Browsing by Author "Aikins, T.K."
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Item Abundance and prey capture success of Common Terns (Sterna hirundo) and Pied Kingfishers (Ceryle rudis) in relation to water clarity in south-east coastal Ghana(Avian Research, 2018-12) Holbech, L.H.; Gbogbo, F.; Aikins, T.K.Background: Water clarity may negatively influence rate of plunge diving and prey capture success of piscivorous plunge-diving birds, and therefore has implications for their conservation in polluted urban wetlands. We studied the relationship between water clarity and the abundance and prey capture success of Pied Kingfishers (Ceryle rudis) and Common Terns (Sterna hirundo) in two polluted coastal waters of south-east Ghana—the Weija Lake and Densu Delta Ramsar Site.Methods: On each wetland, data on abundance and prey capture success of plunge-divers were collected in four spatio-temporal quadrats of 100 m × 100 m and analysed with concurrent measurements of water quality parameters using GLM regression with Pearson’s correlation coefficients.Results: Mean prey capture success of Pied Kingfishers (34.7± 13.1%) and Common Terns (35.3± 11.0%) were similar but the two species responded differently to water clarity. The abundance of Common Terns was significantly higher in less transparent/more turbid water while that of Pied Kingfishers showed no significant relationship with turbid-ity and transparency. In contrast, the prey capture success of Common Terns was neither related to transparency nor turbidity, as opposed to that of Pied Kingfishers which was significantly higher in more turbid/less transparent waters. Correlations between capture success and bird abundance, as well as capture attempts were insignificant, suggest-ing that increased fish abundance associated with cloudy water may not necessarily promote higher abundance and capture success of foraging birds. Thus, when foraging in less transparent water, capture success may depend more on predator avoidance by fish prey than lower prey detectability of foraging birds.Conclusion: Within a gradient of 15–51 cm transparency studied, lower water clarity did not constrain prey capture success of Common Terns and Pied Kingfishers. Further studies on the foraging ecology of plunge-divers in coastal Ghana are however required to make firm conclusions on the relationship between water clarity and foraging birds and fish prey abundances, as well as capture success.Item Aspects Of The Community Ecology Of Waterbirds In Mole National Park(University of Ghana, 2016-06) Aikins, T.K.Mole National Park is the largest and oldest national park in Ghana. With a large number of species of birds, mammals and reptiles, the number of tourists in Mole National Park keeps increasing and therefore creating room for human disturbance in diverse ways. Using the total area count method, this study established the species of waterbirds at Mole National Park and determined the seasonal variations in their diversity and abundance in four permanent wetlands from August 2015 to February 2016. It also assessed the nature and levels of disturbance to waterbirds and determined the alert and flight initiation distances of selected species of waterbirds through daily monitoring of waterbird flushes and the conduction of flushing experiments. A total of 29 species belonging to 6 orders and 12 families were recorded of which Lana Pool had the highest proportion of the birds’ abundance (58.08 %) while Asibey Pool recording the least (6.20 %). With White-faced Whistling Duck (Dendrocygna viduata) being the most abundant species in the study area, the highest number of species (26) occurred in Haraba Pool and the least (18) at Asibey Pool. Species richness and abundance of waterbirds in Mole National Park varied between the wet and dry seasons with the dry season generally recording higher number of waterbird species richness and abundance. Waterbird at Mole National Park on the average spend 84.95 seconds per hour due to flushing. Majority of the flushes were caused by indeterminate factors (70.5 %). Average time spent in flight by a waterbird as a result of human flushing was 17.55 seconds per hour which constitute only 20.66 % of a waterbird’s average time in flight due to flushing. Grey Heron (Ardea cinerea) had the longest mean AD and FID whilst Green-backed Heron (Butorides striata) and Cattle Egret (Bubulcus ibis) respectively recorded the shortest AD and FID. Grass height, grass cover, shrub height, group size and the number of heterospecifics in a group had a significant multiple regression weight with the AD of some waterbirds. It was recommended that bird watchers should schedule their visit to the park during the dry season so as to encounter more species. When considering set-back distances in the design of path ways in Mole National Park, it should consider the alert distance of the largest species as this will help reduce disturbances of smaller ones.Item An evaluation of the level of human disturbance to waterbirds at Mole National Park in Ghana(Wetlands Ecology and Management, 2018-08) Aikins, T.K.; Gbogbo, F.; Owusu, E.H.Anthropogenic activities including recreation were known to cause disturbances to waterbirds in their natural habitat. The Mole National Park, which is considered the largest and oldest in Ghana, attracted significant number of tourists over the years, and consequently induced pressures and disturbances to waterbirds. Thus, there is a need to study the human-wildlife interactions and conflicts. This study established the species list of waterbirds at Mole between August 2015 and February 2016, assessed the nature and levels of human disturbance to the birds and determined the alert and flight initiation distances of selected species. A total of 29 waterbird species were recorded of which White-faced Whistling Duck was the most abundant. At a flush rate of 2.5 per hour with each flush lasting 34.0 s, waterbirds at the park spend 85.0 s/h as a result of flushing of which only 17.6 s/h was attributed to human disturbance. Majority of the flushes (70.5%) were caused by indeterminate factors but the potential adverse impact of human induced flushing and the need to minimize or prevent increased rates in the park was indicated by birds perceiving disturbance from tourist/staff to be of the same risk as predation. It was recommended that a setback distance based on the longest Alert Distance (120.8 ± 31.9 m) and Flight Initiation Distance (32.7 ± 23.8 m), both of which were recorded for the Grey Heron, should be considered in the management of the park’s wetlands. © 2018, Springer Science+Business Media B.V., part of Springer Nature.Item Seasonal variation in species richness and abundance of waterbirds in Mole National Park, Ghana: Implication for conservation and ecotourism(Koedoe, 2018-10) Aikins, T.K.; Gbogbo, F.; Owusu, E.H.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 < 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.