On the altitudinal limits of birds on BasilC Peak (Bioko Island; Equatorial Guinea)

Pérez del Val, J. 2000. On the altitudinal limits of birds on Basile Peak (Bioko Island; Equatorial Guinea). Ostrich 71(1 & 2): 342.

The lower altitudinal limit of the montane avifauna in Africa has generally been set at 1 500- 800 m, corresponding to vegetation belts of the main mountain ranges of East Africa. However, much lower limits have been reported from the East Usambaras (Tanzania), Mount Cameroon, and Bioko Island. Basilé Peak is a volcano of 3 011 m which constitutes the northern half of Bioko Island. Below 400–900 m the forest has been logged and largely replaced by cocoa plantations, but the vegetation is relatively undisturbed at higher altitudes. Annual rainfall ranges between 2 000 mm and 3 500 mm. From January 1990 to July 1992 mist-nets were set at 13 standardised stations on Basilé Peak; 1 427 birds of 71 species were captured. Previous data from non-standardised mist-netting at 6 other localities, together with sight and sound records, published data, and 1 047 skins in the collections of Museo Naçional de Ciençias Naturales (Madrid), Estacion Biologica de Donaiia (Sevilla) and the Natural History Museum (Tring) were also used to compile distribution lists. From published botanical surveys, I recognised four vegetation zones: Lowland Rain Forest up to 800 m; Mountain Rain Forest at 80CL1 800 m; Araliaceus Forest 1 800–2 500 m; and Ericaceus Stands above 2 500 m. An analysis of similarity (using the index of Czechanowski) grouped 68 bird species into altitudinal classes at 200 m intervals. This suggests a division between lowland and montane birds at 800–1 000 m, broadly coinciding with the change between Lowland and Mountain Rain Forest. There does not seem to be a discrete bird community restricted to either of the upper zones (Araliaceus Forest or Ericaeus Stands), with only the Yellow Bishop Euplectes capensis restricted to the upper 500 m of the mountain. Most species which reach the summit are found in all vegetation zones, notably the endemic subspecies of the African Goshawk Accipiter tachiro lopezi. It is suggested that low temperatures, high rainfall, and in particular the seasonal distribution of rainfall, may explain the lower altitudinal limits of the montane avifauna on Bioko and on Mount Cameroon.     

Decline in hunter offtake of blue duikers in Bioko Island,Equatorial Guinea

The blue duiker (Philantomba monticola) is an abundant and widely distributed ungulate in continental sub‐Saharan Africa. High hunting pressure throughout its range may be particularly threatening to the persistence of island populations of the species. In this study, we assessed offtake of blue duikers in Pico Basilé, Bioko Island, Equatorial Guinea. We recorded the number of animals shot or snared by 46 commercial hunters over a 33‐month period, and the location (elevation) of each animal hunted. From this, we estimated catch per hunter (C_H), catch per hunting day (C_D) and catch per unit effort (CPUE). The number of duikers shot or snared across the study period, significantly declined within the mid‐altitude range (901–1500 m). There were no significant drops in C_H or CPUE at low or high altitudes for snared animals. The ratio of immature‐to‐adult animals hunted increased significantly over time within the mid‐altitude range. We suggest that these trends in offtake, especially in the more heavily hunted mid‐altitudes of the study area, indicate a decline in the population within this range. If this situation is widespread throughout the island, it is likely that unregulated bushmeat hunting will have devastating consequences to the biodiversity of Bioko Island, particularly for heavily hunted species that are naturally less abundant.     

Response of bryophytes to exposure and water availability on some European travertines

Abstract

Seventeen travertine-bryophyte taxa were recorded in 212 quadrats from 17 sites, and the cover of the eight commonest species was analysed in terms of aspect, slope, exposure and water relations. Only Aneura pinguis was significantly affected by aspect, while Eucladium verticillatum and Hymenostylium recurvirostrum preferred steep slopes. The last two species, with Didymodon tophaceus, were also found to prefer sheltered sites, while Bryum pseudotriquetrum, Palustriella commutata var. commutata and Pellia endiviifolia were more common in exposed situations. Didymodon tophaceus, Hymenostylium recurvirostrum and Aneura pinguis were mostly confined to seepages and were kept moist by capillarity, while Palustriella commutata var. falcata and Pellia endiviifolia withstood high flows. Cratoneuron filicinum, Palustriella commutata var. commutata and Pellia endiviifolia had wide ecological amplitudes and were among the most frequently recorded species.     

