Beehives deter crop-raiding elephants

By Cody Rogers

A critical analysis assignment based on a seminar given by Dr Lucy E King.

Crop-raiding by African elephants (Loxodonta Africana) poses a combination of social, economic (Figure 1), political and environmental problems. In Tanzania, 60% of farmers rated pests as their primary economic problem (Porter, 1976) and similarly in Zimbabwe, local farmers ranked pests first among 30 obstacles preventing an ideal lifestyle (Wunder, 1997) with farmers displaying ‘ingrained hostility’ towards elephants in particular (Barnes, 1996).

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Figure 1. Direct costs of crop damage on farms by the worst five animals in Uganda (reproduced from Naughton, Rose and Treves, 1999).

The founding of the ivory trade has resulted in an exponential decrease in elephant populations throughout Africa; numbers fell from 129,570 individuals to 15,279 in Kenya between 1973 and 1989 (Douglas-Hamilton, 1989). Human-elephant conflict, due to human encroachment and elephant crop-raiding, has become a major issue and solutions are required in order to mitigate both the effects of crop-raiding and elephant persecution. It is thought that African elephants can be repelled from farms by the presence of African bees (Apis mellifera). Dr Lucy E King has been researching the repellent effects of bees in Kenya and whether or not the presence of bee hives reduces the number of incidents of crop-raiding by elephants. Dr. King, in her first pilot study (King et al. 2009), erected 9 traditional log beehives (Figure 2) along 90m of a trial farm’s northern boundary (Farm A), with Farm B designated as the control with no beehive fence present. Over the 6-week trial period both farmers were able to record crop-raiding events using data sheets. Farmer B gathered daily data on the number of elephants successfully raiding, raid time and the number of elephants that approached his crops and were successfully scared away by traditional deterrent tactics (noise, fire, dogs etc.).

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Figure 2. This diagram shows the construction and application of a traditional log beehive fence. Huts are spaced 6m apart allowing for an 8m space between each hive (reproduced from King et al. 2009).

To evaluate the success of the beehive fences two indicators were formulated; (i) crop-raiding events should be non-existent and (ii) fences should be easy and cheap to create and maintain. During the 6-week trial period the fences were raided on four occasions, causing damage that required minor repairs that could be taken from local resources at no cost, concluding that once erected a hive requires little maintenance. Each traditional log beehive costed approximately US$315 per 100m though multiple harvests of honey has the potential to recover the costs of the beehive fence. Over the study period, a total of 133 raids were recorded at the two focal farms. Farm A had seven successful raids by 38 elephants whereas Farm B experienced twenty-one raids by 166 elephants, including eight failed raid attempts that were prevented by the farmer himself. Additionally, by the end of the harvest season, Farmer B had almost no crops to harvest (with an estimated 90% of his harvest having being destroyed/eaten by raiding elephants), whereas Farmer A was able to harvest successfully.
The perception of the farmers towards the effectiveness of the beehive fences was also an important factor to consider during this study as support from the African community effects the success of such experiments. Attitudes towards the project were positive throughout the trial; group membership increased during the course of the study as word of the trial spread. Also, Farmer A extended (at his own means and cost) the beehive fence to cover a new entrance site after the study. Additionally, following the success of the study all attending members of the beekeeping group displayed interest in having a beehive fence erected around their own farm.

One of the main focusses in Dr. King’s research is the efficiency of the type of beehive used for the beehive fence, ever trying to improve upon previously used beehives. Hives need to be inexpensive to produce and repair, easy to maintain and produce good quality honey that generates a reasonable income. The traditional log beehive used in the pilot study of Dr. King’s work was a basic design, made of hollow logs of bark which are suspended horizontally for safety. These hives are surprisingly light and strong though the coating may split or peel off when the hive is agitated (Vollrath & Douglas-Hamilton, 2002). However, the income that this specific design of hive generates does not equate to the income that other hives produce as the combs cannot be removed unless they are cut which then cannot be returned undamaged to the hive. The Kenyan top-bar hive (KTBH) is a more improved and productive type of beehive (Figure 3) and studies have shown (King, Douglas-Hamilton & Vollrath, 2011) that maintenance is easier and the KTBH improves the quality of the honey harvested from the hives, attracting better prices at the market than honey produced from the traditional log hives. In a later study conducted by Dr. King, the KTBH were used effectively when compared to a traditional deterrent, a thorn bush barrier. A third type of hive, the langstroth hive, has also been developed though this hive costs more to produce, US$800-900 per 240m, and is less favoured.

