Analysis of errors in barometric elevations in northern Nigeria

We present an analysis of errors contributing to the inaccuracy of aneroid altimeter observations under tropical conditions. Instrumental errors were investigated experimentally, while errors due to meterological factors were analyzed using an autocorrelation analysis of actual pressure observations. For an estimated accuracy of ±1.2 to ±2.5 m, it is recommended that a diurnal pressure variation be eliminated from the altimeter field readings and that measurements be restricted to 0500 to 1400 hours LST in the wet season and from 0500 to 1100 hours LST or 1500 to 1830 hours LST in the dry season.

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Channel wave mapping of coal seams in the United Kingdom

Geophysics ◽

10.1190/1.45071131.1 ◽

1980 ◽

Vol 45 (7) ◽

pp. 1131-1143 ◽

Cited By ~ 4

Author(s):

I. M. Mason ◽

D. J. Buchanan ◽

A. K. Booer

Keyword(s):

United Kingdom ◽

Dry Season ◽

Pressure Variation ◽

Autocorrelation Analysis ◽

Wet Season ◽

Coal Seams ◽

The United Kingdom ◽

Tropical Conditions ◽

Channel Wave

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SEASONAL EFFECTS ON LAMB PRODUCTION UNDER TROPICAL CONDITIONS

Nigerian Journal of Animal Production ◽

10.51791/njap.v11i2.2548 ◽

2021 ◽

Vol 11 (2) ◽

pp. 168-174

Author(s):

I. O. A. Adeleye

Keyword(s):

Birth Weight ◽

Inverse Relationship ◽

Dry Season ◽

West African ◽

Seasonal Effects ◽

Multiple Birth ◽

Wet Season ◽

Average Birth Weight ◽

Tropical Conditions ◽

Weaning Age

Observations were made over a period of three years on a total of 336 West African Dwarf (WAD) ewes that were mated to four rams in rotation. Out of a total of 753 lambs obtained, 459 (61%) were produced in the wet season as compared to 294 (39%) produced in the dry season. More lambs were produced as a result of multiple birth (twins and triplets) in the wet than in the dry season. Consequently, the average birth weight of the wet season lambs (1.58kg) was lower than the average birth weight (1.66 kg) of the dry season lambs. Despite this initial disadvantage, the wet season lambs had a higher average weaning weight (9.11 kg) than the dry season lambs (7.83 kg). The effects of season on pre weaning lamb mortality was minimal while the effects of type of birth were quite apparent. Lowest pre-weaning lamb mortality values were recorded for single lambs, followed by twins and triplets, in ascending order. The data also showed that a slightly higher proportion of the male lambs reached weaning age than female lambs. This observation could be associated with reported inverse relationship between lamb birth weight and mortality found in literature.

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Observations on the ecology of Glossina morsitans submorsitans Newst. in the Northern Guinea Savannah of Northern Nigeria

Bulletin of Entomological Research ◽

10.1017/s000748530005700x ◽

1965 ◽

Vol 56 (1) ◽

pp. 1-16 ◽

Cited By ~ 7

Author(s):

A. M. Jordan

Keyword(s):

Dry Season ◽

Published Data ◽

Northern Nigeria ◽

Wet Season ◽

Glossina Morsitans ◽

Vegetation Zone ◽

Breeding Sites ◽

Resting Sites ◽

Glossina Morsitans Submorsitans ◽

Forest Islands

Observations, largely based on regular catches along a fly-round, were made over the five years 1959–64 on a population of Glossina morsitans submorsitans Newst. in the Northern Guinea Savannah of Nigeria. The results showed that the largest numbers of flies were caught in the early dry season (November–January) and that, as the climate became progressively drier and more severe, fly numbers declined to reach their annual minimum at the end of the dry season or in the early rains (March–May). These results are tentatively interpreted in terms of the true density of the flies and their activity. Differences occurred between the various years, some of which could be explained by climatic differences.Of the 7,412 flies caught over the five years, 1,128 (15·2%) were females; the percentage of females was highest in the dry season, rising to a peak of 24·1 per cent, in February, and was below 10 per cent. during the wet season. Many more females were caught on the bodies of the catching team than on vegetation or the ground near the team.The flies rarely fed on civet cat (Civettictis civetta) or duiker (Cephalophus rufilatus, Sylvicapra grimmia), which were the potential hosts most frequently observed in the experimental area, but fed mainly on wart-hog (Phacochoerus aethiopicus) and man, the next most commonly observed potential hosts.During the heavy rains, males of G. m. submorsitans were evenly distributed over the fly-round, but at all other seasons they were concentrated to some extent in areas of thicker vegetation. During the dry season, pupae were found in the dry soil of forest islands and riverine vegetation in the savannah; the wet season breeding sites were not discovered. Previously published data on the resting sites and trypanosome infection rate of G. m. submorsitans in the area are summarised.The results are discussed and compared with the conclusions reached by other workers from earlier more extensive studies on G. m. morsitans Westw. in Tanganyika and on G. m. submorsitans in the Sudan Savannah vegetation zone of Northern Nigeria.

