**2.4 Vegetation categorization**

Vegetations were categorized on the basis of physiognomic features and dominant plant species when present.


#### **Figure 1.**

*Map of Serengeti National Park showing vegetation types. Red dots show birds sampling plots (Map produced by the Serengeti GIS Office, 2022).*

3.*Commiphora* spp.: This was found mainly on ridge tops in shallow stony soils along the road to Fort Ikoma village, in the north to Lobo, and in the eastern woodlands [29, 31, 32]. This vegetation is comprised of *Commiphora schimperi*, *Vegetation and Avifauna Distribution in the Serengeti National Park DOI: http://dx.doi.org/10.5772/intechopen.106165*

#### **Figure 2.**

*Map of Serengeti National Park (solid line) and adjacent protected areas (Source: Serengeti GIS Office, 2022).*

*Commiphora trothae*, and *Commiphora africana* mixed with *Senegalia senegal* (**Figure 6**). Trees of this vegetation grew to 5 m high and were characterized by a small canopy that may reach 6.5 m in diameter [29, 30]. Some *V. hockii*, a tree of similar height, sometimes occurs with *S. senegal.* The grass layer within the stand is dominated by *P. mezianum* and *Sporobolus pyramidalis* [29].

**Figure 3.** *One of the grassland areas in Serengeti National Park.*

**Figure 4.** *A pure stand of Vachellia robusta at Seronera area in Serengeti National Park.*

*Vegetation and Avifauna Distribution in the Serengeti National Park DOI: http://dx.doi.org/10.5772/intechopen.106165*

#### **Figure 5.**

*Vachellia tortilis observed near Serengeti Wildlife Research Centre (SWRC) in Serengeti National Park.*

4.*V. drepanolobium* and *V. seyal*-dominated habitats: This vegetation occurs on poorly drained soils in valley bottoms, and on foot slopes at the base of rocky hills [29]. The two tree species were found in different regions of the park; *V. drepanolobium* occurs widely in the north and west of the park, whereas *V. seyal* was found largely on the Ndabaka flood plain of the far western Serengeti National Park. Both are characterized by a small canopy that may reach 6.5 m in diameter and grow to 6 m in height. The grass layer is dominated by *T. triandra*, *D. macroblephara*, and *P. mezianum* [29].

#### **2.5 Birds assessment**

A total of 10 plots in each of the 4 habitat categories mentioned above were established. Grassland in the park was divided into western at Ndabaka and northern

**Figure 6.** *Stand of Commiphora spp and Senegalia Senegal observed near Banagi hill, central Serengeti National Park.*

at Kogatende, each having five plots and these were paired with their equivalent *V. drepanolobium* and *V. seyal*-dominated habitats, namely five plots of *V. seyal* in the west and five plots of *V. drepanolobium* in the north. Five plots in each of *V. tortilis* and *V. robusta*-dominated vegetations were established, and these were compared with five plots in *Commiphora* spp.-dominated vegetation.

The locations of the sampling plots in the woodland were situated at least 500–800 m apart, marked using the global positioning system (GPS). Plots were surveyed on a monthly basis between February 2010 and February 2012, with 20 min per plot between 6:30 am and 10:30 am. The time of survey for each plot was rotated so that all plots were surveyed equally during the morning from 6:30 am to 10:30 am to avoid bias for the time of day. For example, if a plot was surveyed early on one visit then on the next visit was surveyed last so that effects of time of day were distributed equally over all plots. Birds were counted using the total count method by walking slowly across the plot and back again [33]. Birds were identified by both sight and call, and numbers were recorded. Bird naming was adopted from those published by Zimmerman et al. [4] and Gill and Wright [34].
