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  • 1
    Online Resource
    Online Resource
    Wiley ; 2016
    In:  African Journal of Ecology Vol. 54, No. 3 ( 2016-09), p. 308-316
    In: African Journal of Ecology, Wiley, Vol. 54, No. 3 ( 2016-09), p. 308-316
    Abstract: La collision d'avions avec des oiseaux coûte des millions de dollars à l'aviation du monde entier et va jusqu’à causer des morts. Nous avons conçu et testé un protocole pour étudier les risques posés pour les avions par des oiseaux qui volent au‐dessus de pistes où les avions font leur rotation et montent au moment du décollage. Nous avons enregistré les oiseaux et la hauteur à laquelle ils volaient au‐dessus de la piste 03L de l'Aéroport International OR Tambo, en Afrique du Sud. En 14 heures et 15 min, 7,938 oiseaux de la taille d'un pigeon ou plus grands ont croisé une piste sur 400 m, soit un taux de 8.8 oiseaux par minute, et il y a eu 200 avions qui ont décollé durant cette période. Le plus grand risque de collision avec des oiseaux concerne les ibis sacrés africains et les mouettes à tête grise. Ces oiseaux constituent respectivement une moyenne de 111 kg/10 min. et 47.2 kg/10 min. de biomasse volant au‐dessus de la piste. Nous identifions des options de gestion possibles pour réduire ces risques de collisions. Notre protocole d’étude et le traitement des données sont faciles à utiliser, ils ajouteront une définition (?) importante aux activités existantes pour réduire les collisions et ils peuvent fournir sur les risques des informations comparables aux autorités de l'aérodrome et aux pilotes.
    Type of Medium: Online Resource
    ISSN: 0141-6707 , 1365-2028
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2016
    detail.hit.zdb_id: 2019879-6
    SSG: 12
    SSG: 14
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  • 2
    Online Resource
    Online Resource
    Wiley ; 2016
    In:  African Journal of Ecology Vol. 54, No. 4 ( 2016-12), p. 519-523
    In: African Journal of Ecology, Wiley, Vol. 54, No. 4 ( 2016-12), p. 519-523
    Type of Medium: Online Resource
    ISSN: 0141-6707 , 1365-2028
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2016
    detail.hit.zdb_id: 2019879-6
    SSG: 12
    SSG: 14
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  • 3
    Online Resource
    Online Resource
    AOSIS ; 2017
    In:  Koedoe Vol. 59, No. 1 ( 2017-05-30)
    In: Koedoe, AOSIS, Vol. 59, No. 1 ( 2017-05-30)
    Abstract: With tourism in South Africa expanding, the number of avitourists increases. The increase in infrastructure and human activities in protected areas, if not managed properly, can be harmful to birds. Flight initiation distances (FID) can be used as a method to monitor habituation to disturbances. This study was performed at the Barberspan Bird Sanctuary, North West province, South Africa, to determine the levels of habituation among waterbirds and make appropriate recommendations regarding the management of the reserve. Our results indicated a 0.29 m increase in FID per gram reported mean biomass. Compared with conspecific or congeneric birds from Australia, Europe and North America, South African birds have relatively larger FIDs to human disturbance, which may indicate lower habituation. We also calculated buffer zones based on the maximum FID of the waterbirds for three mass groups. These buffer zones were then matched with the spatial distribution of the birds along the shoreline. We recommend that the mean FID for the blacksmith lapwing, Vanellus armatus (62 m), can be used as approach distance outside the breeding season in areas where the birds are sparsely distributed and 104 m during the breeding season in breeding areas. A large buffer of 200 m is suggested for areas with threatened, sensitive and skittish species. However, it is still preferable for avitourists to use the bird hides along the shores.Conservation implications: This study provides information for conservation management at Barberspan, based on typical birder activity. Smaller birds would need smaller buffer zones, while larger birds need much greater distances from observers to minimise disturbance. Similar studies can be applied elsewhere.
