Devon Grasslands

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General Information

Status:

Global IBA (A1)

Province:

Gauteng

Protection:

Unprotected

Size:

75 330 ha

Number:

SA130

Additional Info

  • Site description

    This IBA was established in 2014 due to the presence of a number of species of conservation concern. The IBA extends from the town of Devon in the north to an area 7 km east of Balfour and 5 km north of Greylingstad.

    The main habitat type is Soweto Highveld Grassland within the Mesic Highveld Grassland Bioregion. This grassland type occurs in moderately undulating landscapes on the Highveld Plateau and supports 'short to medium-high, dense, tufted grassland dominated by Themeda triandra and accompanied by a variety of other grasses such as Elionurus muticus, Eragrostis racemosa, Heteropogon contortus and Tristachya leucothrix' (Mucina et al. 2006). This habitat type is listed as Endangered. A small portion of the IBA in the south contains Tsakane Clay Grassland, which is also Endangered (Mucina et al. 2006). In addition, when combined with conservation targets for fauna and flora, the majority of the Gauteng portion of the proposed IBA is classified as either a Critical Biodiversity Area or an Ecological Support Area in terms of the latest Gauteng provincial conservation plan.

    The proposed IBA includes several small rivers, numerous non-perennial drainage lines, natural wetlands and man-made dams. Although only a very small proportion of these are monitored regularly as part of CWAC, waterbird diversity is known to be high. In summer, and particularly in wet years when pans are full and floodplains become inundated, huge influxes of resident and migratory waterbirds may occur. It is therefore projected, with confidence, that the 20 000 bird threshold is regularly exceeded.

    Birds

    The area is well known for Blue Crane Anthropoides paradiseus and flocks totalling 250–300 birds are recorded most winters. A single Wattled Crane Bugeranus carunculatus forages with the Blue Cranes. Blue Korhaan Eupodotis caerulescens and Secretarybird Sagittarius serpentarius breed here and are commonly observed. Four harrier species occur regularly: African Marsh Harrier Circus ranivorus is resident, Black Harrier C. maurus is a winter visitor and Pallid Harrier C. macrourus and Montagu's Harrier C. pygargus are summer migrants. African Grass Owl Tyto capensis is probably under-recorded as there is suitable habitat for this species throughout the IBA. Black-winged Pratincole Glareola nordmanni sometimes occurs in large numbers; in 2011 one flock estimated at more than 2 000 birds was recorded. Waterbird numbers fluctuate considerably as water levels change on the numerous dams and streams in the area.

    IBA trigger species

    Globally threatened species are Blue Crane (250–300 individuals), Secretarybird (20–25 individuals, breeding), Blue Korhaan, Black-winged Pratincole and Black Harrier. Regionally threatened species are African Grass Owl, Greater Flamingo Phoenicopterus roseus and African Marsh Harrier.

    Other biodiversity

    Other important species are serval Felis serval and South African hedgehog Atelerix frontalis, both of which are Near-Threatened.

    Conservation issues

    Threats

    There are relatively few threats to the IBA, but an underground coal mine is planned in the area. If the application to mine is successful, the mine will begin operations in 2020–21. It is unclear what the footprint of the mine will be.

    Large sections have already been transformed into maize fields and any future expansion of the area under cultivation would be a threat to local biodiversity. Planted pastures and remaining areas of natural grassland are typically grazed by livestock but continue to provide habitat for several trigger species, including Blue Crane, Secretarybird and Blue Korhaan. The potential impact of grazing on species such as the African Grass Owl that require tall, rank grassland has not yet been assessed.

    There is an extensive network of gravel and tarred roads throughout the IBA and hundreds of owls, including African Grass Owl, have been killed by motor vehicles, particularly on the N17. The poor management of grain transportation, which attracts rodent prey to the road surface at night, remains a problem.

    As there are no large cities or towns within the IBA, threats linked to urban areas are not currently relevant. However, this may change as urban areas in Gauteng expand eastwards.

    Conservation action

    Current conservation initiatives are largely limited to survey and monitoring projects such as SABAP2, CAR and CWAC, annual crane counts and the ad hoc collection of data on fence- and collision-associated bird fatalities.

    The IBA is currently unprotected and its protected status needs to be improved in order to ensure the persistence of the trigger species and their habitats. Declaration of the IBA as a protected environment through the relevant provincial stewardship programmes should be promoted.

    Related webpages

    None.

    Contact

    If you have any information about the IBA, such as a new threat that could impact on it, please send an e-mail to iba@birdlife.org.za or call BirdLife South Africa +27 (11) 789 1122.

    Page last updated

    Tuesday, 20 January 2015

    Further Reading

    Compaan PC. 2011 (revised 2013). Gauteng Conservation Plan Version 3.3 (C-Plan 3.3). Technical Report for the Gauteng Department of Agriculture and Rural Development.

    Mucina L, Rutherford MC (eds). 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.

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