Papers by Yaa Ntiamoa-baidu
Wildlife Research Monographs, 2021
Nature & Faune
... It discusses the concept of protected area establishment as a way of in-situ biodiversity con... more ... It discusses the concept of protected area establishment as a way of in-situ biodiversity conservation and 1 Jesse S. Ayivor. ... 131 pp. Giliba, RA, Celestine, S., Mafuru, CS, Paul, M., Kayombo, CJ, Kashindye, AM, Leonard, I. Chirenje, LI and Musamba, E. B. 2011. ...
Oryx
Data on species trade profiles and volumes of wild animals on sale in local markets can provide u... more Data on species trade profiles and volumes of wild animals on sale in local markets can provide useful insights into the bushmeat trade, enabling identification of priorities for management and conservation planning. We monitored bushmeat traded in three markets (Sandema, Chiana and Fumbisi) in the Upper East Region of Ghana during October 2018–October 2019. More than 80% of carcasses sold were amphibians (frogs). Species composition and volumes of bushmeat traded varied significantly across markets. Bushmeat sales were highest during the dry season (75% of total biomass traded). The bulk (60% of total biomass) traded in the local markets was transported long distances for resale in major urban markets in southern Ghana. Large-bodied species were comparatively low in number and sold almost exclusively for resale in southern markets. This study highlights the importance of frog meat as an affordable protein source for consumers and as income for traders in an economically deprived re...
"Sanderlings Calidris al... more "Sanderlings Calidris alba occur worldwide along sandy beaches and have a wide range of non-breeding locations in different climate zones. Previous studies clearly indicated that ambient temperatures have profound effects on daily energy expenditures of Sanderlings. In this study we investigated the foraging ecology of Sanderlings on beaches near Esiama, Ghana and on the Wadden Sea island of Vlieland, The Netherlands. The diet was very different at the two locations. In Vlieland the birds fed predominantly on the polychaete Scolelepis squamata whereas a small shellfish Donax rugosus was taken in Esiama (Fig. 4,5). The latter prey item was very abundant in Esiama where a band of 2-14 m width containing densities of 5,700-14,300 individuals per m2 occurred. This resulted in caloric energy intake rates of 8 kJ/h foraging time in Vlieland and 130 kJ/h in Ghana. On Vlieland the birds spent on average 79% of their time foraging and in Esiama this was only 36% and most time (58 %) was spent resting (Fig. 2). We argue, however, that during the long resting breaks on roosts, Sanderlings in Ghana were in fact digesting and emptying their gut and intestines from indigestable shell remains. During future studies we plan to study annual and seasonal survival of sanderlings wintering at different latitudes in relation to disease risk and predation probability."
PLOS Neglected Tropical Diseases, 2020
Rabies is a fatal neurologic disease caused by lyssavirus infection. Bats are important natural r... more Rabies is a fatal neurologic disease caused by lyssavirus infection. Bats are important natural reservoir hosts of various lyssaviruses that can be transmitted to people. The epidemiology and pathogenesis of rabies in bats are poorly understood, making it difficult to prevent zoonotic transmission. To further our understanding of lyssavirus pathogenesis in a natural bat host, an experimental model using straw-colored fruit bats (Eidolon helvum) and Lagos bat virus, an endemic lyssavirus in this species, was developed. To determine the lowest viral dose resulting in 100% productive infection, bats in five groups (four bats per group) were inoculated intramuscularly with one of five doses, ranging from 100.1 to 104.1 median tissue culture infectious dose (TCID50). More bats died due to the development of rabies after the middle dose (102.1 TCID50, 4/4 bats) than after lower (101.1, 2/4; 101.1, 2/4) or higher (103.1, 2/4; 104.1, 2/4) doses of virus. In the two highest dose groups, 4/8 ...