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Trypanosome infection rates inGlossina morsitans submorsitansNewst. in Northern Nigeria

Bulletin of Entomological Research ◽

10.1017/s0007485300049415 ◽

1964 ◽

Vol 55 (2) ◽

pp. 219-231 ◽

Cited By ~ 31

Author(s):

A. M. Jordan

Keyword(s):

Infection Rate ◽

Dry Season ◽

Tsetse Fly ◽

Effect Of Temperature ◽

General Effect ◽

Northern Nigeria ◽

Trypanosome Infection ◽

Infection Rates ◽

Wet Season ◽

Significant Difference

Previous records and new data on trypanosome infection rates inGlossina morsitans submorsitansNewst. in Northern Nigeria are presented, and discussed in relation to the hosts fed on by this tsetse fly. The new observations were carried out in three areas: at Mando and Gamagira, both lying in a fly-belt north of Kaduna, and in the Yankari Game Reserve in Bauchi Province.Infection rates were obtained by dissection of flies, and the trypanosomes were identified by their locus; the validity of this method of identification is discussed. All infections withTrypanosomaspp. were attributable either to thevivaxgroup or to theconrgolensegroup; nobrucen-group trypanosomes were identified. More than 260 flies from each area were examined during March 1962, at the end of the dry season, and similar numbers during October 1962, at the end of the wet season.There was no significant difference between dry-season and wet-season infection rates in any area. Taking the two seasons together, the rate at Yankari (12%) was significantly higher than the rates at Mando (5%) and Gamagira (3%), which did not differ significantly. These contrasting infection rates could be related to the host species principally fed on by flies in the different areas as shown by blood-meal determinations. The lowest infection rates occurred where Suidae furnished a high proportion of meals (Mando, 51%; Gamagira, 67%) and Bovidae a small proportion (Mando, 16%; Gamagira, 9%). The high infection rate at Yankari was associated with a high proportion of Bovid meals (53%), especially from buffalo (Syncerus nanus) and bushbuck (Tragelaphus scriptus), and a lower proportion of Suid meals (33%). For the three areas the relationship between infection rate and percentage of Bovid meals was statistically significant.The species groups of infecting trypanosomes showed further contrasts between the three areas which were unrelated to the total infection rates. At Gamagira, 81 per cent, of infections werecongolensegroup, and this proportion was significantly higher than that at Mando (45%) or Yankari (37%). The differences could be related to the types of host from which blood-meals were principally derived. The highest proportion ofcongolense-group infections occurred where the highest percentage of meals came from Suidae (Gamagira, 67%), and lower proportions occurred at Mando and Yankari where Suid feeds were relatively fewer (51% and 33%, respectively).These findings are discussed in the light of existing evidence on the factors governing infection rates inGlossina. It is concluded that, within the over-riding influence exerted by temperature through geographical latitude, infection rates are determined by the type of host that forms the principal source of food. In some populations of Glossina the influence of the nature of the main food source can be sufficient to obscure the general effect of temperature in determining the level of infection. Some of the reasons for these relationships are discussed.

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On the origin of the wet-season form of Zonocerus variegatus (L.) (Orth., Acrididae) in southern Nigeria, with some biological notes

Bulletin of Entomological Research ◽

10.1017/s0007485300047489 ◽

1972 ◽

Vol 61 (4) ◽

pp. 661-667 ◽

Cited By ~ 13

Author(s):

T. Ajibola Taylor

Keyword(s):

Rain Forest ◽

Climatic Conditions ◽

Dry Season ◽

Field Observations ◽

Northern Nigeria ◽

Zonocerus Variegatus ◽

Wet Season ◽

Forest Zone ◽

Southern Nigeria ◽

Breeding Seasons

Previous reports and field observations at Ibadan and in northern Nigeria have established the occurrence of a dry-season form and a wet-season form of Zonocerus variegatus (L.). The wet-season form in the savanna areas of northern Nigeria is shown to be virtually identical with that from southern Nigeria on the basis of breeding seasons, habitat and morphometrics. Morphometrics show the wet- and dry-season forms to be distinct. It is suggested that the dry-season form in the wet rain forest zone spread into the dry savanna areas giving rise to a wet-season form adapted to the different climatic conditions. The increasing occurrence of the wetseason form in the south probably represents a re-invasion by the northern wetseason form.

