scholarly journals GPS-identified vulnerabilities of savannah-woodland primates to leopard predation and their implications for early hominins

2018 ◽  
Vol 118 ◽  
pp. 1-13 ◽  
Author(s):  
Lynne A. Isbell ◽  
Laura R. Bidner ◽  
Eric K. Van Cleave ◽  
Akiko Matsumoto-Oda ◽  
Margaret C. Crofoot
Keyword(s):  
Savannah Woodland

Aircraft Applications of Insecticides in East Africa. IV.—The Application of Coarse Aerosols in Savannah Woodland containing the Tsetse Flies Glossina morsitans and G. swynnertoni

1953 ◽  
Vol 44 (4) ◽  
pp. 627-640 ◽  
Author(s):  
K. S. Hocking ◽  
H. C. M. Parr ◽  
D. Yeo ◽  
D. Anstey
Keyword(s):  
East Africa ◽  
Meteorological Conditions ◽  
The Other ◽  
Tsetse Flies ◽  
Small Populations ◽  
Central Province ◽  
Glossina Morsitans ◽  
Short Period ◽  
Savannah Woodland ◽  
Mass Median

Attempts have been made to eradicate the tsetse flies G. morsitans and G. swynnertoni from two blocks of savannah woodland situated in the Central Province of Tanganyika.The insecticides were applied from aircraft. Coarse aerosols were used, with mass median diameters of approximately 90 microns; droplet diameters varied from 4 microns to 250 microns approximately.Eight applications of insecticides were made at intervals of two weeks. Each application was carried out at a nominal dosage of 0·25 gallons per acre, which was equivalent to 0·20 1b. per acre of the p, p'isomer of DDT or 0·03 lb. per acre of the γ isomer of BHC.In the area treated with DDT it is possible that both species of flies were eradicated for a short period, but small populations were re-established there by immigrant flies. In the other block the reduction was not so great, but it is not considered that this was due to a lesser effectiveness of the BHC, but to a combination of circumstances that led to less effective applications.Some general observations are made upon the use of aircraft for this sort of work, particularly in connection with the effect of meteorological conditions.

Aircraft Applications of Insecticides in East Africa. VI.—Applications of a coarse Aerosol containning DDT to control the Tsetse Flies, Glossina morsitans Westw., Glossina swynnertoni Aust. and Glossina pallidipes Aust.

1954 ◽  
Vol 45 (3) ◽  
pp. 585-603 ◽  
Author(s):  
K. S. Hocking ◽  
D. Yeo ◽  
D. G. Anstey
Keyword(s):  
Random Effects ◽  
Glossina Pallidipes ◽  
Tsetse Flies ◽  
Glossina Morsitans ◽  
Median Diameter ◽  
Coarse Aerosol ◽  
Savannah Woodland ◽  
Mass Median ◽  
Glossina Swynnertoni ◽  
Mass Median Diameter

An experiment is described where applications of a coarse aerosol were made to savannah woodland containing the tsetse flies, Glossina moritans Westw., G. swynnertoni Aust. and G. pallidipes Aust.Seven applications were made, each at a nominal dosage of 0·25 lb. of technical DDT per acre and 0·25 gallons of solution per acre. The applications in any particular part of the treaed woodland covered an interval of 90 days, or rather more than two pupal periods.The coarse aerosol was produced by emitting the insecticidal solution under pressure through fine nozzles fitted to a boom. It had a mass median diameter of approximately 60 microns, and droplet dismeters varied from a few microns to approximately 200 microns.The population of G. pallidipes was so drastically reduced that it has subsequently dies out. The reduction of G. morsitans was approximately 95 per cent. The differences between the reductions are attributed mainly to differences between the ease with which the three species can be killed. It is pointed out that this is not necessarily equivalent to differences in susceptibility.Comparisons are made with previous experiments, and the different results of the various experiments are difficult to explian satisfactory. The increased cover in savannah areas during the leafy period may have reduced the effectiveness of the applications, and the total periods covered by the various series of applications were probably also important. Random effects, leading to ineffective treatments, may also be important.Costs are discussed.