Annual Review of Environment and Resources, 2021
Several hundred species are hunted for wild meat in the tropics, supporting the diets, customs, a... more Several hundred species are hunted for wild meat in the tropics, supporting the diets, customs, and livelihoods of millions of people. However, unsustainable hunting is one of the most urgent threats to wildlife and ecosystems worldwide and has serious ramifications for people whose subsistence and income are tied to wild meat. Over the past 18 years, although research efforts have increased, scientific knowledge has largely not translated into action. One major barrier to progress has been insufficient monitoring and evaluation, meaning that the effectiveness of interventions cannot be ascertained. Emerging issues include the difficulty of designing regulatory frameworks that disentangle the different purposes of hunting, the large scale of urban consumption, and the implications of wild meat consumption for human health. To address these intractable challenges, wepropose eight new recommendations for research and action for sustainable wild meat use, which would support the achiev...
Biological Conservation, 2019
Wild meat (or bushmeat) is consumed as a luxury item in many African cities. By contrast, bushmea... more Wild meat (or bushmeat) is consumed as a luxury item in many African cities. By contrast, bushmeat is an important source of food and income for many poor households in rural areas. To curb the flow of bushmeat from rural to urban areas, understanding drivers of demand in city markets, and their impact on hunter revenues remains fundamental. Here, we present a simple econometric model for the trade of a commercially important bushmeat species in Ghana, the grasscutter (Thryonomys swinderianus). We explore own-price and cross-price elasticity of demand of grasscutter meat relative to commonly consumed alternative meats (goat, beef, poultry and fish) in the Atwemonom market in Kumasi city, Ghana. We show that: 1) grasscutter demand is elastic to its own price, 2) beef has an elastic cross-price elasticity, and 3) grasscutter is a luxury good, highly sensitive to consumer income. The elastic nature of the market suggests that price control policies e.g. "wild meat" tax, could reduce demand. Given that beef is the best substitute in our study area, we suggest that investment in Ghana's underdeveloped cattle industry may reduce wildlife demand while also supporting herding economies. Critically, our results demonstrated that policies that aim to reduce bushmeat demand are likely to impact hunter revenues. This finding underscores the need for complimentary investments in the rural economy to drive incomes and offset any revenue losses as a result of a decline in bushmeat demand.
International Journal of Biodiversity and Conservation, Apr 30, 2015
The small mammal community at Kogyae Strict Nature Reserve (KSNR) in the Ashanti Region of Ghana ... more The small mammal community at Kogyae Strict Nature Reserve (KSNR) in the Ashanti Region of Ghana were studied in two habitats during the wet and dry seasons to investigate seasonal changes in species richness, abundance, composition and diversity. Ninety-six individuals belonging to nine species were recorded in 720 trap-nights, giving overall trap-success of 13.33%. Species richness (Sr), trap-success (Ts) and relative abundance (Ra) were higher (Sr = 6 species; Ts = 23.1%; Ra = 86.5%) in wooded grassland than forest (Ra = 4 species; Ts = 3.6%; Ra = 13.5%). However, species diversity was higher (Shannon-Wiener index Hʹ = 1.157) in forest than in wooded grassland (Hʹ = 1.089). Mastomys erythroleucus dominated in wooded grassland (68%) and Hylomyscus alleni in forest (53.8%). The species composition was unique for both habitats, with Mus musculoides being the only species common to both habitats. Seasonal changes in community assemblages were evident in both habitats, with species richness, diversity and abundance of the dominant species being highest in the wet seasons. Sex-ratio was unity in both habitats, and remained fairly constant throughout the rainy and dry seasons. Breeding activity was evident all-year-round for most species, but peaked in the rainy season. Our findings are consistent with that of other studies in Ghana and elsewhere in the African subregion, highlighting the importance of rainfall to the ecology of tropical small mammals.
