Detection of interannual population trends in seven herbivores from a West African savannah: a comparison between dung counts and direct counts of individuals

2017 ◽  
Vol 55 (4) ◽  
pp. 609-617 ◽  
Author(s):  
Emmanuel M. Hema ◽  
Massimiliano Di Vittorio ◽  
Richard F.W. Barnes ◽  
Wendengoudi Guenda ◽  
Luca Luiselli
Keyword(s):  
West African ◽  
Population Trends ◽  
West African Savannah ◽  
Direct Counts

scholarly journals Detecting phenological changes in plant functional types over West African savannah dominated landscape

2020 ◽  
Vol 42 (2) ◽  
pp. 567-594
Author(s):  
Sa’Ad Ibrahim ◽  
Jörg Kaduk ◽  
Kevin Tansey ◽  
Heiko Balzter ◽  
Umar Mohammed Lawal
Keyword(s):  
West African ◽  
Plant Functional Types ◽  
Functional Types ◽  
Phenological Changes ◽  
West African Savannah

Seasonal population changes in cocoa capsids (Hemiptera, Miridae) in Ghana

1968 ◽  
Vol 58 (2) ◽  
pp. 279-294 ◽  
Author(s):  
D. G. Gibbs ◽  
A. D. Pickett ◽  
Dennis Leston
Keyword(s):  
Light Trap ◽  
West African ◽  
Mercury Vapour ◽  
Feeding Sites ◽  
Vegetative Tissues ◽  
Main Crop ◽  
Sahlbergella Singularis ◽  
Dry Conditions ◽  
Seasonal Population ◽  
Direct Counts

Pupulations of the West African cocoa capsids Distantiella theobroma (Dist.) and Sahlbergella singularis Hagl. were sampled in 1966–67 by several methods: fast knockdown over sheets with pyrethrum, mercury-vapour light-trap, direct counts in a small artificially established area of high population, and observations of presence or absence in randomly selected inspection squares.A population build-up in mature cocoa accompanies and probably directly depends on development of the main crop from July or August to October. When pods become scarce after harvesting there is in S. singilaris a period of dispersal in which the species becomes more widespread as feeding is transferred to vegetative tissues, and in D. theobroma a more local change of feeding sites.Subsequent events vary greatly between areas and between years. It is suggested that the extent to which capsids are able to utilise vegetative tissues varies and depends on nutritional changes in the external parenchymatous tissues from which their food is obtained.Low humidities during spells of harmattan in January and February almost certainly kill larvae in exposed situations, but feeding conditions following such periods may be particularly favourable to capsids as large rapid population increases can occur locally. The factors involved are obscure but may be related to processes of regeneration stimulated by leaf loss and other damage in dry conditions.The densities and seasonal patterns found are discussed in relation to results of previous workers and some implications for control briefly considered.

Displacements of Simulium damnosum and strategy of control against onchocerciasis

1979 ◽  
Vol 287 (1022) ◽  
pp. 277-288 ◽  
Keyword(s):  
Sensu Stricto ◽  
Control Programme ◽  
West African ◽  
Simulium Damnosum ◽  
Logistic Problem ◽  
Degree Of Control ◽  
High Degree ◽  
Onchocerciasis Control ◽  
Upper Volta ◽  
West African Savannah

Regular aerial treatment of 14000 km of watercourses has achieved and maintained, over an area of 700000 km 2 of West African savannah, a very high degree of control of the larvae of Simulium damnosum sensu stricto and S. sibanum , the vectors of onchocerciasis in this area. However, particular and relatively restricted parts of this area, mainly in northern Ivory Coast and neighbouring parts of Upper Volta, experience regular and prolonged reinvasions by parous female vectors, which have already taken bloodmeals (and many of them carrying the parasites) and arrive from unknown sources probably hundreds of kilometres away, from directions probably between southwest and north. This reinvasion, now experienced in three successive years, represents the outstanding scientific, epidemiological and logistic problem still facing the WHO Onchocerciasis Control Programme. An outline is presented of the multidisciplinary investigations being undertaken to find a solution.