Aircraft applications of insecticides in East Africa

1961 ◽  
Vol 52 (2) ◽  
pp. 293-303 ◽  
Author(s):  
R. Foster ◽  
P. J. White ◽  
D. Yeo
Keyword(s):  
Meteorological Conditions ◽  
Small Scale ◽  
Central Province ◽  
Biological Factors ◽  
Cent Solution ◽  
Glossina Morsitans ◽  
Operational Costs ◽  
Low Volume ◽  
Aircraft Application ◽  
Savannah Woodland

SummaryFollowing successful small-scale trials, an attempt was made, by aircraft application of insecticide, to eradicate Glossina morsitans Westw. and G. pallidipes Aust. from an isolated block of savannah woodland, approximately 11 sq. miles in extent, at Chungai in the Central Province of Tanganyika between July 1958 and January 1959. A single-engined aircraft, fitted with two belt-driven rotary-cage atomisers, was used to apply a 5 per cent, solution of γ BHC in power kerosene at a nominal dosage of 0·08 gal. per acre (0.04 lb. γ BHC per acre). Seven applications were made at approximately 28-day intervals, the time taken to complete an application varying from five to eight days. The operation failed to control the flies. Although each of the first two applications reduced the apparent density of G. morsitans by about 90 per cent, and that of G. pallidipes by a lesser, although still considerable, factor, later applications gave varying and often low mortalities, and the populations increased slowly for some time, the insecticide applications causing only temporary depressions in numbers. Numbers fell towards the end of the operation, but final reductions were only about 50 per cent, or less. Kills of female flies were low, and this undoubtedly led to the eventual failure.The low volume-dosage, a drop spectrum that possibly contained too few droplets of the required size, meteorological conditions, and biological factors that apparently favoured the survival of female flies are suggested as contributory elements to the low mortalities.Operational costs were considerably lower than in previous work.

Aircraft Applications of Insecticides in East Africa. II.—An experimental Attempt to Produce a Fly-free Corridor through a Belt of Tsetse-infested Woodland

1953 ◽  
Vol 44 (3) ◽  
pp. 601-609 ◽  
Author(s):  
K. S. Hocking ◽  
H. C. M. Parr ◽  
D. Yeo ◽  
P. A. Robins
Keyword(s):  
East Africa ◽  
Wind Direction ◽  
Tsetse Fly ◽  
Low Level ◽  
Median Diameter ◽  
Savannah Woodland ◽  
Mass Median ◽  
Mass Median Diameter

An experimental attempt was made to produce a fly-free corridor through a belt of savannah woodland containing the tsetse fly G. swynnertoni.An area two miles wide and four miles long was treated with a coarse spray of a 4·6 per cent, w/v solution of DDT in Shell Diesoline. The dosage per application was 0·5 gallons per acre, and seven applications were made, at intervals of approximately two weeks, so that the treatment covered two pupal periods.The fly density had fallen to a very low level by the end of the experiment, and the area remained virtually free from flies for the subsequent two months. An examination of the data suggests, however, that the fly population was maintained largely by immigrant flies, and was certainly subject to wide variations, and it seems certain that the effect of the applications would have been considerably less upon a stable, self-supporting population.The drop spectrum of the ground deposit had a mass median diameter of 0·35 mm., and the recovery of insecticide in the area was approximately 60 per cent. Leeward and under sides of obstacles did not receive a dose although in some cases dosages were obtained on apparently leeward sides, probably because of local reversals of wind direction.

