Birds as bio-indicators of the ecological integrity of the River,

CHAPTER 2

The catchment and study area

2.1 GENERAL DESCRIPTION OF THE SABIE RIVER CATCHMENT

2.1.1 TOPOGRAPHY

A catchment can be defined as the land area from which a river or reservoir is fed (Davies & Day, 1998). The Sabie River catchment falls within the Incomati River basin, which is an international drainage basin occupied by , Swaziland and (Figure 2.1). The area of the Sabie River catchment is 7096 km2, of which 6347 km2 falls within South Africa. The Sabie River is the main stream of the catchment, with the Sand and Marite Rivers acting as major tributaries, and the Mac Mac River being a tertiary drainage.

The Sabie River rises in the west of the catchment in the mountains north of the Long Tom pass at an altitude of about 2200 m. The rises about 50 km further to the northeast in the Blyderivierspoort Nature Reserve, at an altitude of 1500 m a.m.s.l., and has a total length of about 125 km to its confluence with the Sabie River, whilst the Marite River has a total length of about 58 km to its confluence with the Sabie River. The Sabie River has a total length of about 230 km to its confluence with the Incomati River in Mozambique, at an altitude of about 40m a.m.s.l. (Deacon, 1996).

The topographical features of the Sabie River catchment have been used to divide it into two distinct topographical regions, namely, the Middleveld and Lowveld regions. The Middleveld region, which occupies the western portion of the catchment, is generally characterized by an undulating topography that is more mountainous in the west. The Lowveld region is characterized by a flat to

Chapter 2: Sabie River catchment and study area 1 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

Figure 2.1: Map of Sabie River Catchment and Tributaries

Chapter 2: Sabie River catchment and study area 2 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

gently undulating topography, except in the east in the vicinity of the Lebombo mountains. There are no large flood plains, wetlands or swamps in the Sabie River catchment (Deacon, 1996).

2.1.2 GEOLOGY AND GEOMORPHOLOGY

Increased demands on limited water resources and changes in land usage lead to modifications in the flow regime and consequently, the morphology of river systems. This leads to changes in available habitat for different faunal and floral species dependent on the river. The organization, structure and development of stream communities are largely determined by the organization, structure and dynamics of the physical stream habitat, together with the pool of species available for colonization. It therefore becomes necessary to understand these physical patterns across space and time and relate them to biotic patterns in order to establish the ecological effects of changes to the physical system (van Niekerk & Heritage, 1993).

Using classification systems based on differences measured from aerial photographs, topographical maps, geological maps, satellite imagery and extensive validation in the field, geomorphic patterns may be causally linked to physical factors regulating instream characteristics, and therefore the biota. Recently developed stream classification systems have had a hierarchical perspective which links large regional scales (catchments) with small microhabitat scales. This approach provides a useful framework for studying components of a river system over the wide range of scales which are important to ecologists (van Niekerk & Heritage, 1993).

A suitable stream classification system was successfully developed by Frissel et al. in 1986, using a spatially nested hierarchy in which a system at one level for the environment of its subsystems at lower levels (van Niekerk & Heritage, 1993). The basic building blocks are the morphological units, each of which has

Chapter 2: Sabie River catchment and study area 3 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga distinctive substrate characteristics or microhabitats. The morphological units develop in different combinations within a variety of channel types. Channel types that have a functional relationship to each other are grouped into reaches. A segment (or macro-reach) may comprise one or more reaches and have distinctive geological, hydrological, sedimentological, morphological and vegetational characteristics. The segments are associated with differing patterns of sedimentation. A zone has boundaries defined by major breaks in slope, which are usually associated with major changes in geology. The river incorporates the riparian margin from source to mouth, incorporating all of the zones. The catchment, consisting of all tributaries and sub-catchments is the collection of areas having distinct patterns of climate, geology, soils, vegetation and land-use which contribute unique runoff and/or sediment discharges into the tributaries and main river (van Niekerk & Heritage, 1993).

