Author: Therese

Introduction
African herbivores have for a long time interested researchers all over the world and the questions and aims have been many. African herbivores and their behaviour have been the interest in this study and mainly the Gazella thomsoni (Thomson’s gazelle). Gazella thomsoni is one of the great migratory species which moves between Serengeti (Tanzania) and the Masai Mara (Kenya) every year. In these parks/reserves, fire is a common tool for maintaining savanna diversity (Lunt and Morgan 2002). Why fires are commonly used is low costs, universal ability and that they can be used over large areas (Mistry 1998). After a fire the nutritional quality and release of nutrient is high in turn leading to high re-growth of the grass (Russel-Smith et al. 1998).
We observed a total amount of 18 herbivore and the behaviours used for analysis was grazing, lying, stand/self-lick and walk/run. The behaviours and preferences were compared at three different treatment, control, early fire and late fire and were conducted in the Masai Mara National Reserve 2004, Kenya, and the aim was to see if; fire affected the choice of habitat and if areas with fire treatment affected the behaviour of African herbivores.

Method
For the sampling of data the we used the line transect method (Buckland et al. 1993) and each transect is 1000 m in length and 300 m in width. A total amount of 36 transect were used: nine transects burned in June 2004 (early fire), nine transects burned in October 2004 (late fire) and 18 transects not burned within the last year (control) (Figure 1). For estimations of the fire intensity, biomass was cut on twenty 0.125m2 squares before fire. Fuel loads ≤150 g m-2 is a cold fire and fuel loads >300g m-2 is a hot fire, hot fires cause more damage (Dublin 1995).

Results
The biomass was on all transect above 300 g m-2 which resulted in hot fires. The total count on herbivores was 3447 observations and 19571 individual observations. These observations was pooled together in one group and analysed as all herbivores. Thomson’s gazelle was also analysed separately. When comparing different habitats (control, early fire and late fire), the majority of animals preferred the late fire then early fire and last the control areas (Figure 2 and Table 1).

Figure 2. Habitat usage betrween different treatments showed as individuals per Ha.

Table 1. Values for Mann-Whitney U-test comparing the three treatments.

Figure 1. The different areas used in the study, divided in control, early fire and late fire.

Species	Treatment	Z-value	P-value
All / herbivores	Control: Early fire / Control: Late fire / Eary fire: Late fire	-2.984 / -3.550 / -2.605	0.003 / <0.001 / 0.009
Gazella / thomsoni	Control: Early fire / Control: Late fire / Early fire: Late fire	-4.324 / -4.491 / -3.578	<0.001 / <0.001 / <0.001

Conclusion and discussion
The results in this study have concluded that there is a preference for late fire treatment amongst all herbivores. Why this is so, is probably due to nutritional values of the grass, position of the C. taurinus, predation pressure, interspecific competition or intraspecific competition etc. I have also concluded that there are differences in when or where to perform a specific behaviour, still due to lots of different factors working together. Depending on how the species are developed, in case of ruminating or non-ruminating, water tolerant or not, GR eater or IM eater, grazers preferring short grass or high grass, it will be the features of the animal that decides what area to use and when.

Results cont.
For the Thomson’s gazelle the control areas were excluded in the analysis due to low counts. They preferred grazing at late fire treatment (P>0.001) where grass is fresh and were nutritional values are high (Russel-Smith et al. 1998) lying did not differ between treatments. Stand/self-lick (P>0.001) and walk/run (P=0.033) was preferred at the early fire (Figure 3).

Figure 3. Proportion behaviour of Gazella thomsoni comparing between early fire and late fire

Bush fires and the affect on animal behaviour and abundance in Masai Mara National Reserve, Kenya.
Therese Snöberg MSc Biology/IFM Linköping University

Aknowledgement
International Livestock Research Institute, ILRI, for helping with the research permit. Brian Heath and Mara Conservancy for help and support. Fredrik Engström for working together with me on the project

References
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Lunt, ID, Morgan JW (1999) Effects of time-since-fire on the tussock dynamics of a dominant grass (Themeda triandra) in a temperate Australian grassland. Biological Conservation 88, 379-386.
Mistry J (1998) Decision-making for fire use among farmers in savannas: an exploratory study in the Distrito Federal, central Brazil. Journal of Environmental Management 54,321 334.
Russel-Smith J, Ryan PG, Klessa D, Waight G, Harwood R (1998). Fire regimes, fire sensitive vegetation and fire management of the sandstone Arnhem plateau, monsoonal Northern Australia. Journal of Applied Ecology. 35:6, 829-846.