    Type of Medium: Online Resource
    ISSN: 2071-0771 , 0075-6458
    Language: Unknown
    Publisher: AOSIS
    Publication Date: 2017
    detail.hit.zdb_id: 2413347-4
    SSG: 12
    SSG: 6,31
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  • 4
    Online Resource
    Online Resource
    AOSIS ; 2016
    In:  Koedoe Vol. 58, No. 1 ( 2016-03-31)
    In: Koedoe, AOSIS, Vol. 58, No. 1 ( 2016-03-31)
    Abstract: Research and conservation of wild crocodiles and husbandry of captive crocodiles requires the reliable identification of individuals. We present a method using the individual colour markings on the first 10 single-crest scutes on the tails of Nile crocodiles (Crocodylus niloticus). The scutes are scored by number for colour, with a prefix for left or right providing a binary 11-digit identification number (identification numbers [IDs]; e.g. 12232232242 and 22333233232) per crocodile. A survey of 359 captive Nile crocodiles showed no duplication. However, 42% had asymmetrical scute markings requiring a binary approach. There does not seem to be a change in patterns with age, except that the number of missing scutes increased. A small trial showed that this method can be applied in the field, although more work is needed to determine observer bias and establish parameters for observability in the field. It is unlikely that both left and right IDs would be obtainable for each individual, but other distinctive markings such as scute shape and damage can be used to register the two IDs to one individual. Having two independent IDs for each crocodile provides the possibility of two independent population estimates for equal effort without having to link left and right IDs to individuals. Our proposed method would be useful in conservation, individual tracking and husbandry.Conservation implications: A non-invasive marking and recapture method for Nile crocodile is presented whereby the first 10 single-crest scutes are scored for colour, allowing conservation practitioners to count and monitor crocodile populations and individuals. This method provides two equal-effort estimations of population size, as left and right hand sides are scored independently.Keywords: Crocodylus niloticus; identification; mark - recapture; mark - resight
    Type of Medium: Online Resource
    ISSN: 2071-0771 , 0075-6458
    Language: Unknown
    Publisher: AOSIS
    Publication Date: 2016
    detail.hit.zdb_id: 2413347-4
    SSG: 12
    SSG: 6,31
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  • 5
    Online Resource
    Online Resource
    Informa UK Limited ; 2020
    In:  African Zoology Vol. 55, No. 4 ( 2020-10-01), p. 278-291
    In: African Zoology, Informa UK Limited, Vol. 55, No. 4 ( 2020-10-01), p. 278-291
    Type of Medium: Online Resource
    ISSN: 1562-7020 , 2224-073X
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2070936-5
    SSG: 12
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  • 6
    Online Resource
    Online Resource
    Academy of Science of South Africa ; 2020
    In:  South African Journal of Science Vol. 116, No. 5/6 ( 2020-05-27)
    In: South African Journal of Science, Academy of Science of South Africa, Vol. 116, No. 5/6 ( 2020-05-27)
    Abstract: We review and evaluate the major land-based sources and pathways of plastic waste that lead to marine pollution in a South African context. Many of the formal solid waste and waste-water management facilities in South Africa are not fully functional, contributing towards plastic releases to the environment. Much plastic also enters the environment directly by informal and illegal dumping. Once in the environment, plastic is transported and distributed by air, inland waterways and human activity, with complex dynamics that are not fully understood. Depending on the size and type of plastic and environmental factors like wind action and run-off, plastic can be deposited into sinks such as soil, river sediments and vegetation, or carried to the ocean. Contrary to an initial assumption that South Africa is the 11th worst contributor to marine plastic pollution, we estimate from more accurate and recent data that between 15 000 and 40 000 tonnes per year is carried to the oceans. This amount is six-fold less than a previous estimate. Despite many data and information gaps that require urgent attention through research and monitoring, it is clear that the status quo will lead to a worsening of already severe plastic pollution of all environments. South Africa needs to reduce plastic entering the environment by reducing illegal and informal dumping, effectively implementing and improving waste management infrastructure, and intensifying long-term awareness campaigns. Most importantly, however, immediate and effective mitigation is required. Significance: More accurate and recent data show that between 15 000 and 40 000 tonnes of plastic is carried to the oceans from South Africa per year – six-fold less than the widely used previous estimate. Riverine sediments are potentially major sinks for plastic en route to the ocean. Management of treated waste-water sludge, as well as the state of waste-water treatment plants (WWTPs) are key concerns. WWTPs are reported to remove most plastic from the water content. The state of South African WWTPs have deteriorated to such an extent that up to 40% of the country’s waste water is untreated and data and management practices of sludge are unavailable. There are major data gaps in the South African waste sector, which lead to miscalculations and uncertainties about the country’s contribution to marine plastic debris.
    Type of Medium: Online Resource
    ISSN: 1996-7489
    Language: Unknown
    Publisher: Academy of Science of South Africa
    Publication Date: 2020
    detail.hit.zdb_id: 2067033-3
    detail.hit.zdb_id: 2482725-3
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  • 7
    Online Resource
    Online Resource
    Wiley ; 2019
    In:  African Journal of Ecology Vol. 57, No. 1 ( 2019-03), p. 41-50
    In: African Journal of Ecology, Wiley, Vol. 57, No. 1 ( 2019-03), p. 41-50
    Abstract: Les oiseaux du genre Cisticola vivent presque partout en Afrique australe, dans des habitats qui vont de basse à haute altitude, des zones humides à arides, ce qui fait que des espèces ont des distributions uniques. Pour déterminer si les cisticoles ont développé une imperméabilité à l'eau spécifique pour chaque espèce et une résistance à la pénétration de l'eau compatible avec leurs habitats, nous avons mesuré le diamètre des barbes et l'espacement entre les plumes du ventre, de la poitrine et du cou de six espèces et relié les résultats aux chutes de pluie annuelles moyennes et à l'altitude de cinq lieux différents. L'imperméabilité à l'eau n’était pas significativement associée à l'altitude ou à la température maximum moyenne en été. Mais elle augmentait significativement là où les chutes de pluie annuelles étaient comprises entre 550 et 600 mm/an pour les plumes du ventre et de la poitrine, mais pas celles du cou. Cette augmentation était évidente aussi bien chez les espèces qui vivent en de nombreux endroits que chez différentes espèces qui ne vivent que sur un seul site. Cependant, les deux espèces qui vivent dans les sites les plus humides présentaient une faible imperméabilité mais une résistance plus grande à la pénétration de l'eau. Ces résultats suggèrent que l'imperméabilité à l'eau et la résistance à la pénétration de l'eau font partie de forces évolutives qui façonnent la microstructure des tectrices de Cisticola .
    Type of Medium: Online Resource
    ISSN: 0141-6707 , 1365-2028
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2019
    detail.hit.zdb_id: 2019879-6
    SSG: 12
    SSG: 14
    Location Call Number Limitation Availability
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