The Sabie River is underlain by a wide variety of bedrock lithologies, comprising sedimentary, intrusive and extrusive igneous and metamorphic rocks. Lithological differences in the geology control the longitudinal slope profile of the Sabie River and consequently also the geomorphological form. The Mpumalanga region has been subject to uplift in the recent geological past (10Ka to 100Ka), resulting in the incision of the Sabie River into bedrock. This has created a channel that has a 'floodplain' restricted by the width of incision into bedrock. This incised feature has been termed the macro-channel, as opposed to the smaller, active, perennially flowing channels and seasonally flooded features within its confines (van Niekerk & Heritage, 1993).

The Sabie is a physically diverse river system that displays marked changes in channel type as the distribution of sediment over bedrock varies (Heritage et al., 2001). Sediment deposition upstream of bedrock outcrops has led to some extensive alluvial sections developing in the river, whilst elsewhere the river channel is formed predominantly in bedrock. Sediment movement into the river system is episodic, associated with summer rainfall events, and typically

Chapter 2: Sabie River catchment and study area 4 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

accumulates in low gradient sections. The sediment in the macro channel is supplied mainly from sand bed tributaries and is reworked within the channel during medium and high flow periods. Under favourable (low to medium flow) conditions, sediment deposits become colonized by vegetation (e.g. the reed Phragmites mauritianus) and become stable, relatively permanent features (Rountree, 1997). The mineral and hence mining potential of the Sabie River is of a limited nature, occurring mainly in the east and in the west of the catchment. Present mining and industrial activity is limited in extent and size (Chunnet et al., 1990).

2.1.3 RIPARIAN VEGETATION

A riparian zone encompasses the stream channel and that portion of the terrestrial vegetation where vegetation may be influenced by elevated water tables during floods, and occupies one of the most dynamic areas of the landscape. As such, they are diverse and complex biophysical habitats, subject to frequent, high magnitude disturbances. However, riparian systems have been noted for their resilience, i.e. their ability to recover quickly from disturbance. Rapid growth rates, high fecundity, and capacity for asexual reproduction are among the factors that allow for rapid recovery of riparian plants after disturbance (Rountree, 1997).

The riparian zone plays many essential roles in the functioning of the river ecosystem, such as flow regulation, water quality regulation, habitat provision for many plants and animals, and lastly, serving as a corridor between different habitat types (WRC, 2001).

Riparian zones and their associated biota are influenced and altered by two main factors, namely floods and the introduction of alien vegetation. Floods are the primary source of disturbance and are considered to be the driving force responsible for the existence, persistence, productivity and interactions of the

Chapter 2: Sabie River catchment and study area 5 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga major biota in rivers. Associated with these high levels of disturbance are very high levels of plant biodiversity. When these disturbances are suppressed or removed, substantial vegetational changes result. However, frequent flooding discourages the establishment of terrestrial vegetation, both by surface erosion and physiological effects of inundation (Rountree, 1997).

Riparian zones are particularly vulnerable to invasion by alien vegetation (because they are good dispersal routes for seeds) and this is becoming a huge ecological problem in South Africa. Alien vegetation is a problem because it takes up more water than indigenous vegetation, it also takes up habitat for indigenous vegetation. Alien vegetation changes the aesthetic characteristics of the riparian zone and damages buffering capabilities (WRC, 2001).

A national monitoring programme, the River Health Programme (RHP) has been designed for South Africa, and focuses on measuring and assessing the ecological state of riverine ecosystems. This programme included the need to develop and apply a rapid index to assess the condition of riparian vegetation. Nigel Kemper was appointed by the Water Research Commission to undertake the development of the Riparian Vegetation Index (RVI) (Kemper, 2001). The output of the RVI is expressed as percentage deviation from natural or modified conditions (WRC, 2001). Since it's implementation, the RVI has been applied to the Sabie River by being incorporated into the RHP.