Limnological Aspects of Two Tropical Crater Lakes (Lago Biao and Lago Loreto) on the Island of Bioko (Equatorial Guinea)

The limnology of Lago Biao and Lago Loreto, two tropical crater lakes on the island of Bioko, was investigated for the first time in January of 2002. Lago Biao fills a caldera at 1750 m altitude and is 18.5 m deep. This lake was characterized by low conductivity (11.6-13.3 S cm^–1), low pH (5.9-6.2), an oxycline between 6 and 10 m depth (90-27% saturation), and a Secchi depth of 5.5 m. Dinoflagellates, desmids, and green algae dominated the phytoplankton community. The rotifers Anuraeopsis fissa, Polyarthra indica, Trichocerca simoneae, and T. similis were most abundant above or in the thermocline. During the day Tropocyclops prasinus tjeefi and Chaoborus cf. ceratopogones concentrated in the oxycline, whereas Daphnia laevis was most abundant between 0 and 4 m depth. In contrast, L. Loreto is 82 m deep and probably fills an explosion crater (maar) at 1050 m altitude. The lake had a turbid, yellowish appearance and a Secchi depth of only 0.6 m. Oxygen content dropped from 121% at the surface to 6% in 10 m depth. The pH declined from 9.15 at the surface to 7.4 in only 2.5 m depth and became acidic at approximately 15 m depth. One species of cyanobacterium, one dinoflagellate and one green alga dominated the phytoplankton and together reached densities of 12 100 cells ml^–1. Only one rotifer (Brachionus angularis) and one copepod (Tropocyclops prasinus tjeefi) species colonized the open water. Intact algal cells and zooplankton specimens were encountered near the bottom.     

Reduced Prevalence of Malaria Infection in Children Living in Houses with Window Screening or Closed Eaves on Bioko Island,Equatorial Guinea

Background

Previous studies demonstrated that fewer mosquitoes enter houses which are screened or have closed eaves. There is little evidence about the effect on malaria infection in humans that changes in house construction may have. This study examines the impact of protective housing improvements on malaria infection on Bioko Island.

Methodology/Principal Findings

Data from the annual malaria indicator surveys between 2009 and 2012 were used to assess trends in housing characteristics and their effect on RDT confirmed malaria infection in household members. Odds ratios were adjusted for socio-economic status of the household.22726 children between the ages of 2 and 14 years were tested for P. falciparum. Prevalence of infection in those living in houses with open eaves was 23.0% compared to 18.8% for those living in houses with closed eaves (OR = 0.81, 95% CI 0.67 - 0.98). The prevalence of infection for children in screened houses was 9.1% versus 20.1% for those living in unscreened houses (OR = 0.44, 95% CI 0.27 - 0.71). The proportion of houses with closed eaves increased from 66.0% in 2009 to 74.3% in 2012 (test for trend p = 0.01). The proportion of screened houses remained unchanged over time at 1.3%.

Conclusion/Significance

As a malaria control intervention, house modification has the advantages that it is not affected by the growing threat of insecticide resistance; it protects all household members equally and at all times while indoors; and it offers protection against a number of vector borne diseases. The study provides evidence in support of efforts to regulate or encourage housing improvements which impede vector access into residences as part of an integrated vector control approach to complement existing measures which have been only partially successful in reducing malaria transmission in some parts of Bioko.     

