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Bird atlases have become an important source of distribution data for broad-scale analyses in ecology, biogeography and conservation. However, national bird atlases are undertaken in different ways in different countries, usually with little formal assessment of alternatives. Existing research suggests that the differences in accuracy between line and point transects are influenced by context, habitat and other details of the sampling protocol. To determine the best approach to use for southern Africa, where collection of data for atlases must cope with a wide range of field conditions, we compared data from a point-count approach to data from line transects on 302 routes in 19 South African National Parks. Data were analysed using paired sample tests, linear models, qualitative assessment and a Bayesian multispecies occupancy model to estimate species richness, while accounting for imperfect detection. On average, five more bird species were recorded along a route using point counts, even though the line transects covered three times more area. There was no obvious difference in the kinds of species recorded. Occupancy models showed that point counts consistently and substantially outperformed transects in estimating species richness. In transects, low detection probability leads to highly biased and imprecise estimates. For almost identical observer effort, standardised point counts along a route provided significantly higher quality data than transects.
A historical overview of the leech fauna of Morocco, based on both literature data, museum collections and new material, sampled in more than 100 sites in the Moulouya River basin (eastern region of Morocco), is provided. Twenty species from five families and ten genera are currently known, of which Helobdella europea Kutschera, 1987, is a new record for the country and North Africa as a whole. Herein, we add many new distribution records. The current list will need to be revised as new species distributions are recorded in the region. Notes on the species distribution are given along with comments on their habitat preferences. A concise biogeographic analysis outlines the similarities in the distribution of some species at regional and continental scales. This contribution is intended to provide information concerning the leech fauna of Morocco and is considered a foundation for future studies.
Myriapods are remarkably diverse and encompass many endemic species, yet they remain poorly studied in Cameroon. We investigated the influence of anthropogenic activities on myriapod assemblage structures along an altitudinal gradient at Mount Kala. Myriapods were collected by pitfall trapping, hand sorting and litter sifting in four altitudinal levels and habitats (820 m, 920 m, 1 020 m and 1 120 m above sea level) from November 2017 to July 2018. A total of 1 131 individuals from 58 species in 3 classes (Diplopoda, Chilopoda and Symphyla), 36 genera and 17 families were recorded at Mount Kala. The Diplopoda was the most abundant and diverse class (94.69% and 49 species), followed by Chilopoda (4.51% and 8 species) and Symphyla (0.80% and 1 species). Aporodesmus gabonicus Lucas, 1858 and Karkinikus colonus Attems, 1914 were the most abundant species in the study site. Along the altitudinal gradient, the myriapod species richness decreased in anthropised areas (820 m to 920 m above sea level), reached a maximum in transitional forest (920 m to 1 020 m above sea level) and slightly decreased within the submontane forests (1 020 m to 1 120 m above sea level). Myriapod abundance followed the same trend. However, our results also indicate a high species richness turnover observed between altitudinal levels suggesting that most species are adapted to a particular habitat and could serve as indicators of environmental changes. Accordingly, this study demonstrates a negative relationship between anthropisation and myriapod diversity, as well as the implications towards the management of the Mount Kala forest.
Psychotria microphylla is an ichthyotoxic botanical used to stupefy fish prior to harvesting in aquatic systems. The current study investigated the effect of P. microphylla leaf extract on the oxidative stress and biochemical parameters of the giant African land snail, Achatina achatina. Adult A. achatina were administered 0.35, 0.45 and 0.55 mg l–1 leaf extract of P. microphylla and sampling was done after 24, 48, 72 and 96 h durations. Oxidative stress was evident by the significant increase in lipid peroxidation (LPO). Maximum LPO values of 36.13% and 63.69% were observed in A. achatina administered 0.55 mg l–1 of the leaf extract at 24 h and 96 h respectively. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) significantly decreased, whereas the values of glutathione reductase (GR) increased significantly compared to the control. Extract-induced toxicity was evident by the significant increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activity relative to the control. The current findings indicate the potential toxicity of P. microphylla and suggest that it could be used for control of terrestrial snail pests.
Although validation of the rate of growth zone deposition is a prerequisite for accurate age estimation, such studies are non-existent for the endemic Labeobarbus species in Lake Tana. Therefore, the aim of the current study was to validate the periodicity of growth zone deposition in asteriscus otolith of L. tsanensis and L. platydorsus. A total of 723 and 496 asteriscus otolith pairs from L. tsanensis and L. platydorsus, respectively, were examined. Binary-circular models, based on edge analysis (EA) and linear-circular models, based on marginal increment analysis (MIA) were employed to validate the rate of growth zone deposition. The results of EA indicate that there is an annual growth zone deposition for L. tsanensis and L. platydorsus. For both species, the highest proportion of translucent zones was detected between October and January, with a peak in January. The results of the MIA corroborated this for both species. In addition, the lowest marginal increment ratio (MIR) was recorded in January for both species. The annual growth zone deposition in asteristicus otoliths of these species is likely caused by the relatively low water temperature coinciding with the peak breeding activity of the species.
Evolution is driven by natural selection acting on variable phenotypic traits. Understanding the molecular basis of those traits is crucial for elucidating the mechanisms of natural selection. The southern African jackal buzzard (Buteo rufofuscus) displays extreme plumage colour polymorphism, with colouration on the chest varying from dark black to pale white. In a number of birds and other vertebrates, genetic variation at the melanocortin-1 receptor (Mc1r) gene is associated with melanin-based colour variation. Here, the Mc1r gene was sequenced from 12 jackal buzzard individuals displaying three distinct colour morphs (dark, intermediate and pale). A single nucleotide change was found, which although it resulted in an amino acid change, was shared by all jackal buzzards irrespective of colour morph. Although the Mc1r has played an important role in colour polymorphism in other species, in this study no association between Mc1r genotype and plumage polymorphism in jackal buzzards was found.
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