West Africa is the only region where a higher proportion of elephant range (about 60%) is found inside designated protected areas than outside. Many of these protected areas, however, are forest reserves, which only afford limited protection (Blanc et al., 2007) but as expanding human populations compete with elephants for habitat (Blanc et al., 2007) and resources (Conover, 2002), the future of forest elephant populations may soon depend entirely on protected areas (Barnes, 1999). The protected range of elephants in Ghana is about 22.8% (Blanc et al., 2007),  and  elephants  in  Ghana  continue  to  be  under pressure from habitat fragmentation and high human population densities (Barnes, 2002). Shifting cultivation up to the boundaries of protected areas exacerbates the problem of crop raiding by elephants, which is severe wherever elephants occur (Barnes, 2002).

In their position as keystone species that play a major role in stabilizing plant and animal communities (Campos-Arceiz and Blake, 2011; Beaune et al., 2013), or charismatic icons of conservation (Dublin and Hoare, 2004), elephants should enjoy adequate security in protected areas. However, a severe conflict  has developed between elephants and humans, sometimes leading to serious fatalities on either side (Kiiru, 1995; Nelson et al., 2003; Omondi et al., 2004; Malima et al., 2005; Campfire, 2007;  Kioko et al., 2008).

Study area

The study was undertaken around the Kakum Conservation Area (KCA), Central Region, Ghana, lying between longitude 1° 30 ’ W - 1°51’ W and 5° 20 ’ N – 5° 40 ’ N (Figures 1 and 2) from October, 2011 to September, 2012. The KCA consists of the Kakum National Park (KNP) and the Assin Attandanso Resource Reserve (AARR) and is managed as a national park by the Wildlife Division of Forestry Commission. Towards the end of the 19^th century, the Kakum forest was among the various reserves set aside as the “Celtis-Lophira hardwood Ghana’s Production Resource Reserve”; but the boundaries were not clearly demarcated until 1925. In 1940, the Assin Attandanso forest was added to form a 366 km² contiguous block in the moist evergreen forest zone (Hall and Swaine, 1976). Timber exploitation especially of Khaya ivorensis (mahogany) escalated from the 1950s until 1989 when the reserve was placed under the then Ghana Wildlife Department (GWD). Over the years, many laws (e.g. 1961 Wild Animals Preservation Act and the Legislative Amendments of 1971) had to be passed to make the existence of the park a reality. The KCA was finally gazetted as a national park and resource reserve by Legislative Instrument 1525 of 1992 under the administrative jurisdiction of the GWD.

The dominant vegetation type is moist forest, with other vegetation types being swamp forest (permanent and periodic) and riverine forest. The canopy coverage is closed or open, with irregular distribution of about 105 species of vascular plants (Wiafe et al., 2010). A small elephant population of about 160 (Dudley et al., 1992; IUCN, 2004) exists within the Kakum Conservation Area among populations of other mammals. KCA is surrounded by agricultural farms and about 52 communities with an estimated total population of 50,000 people. The main source of income of the indigenes is agriculture, supported by logging, hunting, trading, small-scale mining, charcoal burning and domestic animal rearing.

Range mapping

The study area was divided into nine sites, namely Kruwa, Briscoe II, Adiembra, Ahomaho, Aboabo, Afiaso, Antwikwaa, Mfuom and Abrafo (Figures 2 and 3). These sites were named after the nearest fringe communities or staff camps. GPS readings were taken along the boundaries of the ranges raided or visited by elephants, each at about 400 m intervals or less where necessary. GPS readings were also taken at the centre of each nearby community or staff camp. Range around KCA found to have been raided or visited by the elephants were investigated over the study period. Factors that attracted the elephants to the range, the vegetation type and the general habitat features at raided ranges were recorded.

Raid behaviour

A distance of about 50 m from the elephants was maintained to walk behind them to investigate their activities and raid  behavior and determine the herd sizes and raid frequency of herd sizes in such raid ranges.

Range mapping

Sixty-three elephant raid ranges were mapped around KCA during the one-year study and these covered a total land area of 289,447.30 m² (Table 1). Afiaso site recorded the highest number of 15 raided ranges covering a total land area of 86,698.40 m² representing 30% of the total land area raided, while Briscoe II site recorded the lowest of the two raided ranges covering 1,625.60 m² (0.6% of total land area) (Table 1). It was observed that people farmed to the immediate boundaries of the park (Figure 3) as pointed out by previous studies (Barnes et al., 2003; Monney et al., 2010). Crops raided were cocoa (Theobroma cacao), cassava (Manihot esculentus), plantain (Musa paradisiaca), cocoyam (Xanthosoma sp.), banana (Musa sapientum), yam (Dioscorea sp.) and pawpaw (Carica papaya) (Table 1).