First report of the oriental mosquito Aedes albopictus on the West African island of Bioko,Equatorial Guinea

The invasive oriental mosquito Aedes (Stegomyia) albopictus (Skuse) (Diptera: Culicidae) was detected on Bioko Island for the first time in November 2001. It was found to be well established breeding in artificial containers at Planta, near Malabo, the capital of Equatorial Guinea. Associated species of mosquito larvae were Aedes aegypti (L.), Ae. africanus (Theobald), Culex near decens Theobald, Cx. duttoni Theobald, Cx. quinquefasciatus Say, Cx. tigripes De Grandpré & De Charmoy, Eretmapodites quinquevittatus Theobald and Mansonia africana (Theobald). This is the third tropical African country to be invaded by Ae. albopictus, which has recently spread to many parts of the Americas and Europe--with vector competence for dengue, yellow fever and other arboviruses. In the Afrotropical environment, it will be interesting to monitor the ecological balance and/or displacement between introduced Ae. albopictus and indigenous Ae. aegpyti (domestic, peri-domestic and sylvatic populations).     

Checklist of Commelinaceae of Equatorial Guinea (Annobón,Bioko and Río Muni)

A checklist of Commelinaceae of Equatorial Guinea, comprising 46 taxa in 12 genera, is presented. The best represented genus is Palisota, with 11 species. Bibliographical references for Commelinaceae from Equatorial Guinea have been gathered and checked. Eleven species of Commelinaceae are recorded for the first time in the country. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 106–122.     

Seroprevalence of Human Immunodeficiency Virus,Hepatitis B Virus,Hepatitis C Virus,and Treponema pallidum Infections among Blood Donors on Bioko Island,Equatorial Guinea

Background

Regular screening of transfusion-transmissible infections (TTIs), such as human immunodeficiency virus (HIV), hepatitis B and hepatitis C virus (HBV and HCV, respectively), and Treponema pallidum, in blood donors is essential to guaranteeing clinical transfusion safety. This study aimed to determine the seroprevalence of four TTIs among blood donors on Bioko Island, Equatorial Guinea (EG).

Methods

A retrospective survey of blood donors from January 2011 to April 2013 was conducted to assess the presence of HIV, HBV, HCV and T. pallidum. The medical records were analyzed to verify the seroprevalence of these TTIs among blood donations stratified by gender, age and geographical region.

Results

Of the total 2937 consecutive blood donors, 1098 (37.39%) had a minimum of one TTI and 185 (6.29%) harbored co-infections. The general seroprevalence of HIV, HBV, HCV and T. pallidum were 7.83%, 10.01%, 3.71% and 21.51%, respectively. The most frequent TTI co-infections were HBV-T. pallidum 60 (2.04%) and HIV-T. pallidum 46 (1.57%). The seroprevalence of HIV, HBV, HCV and T. pallidum were highest among blood donors 38 to 47 years, 18 to 27 years and ≥ 48 years age, respectively (P<0.05). The seroprevalence of TTIs varied according to the population from which the blood was collected on Bioko Island.

Conclusions

Our results firstly provide a comprehensive overview of TTIs among blood donors on Bioko Island. Strict screening of blood donors and improved hematological examinations using standard operating procedures are recommended.     

Increased risks of malaria due to limited residual life of insecticide and outdoor biting versus protection by combined use of nets and indoor residual spraying on Bioko Island, Equatorial Guinea