The RVI pointed out many potential drivers of ecological change in the riparian zone of the Sabie River. In the upper catchment, forestry activities close to or within the riparian zone are the primary threat to health of the riparian habitats and vegetation. Lack of ground cover underneath the trees causes instability and erosion of soils. The extent of invasion/encroachment by alien vegetation is a serious threat to ecosystem health. Sawdust from sawmills impacts on the riparian zone; the dust smothers vegetation, lowering vegetation health and diversity. The riparian zones in the middle catchment experience overgrazing,

Chapter 2: Sabie River catchment and study area 6 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

and where it occurs close to the riparian zone, has caused extensive erosion and sedimentation. The lower catchment falls within the borders of the . Although riparian vegetation and habitats here are largely natural, some alien vegetation does occur, and in some areas riparian vegetation has been cleared to provide tourists with clear views of the rivers and pools (WRC, 2001).

Van Coller and Rogers conducted a description of the riparian vegetation along the Sabie River in 1995. Spatial distribution patterns of the woody and reed riparian vegetation were related to characteristics of the physical environment. Five vegetation types that comprise all the species with the riparian zone were identified, and each vegetation type associated with certain characteristics of hydrological and geomorphological features of the macro-channel floor and macro-channel bank. Some exotic invasives have become a concern along the Sabie River riparian zone, in particular Lantana camara and to a lesser degree Melia azedarach. Higher up in the catchment outside the Kruger National Park, many Pinus and Eucalypt species occur as a result of commercial forestry (Mackenzie et al., 1996).

2.1.4. REGIONAL CLIMATE

Frontal rainfall is highest in the highland areas (2000 mm/a), and declines rapidly towards the border between South Africa and Mozambique (450 mm/a). This rainfall is concentrated in the summer months, from November to March. Cyclonic activity is also occasionally recorded within the catchment. Evaporation varies from 1700 mm in the east, to 1400 mm in the west, with summer values higher than winter values in the Lowveld (Heritage et al., 2001). Flows in the Sabie River peak in summer, and low flows are experienced at the end of the winter dry season, although no-flow conditions have never been recorded (WRC, 2001).

Chapter 2: Sabie River catchment and study area 7 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

2.1.5. LANDUSE WITHIN THE CATCHMENT

Land use in the upper catchment is characterized by forestry. Some 20 000 ha of the upper catchment were cleared of natural vegetation to make place for alien plant species. The middle parts of the catchment experience rural community activities such as subsistence and small scale farming of livestock and fruit. Overgrazing is a problem in this area, and where it occurs close to the riparian zone, has caused extensive erosion and sedimentation. The lower parts of the catchment are protected by conservation activities, in particular the Kruger National Park (Chunnet et al., 1990).

The population of the Sabie River catchment is expected to increase from about 338 000 persons in 1985 to about 691 000 persons in 2010. About 80 000 persons outside the catchment boundaries were also dependent on water from the Sabie River catchment in 1985, this number is expected to increase to about 166 000 persons in 2010 (Chunnet et al., 1990).

2.1.5.1 The upper catchment

- Afforestation in the upper reaches of the catchment The upper catchment of the Sabie River has been exploited as far as possible for forestry, and this has reduced the runoff by 115 million m3 y -1 (about 20% of 'virgin' runoff) (Davies & Day, 1998). The total area of exotic afforestation in the Sabie River catchment amounted to 69 000 ha in 1972. Since then, additional exotic afforestation in South Africa has been controlled by means of a permit system and has only shown a modest increase in the catchment. The afforestation is concentrated in the west of the catchment. The timber that is produced is used largely for the manufacture of processed wood products, which are mainly used in the construction industry (Deacon, 1996).

Chapter 2: Sabie River catchment and study area 8 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

Afforestation has had a negative impact on the avifauna of South Africa, particularly in the Grassland Biome, where most plantations are cultivated and where treeless ecosystems are replaced by monocultures of exotic plantations. Although some bird species inhabit these exotic plantations, very few venture into the interiors of plantations. More species are found on the plantation edges where the birds exploit the exotic trees for nesting and roosting. However, edge users are still dependent on large areas of natural and other, less exotic habitats for foraging (Malan, 2001).