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Figure 3. Kenyan top-bar hive design – the beehut houses are covered by a rainproof roof made from corrugated iron and is protected from the sun by a flat-thatched roof. Houses are connected by hanging wire which an approaching elephant will instinctively try to pass between, causing the hives to swing erratically often provoking and release the bees (reproduced from King, Douglas-Hamilton & Vollrath, 2011)

The main purpose of Dr. King’s research is finding an appropriate deterrent to stop elephants from crop-raiding farms that are inexpensive and easy to maintain. Previous work studying the effectiveness of deterrents such as elephant warning calls, electrical fencing and trip-alarm techniques have been analysed in various studies throughout the literature. O’Connell-Rodwell et al. (2000) tested the effectiveness of these deterrents and found that only electrical fencing reduced elephant damage at a community level, though the price of erecting the fence, which cost approximately US$5,900, outweighed saving calculations from preventing crop destruction, making this deterrent method unpopular.
More affordable farm-based elephant deterrents, using locally available materials, are becoming more popular due to their cost effectiveness. Graham & Ochieng (2008) trialled a number of these farm-based deterrents which were: (i) Chilli rope fences (ii) Cow bells (iii) Chilli smoke briquettes (iv) Noise makes and (v) Watchtowers and solar powered torches. The study found that though levels of crop raiding declined after the initial introduction of treatments, levels did not decline significantly when compared to control farms (Figure 4). Other studies have shown that chilli-based methods are ineffective, expensive and labour intensive (Karidozo & Osborn, 2014) and that they do not add any significant deterrent effect but do add unnecessary expense and create additional work (Hedges & Gunaryadi, 2009).

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Figure 4. A graph showing comparisons between the number of attempted and successful raids on different treatments (based on Karidozo & Osborn, 2014).

Another deterrent method using capsicum oleoresin spray was tested by Osborn (2002) and it was found that elephants were repelled from fields significantly faster than by traditional methods as the atomised cloud produces a severe irritating effect on any mucous membrane it comes into contact with (Nelson, Bidwell & Sillero-Zubiri, 2003). Osborn & Rasmussen (1995) also tested the spray on wild African elephants in Zimbabwe and all tests gave a positive repellent effect Furthermore, the spray remains effective for 20 minutes and costs US$18 per unit though there are issues with wind dispersal and accidental human exposure.

Recent developments in this area include research into the response African elephants have to undesirable noises such as the sound of disturbed bees. King, Douglas-Hamilton & Vollrath (2007) conducted an experiment investigating the effect that the sound of disturbed bees has on elephant behaviour. In a sample of 18 family subgroups of elephants, the majority reacted negatively – immediately walking/running away, when exposed to the buzz of disturbed bees. Of the 17 families, 16 (94%) left the tree under which they had been occupying within 18 seconds of the bee sound being played. It is possible that this deterrent method, using the sound of bees, can be a less expensive and labour intensive alternative to using live beehives. Additionally, studies looking in to the effectiveness of elephant distress calls as a deterrent have proved inconclusive, sometimes invoking aggression (O’Connell-Rodwell et al. 2000) and inducing habituation (Hoare, 2001; Osborn & Rasmussen, 1995). Furthermore, trip-wire alarms have also been experimented on and elephants are quick to habituate to the noise, though the alarms do serve as a useful warning system to farmers (O’Connell-Rodwell et al. 2000). As well as this, the sounds of domestic cattle have also been played near elephants to gauge reactions; breeding herds retreated though it showed little effect on all male groups (Kangwana, 1996; Hoare, 2001).

The positive effects seen throughout Dr. King studies using beehives suggest that they are a successful deterrent, though using a combination of other effective deterrents such as drum beating, guarding and dogs (Sitati, Walpole & Leader-Williams, 2006) could prove more effective. Though effectiveness as a deterrent is not affected by the type of beehive used, other factors such as maintenance and income generate are affected. Beehive design should be carefully considered in order to ensure that cost is kept to a minimum, maintenance is easy and simple and the income generated is high. Using chilli-based products to spread on interlinking wires (Osborn, 2002) may also be an option but its effectiveness is controversial (Karidozo & Osborn, 2014). Though Dr. King’s studies have only been conducted on small scales, the results produced from them have shown real promise. Conducting a larger scale study which uses both beehives and other cost efficient deterrent methods that have proven to be successful such as capsicum oleoresin spray, may provide an even more successful deterrent method and prevent future crop-raiding incidents by African elephants.

References

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Douglas-Hamilton, I. (1989) Overview of status and treads of the African elephants. The ivory trade and future of the African elephant. Oxford: Ivory Trade Review Group.

Graham, M. & Ochieng, T. (2008) Uptake and performance of farm-based measures for reducing crop raiding elephants Loxodonta Africana among smallholder farms in Laikipia District, Kenya. Oryx, 42, 76-82.

Hedges, S. & Gunaryadi, D. (2009) Reducing human-elephant conflict: do chillies help deter elephants from entering crop fields? Oryx, 44, 139-146.

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Karidozo, M. & Osborn, F. (2014) Community Based Conflict Mitigation Trials: Results of Field Tests of Chilli as an Elephant Deterrent. Journal of Biodiversity and Environmental Sciences, 3, 1-6.

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King, L., Douglas-Hamilton, I. & Vollrath, F. (2011) Beehive fences as effective deterrents for crop-raiding elephants: field trials in northern Kenya. African Journal of Ecology, 49, 431-439.

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