Linking human activities to wildfires in Tsavo Conservation Area: a social-ecological study

Introduction

The role of wildfires in ecosystems is a topic of debate, as fire is an important ecological tool and can be destructive especially in critical ecosystems such as protected areas. Fires play a vital role in various ecosystems by enabling processes such as habitat maintenance and nutrient cycling. They are crucial in regulating species interactions, population sizes, community composition and organism traits (McLauchlan et al. 2020). Wildfires help shape vegetation structure and composition, which ultimately supports ecosystem biodiversity (He et al. 2019). Additionally, wildfires establish new habitats that allow for the emergence of fire-tolerant species of plants and animals (Pausas and Keeley 2019). On the other hand, uncontrolled and destructive fires pose significant threats to both the environment and human lives (Aponte et al. 2016; Dos Santos et al. 2021). These events, referred to by various names like bushfires, forest fires and wildland fires (Krah et al. 2020), can lead to severe ecological consequences, including the loss of flora and fauna, and alongside hurricanes, droughts and floods, are considered major natural disturbances (Kouassi et al. 2018; Colantoni et al. 2020). The vegetation destroyed by wildfires serves as habitat for many species, including those already at risk of extinction (Ward et al. 2020).

Human activities are the main cause of wildfires worldwide, accounting for approximately 80% of occurrences (Jain et al. 2021). For instance, in India, 98% of wildfire incidences are caused by human actions, the majority of which are linked to arson, negligence and unidentified causes (Jhariya and Raj 2014). An average of 8000 wildfires occurred in Canada annually from 1970 to 2017, leading to the destruction of over 2.25 million ha of land and displacing more than 125,000 people between 1998 and 2021 (Tymstra et al. 2020; Copes-Gerbitz et al. 2022). Likewise, in Zimbabwe, human activities such as pest management and land clearing are responsible for 95% of wildfire occurrences. These activities include preparing land for planting crops, burning plant remains for pest control and clearing virgin land. Other human livelihood activities include bee smoking, hunting, careless disposal of ashes as motorists take breaks along the roadside and improper disposal of cigarette butts after smoking (Choga and Nyamadzawo 2018).

In Kenya, the growing human population and settlements are increasing the resource demand. Such changes are driving people to move to areas with less population, particularly the southern region, including the Tsavo Conservation Area (TCA) (Muriuki et al. 2011). This migration has led to an increase in human settlements around the protected areas of Tsavo, raising the risk of wildfires. While fire has long been an important tool in many parts of the world, local ethnic communities often use fire in land management practices, including the intentional burning of grasslands to encourage regrowth for livestock (Muriuki et al. 2011; Croker et al. 2024). Additionally, poaching, agricultural practices and charcoal production contribute to wildfire ignition (Henry et al. 2019). Research indicates that the main human activities that trigger wildfires in the TCA are charcoal burning, honey harvesting and timber extraction (Kamau and Medley 2014). To manage wildfires effectively, especially in protected areas like the national parks in Tsavo, it is vital to comprehend the specific human activity that causes these fires.

Despite numerous positive effects of wildfires on ecosystems, their increasing magnitude globally has led to devastating and extensive losses (Tedim et al. 2018). In Kenya’s TCA, wildfire occurrences have steadily increased over the past century, impacting unprotected and protected areas (Croker et al. 2024). According to the Maasai Wilderness Conservation Trust report of 2016, the most notable of these fires occurred in 2020, burning approximately 467,000 ha within 2 weeks. Although the TCA is mainly composed of national parks protected from human activities, the parks are still susceptible to external social-ecological pressures (Mistry et al. 2016). The interaction between ethnic communities surrounding the parks and the protected ecosystem in TCA creates an urgent need for research into the wildfires in the TCA. This study aimed to investigate the human activities that are linked to wildfire incidences in the TCA. We hypothesised that variations in the proportion of burned areas across different protected areas of the TCA are linked to differences in human activities, which are influenced by the diverse ethnic communities in the area. The objectives were to examine the proportion of burned areas in the three national parks within the TCA and to identify human activities associated with wildfires in the region. Ultimately, the findings aim to inform land and wildfire management efforts, helping to develop community-led mitigation strategies tailored to the unique circumstances of each region within the TCA.