Since law protects the indigenous habitats and vegetation growing next to streams in plantation areas, mainly to maintain water yield and quality, a large- scale establishment of narrow, indigenous vegetated riparian strips has taken place. The protection of indigenous forests flanking streams is a common management practice to guard stream from the effects of neighbouring or upslope forestry or agricultural activities. In South Africa, plantations are not allowed to be cultivated 10 – 200 m from streams in order to maximize water flow, protect aquatic ecosystems and maintain biodiversity (Malan, 2001).

- Habitat condition and water quality in the upper catchment The headwaters of the Sabie River and its tributaries arise in the upper parts of the Drakensberg Escarpment. These rivers are cold mountain streams, and are narrow with moderate to steep gradients. The dominant vegetation is a combination of mountain grassland (on upland areas) and afromontane forest (in gorges and lower slopes). There is extensive forestry in the region. Roads and plantations close to or within the riparian zone are the primary threat to the biodiversity of the natural habitats and vegetation. Sawdust from sawmills impacts the riparian zone and washes into the river during rain. Cresols and phenols leach out of sawdust, acidifying the soil and water. Finer dust particles clog the gills of fish. The overall present ecological state of the Sabie is good. Invertebrates indicate that the water quality is very good, although fish populations are somewhat impaired, reflecting a fair to poor state. Trout is a

Chapter 2: Sabie River catchment and study area 9 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

threat to in-stream ecological health, through diversion of water for dams and weirs, which impact on the water flows in the area. Trout also preys on, and competes with, indigenous fish species (WRC, 2001).

2.1.5.2. The middle catchment

- Agriculture and livestock in the middle reaches of the catchment With an estimated abstraction of 73% of the total amount of water used in South Africa, the agricultural sector makes the greatest demand on the country's water resources. Dense and rapidly growing human populations are also placing increasing demands upon the Sabie River for water for irrigated agriculture. To meet these demands, a dozen impoundment sites have been identified by DWAF in the Sabie and in its major tributaries, the Sand and Marite rivers. If the growing demands were to be met in full, the Sabie would cease to flow during most dry seasons (June to October), a situation that did occur in 1992, and that commonly occurs in the Levuvhu and Letaba rivers (Davies & Day, 1998). By 1996, a total of 11 650 ha of irrigation development had either been developed or had already been planned in the Sabie River catchment. Of this development, approximately 571 ha and 1595 ha in the Sabie and Sand River catchments respectively are not in production, mainly due to a shortage of water. Consequently, only 9484 ha were in production by 1996. The largest irrigated areas comprise bananas, citrus, other sub-tropical fruits, tobacco, maize and tomatoes (Deacon, 1996).

- Habitat condition and water quality in the middle catchment Most of this part of the catchment lies in the Lowveld. In the upper parts, cascades and rapids abound, in the lower regions rivers are wide, have gentle gradients, riffles and deep sandy pools, and are characterized by reed beds. The overall ecological state is considered to be good. In-stream habitats and fish are good; riparian habitats and vegetation varies between good and poor. The

Chapter 2: Sabie River catchment and study area 10 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

invertebrate index also reflects a varied picture, with results in this section ranging between natural and poor (WRC, 2001).

2.1.5.3. The Lower Catchment

- Conservation areas in the lower reaches of the catchment There are at least six game or nature reserves, or portions thereof, in the Sabie River catchment, and these occupy a total area of approximately 3 000 km2 (Chunnet et al., 1990). The natural riverine vegetation along the Sabie River in the Kruger National Park, and along the Sand River, in the Sabie Sand Reserve and in the Kruger National Park, is largely dependent on water flowing across the western borders of these nature reserves (Chunnet et al., 1990).

The non-consumptive flow required for conservation of the riverine ecosystems in the nature reserves has already been seriously reduced by expected short-term increases in water use upstream of the nature reserves (Chunnet et al., 1990). All of the rivers of the Kruger National Park (KNP) are under severe threat, and yet their importance to the continuous existence of the park is vital. Because of the importance of the KNP from a conservation point of view, and also as a major earner of foreign currency, a major multi-disciplinary and multi-institutional research programme commenced in 1990 to investigate aspects of all the rivers of the park, but in particular of the polluted Olifants, the severely degraded and once-perennial Letaba and Levuvhu Rivers, and the Sabie, probably Kruger's key river, which has recently shown the first signs of over-exploitation (Davies & Day, 1998).