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The eradication of Glossina morsitans submorsitans Newst. and Glossina tachinoides Westw. in part of a river flood plain in Northern Nigeria by chemical means. Part III.

Bulletin of Entomological Research ◽

10.1017/s0007485300057977 ◽

1960 ◽

Vol 51 (2) ◽

pp. 265-270 ◽

Cited By ~ 10

Author(s):

H. Davies ◽

P. Blasdale

Keyword(s):

Aqueous Suspension ◽

Flood Plain ◽

Dry Season ◽

Northern Nigeria ◽

Wet Season ◽

Glossina Morsitans ◽

Grazing Land ◽

Glossina Morsitans Submorsitans ◽

The Cost ◽

High Degree

An account is given of work carried out during the third year to eradicate Glossina morsitans submorsitans Newst. and G. tachinoides Westw. from an elongated fly-belt situated in the Sudan savannah vegetational zone of Northern Nigeria, which is an important cattle-raising area.The total area of the fly-belt, which is isolated as far as G. morsitans is concerned, measures about 120 miles in length and extends, in places, up to almost 10 miles in width. The country involved forms the flood plains and adjacent uplands of the Komadugu Gana river.Sixty-nine sq. miles were sprayed with DDT during the 1957–58 dry season(between end of January and end of April 1958), and 18 months after completion of work no tsetse has been found in the treated area. These 69 sq. miles formed the dry-season habitat of the fly on this section of the river, and the cost of insecticide and labour involved amounted to approximately £86 per sq. mile. As the zone infested in the wet season greatly exceeded this dry-season concentration area, reclamation costs per sq. mile, when applied to the amount of grazing land made safe for cattle, amounted to much less than the figure quoted.Successful continuation of this project is ascribed to three salient features of the technique employed: —(a) A single application only, of a 3·75 per cent, aqueous suspension of DDT from a wettable powder, is sufficient for complete eradication.(b) A high degree of discriminative or selective spraying is possible: for the elimination of G. morsitans, spraying can be mostly confined to larger tree trunks, in shade, up to a hei ght of about 5 ft.(c) Artificial or natural barriers to isolate each season's work, and so prevent re-invasion, are not necessary where the fly-belt is of a comparatively narrow and elongated nature. Spraying the re-infested area during the following season is more economical.

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The mosquitos of Zaria Province, Northern Nigeria

Bulletin of Entomological Research ◽

10.1017/s0007485300055024 ◽

1960 ◽

Vol 51 (1) ◽

pp. 145-171 ◽

Cited By ~ 24

Author(s):

P. W. Hanney

Keyword(s):