Aircraft Applications of Insecticides in East Africa. XI.—Applications of a coarse Aerosol to control Glossina morsitans Westw. At Urambo, Tanganyika, and G. morsitans Westw. and G. pallidipes Aust. In Lango County, Uganda

1956 ◽  
Vol 47 (4) ◽  
pp. 631-644 ◽  
Author(s):  
K. S. Hocking ◽  
D. Yeo
Keyword(s):  
Land Development ◽  
Small Population ◽  
Tsetse Flies ◽  
Treatment Level ◽  
Glossina Morsitans ◽  
Treated Area ◽  
Pre Treatment ◽  
Coarse Aerosol ◽  
Savannah Woodland ◽  
Mass Median

Two experiments are described where applications of coarse aerosols have been made to areas of savannah woodland infested with tsetse flies (Glossina spp.).The applications were made at nominal dosages of 0·25 gallons per acre, which was equivalent to either 0·20 lb. of p.p′DDT per acre, or 0·03 lb. of γ BHC per acre. The coarse aerosols had mass median diameters of approximately 60 microns.In one experiment, carried out at Urambo, Tanganyika, a reduction of 95 per cent, was obtained in populations of G. morsitans Westw. This kill was somewhat lower than in many other experiments, a fact that can be attributed mainly to our inability to maintain the cycle of applications. Immigration of flies into the treated area caused a relatively rapid increase in fly numbers to levels comparable to the pre-treatment populations, and in this respect the experiment was a failure.The other experiment, in Lango County, Uganda, was highly successful, and reduced a population of G. morsitans to 0·05 per cent, of its pre-treatment level, and eradicated a small population of G. pallidipes Aust. It is indeed likely that no stable population now exists in the area, and that the very few flies caught there since the end of the applications have been wanderers from other infested woodland. The continued success of the experiment is considered to be due to the effective isolation of the area.Some brief comments are made upon the costs of the method, and on its value under conditions of land development in Africa.

scholarly journals Integration of Optical and X-Band Radar Data for Pasture Biomass Estimation in an Open Savannah Woodland

2016 ◽  
Vol 8 (12) ◽  
pp. 989 ◽  
Author(s):  
Michael Schmidt ◽  
John Carter ◽  
Grant Stone ◽  
Peter O’Reagain
Keyword(s):  
Radar Data ◽  
Biomass Estimation ◽  
X Band ◽  
Savannah Woodland

A modified Lumsden suction-trap for biting insects

1961 ◽  
Vol 52 (2) ◽  
pp. 233-238 ◽  
Author(s):  
M. Morris
Keyword(s):  
Activity Rhythm ◽  
Tsetse Fly ◽  
Tsetse Flies ◽  
Survey Team ◽  
Survey Technique ◽  
Restricted Activity ◽  
Trap Catches ◽  
The Relationship ◽  
Savannah Zone ◽  
Savannah Woodland

SummaryA detailed tsetse-fly survey of 41,000 sq. miles in the inland savannah zone of the Gold Coast (Ghana) was completed in five years using an entirely African staff and working only six months each year.This undertaking was made possible because studies of the species of Glossina concerned, G. palpalis (R.-D.), G. tachinoides Westw. and G. morsitans sub-morsitans Newst., had provided knowledge of their habitat, food-hosts and activity rhythm, on which could be based a standard yet simple survey technique, within the compass of independent native teams.The restricted activity rhythm of the flies, subject to both daily and seasonal variations, meant that nothing less than a ‘day’ of eight hours of observation could be accepted as a valid sampling unit.With tsetse flies at low densities, a day's search was inadequate, giving only 40 per cent, reliability compared with 6-day observations. Four days' search gave 90 per cent, reliability and was adopted as the minimum period of search.Each survey team was under the charge of a Kecorder or Field Assistant, with fly-boys devoting the whole of their time to catching. Comparability of survey data was ensured by keeping teams to the same size, two fly-boys being the optimum, since it was found that the size of the catch was not always proportionate to the number of boys, the relationship varying according to a variety of factors.In surveying G. palpalis and G. tachinoides the ‘picket’ system of more or less stationary teams, measuring their catches by the ‘day ’, was found overwhelmingly superior to the ‘fly-round’ technique.The survey procedure described for savannah woodland country was not effective in sampling G. nigrofusca Newst. in the Ashanti forest or G. longipalpis Wied. in the coastal savannah, but Morris's ‘animal’ traps were found to take both species readily in places where they had not been detected or only occasionally caught by fly-boys. Experiments showed that trap catches were superior, both numerically and in giving a more representative sample of the tsetse population present. It was also shown that trapping could be a valuable means of studying the biology of these two ‘man-shy’ species of Glossina. Traps were also effective in taking G. pallicera Big. and G. medicorum Aust.The greater value of traps compared with fly-boys as a means of sampling various species of tsetse fly is discussed, and suggestions are put forward for developing trapping as a method of survey.The type of trap employed is regularly catching insects of several other families, including a number of species among the Tabanidae, and of several other orders.