- Habitat condition and water quality in the lower catchment Due to the Kruger National Park and private conservation activities, much of this area is in a natural state. However, urbanization and other land uses threaten the unprotected areas. The instream components (habitats, fish and invertebrates) reflect a natural to good state. However, the Corumana Dam

Chapter 2: Sabie River catchment and study area 11 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

inside Mozambique pushes up into the Kruger National Park, resulting in reduced velocity of flows, damping of seasonal flow fluctuations and increased deposition of sediments. Although riparian vegetation and habitat here are largely natural, some alien vegetation does occur, and in some areas riparian vegetation has been cleared to provide tourists with clear views of the rivers and pools (WRC, 2001).

2.1.6 SUCCESSIONAL CHANGES IN THE SABIE RIVER

Biotic communities go through a youth-to-maturity development process analogous to the growth and development of an individual organism. Community development over the short term (1000 years or less) is known as ecological succession. This is perhaps better thought of as ecosystem development because it is an active process involving changes in both the organisms and the physical environment. During ecological succession, there are definite patterns in these changes which, in the absence of major disturbances, are predictable. When an area becomes available for community development, opportunistic plants and animals colonize it in a series of temporary, or pioneer, communities called seral stages. Gradually, more permanent communities develop, until a mature or climax stage takes over. Its biotic composition is determined by the regional climate and the local substratum, topography, and water conditions (Odum, 1997).

Even without external perturbations, the climax stage may not remain unchanged forever. Self-destructive biological changes, similar to what we would call aging in an individual, may be occurring. For example, young trees may not be quite replacing the old ones as they die, or regeneration of nutrients may be lagging and the community metabolism slowing down (Rountree, 1997).

High frequencies and magnitudes of disturbance can detrimentally affect diversity in an ecosystem. Stability is the ability of an ecosystem to return to an

Chapter 2: Sabie River catchment and study area 12 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

equilibrium state after a temporary disturbance. The resilience of an ecosystem determines the persistence of relationships within a system and is a measure of the ability of these systems to absorb changes of variables and still persist. A system can thus be very resilient and still fluctuate greatly, i.e., have a low stability. These concepts of resilience and stability are meaningful when considering riparian systems (Rountree, 1997).

2.2 THE STUDY AREA

Site Selection

In considering the selection of suitable sites for the purposes of this study, it was necessary to take into account certain factors. These factors include:

- The existence of sites for which bird (and macroinvertebrate) distribution information is available. - The representativeness of sites regarding the diversity of available habitats for birds (and biotopes for macroinvertebrates). - The ease with which the bird monitoring (and macroinvertebrate sampling) could be employed at a site, also taking into account changes in riparian vegetation and stream flow during different seasons. - The accessibility of sites. - The presence of potentially dangerous factors, which may be present at isolated, rural sites; or the presence of hippos and crocodiles in the water and riparian vegetation. - The presence of known human impacts such as forestry, saw mills, riparian vegetation removal, agriculture, diffuse and point sources of pollution, and settlements.

Chapter 2: Sabie River catchment and study area 13 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

Based on the above-mentioned criteria, the following sites were selected (Figure 2.1 and Table 2.1):

Site 1: This site is situated in the commercial Pine and Bluegum plantations in the upper catchment of the Sabie River, upstream of the town of Sabie. Site 1 is classified as being in the Great Escarpment ecoregion. This site was chosen because of its central locality within the plantations (Appendix 2.1 - Plate 2.1A & 2.1B; Appendix 2.2 - Figure A.1), in order to determine what impacts the afforestation might have on the natural riparian vegetation, on the water quality/quantity and on the bird communities.