Guest Editors’ Introduction to the Power of Performance—the Performance of Power Forum

2019 ◽  
Vol 62 (1) ◽  
pp. 67-75
Author(s):  
Till Förster ◽  
Aïdas Sanogo
Keyword(s):  
Local Communities ◽  
West African ◽  
The State ◽  
The West ◽  
New Institutions ◽  
West African Savannah ◽  
Do So

Abstract:The West African savannah is an area where old and new institutions fill the lacunae that limited statehood has left. Some of them claim a long history, others have emerged recently as a reaction to military and civil crises. The performance of power, its display and presentation, is a theme that all these associations share. They do so on different occasions and by different means, which highlights their diverging ethics and attitudes towards their local communities and the state. This introduction to the guest edited forum outlines central themes of these performances and discusses performativity in West African power associations.

scholarly journals Estimation of live bodyweight from linear body measurements and body condition score in the West African Savannah Shorthorn cattle in North-West Benin

2018 ◽  
Vol 4 (1) ◽  
pp. 1549767 ◽  
Author(s):  
Sèyi Fridaïus Ulrich Vanvanhossou ◽  
Rodrigue Vivien Cao Diogo ◽  
Luc Hippolyte Dossa ◽  
Pedro González-Redondo
Keyword(s):  
Body Condition ◽  
Body Condition Score ◽  
West African ◽  
Body Measurements ◽  
The West ◽  
North West ◽  
Condition Score ◽  
Linear Body ◽  
West African Savannah

Assessment of dry-matter yield from grain yield in the West African Savannah Zone

1984 ◽  
Vol 103 (3) ◽  
pp. 695-698 ◽  
Author(s):  
J. M. Powell
Keyword(s):  
Dry Matter ◽  
Crop Residue ◽  
Crop Residues ◽  
Grain Legumes ◽  
West African ◽  
Animal Products ◽  
Increasing Demand ◽  
Savannah Zone ◽  
West African Savannah

Crop residues, consisting of cereal stovers and hays made from the vegetative parts of grain legumes, are important dry-season feeds for ruminant livestock in the Savannah Zone of West Africa (van Raay, 1975; McCown, Haaland & de Haan, 1979; Jahnke, 1982). With the increasing demand on land to produce more crops and animal products, traditional systems are under pressure. There is need for a reliable means to quantify the supply of feed from various sources and to monitor the type, quantity and quality of crop residue available to livestock.

scholarly journals First assessment of age and sex structures of elephants by using dung size analysis in a West African savannah

2017 ◽  
Vol 3 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Emmanuel M. Hema ◽  
Massimiliano Di Vittorio ◽  
Fabio Petrozzi ◽  
Luca Luiselli ◽  
Wendengoudi Guenda
Keyword(s):  
Sex Ratio ◽  
Frequency Distribution ◽  
West African ◽  
Size Analysis ◽  
Observation Data ◽  
Age Class ◽  
Significant Difference ◽  
Dry Seasons ◽  
Age And Sex ◽  
West African Savannah

Abstract1. An age and sex structure study of the West African savannah elephant (Loxodonta africana africana) population of the Nazinga Game ranch (Burkina Faso) was carried out using direct sightings of individuals near water points, where they group during hot periods of the day, and droppings circumference measurements of dung pile along line transects, during the dry seasons of 2007 and 2008. The age structure, from direct observation data, was estimated by classifying the individuals into 9 age-class-categories based on body size and eruption (length) of tusks.2. The frequency distribution of number of individuals into the age-class-categories showed high similarity with the distribution of circumference measurements of dung-piles that the individuals were seen depositing. Fifty dung-piles measured soon after they were deposited (Class A) and after they dried (to class C) showed a significant difference between the circumference measurements in relation to the time elapsed between the measurements.3. The frequency distribution of dung circumference classes of the observed elephants was similar to that of the dung-piles measured along the transects in 2008. Therefore, dung-piles measurements were used to estimate the Nazinga Game Ranch savanna elephant population’s age and sex structures at the end of dry seasons of 2007 and 2008. We advocated that the Nazinga elephant population consisted mainly of sub-adults.4. The sex ratio was estimated to be in favour of females (1/2). The age-class-specific sex ratio was uneven for calves and young individuals, while being in favour of females with adults. Individuals of less than 1 year represented 6% of the population during the study period.

Selective disturbance by elephants (Loxodonta africana) on eight tree species in a West African savannah

2017 ◽  
Vol 32 (2) ◽  
pp. 205-214
Author(s):  
Emmanuel M. Hema ◽  
Richard F. W. Barnes ◽  
Massimiliano Di Vittorio ◽  
Luca Luiselli ◽  
Wendengoudi Guenda
Keyword(s):  
Tree Species ◽  
Loxodonta Africana ◽  
West African ◽  
West African Savannah
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