ABSTRACT: BACKGROUND: Malaria is endemic on Bioko Island, Equatorial Guinea, with year-round transmission. In 2004 an intensive malaria control strategy primarily based on indoor residual spraying (IRS) was launched. The limited residual life of IRS poses particular challenges in a setting with year-round transmission, such as Bioko. Recent reports of outdoor biting by Anopheles gambiae are an additional cause for concern. In this study, the effect of the short residual life of bendiocarb insecticide and of children spending time outdoors at night, on malaria infection prevalence was examined. METHODS: Data from the 2011 annual malaria indicator survey and from standard WHO cone bioassays were used to examine the relationship between time since IRS, mosquito mortality and prevalence of infection in children. How often children spend time outside at night and the association of this behaviour with malaria infection were also examined. RESULTS: Prevalence of malaria infection in two to 14 year-olds in 2011 was 18.4 %, 21.0 % and 28.1 % in communities with median time since IRS of three, four and five months respectively. After adjusting for confounders, each extra month since IRS corresponded to an odds ratio (OR) of 1.44 (95 % CI 1.15-1.81) for infection prevalence in two to 14 year-olds. Mosquito mortality was 100 %, 96 %, 81 % and 78 %, at month 2, 3, 4 and 5 respectively after spraying. Only 4.1 % of children spent time outside the night before the survey between the hours of 22.00 and 06.00 and those who did were not at a higher risk of infection (OR 0.87, 95 % CI 0.50-1.54). Sleeping under a mosquito net provided additive protection (OR 0.68, 95 % CI 0.54-0.86). CONCLUSIONS: The results demonstrate the epidemiological impact of reduced mosquito mortality with time since IRS. The study underscores that in settings of year-round transmission there is a compelling need for longer-lasting IRS insecticides, but that in the interim, high coverage of long-lasting insecticidal nets (LLINs) may ameliorate the loss of effect of current shorterlasting IRS insecticides. Moreover, continued use of IRS and LLINs for indoor-oriented vector control is warranted given that there is no evidence that spending time outdoors at night increases infection prevalence in children.     

The blackflies (Diptera: Simuliidae) of Bioko (Republic of Equatorial Guinea) and the Gulf of Guinea with a description of the larvae of the 'Pomeroy' form of Simulium cervicornutum

Abstract.  Like many other organisms, Simuliidae often show a high degree of endemism on oceanic islands, and the Gulf of Guinea, including its islands, is a region of general biogeographical interest in view of the uniqueness of its flora and fauna. This paper presents a comprehensive review of the Simuliidae in the region, and is the first faunistic record of blackflies from Bioko. Simuliidae (larvae, pupae and neonate adults) were collected from Bioko and from around Mount Cameroon and compared with previous findings from Mount Cameroon, Príncipe and São Tomé. Twenty-seven species are known from the region. Twenty-five species have been recorded around Mount Cameroon, eight species on Bioko, three species on São Tomé and one species on Príncipe. Two taxonomic 'forms' (one on Bioko alone, and one on both Bioko and around Mount Cameroon) and one species (found only on São Tomé) are endemic to the region. A study of the variation in the morphology of Simulium cervicornutum revealed two morphotypes, one from Bioko and around Mount Cameroon and the other from the rest of Africa. The speciation and biogeography of the Simuliidae in the Gulf of Guinea are discussed.     

A review of the genus Fallaciella (Bryopsida: Lembophyllaceae), including a new species from South Island,New Zealand

Abstract

An overview of the genus Fallaciella is provided, including reasons for its placement in the Lembophyllaceae. A new species, Fallaciella robusta sp. nov., is described from South Island, New Zealand. The differences between the two known species of Fallaciella are outlined and the main points summarized in a key. Illustrations are provided for both species, and a distribution map is provided for F. robusta.     

Some new species of Haplotaxidae (Oligochaeta) from Guinea and remarks on the history of the family

Three new species of Haplotaxidae collected by Dr. A. Villiers in a cave near Kindia, Guinea, are described. One species belongs to the genus Metataxis Righi, 1985 (M. carnivorus sp. nov.) which is distributed in Western Africa and Eastern America. Another new species is similar to Lycodrilus kraepelini Michaelsen, 1914 incertae sedis: a new genus Villiersia is proposed for both species (V. guanivora sp. nov., V. kraepelini nov. comb.).A third species, of which only immature specimens are available, is tentatively attributed to the genus Haplotaxis: it is remarkable because of its peculiar setae and commissural vessels (H. villiersi sp. nov.).The three species appear to feed on bat guano and, occasionally, on aquatic arthropods. Metataxis, Tiguassu and Villiersia belong to the section of Haplotaxidae endowed with paired sperm sacs and ovisacs.The relations of Haplotaxidae with other families are discussed and it is suggested that the passage from the haplotaxid condition to that of sparganophilids and more advanced lumbriciforms is connected to a change of reproductive strategy and to an enhanced metabolism.     