Materials and methods

Study area

The study was conducted in the TCA, which spans approximately 40,000 km² in southeastern part of Kenya. The TCA is situated between latitudes 1°59′S and 4°08′S and longitudes 37°45′E and 39°16′E. This area is rich in biodiversity and is especially recognised as a hotspot for elephants (Loxodonta africana) and other large mammals (Lala et al. 2021). It is the largest protected area in Kenya, accounting for over 4% of the country’s total landmass. The TCA includes three national parks: Chyulu Hills, Tsavo East and Tsavo West, which constitute the bulk of the conservation area. It also incorporates South Kitui National Reserve, community conservancies, ranches and agricultural lands (Koskei et al. 2022) (Fig. 1). The three national parks are under Kenya Wildlife Service (KWS) (Kenya Wildlife Service 2008).

Fig. 1.

Map of Tsavo Conservation Area (TCA) showing protected areas: Tsavo West, Tsavo East, Chyulu Hill National Parks; South Kitui National Reserve, community conservancies, farms and study wards.

The TCA experiences two rainy seasons in a year: the short rains in November and December, and the long rains in March, April and May. The highlands in the TCA get relatively higher rainfall, around 1200 mm each year, while the lowlands receive approximately 500 mm per year. Chyulu Hills National Park represent the high-altitude area of the TCA, whereas Tsavo West and Tsavo East parks represent the low-altitude regions. The temperature in this region is influenced by altitude, with highlands having temperatures ranging from 18 to 27°C, while the lowlands range from 23 to 35°C. (Nyambariga et al. 2023).

The area’s landscape is characterised by the Taita Hills, Yatta Plateau and Sagalla Hills. The vegetation varies from region to region, with some areas covered by grasslands, some by wooded bushlands and others by both. The dominant species of plant communities are Commiphora species and Vachellia abyssinica (Koskei et al. 2022). Human-wildlife conflicts are common in the TCA, particularly in regions with the highest population density and growth (Mukeka et al. 2020). The most reported cases of human-wildlife conflict in the TCA involve poaching. The poachers use fire in their hunting activity which contributes immensely to wildfires in the area (Kamau and Medley 2014; Rashidi 2018).

The TCA is bordered by various ethnic groups. To the west of Chyulu Hills live the Maasai community, primarily pastoralists. To the east of Chyulu Hills National Park are the Kamba ethnic group, who are largely small-scale farmers and keep livestock at a smaller scale. The Kamba community also occupy the northern side of Tsavo East and Tsavo West National Parks. The Taita community is located between Tsavo East and Tsavo West national parks and, like the Kamba people, they are small-scale farmers and practice livestock keeping. Other ethnic groups in the south and southeastern parts of the TCA include the Orma, who mainly practice pastoralism; the Duruma, who are mainly farmers; and the immigrant Somalis, who also practice pastoralism (Kenya Wildlife Service 2008).

Results

Burned area per protected area in the TCA

The results showed that the average burned area across the three parks within the TCA was 249.49 km² (s.d. = 346.79 km²) over the 22-year period. The Chyulu Hill National Park recorded the highest annual mean proportion of burned area at 0.089 (s.d. = 0.059), followed by Tsavo West at 0.023 (s.d. = 0.045), while Tsavo East had the lowest mean proportion at 0.002 (s.d. = 0.002). A one-way ANOVA comparing the mean proportions of burned areas between the three parks, was significantly different (F_2,63 = 24.612, P < 0.001). Fig. 2 illustrates the proportion of burned areas in each park within the TCA.

Fig. 2.

Mean annual proportion of burned area for the 22 year period in the three parks within the TCA.

Frequency of human activities associated with wildfires in different parks within the TCA

The results showed that poaching is strongly connected to wildfires in Tsavo East and Tsavo West National Parks (100%, n = 5; 100%, n = 11, respectively), whereas Chyulu Hills National Park indicated a relatively lower link (83% n = 5). Honey harvesting is highly connected to wildfires in Chyulu Hills National Park (100% n = 6) and linked lowly in Tsavo East National Park (40%, n = 2). Charcoal burning is also a common activity in Tsavo West National Park (100%, n = 11) but less in the other two regions. Khat harvesting and Cannabis farming were exclusive to Chyulu Hills National Park, suggesting variation in human activities within the TCA. Crop farming was consistent across protected areas. Carelessness in disposing cigarette remnants connected to wildfires was highest in Tsavo East (100%) and lowest linked in Chyulu Hills (50%). Lastly, the burning of elephant dung was minimal, climaxing at 20% in Tsavo East (Fig. 3).

