean deer and red muntjac. In models, anthropogenic and climatic variables were the main predictors of habitat use. Distances to cultivated area and to settlement were the most important for A. kuhlii in the dry season. Distances to cultivated area and annual rainfall were significant for M. muntjak in both seasons. Then we modelled their predictive range using Maximum entropy modelling (Maxent). We concluded that forest landscape is the fundamental scale for deer management, and that secondary forests are potentially important landscape elements for deer conservation. Important areas for conservation were identified accounting of habitat transformation in both study areas.  相似文献   

17.
Home range size, habitat utilization, and activity patterns of five adult Bairds tapirs (Tapirus bairdii) were studied via radiotelemetry from June 1995 to May 1996 in Corcovado National Park, Costa Rica. Estimates of 4153 animal locations were made. Home range sizes (95% minimum convex polygon) for the entire study period (wet season and dry season) averaged 125.0 ha (SD = 72.7), 94.9 ha (SD = 47.6), and 96.8 ha (SD = 51.2), respectively. Monthly home range sizes averaged 55.5 ha (SD = 32.1) and did not vary between seasons. Across the entire study, secondary forest, the most commonly used habitat type (61.3%) was utilized more than expected as predicted by availability (49.6%), while the second most used habitat, primary forest, was used (25.0%) less than expected (36.2%). The same general habitat selection pattern was observed in the dry season. Wet season habitat utilization values showed tapirs using both primary and secondary forest habitats in proportion to their availability. Diurnal and nocturnal activity levels were estimated at 20.2 and 80.4 percent, respectively. More diurnal and less nocturnal activity was observed during the wet season compared to the dry season.  相似文献   

18.
Shade coffee plantations can be important refuges for epiphytes, but are not suitable for all species. To test if the performance of early life stages, often the most sensitive phase, is responsible for the species’ ability to colonize coffee plantations, we compared growth and mortality rates of three epiphytic bromeliad species that differ in their ability to colonize secondary arboreal vegetation by transplanting juveniles to trees in forests, and shade trees in old and young coffee plantations in Central Veracruz, Mexico. Growth rates of Tillandsia viridiflora, generally restricted to forests, and Tillandsia juncea, an early colonizer, were related to the pattern of the species occurrence among habitats with growth rates of T. viridiflora being generally higher in forests and growth of T. juncea higher in coffee plantations. Performance of the third species, Tillandsia heterophylla, which is intermediate in habitat preference, was not clearly related to habitat. No difference in growth rates was found between plants transplanted in wet or dry season. In general, mortality in transplanted bromeliads was relatively low (mostly < 5% per month). In coffee plantations herbivory had a severe effect during part of the wet season, when mortality in young coffee plantations reached between 15 and 24 percent per month. Given the substantial contribution of herbivory to the mortality of juvenile plants and the significant differences between habitats, herbivory may be co‐limiting the colonization of young coffee plantations by some epiphytic bromeliads.  相似文献   

19.
Efforts to maximise crop yields are fuelling agricultural intensification, exacerbating the biodiversity crisis. Low‐intensity agricultural practices, however, may not sacrifice yields if they support biodiversity‐driven ecosystem services. We quantified the value native predators provide to farmers by consuming coffee's most damaging insect pest, the coffee berry borer beetle (Hypothenemus hampei). Our experiments in Costa Rica showed birds reduced infestation by ~ 50%, bats played a marginal role, and farmland forest cover increased pest removal. We identified borer‐consuming bird species by assaying faeces for borer DNA and found higher borer‐predator abundances on more forested plantations. Our coarse estimate is that forest patches doubled pest control over 230 km2 by providing habitat for ~ 55 000 borer‐consuming birds. These pest‐control services prevented US$75–US$310 ha‐year−1 in damage, a benefit per plantation on par with the average annual income of a Costa Rican citizen. Retaining forest and accounting for pest control demonstrates a win–win for biodiversity and coffee farmers.  相似文献   

20.
The present study aimed to investigate the diet of African manatees in Cameroon to better inform conservation decisions within protected areas. A large knowledge gap on diet and seasonal changes in forage availability limits the ability to develop informed local management plans for the African manatee in much of its range. This research took place in the Sanaga River Watershed, which includes two protected areas in the Littoral Region of Cameroon: the Douala‐Edea National Park and the Lake Ossa Wildlife Reserve. We analyzed 113 manatee fecal samples and surveyed shoreline emergent and submerged vegetation within the Sanaga River Watershed. We used microhistological analyses to determine the relative contribution of each plant species to African manatee diets and compared across locations and across seasons (wet vs. dry season). We found that the shoreline vegetation is diverse with over 160 plant species, unevenly distributed across space and season, and dominated by emergent vegetation mostly represented by the antelope grass (Echinochloa pyramidalis). We recorded a total of 36 plant species from fecal samples with a spatial and temporal distribution mostly reflecting that of the corresponding shoreline vegetation. African manatees appear to be primarily opportunistically feeding on available vegetation across the seasons and habitat. This work documents the current, but changing, state of plant availability in the Sanaga River Watershed and reports the African manatee diet in Cameroon for the first time. This information can play a critical role in successfully managing the species and these protected areas. If we wish to protect the African manatee and the aquatic ecosystems within the Sanaga River Watershed, we must understand how forage availability changes over time, especially as its waters become nutrient enriched, eutrophic, and exposed to invasive species of plants in a changing world.  相似文献   

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