Dry Season ◽

The Other ◽

Northern Nigeria ◽

Wet Season ◽

Domestic Species ◽

Other Hand ◽

Two Peaks ◽

Trap Catches ◽

First Time ◽

Exit Trap

A general survey of the species of Anopheles in Zaria Province, Northern Nigeria, carried out between June 1957 and December 1958, was designed primarily to ascertain the bionomics of actual and potential vectors of malaria there. The studies, which were centred upon the four principal domestic Anophelines, A. gambiae Giles, A. funestus Giles, A. nili (Theo.) and A. wellcomei Theo., were carried out by making regular floor-sheet collections and entranceand exit-trap catches in native huts, together with biting catches inside and outside huts. Data on other Anophelines and Culicines, taken at the same time, were also recorded.The studies show that in this region, where malaria is holoendemic, all four species are endophagous to a greater or lesser extent although both A. gambiae and A. nili prefer to feed outside if a host is available. Only two species have been incriminated as vectors, A. gambiae, which had a sporozoite rate of between 4 and 7 per cent., and A. funestus with between 3 and 8 per cent., according to the season.Collections by floor-sheets and by catches at human bait showed that A. gambiae, A funestus and A. nili were predominantly wet-season species, although in one village area studied A. funestus also occurred in fairly high numbers throughout the dry season. A. wellcomei, on the other hand, was shown to be a predominantly dry-season species.By using traps and making collections with human bait, the entrance, exit and biting times of A. gambiae, A. funestus and A. nili were ascertained. The largest numbers of A. gambiae and A. funestus entered huts between 9.0 and 11.0 p.m. and left between 3.0 and 5.0 a.m., the maximum biting activity for A. gambiae being between midnight and 5.0 a.m., and for A. funestus between 11.0 p.m. and dawn. A. nili differed considerably from the other two species, having two peaks of maximum entry, between 9.0 and 11.0 p.m. and 1.0 and 3.0 a.m., the period of maximum exodus being between 1.0 and 5.0 a.m., with a peak of biting activity between 10.0 p.m. and 1.0 a.m. It was found that a very high proportion of the mosquitos caught leaving the huts was unfed; between 1.0 and 5.0 a.m., 64 per cent, of A. gambiae leaving, 63 per cent, of A. funestus and 30 per cent, of A. nili were unfed.Apart from the four domestic species of Anopheles mentioned above, the only other anthropophilous species which could be described as common in the vicinity of Kaduna were A. coustani Lav., A. theileri Edw., A. flavicosta Edw. and A. rufipes (Gough). A. implexus (Theo.) is recorded from Nigeria for the first time.The commonest species of Culicines taken at human bait during outside night collections were Mansonia africana (Theo.), M. uniformis (Theo.), M. cristata (Theo.), Aëdes lineatopennis (Ludl.) and Culex poicilipes (Theo.). Of these, M. uniformis was by far the most regular and persistent biter throughout the year. M. africana, on the other hand, was only taken in any numbers during October.In an appendix, a list of 17 species of Anopheles (including 3 varieties), 65 of the CUlicinae and two of the TOxorhynchitinae known to occur in Zaria Province is given, with notes on their distribution and bionomics.

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Cultivars, Fertilizers, Crop Protection and Economics of Carrot Production in Northern Nigeria

Experimental Agriculture ◽

10.1017/s0014479700023668 ◽

1973 ◽

Vol 9 (1) ◽

pp. 47-54

Author(s):

J. H. Green

Keyword(s):

Trace Elements ◽

Crop Protection ◽

Dry Season ◽

Northern Nigeria ◽

Wet Season ◽

Alternaria Dauci ◽

Beneficial Response ◽

Successful Control ◽

Peasant Farmers

SUMMARYComparison of up to ten carrot cultivars at various sites in a three-year period did not show that any cultivar consistently outyielded the others. Investigations at Samaru between 1969 and 1971 indicated that application of 100 kg. of N was beneficial, response to P was not consistent and there was no response to K or trace elements. Economics of production by peasant farmers is discussed and conclusions drawn that irrigated carrots, grown in the dry season, could be very profitable. No successful control was found for blight (Alternaria dauci) which severely inhibits the production of a wet season crop.

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Altitudinal and seasonal distribution of butterflies (Lepidoptera, Papilionoidea) in Cerro Bufa El Diente, Tamaulipas, Mexico

ZooKeys ◽

10.3897/zookeys900.36978 ◽

2019 ◽

Vol 900 ◽

pp. 31-68

Author(s):

Edmar Meléndez-Jaramillo ◽

Cesar M. Cantú-Ayala ◽

Uriel Jeshua Sánchez-Reyes ◽

Fatima Magdalena Sandoval-Becerra ◽

Bernal Herrera-Fernández

Keyword(s):