Fig. 3.

Proportion of key informants from different regions who linked human activities to wildfires.

Discussion

This study has shown that wildfire incidents occur throughout the TCA, but they are unevenly distributed across the area. Chyulu Hills National Park recorded the highest proportion of burned area, followed by Tsavo West and Tsavo East National Parks, respectively. The study attributes variation in the proportion of burned area to differences in the number of human activities linked to wildfires in each protected area. More human activities were linked to wildfires in Chyulu Hills National Park than the other two. These findings are likely due to the heterogeneous nature of the TCA, which includes differences in vegetation cover, rainfall patterns, altitude and population size across its various regions (Kenya Wildlife Service 2008). Additionally, the Chyulu Hill National Park experiences more frequent burns and it has higher number of human activities associated to wildfires probably due to its greater potential for accumulating more fuel load, as it has more vegetation compared to the other two parks (Kiumbuku 2022). Furthermore, the park receives higher rainfall which has earned it the designation of a water tower in Kenya, producing more water than the Taita Hills towers. Its higher altitude likely contributes to the increased rainfall it experiences compared to the other two parks of the TCA (Kiringe et al. 2016). Rainfall increases with elevation in the TCA, and Chyulu Hills National Park, at an altitude of 1810 m, occupies the highest point (Mukeka et al. 2020). Chyulu Hills, which receives more rain, is likely to support thicker vegetation, leading to an increase in fuel loads for wildfires. Moreover, the Chyulu Hills National Park experiences more human activities, probably because its surroundings has a higher human population compared to Tsavo West and Tsavo East (Kenya National Bureau of Statistics 2019).

The study indicated that wildfires across the TCA are predominantly linked to human activities rather than natural causes. The findings also indicate a significant association between human-related activities and wildfires in the TCA. Human activities are directly and indirectly connected to wildfire incidences in the area. These findings align with previous research conducted only in the Chyulu Hills National Park area by Kamau and Medley (2014). The results also match the findings of a study conducted in the Mount Kenya forest that found a significant association between human activities and wildfires (Ndalila et al. 2024). Additionally, this study’s results are consistent with studies such as Chinamatira et al. (2016) in Zimbabwe, which found wildfires predominantly attributed to human activities rather than natural forces. It also corroborates findings by Mgina and Wawa (2020) in Tanzania, highlighting human activities as the primary causes of wildfires in their forest plantations.

These results also identified 11 specific human activities linked to wildfires in the TCA: poaching, honey harvesting, charcoal burning, illegal cultivation of cannabis (Bhang), wild khat harvesting (Catha edulis), arson, crop farming, burning of elephant dung to deter wild animals, cultural beliefs associating smoke with rain attraction, pastoralism, and carelessness in disposal of cigarette remnants. These findings echo similar studies, such as one conducted in Zimbabwe which identified poaching, beekeeping activities, cigarette stub disposal and farm clearing as activities linked to wildfires (Chinamatira et al. 2016). The activities reported in our study also mirror those documented by Kamau and Medley (2014), who linked hunting, charcoal burning, wild khat harvesting, Cannabis cultivation and land clearance to wildfires.

The results also revealed a range of participant opinions across the three regions within the TCA, likely due to the area’s divergent nature. For instance, all key informants from Chyulu Hills National Park (100%, n = 6) linked honey harvesting with wildfire incidences, unlike participants from Tsavo West (70%, n = 8) and Tsavo East (40%, n = 2). This association could be attributed to the increased rainfall received in Chyulu Hills National Park compared to the rest of the TCA (Kiringe et al. 2016). Higher rainfall supports more plant species, which provides food for bees. Additionally, the diversity in opinions can be explained by different ethnic communities in the three regions. The study also showed some unexpected findings; for example, it might have been expected that more informants from the Chyulu Hills National Park region would link crop farming to wildfire incidences than those from the other two regions. However, the activity was strongly connected with wildfires in Tsavo East (100%, n = 5), followed by Tsavo West (90%, n = 10). This could be due to the fact that Chyulu Hills region is wetter, which makes it more difficult to use fire for land clearing compared to the drier areas (Munyao et al. 2020).