Site 2: This site is situated at a recreational resort in the town of Sabie, and falls into the Lowveld ecoregion. Site 2 was chosen in order to determine the possible impacts of complete riparian vegetation removal and the presence of human activity (in the form of a holiday resort) on the riparian and instream bird communities. At Site 2, the riparian vegetation on the right bank has been removed in sections and replaced by a holiday resort. However, the left bank is mostly undisturbed and the natural riparian vegetation remains largely intact (Appendix 2.1 - Plate 2.1C & 2.1D; Appendix 2.2 – Figure A.2).

Site 3: Site 3 is situated just upstream of the town of , which is classified into the Lowveld ecoregion. This site was selected in order to determine what effects the total removal of riparian vegetation, and the cultivation of crops has on the bird communities in the riparian and instream zones. The riparian vegetation on the left bank has been removed and replaced with short, mowed grass. In the terrestrial zone of the left bank, the natural vegetation has been replaced by agriculture (citrus and macadamia trees). The riparian vegetation on the right bank is still largely intact, although the terrestrial zone and some areas of the

Chapter 2: Sabie River catchment and study area 14 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

riparian zone has sections which are replaced by plantations and holiday resorts (Appendix 2.1 - Plate 2.1E & 2.1F; Appendix 2.2 – Figure A.3)

Site 4: This site is situated downstream of Hazyview town, in a rural area where subsistence farming occurs. Overgrazing, trampling and erosion are some of the major concerns at Site 4, with poor farming practices, poaching and hunting all contributing to the degradation of this site (Appendix 2.1 - Plate 2.1G & 2.1H; Appendix 2.2 – Figure A.4). Although the riparian zones on both left and right banks consist mostly of natural vegetation, a lot of it has been destroyed by the burning and chopping of trees (to make curio's), the collection of firewood and the trampling by cattle.

Site 5 (Inside the Kruger National Park): This site is situated on the Western border of the Kruger National Park (KNP), where the Sabie River forms the boundary between the KNP and surrounding farming and rural areas (Appendix 2.1 - Plate 2.1I & 2.1J; Appendix 2.2 – Figure A.5). This site was selected in order to detect the changes in bird communities between the riverine zone outside the KNP, which is subject to habitat and water quality alteration; and the riverine zone inside the KNP, whose habitat is undisturbed by humans, but whose water quality may still be poor from the effects of impacts upstream. At Site 5, the right bank falls inside the KNP, although the left bank is on the border of the KNP and surrounding farming and rural areas and activities, such as subsistence agriculture and human dwellings.

Site 6 (Inside the Kruger National Park): This site is just upstream of the confluence of the Sabie and the Sand Rivers. The habitat at this site is relatively undisturbed by humans. The riparian and instream habitats are diverse. However, a sand road on the left bank, and tar road on right bank result in some noise and disturbance. The tar road is one of the busiest

Chapter 2: Sabie River catchment and study area 15 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

roads in the southern areas of the Kruger National Park, and therefore the disturbance at this site is continual (Appendix 2.1 - Plate 2.1K & 2.1L; Appendix 2.2 – Figure A.6).

Site 7 (Inside the Kruger National Park): This site is situated opposite to Lower Sabie Rest Camp, where a dam has been constructed in the Sabie River (Appendix 2.1 - Plate 2.1M & 2.1N; Appendix 2.2 – Figure A.7). This site was chosen in order to determine what effect the dam, and resultant sediment deposition (formation of sandbars) has on the riverine bird communities. Human impacts at this site also present themselves in the form of noise and high activity levels at the Rest Camp and on surrounding roads.

Site 8 (Inside the Kruger National Park): Site 8 is the last possible point on the Sabie River at which bird monitoring of the River can take place inside SA. The site is situated close to the Eastern border of the KNP, where the Sabie River flows into the Corumana Dam in Mozambique (Appendix 2.1 - Plate 2.1O & 2.1P; Appendix 2.2 – Figure A.8). This site is expected to be least influenced by human activities, and has a wide variety of habitat types.