Raid behaviour

Though the elephants fed mostly on mature plants, not all raids recorded in this study were accompanied by feeding. There were some examples of raids without consumption at four sites, namely Kruwa, Adiembra, Antwikwaa and Aboabo (Table 3). Some ranges occupied by oil palm (Elaeis guineensis) or bushes including Chromolaena odorata, Securinega virosa, Aspilia africana, Mallotus oppsitifolius and Mimosa pudica, never suffered any elephant raids (Table 2). There were no records of oil palm raids by the elephants around KCA throughout the study period. It was observed that elephants walked through palm plantations to consume pawpaw plants on 13 occasions (Table 2). Other farms which were also not raided were those in which crops were at the seedling and growing stages or with active pepper fences (fences still smelling of pepper). Farms with inactive pepper fences (no pepper smell) were however raided. Pepper fencing involves soaking rags in a mixture of ground pepper and grease and hanging the rags on fences around each farm. Four farm ranges covering a total land area of 6,268.30 m² (Table 2) were never raided by the elephants due to the pepper fences at the boundaries of those farms. The elephants were observed attempting to raid such farms on many occasions but were repelled by the scent of pepper. However,   at   some   sites    such    as    Mfuom  (Figure 4)  and Abrafo, because pepper scent waned, elephant raids were detected. Visits to farms by the elephants did not always result in crop raiding. For example, four times at Kruwa and two at Mfuom, the elephants walked through farms with only young growing crops such as seedlings without raiding.

We  observed  that  the  elephants  showed  special preference for some plants, notably pawpaw (Carica papaya) and bako (Tieghemella heckelii). This was evidenced by the frequency at which bako or pawpaw was selected from non-raided ranges after walking past other plants intact except for the obvious trampling as the elephants moved through them. For a mature pawpaw, almost the entire plant is taken as food, while in the case of the bako, only the fruit was of interest to the elephants.

It was observed that elephants raided in herds of two to eight individuals (Table 5) though the field staff used to see herd sizes up to 15. Results of regression analysis indicated a non-significant negative relationship between herd size and frequency of raids with a probability of less than 50% of the raid events (Y = -0.975x + 9.04, r = -.607, R² = 0.37, t = -1.708, p = 0.148). Therefore, the hypothesis that the frequency of raid events is influenced by the size of a herd was rejected.

Seasonal raiding

Raids were recorded in both rainy and dry seasons, even though figures recorded for the rainy season were higher than those in the dry season (Table 4). Chi-square tests however indicated no significant  differences  (χ²  = 15.48, df = 8, p = 0.059), and thus the hypothesis that raids were more prevalent in the rainy season than the dry season around KCA was rejected.

The  results  of   this   study  are  consistent  with  the expectation by Monney et al. (2010). For crop raiding to escalate around KCA, indeed, crop raiding by elephants has doubled in less than two years, with 63 raided farms covering a total land area of 289,447.30 m² as compared to 33 raids covering 103,496.20 m² land area (Monney et al., 2010). This is probably because the elephants became   adapted   to   some   deterrent   measures   that restrained them previously. For example, it was showed that pepper fencing had been ignored by some of the farmers (Monney et al., 2010; Wiafe and Sam, 2014) and it appeared that the elephants tool advanture from lapses in this deterrent measure and raided when the effect of the pepper had waned (Monney et al., 2010; Wiafe and Sam, 2014).

Field staff confirmed that the elephants could smell the pepper application and stayed far away from the source though no estimates of how far they stay away had been made so far. The implication of this observation is that pepper fencing to protect farms far away from the reserve boundary may be unnecessary and may rather elicit raids by the elephants when the scent of pepper wanes. Also, bako and pawpaw plants were found to trigger crop raiding as the adventure the animals took towards these plants linked them to some nearby farms. Even though this study has inadequate data in the case of the bako tree, this has been confirmed by the field staff. Thus, farmers far away from the park’s boundary would be better advised to get rid of pawpaw trees from their farms. In previous studies, plantain, cassava and cocoa farms were found to be the most commonly raided and sources of great risk to farmers around KCA (Barnes et al., 1995; Barnes et al., 2005) and around Bia National Park, Ghana (Sam et al., 2005). Other studies reported banana as the most preferred, for example around the Kibale  National  Park,  Uganda (Naughton-Treves, 1998) and across Gabon (Lahm, 1994).