A review of the systematics and phylogeny of the African Proteaceae

1998 ◽  
Vol 11 (4) ◽  
pp. 267 ◽  
Author(s):  
J. P. Rourke
Keyword(s):  
South African ◽  
Phylogenetic Relationships ◽  
Selection Pressure ◽  
Cladistic Analysis ◽  
Morphological Characters ◽  
The Other ◽  
Western Cape ◽  
The South ◽  
Savannah Woodland

In Africa the Proteaceae are represented by 16 genera of which two (Dilobeia Thouars. and Malagasia L.Johnson and B.Briggs) are endemic to Madagascar and one (Faurea Harv.) is common to both Madagascar and Africa where it is widespread in forest and savannah woodland from the southern Cape to Eritrea. The remaining 13 genera are Cape-centred (10 are endemic to the western Cape) and with the exception of the monotypic riverine Brabejum L. (Grevilleoideae), are confined to fynbos (heathland) communities on oligotrophic soils. These 12 Cape heathland genera currently assigned to two subtribes (Proteinae and Aulacinae) within the subfamily Proteoideae have all been recently revised or are in the final stages of revision. Preliminary cladistic studies now suggest that they could be arranged in several new subtribes within the subfamily Proteoideae to reflect more accurately their phylogenetic relationships. Using morphological characters in a cladistic analysis, the South African Proteoideae (tribe Proteeae) resolve into two broad groups; Aulax Berg., Faurea Harv. and Protea L. form a weakly supported group while the second, large, well-supported group resolves into two clades in which the heterogeneous Leucadendron R.Br. stands apart while the other clade underpinned by Vexatorella Rourke resolves into two further groups, the ‘Leucospermum group’ and the ‘Serruria group’. The dioecious genera Leucadendron and Aulax previously united in the subtribe Aulacinae have been shown to differ markedly and should probably be placed in separate subtribes. Selection pressure, especially from fire and pollinators, has resulted in major morphological modifications in the 12 fynbos genera from the western Cape.

Population Dynamics of the Australian Plague Locust, Chortoicetes Terminifera (Walker) in Central Western New South Wales. Ii. Factors Influencing Natality and Survival.

1982 ◽  
Vol 30 (2) ◽  
pp. 199 ◽  
Author(s):  
RA Farrow
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Natural Enemies ◽  
New South ◽  
New South Wales ◽  
Development Stages ◽  
Factors Influencing ◽  
South Wales ◽  
Savannah Woodland ◽  
Australian Plague Locust

Unrealized natality and mortalities at successive development stages were measured during synchronized breeding by populations of the Australian plague locust. Studies were made over a 3-y period, covering nine generations, on small plots situated in pastures derived originally from savannah woodland in central western New South Wales. Variations in natality and mortalities were influenced more by variation in soil moisture, primarily through its effect on pasture conditions, than by the effects of natural enemies; these variations were closely correlated with seasonal rainfall. Unidentified losses, independent of known variables, were recorded in the hopper stage and were highest in the hatchling. Such losses invariably exceeded 60% even under the most favourable conditions encountered in the field during the study period. The quantitative relationships established in this study between the plague locust and its natural enemies and other environmental factors suggest that prospects for the biological control of this pest by either native or introduced species are poor.

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