Ardea, 2014
The buffer effect concept describes density-dependent patterns of habitat and resource use. At lo... more The buffer effect concept describes density-dependent patterns of habitat and resource use. At low densities, individuals would occur predominantly at the most profitable sites, but with sustained population increase a higher proportion of individuals are forced onto poorer quality sites . As more birds start using sites of lower quality, population growth will slow down because of decreases in average survival and/or reproduction . The concept, first described by , has been developed to define the carrying capacity of areas and has been applied to several species in both breeding and non-breeding seasons and at a range of scales from patches within a site to sites across a country . So far, the buffer effect has been demonstrated in only two wintering shorebirds, both from Great Britain; Grey Plover Pluvialis squatarola by and Black-tailed Godwit Limosa limosa islandica by . In this study we test for evidence of the buffer effect using a 20-year monthly count series of a growing population of Sanderling Calidris alba in Ghana, West-Africa. Sanderlings are long-distance migrant shorebirds that breed in the High Arctic tundra of eastern Canada, Greenland and central Siberia . In the non-breeding season they are widely distributed in coastal areas, particularly along sandy beaches (Reneerkens et al. 2009a). Ring recoveries
Open Journal of Ecology, 2014
Climate change is projected to impact human health, particularly incidence of water related and v... more Climate change is projected to impact human health, particularly incidence of water related and vector borne diseases, such as malaria. A better understanding of the relationship between rainfall patterns and malaria cases is thus required for effective climate change adaptation strategies involving planning and implementation of appropriate disease control interventions. We analyzed climatic data and reported cases of malaria spanning a period of eight years (2001 to 2008) from two ecological zones in Ghana (Ejura and Winneba in the transition and coastal savannah zones respectively) to determine the association between malaria cases, and temperature and rainfall patterns and the potential effects of climate change on malaria epidemiological trends. Monthly peaks of malaria caseloads lagged behind monthly rainfall peaks. Correlation between malaria caseloads and rainfall intensity, and minimum temperature were generally weak at both sites. Lag correlations of up to four months yielded better agreement between the variables, especially at Ejura where a two-month lag between malaria caseloads and rainfall was significantly high but negatively correlated (r = -0.72; p value < 0.05). Mean monthly maximum temperature and monthly malaria caseloads at Ejura showed a strong negative correlation at zero month lag (r = -0.70, p value < 0.05), with a similar, but weaker relationship at Winneba, (r = -0.51). On the other hand, a positive significant correlation (r = 0.68, p value < 0.05) between malaria caseloads and maximum temperature was observed for Ejura at a four-month lag, while Winneba showed a strong correlation (r = 0.70; p value < 0.05) between the parameters at a two-month lag. The results suggest maximum temperature as a better predictor of malaria trends than minimum temperature or precipitation, particularly in the transition zone. Climate change effects on malaria caseloads seem multi-factorial. For effective malaria control, interventions could be synchronized with the most important climatic predictors of the disease for greater impact.
Ostrich, 2000
... 'Ghana mldlije Sociew, P 0. Box 13252, Accra, Ghana. Ntiamoa-Baidu,Y., Asamoah, SA, Owus... more ... 'Ghana mldlije Sociew, P 0. Box 13252, Accra, Ghana. Ntiamoa-Baidu,Y., Asamoah, SA, Owusu, EH & Owusu-Boateng, K. 2000. ... Birds of West Africa. Collins, London, 35 1 pp Terborgh, J., Robinson, SK, Parker III, TA, Mum, CA & Pierpont, N. 1990. ...
Biological Conservation, 2011
Harvesting, consumption and trade of bushmeat are important causes of both biodiversity loss and ... more Harvesting, consumption and trade of bushmeat are important causes of both biodiversity loss and potential zoonotic disease emergence. In order to identify possible ways to mitigate these threats, it is essential to improve our understanding of the mechanisms by which bushmeat gets from the site of capture to the consumer's table. In this paper we highlight the previously unrecognized scale of hunting of the African straw-colored fruit bat, Eidolon helvum, a species which is important in both ecological and public health contexts, and describe the commodity chain in southern Ghana for its trade. Based on interviews with 551 Ghanaians, including bat hunters, vendors and consumers, we estimate that a minimum of 128,000 E. helvum bats are sold each year through a commodity chain stretching up to 400 km and involving multiple vendors. Unlike the general bushmeat trade in Ghana, where animals are sold in both specialized bushmeat markets and in restaurants, E. helvum is sold primarily in marketplaces; many bats are also kept by hunters for personal consumption. The offtake estimated in this paper raises serious conservation concerns, while the commodity chain identified in this study may offer possible points for management intervention. The separation of the E. helvum commodity chain from that of other bushmeat highlights the need for species-specific research in this area, particularly for bats, whose status as bushmeat is largely unknown.