A contribution to the knowledge of liphistiid spiders

These spiders resemble fossil spiders of the Carboniferous. Although they are unique in retaining several primitive characters it is thought best to include them in the sub-Order Mygalomorphae and to abandon the special sub-Order Liphistiomorphae.
The family Heptathelidae to include those species with seven instead of eight spinnerets as in the Liphistiidae is also abandoned.
The species Liphistius thorelli Sim. from Sumatra is regarded as a synonym of the other Sumatran species L. sumatranus Thor.
Eight species of Liphistius and two of Heptathela are now recognized. Their distribution is confined, according to present knowledge, to Burma, Thailand, Vietnam, China, Japan, Malaysia and Sumatra. This may provide useful evidence in the question, as yet unsettled, of the origin of south-east Asia in terms of continental drift.
A special visit has been paid to Sumatra to rediscover Liphistius sumatranus (of which only one specimen was found and described in 1879) to establish with certainty that it is distinct from the Malaysian L. desultor . This was achieved and the species are now compared.
Some biological observations are provided.     

A contribution to the knowledge of Agathidinae (Hymenoptera: Braconidae) from Iran with description of a new species

The subfamily Agathidinae was studied in parts of northern Iran. Six species were collected and identified. Among them, Cremnops desertor (L., 1758) is recorded for the first time from Iran. Lytopylus persicus Farahani & Talebi sp. n. is described and illustrated. A key to the West Palaearctic species of the genus Lytopylus Förster and an updated checklist of Iranian Agathidinae are provided.     

Systematics of the Gyrosigma balticum complex (Bacillariophyta), including three new species

Three new species in the genus Gyrosigma Hassall (G. caliG. Reid sp. nov., G. gibbyiG. Reid sp. nov. and G. murphyi G. Reid sp. nov) are described. A cladistic analysis on the basis of 10 morphological characters, was undertaken to investigate the interrelationships of these new species within Gyrosigma. As well as ‘standard’ cladistic analysis, which apportions equal weight to all characters, a posteriori differential weighting was also investigated. Pleurosigma subtilis Brébisson is transferred to Gyrosigma, as G. subtile (Brébisson) G. Reid comb. nov., because it is more closely related to other species of Gyrosigma than to Pleurosigma Smith. G. balticum var. californicum Grunow in Cleve and Möller is elevated to specific status [as G. californicum (Grunow in Cleve and Möller) G. Reid stat. nov.], because it does not form a monophyletic group with G. balticum (Ehrenberg) Rabenhorst.     

苔藓植物对西南部分地区大气污染(包括酸雨)的指示意义的初步研究

本文在对我国西南部分酸雨污染重区的树附生苔藓的种类、分布、盖度和频度的野外调查基础上,计算了各样点的大气净度指数(IAP)。据此,可将样区划分为:1)严重污染区,树附生苔藓0～2种,IAP值10以下,降水pH值3—3.5;2)污染区,树附生苔藓4—13种,IAP值10—30,降水pH值4—5;3)基本纯净区,树附生苔藓19种以上,IAP值40—90,降水pH值5.5—6.5。人工模拟酸雨对苔藓植物生长的影响的实验表明,pH3.0以下酸雨可使大部分苔藓种类在半年内死亡;pH4.5酸雨使80％苔藓植物在1年时间内死亡,但少数抗酸性种类,在pH3.0酸雨下仍生长良好。     

Astragalus raphaelis (Fabaceae), a critical species from Sicily and taxonomic remarks on A. sect. Sesamei

The taxonomic position of Astragalus raphaelis, a rare and misappreciated species endemic to Sicily, has been examined. In addition, its geographical distribution, ecology and conservation status, diagnostic morphological characters, pod and seed micro‐morphology and relationship with A. stella are provided. Phenetic and phylogenetic trees (based on morphological data) for A. sect Sesamei shows that A. raphaelis is a taxonomically quite isolated species, with some relationships to A. sesamoides.