This study identified poaching as the most prevalent human activity linked to wildfires in the TCA. The high incidence of hunting is likely due to valuable wildlife species in the TCA, including cheetahs, leopards, African elephants, lions and black rhinos, some of which are endangered (Kiumbuku 2022). The area also supports several endangered herbivores such as hirola (Beatragus hunteri) and Grevy’s zebra (Equus grevyi) (Henschel et al. 2020). The key informants in the field provided insights into how poaching contributes to wildfires. When asked about the connection between poaching and wildfires, one key informant stated:

Poachers burn for different reasons. Some set fires to distract rangers and keep them occupied with firefighting while they engage in hunting. Others use fire to drive wild animals towards their traps, while some burn to stimulate the growth of fresh grass and shoots, attracting small herbivores they target.

These findings align with research conducted in the Siberian Tiger Conservation in Russia, where poaching was identified as the primary human activity linked to wildfires (Conor 2018). Hunting was also highlighted as a significant human activity associated with wildfires (Choga and Nyamadzawo 2018). Similar findings were reported by Nyongesa and Vacik (2019) in their research in the Gathiuru forest of the Mount Kenya region, where fire was noted to be used by poachers for roasting wild animal meat and as a hunting tool.

Other highly ranked activities included honey harvesting and charcoal burning, which were observed to occur across the entire ecosystem. Our study, conducted through key informant interviews, explored how beekeeping contributes to wildfires. When asked about the connection between honey harvesting and wildfires, one respondent explained:

Most people involve themselves in beekeeping, traditionally using fire to smoke out bees during honey harvesting. This practice happens on farms where beekeeping is practiced, or individuals may venture into protected areas to harvest honey from wild bees. Accidentally, the fire used in this process may escape to the surrounding bush, potentially leading to wildfires.

The finding that honey harvesting is connected to wildfires across the entire TCA supports the findings of Ricketts and Shackleton (2020), who noted that honey harvesters accidentally cause wildfires through smoking hives. Similar studies in Tanzania have also indicated that traditional methods involving fire in honey harvesting contribute to wildfire occurrences (Mgina and Wawa 2020; Balele 2021).

The interview method also clarified how charcoal burning is directly linked to wildfires. According to responses from the majority of respondents, ‘Charcoal burning is illegal in Kenya and is mostly conducted at night and deep in the forest where law enforcers cannot reach. During dry periods, charcoal burning becomes more common, enabling the easy spread of fire from charcoal pits to neighbouring vegetation. Traditional kilns, where firewood is placed in a pit dug into the ground and covered with soil, also contribute to wildfires. Often, burning charcoal debris is left carelessly, and when carried by the wind, it can ignite wildfires. These findings are consistent with research conducted in the Gathiuru forest in the Mount Kenya region, where illegal charcoal burning was found to cause significant wildfires (Nyongesa and Vacik 2019). This study also linked farmland preparation to wildfires. A village elder interviewed stated: ‘During land preparation, we use fire to burn grass and shrubs. It’s the easiest way to clear the land, and this practice mostly occurs during the driest months of September and October, making it more likely for the fire to spread to unintended areas such as neighbouring forests. To minimise risks, farmers are advised to notify neighbours before burning to help suppress the fire if it gets out of control, and to avoid burning in the evening when winds are stronger’. The findings align with a study conducted in a Tanzanian forest plantation by Mgina and Wawa (2020), which indicates that fire is used for land clearing after harvesting, a practice common during dry periods. Their research suggests that traditional fire use in farm preparation is linked to insufficient knowledge and poverty. These findings underscore the necessity for educational campaigns among farmers about the risks and drawbacks associated with using fire for land preparation. They also highlight the importance of training farmers in establishing fire breaks to reduce the likelihood of fires spreading to unintended areas.

In Kenya, pastoralism is traditionally practiced in drier regions (Cuni-Sanchez et al. 2019; Mwangi et al. 2020). Conversely, pastoralism was noted as one of the main contributor to wildfires across different regions within the TCA, and it was highly ranked in Tsavo East’s focus discussion. This is expected given that Tsavo East is the driest part of the TCA, making pastoralism the predominant economic activity in this area. Given that a significant portion of the TCA is semi-arid and characterised by grassland and woodland (Mukeka et al. 2020), the area is conducive to pastoralism. During our study, responses gathered from key informant interviews shed light on how pastoralism contributes to wildfires:

Pastoralists burn the forest to encourage regrowth of new and fresh grasses and shoots. They also use fire in pest management, believing it helps control ticks and diseases. Additionally, since herding activities in this region mainly occur during the dry period, pastoralists sometimes move from one place to another, in the process they use fire to scare wild animals and cook.