Vegetation Type ◽

Cloud Forest ◽

Alpha Diversity ◽

Dry Season ◽

High Mountain ◽

Total Abundance ◽

Wet Season ◽

Conservation Areas ◽

Monthly Basis ◽

Tropical Conditions

Butterflies are one of the most recognized and useful groups for the monitoring and establishment of important conservation areas and management policies. In the present study, we estimate the richness and diversity, as well as the association value of submontane scrub, oak forest, and cloud forest species at Cerro Bufa El Diente, within the Sierra de San Carlos priority land region, located in the Central-western region of Tamaulipas, Mexico. Three sampling sites were established based on criteria of vegetation distribution per altitudinal floor. One site for each altitudinal floor and vegetation type. Sampling was carried out in permanent transects on a monthly basis at each site, using an aerial entomological net and ten Van Someren-Rydon traps, during four sampling periods: early dry season, late dry season, early wet season and late wet season. In total, 7,611 specimens belonging to six families, 20 subfamilies, 32 tribes, 148 genera and 243 species of the study area were collected. Nymphalidae was the most abundant family with 3,454 specimens, representing 45.38% of total abundance in the study area. Lower abundance was recorded in Hesperiidae (19.17%), Pieridae (16.41%), Lycaenidae (10.17%), Papilionidae (5.12%), and finally Riodinidae (3.74%). The highest species richness was presented in the family Hesperiidae with 34.57% of the total obtained species followed by Nymphalidae (30.45%), Lycaenidae (15.23%), Pieridae (9.88%), Papilionidae (5.76%), and Riodinidae (4.12%). Twenty-seven species were categorized as abundant, these species, Anaea aidea (Guérin-Méneville, 1844), Libytheana carinenta larvata (Strecker, 1878), Pyrgus oileus (Linnaeus, 1767), Mestra amymone (Ménétriés, 1857) and Phoebis agarithe agarithe (Boisduval, 1836) presented the highest number of specimens. Sixty-five species were considered common, constituting 41.73% of the total number of butterflies, 63 frequent (9.76% of the total abundance), 55 limited (2.54%) and 33 rare (0.43%). The greatest number of specimens and species, as well as alpha diversity, were presented on the lowest altitudinal floor, made up of submontane scrub, and decreased significantly with increasing altitude. According to the cluster analysis, low and intermediate altitude sites constitute an area of distribution of species that prefer tropical conditions, while the third-floor site forms an independent group of high mountain species. The greatest abundance and richness of species, as well as alpha diversity, was obtained during the last wet season, decreasing significantly towards the early dry season. Moreover, through the use of the association value, 19 species were designated as indicators, three for the last altitudinal floor, three for the intermediate and 13 for the first. The present work represents the first report of the altitudinal variation in richness, abundance and diversity of butterflies in the northeast of Mexico. These results highlight the importance of the conservation of this heterogeneous habitat and establish reference data for the diurnal Lepidoptera fauna of the region.

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The seasonal changes of the gut microbiome of the population living in traditional lifestyles are represented by characteristic species-level and functional-level SNP enrichment patterns

BMC Genomics ◽

10.1186/s12864-021-07372-0 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Xue Zhu ◽

Jiyue Qin ◽

Chongyang Tan ◽

Kang Ning

Keyword(s):

Gut Microbiome ◽

Seasonal Changes ◽

Dry Season ◽

Urban Setting ◽

Snp Analysis ◽

Wet Season ◽

Human Gut ◽

Human Gut Microbiome ◽

Genome Level ◽

Prevalent Species

Abstract Background Most studies investigating human gut microbiome dynamics are conducted on humans living in an urban setting. However, few studies have researched the gut microbiome of the populations living traditional lifestyles. These understudied populations are arguably better subjects in answering human-gut microbiome evolution because of their lower exposure to antibiotics and higher dependence on natural resources. Hadza hunter-gatherers in Tanzania have exhibited high biodiversity and seasonal patterns in their gut microbiome composition at the family level, where some taxa disappear in one season and reappear later. Such seasonal changes have been profiled, but the nucleotide changes remain unexplored at the genome level. Thus, it is still elusive how microbial communities change with seasonal changes at the genome level. Results In this study, we performed a strain-level single nucleotide polymorphism (SNP) analysis on 40 Hadza fecal metagenome samples spanning three seasons. With more SNP presented in the wet season, eight prevalent species have significant SNP enrichment with the increasing number of SNP calling by VarScan2, among which only three species have relatively high abundances. Eighty-three genes have the most SNP distributions between the wet season and dry season. Many of these genes are derived from Ruminococcus obeum, and mainly participated in metabolic pathways including carbon metabolism, pyruvate metabolism, and glycolysis. Conclusions Eight prevalent species have significant SNP enrichments with the increasing number of SNP, among which only Eubacterium biforme, Eubacterium hallii and Ruminococcus obeum have relatively high species abundances. Many genes in the microbiomes also presented characteristic SNP distributions between the wet season and the dry season. This implies that the seasonal changes might indirectly impact the mutation patterns for specific species and functions for the gut microbiome of the population that lives in traditional lifestyles through changing the diet in wet and dry seasons, indicating the role of these variants in these species’ adaptation to the changing environment and diets.

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