The length of each transect at each site was measured, and co-ordinates recorded at each starting point and ending point of each transect (Table 2.1). This ensured that the same route was followed during each survey, to maintain comparability across the surveys. The length of transects differed according to the accessibility through the riparian zone and along the water’s edge, as well as the habitat layout at each site. The sites which were situated higher up in the catchment were generally shorter, due to the encroachment of exotic vegetation that has occurred at these sites, which made it difficult to move through the riparian zones. The habitats at these sites were also very uniform, and could be adequately sampled within shorter distances. Another factor which limited the

Chapter 2: Sabie River catchment and study area 16 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga length of the transects outside the KNP was the habitat fragmentation caused by fences and inaccessible properties. However, the sites in the lower reaches of the river had more diverse habitats, and required longer transects in order to adequately cover all habitat types at each site. The easier the habitat was to traverse, the longer the transect was, as a greater distance could be covered during the optimum time period suggested for bird monitoring, i.e. from sunrise to 4 hours after sunrise. The average length of the transects done during this study was 1645m (Table 2.1).

Table 2.1: Latitude and Longitude of the sites selected for the purpose of this study. SITE START TRANSECT END TRANSECT TRANSECT LENGTH 1 E25º 08.037’ E25º 08.219’ 600m S30º 41.293’ S30º 40.999’

2 E25º 05.573’ E25º 05.938’ 1800m S30º 46.189’ S30º 45.127’

3 E25º 01.823’ E25º 01.784’ 1200m S31º 06.114’ S31º 05.415’

4 E25º 01.377’ E25º 01.110’ 1300m S31º 13.372’ S31º 13.878’

5 E24º 58.920’ E24º 59.286’ 2300m S31º 18.449’ S31º 17.140’

6 E24º 57.461’ E24º 57.750’ 1900m S31º 42.514’ S31º 41.461’

7 E25º 06.955’ E25º 06.172’ 2000m S31º 55.042’ S31º 54.136’

8 E25º 10.927’ E25º 10.915’ 2060m S32º 01.826’ S32º 00.815’

Average transect length: 1645m

Chapter 2: Sabie River catchment and study area 17 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

2.3. REFERENCES

CHUNNET, FOURIE & PARTNERS (1990). A description of the Kruger Park Rivers Research Programme (Second Phase).

DAVIES, B. & DAY, J. (1998). Vanishing Waters. U.C.T. Press, University of Cape Town, South Africa, 487pp.

DEACON, A.R. (1996). Sabie Sand IFR Workshop Starter Document. Department of Water Affairs and Forestry, Pretoria, South Africa.

HERITAGE, G.L., MOON, B.P., JEWITT, G.P., LARGE, A.R.. & ROUNTREE, M. (2001). The February 2000 floods on the Sabie River, South Africa: an examination of their magnitude and frequency. Koedoe 44(1): 37-44. Pretoria. ISSN 0075-6458.

KEMPER, N.P. (2001). Riparian Vegetation Index (RVI) - Final Report. WRC Report No. 850/3/01, Water Research Commission, Pretoria, South Africa..

MALAN, G. (2001). The avifauna of riparian - Pinus habitat edges at Mooiplaas forestry estate, KwaZulu-Natal, South Africa. South African Journal of Wildlife Research 31 (3 & 4): 73-84.

MACKENZIE, J.A., JEWITT, G.P.W., HERTIAGE, G.L., & ROGERS, K. (1996). The Riparian Vegetation Model.

ODUM, E.P. (1997). Ecology: A bridge between science and society. Sinauer Associates, Inc. Canada.

Chapter 2: Sabie River catchment and study area 18 Birds as bio-indicators of the ecological integrity of the Sabie River, Mpumalanga

ROUNTREE, M.W. (1997). Landscape state change in the Sabie River, Kruger National Park, from 1986 to 1996. University of the Witwatersrand, .

VAN NIEKERK, A.W. & HERITAGE, G.L. (1993). Geomorphology of the Sabie River: Overview and Classification. Report No: 2/93. Center for Water in the Environment, South Africa.

WATER RESEARCH COMMISSION (WRC), (2001). State of the Rivers Report - Crocodile, Sabie-Sand & Olifants River System. WRC Report No. TT 147/01: 39pp.

Chapter 2: Sabie River catchment and study area 19