Our findings align with the literature from Van Zyl et al. (2019), which suggests that pastoralists contribute to wildfires in protected areas. However, our study’s observation that pastoralism contributes to wildfires contrasts with the findings of Colantoni et al. (2020) in Greece, who argue that a decline in nomadic livestock and pastoralism may increase wildfire incidences. Their argument is based on the idea that livestock graze on vegetation, reducing biomass that could otherwise fuel wildfires. These contrasting findings highlight the importance of involving local communities in wildfire management strategies. The study from Greece proposes a strategy where well-managed grazing programs for livestock in protected areas could help reduce wildfire risk by decreasing fuel available for fires. Successful implementation of such a strategy requires collaboration between conservation managers and pastoralists (Van Zyl et al. 2019).

Illegal farming of bhang and wild khat harvesting as contributors to wildfires were only reported in the Chyulu Hills National Park region, likely due to its cooler climate and higher rainfall compared to Tsavo West and Tsavo East (Munyao et al. 2020). These conditions create a favorable environment for the growth of bhang and khat. Bhang farming has been associated with numerous social and ecological challenges, including increased crime, school dropouts and fire outbreaks (Ngoc Thach et al. 2018). Respondents from the Chyulu Hills region, where these activities occur, explained that due to their illegality, bhang cultivation often occurs deep within forests where law enforcement struggles to reach. They reported that fires are used to clear bushland for Bhang cultivation, and sometimes these fires escalate into wildfires. This finding aligns with research from Canada, where indoor bhang cultivation led to electrical system overloads and structural fires (Ngoc Thach et al. 2018). It also supports earlier studies in Chyulu Hills region that highlighted bhang farming and illegal khat harvesting in forests as wildfire risks (Kamau and Medley 2014).

The issue of bhang farming remains contentious globally, including in Kenya where it is illegal (Ndanyi 2021). The high value of bhang has sparked debates on its legalisation in many countries, Kenya included. Proponents argue that regulation through licensing and permits could enhance public safety and environmental protection (Khanal et al. 2021). Concerns about wild khat harvesting in forests as a livelihood activity linked to wildfires in Chyulu Hills National Park were echoed by most interview respondents from that region. They noted that wild khat is burned to promote the growth of fresh shoots, but this process can sometimes lead to serious wildfires when fires are out of control.

Another human activity linked to wildfires in the TCA is arson. Arsonists are individuals who, unable to obtain harvesting licenses, permits, or access permissions to protected areas, resort to burning forests as a form of retaliation (Mgina and Wawa 2020). According to a forest officer from Taita Taveta County interviewed for this study, arsonists have various motivations: some set fires intentionally to exact revenge after conflicts with park rangers or local communities; others do so to pressure management into selling them wood products; and some burn forests as a form of protest against the presence of national parks, perceiving their land as unjustly taken. These findings align with research in Tanzania’s forest plantations, which identified arsonists as significant contributors to wildfires (Mgina and Wawa 2020). The results highlight the need for policy reforms and review to better integrate local communities into the management of protected areas. Management policies should clearly articulate how communities can benefit from these areas, and efforts should be made to educate surrounding communities through workshops and seminars about the short-term and long-term advantages of protected areas.

Conclusion and recommendations

In conclusion, this study has contributed two key findings. First, it highlights that Chyulu Hills National Park, within the Tsavo Conservation Area, is particularly vulnerable to wildfires. The park is notably prone to more frequent burns and has a higher concentration of human activities linked to wildfires. Second, the study found that certain human activities are unique to specific regions. For example, illegal bhang farming and wild khat harvesting were only reported in the Chyulu Hills National Park. This regional variation may be attributed to the diverse nature of the TCA. Additionally, the study confirms that wildfires across national parks in the TCA are closely linked to human activities, with poaching being the most prevalent activity associated with wildfires. The identification of 11 human activities tied to wildfires highlights the urgent need for a reassessment of current wildfire management strategies. Policies should focus on incorporating local communities into the management of protected areas and establishing clear laws, sanctions and penalties for offenses related to wildfires. Furthermore, it is crucial to align wildfire-related policies between national and county governments, given their direct and indirect effects on wildfire risks. Lastly, the study recommends further research on integrated approaches to wildfire management in the TCA.

Supplementary material

Supplementary material is available online.