The northward departure of 13 wader species was studied in the Baie d' Aouatif, Bane d'Arguin, Ma... more The northward departure of 13 wader species was studied in the Baie d' Aouatif, Bane d'Arguin, Mauritania, in the springs of 1985, 1986 and 1988. Waders left the area in the late afternoon. Wind speed and direction were registered near ground level (all years) and at altitudes up to 5 km (in 1988). A total of 31 000 waders were observed heading northwards, with those species wintering locally in largest numbers being most common. The majority of wader species showed fairly short periods of departure and unimodal departure peaks. Redshank and Dunlin departed over extended periods. Average departure dates of species correlated positively with the estimated midpoints of ranges in breeding latitude (ca. 2 d per 0 latitude). Since winds at ground level did not correlate with winds at higher altitudes, and since it is likely that the departing waders traveled at great heights, it was not surprising that there is no correlation between the average afternoon tail wind vector at ground level and the daily departure intensity. We suggest that the timing of departure from the Bane d'Arguin is largely under internal, instead of under direct environmental, control.
Ardea, 1990
About 35% of the W. European population of the Avocet winters south of the Sahara. At least 4% of... more About 35% of the W. European population of the Avocet winters south of the Sahara. At least 4% of these birds utilize the Banc d'Arguin as a stopover site for some hours. It is proposed that the area functions as a 'meeting point' where Avocets merge into larger flocks at departure. The timing of migration suggests that most birds wintering in Africa originate from NW. Europe, as was also confirmed by the resighting of three colourmarked individuals. IPoundation Working Group for International Wader and Waterfowl Research (WIWO), c/o Driebergseweg 16 c , 3708
Philosophical Transactions of the Royal Society B: Biological Sciences, 2012
Many serious emerging zoonotic infections have recently arisen from bats, including Ebola, Marbur... more Many serious emerging zoonotic infections have recently arisen from bats, including Ebola, Marburg, SARS-coronavirus, Hendra, Nipah, and a number of rabies and rabies-related viruses, consistent with the overall observation that wildlife are an important source of emerging zoonoses for the human population. Mechanisms underlying the recognized association between ecosystem health and human health remain poorly understood and responding appropriately to the ecological, social and economic conditions that facilitate disease emergence and transmission represents a substantial societal challenge. In the context of disease emergence from wildlife, wildlife and habitat should be conserved, which in turn will preserve vital ecosystem structure and function, which has broader implications for human wellbeing and environmental sustainability, while simultaneously minimizing the spillover of pathogens from wild animals into human beings. In this review, we propose a novel framework for the ho...
Infectious diseases result from multiple interactions among microbes and hosts, but community eco... more Infectious diseases result from multiple interactions among microbes and hosts, but community ecology approaches are rarely applied. Manipulation of vector populations provides a unique opportunity to test the importance of vectors in infection cycles while also observing changes in pathogen community diversity and species interactions. Yet for many vector-borne infections in wildlife, a biological vector has not been experimentally verified and few manipulative studies have been performed. Using a captive colony of fruit bats in Ghana, we observed changes in the community of Bartonella bacteria over time after the decline and subsequent reintroduction of bat flies. With reduced transmission, community changes were attributed to ecological drift and potential selection through interspecies competition mediated by host immunity. This work demonstrated that forces maintaining diversity in communities of free-living macroorganisms act in similar ways in communities of symbiotic microor...
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Papers by Yaa Ntiamoa-baidu