Articles by Author: Johann H Van Niekerk

Search results for Johann H Van Niekerk

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  1. Hierarchical analysis of Swainson’s Spurfowl <em>Pternistis swainsonii</em> habitat use on Highveld maize and livestock farms

    Hierarchical analysis of Swainson’s Spurfowl <em>Pternistis swainsonii</em> habitat use on Highveld maize and livestock farms

    Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology
    This paper explains habitat use by Swainson’s Spurfowl Pternistis swainsonii on maize Zea mays and livestock farms on the Highveld south-east of Johannesburg, South Africa. The purpose is to describe habitat modification methods to manipulate the abundance of Swainson’s Spurfowl...
  2. Female-only care of Swainson’s Spurfowl <em>Pternistis swainsonii</em> chicks frees males for territorial maintenance

    Female-only care of Swainson’s Spurfowl <em>Pternistis swainsonii</em> chicks frees males for territorial maintenance

    Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology
    Uniparental care often means that males do not contribute to the wellbeing of their offspring. For this reason, little attention has been given to avian species where the absent male contributes indirectly to the wellbeing of his chicks. This paper...
  3. Coalition formation, mate selection and pairing behaviour of the Crested Francolin

    Coalition formation, mate selection and pairing behaviour of the Crested Francolin

    Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology
    Transect field observations were conducted on the behaviour of Crested Francolin Dendroperdix sephaena to describe male coalitions in the Borakalalo National Park, North West province, South Africa during May, August, October and December 2008, and again in July 2009. Crested...
  4. Age categories and corresponding gender characteristics of five Crested Francolin subspecies (genus <em>Dendroperdix</em>)

    Age categories and corresponding gender characteristics of five Crested Francolin subspecies (genus <em>Dendroperdix</em>)

    Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology
    Fifty-five Crested Francolins, Dendroperdix sephaena sephaena, were trapped, marked, retrapped and observed from 1984 to 1988 to assess and describe gender and age criteria based on morphological measurements and plumage characteristics on the farm La Boheme (Rustenburg, North West province,...
  5. Roosting requirements of Helmeted Guineafowl <em>Numida meleagris</em> on Highveld grain and livestock farms with alien tree groves, Gauteng province, South Africa

    Roosting requirements of Helmeted Guineafowl <em>Numida meleagris</em> on Highveld grain and livestock farms with alien tree groves, Gauteng province, South Africa

    Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology
    This study describes the relationship between Helmeted Guineafowl Numida meleagris and invasive alien trees on livestock and maize farms south-east of Johannesburg, Gauteng province, South Africa. The dependence of the birds on alien trees affects strategies for the removal of...
  6. Die ontginning van Noord-Transvaal se Houtbronne in die Negentiende Eeu en Vroeë Bewaringsmaatreëls

    Item type: Journal Article • Journal: South African Forestry Journal
    The exploitation by Europeans of the indigenous tree of the Northern Transvaal date back to the settlement of Schoemansdal in 1848. The main areas for wood cutting operations were the Soutpansberg mountain range, Woodbush, Soekmekaar and regions in the Lowveld.
  7. Belangrike ongewingsfaktore wat die natuurlike verspreiding van <em>schmidtia kalahariensis</em> stent en <em>enneapogon cenchroides</em> (licht) c. e. hubbard (e. <em>mollis</em> lehm) in Suidwes‐Afrika beïnvloed<sup>1</sup>

    Belangrike ongewingsfaktore wat die natuurlike verspreiding van <em>schmidtia kalahariensis</em> stent en <em>enneapogon cenchroides</em> (licht) c. e. hubbard (e. <em>mollis</em> lehm) in Suidwes‐Afrika beïnvloed<sup>1</sup>

    Die resultate van ‘n studie van die reaksie van twee belangrike eenjarige weidingsgrasse van Suidwes‐Afrika, Schmidtia kalahariensis en Enneapogon cenchroides, teenoor verskillende omgewingsfaktore word gerapporteer. Verskille tussen die twee spesies ten opsigte van ligenergievereistes, lengte van die lewensiklus, voedingsbehoeftes, smaaklikheid...
  8. The effect of stocking rate and lick supplementation on the performance of lactating beef cows and its impact on Highland Sourveld

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    The Highland Sourveld of Natal is an important beef producing area. Although it covers only 13% of the total area of the province, it supports 18% of the beef cattle population.
  9. The effect of tebuthiuron on the vegetation of the thorn Bushveld of the Northern Cape – a preliminary report

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Two formulations of tebuthiuron i.e. Graslan 20P and Graslan 40P are currently being evaluated in the Molopo area. Tebuthiuron was applied aerially at ten application rates, in combination with two application dates.
  10. Die evaluasie van droëland <em>Cenchrus ciliaris</em> L. cv Molopo vir speenkalf‐produksie in die sentrale grasveld

    Item type: Journal Article • Journal: Journal of the Grassland Society of Southern Africa
    Speenkalfproduksie op droëland Cenchrus ciliaris‐weiding is by drie veeladings onder aanhoudende beweiding ondersoek (1978–83). Verskille in beskikbare bogrondse fitomassa (BBF), speenmassa en die ekonomie van speenkalfproduksie word bespreek.