A price on their heads? Assessing foreign demand as a driver of hornbill hunting in Cameroon

Abstract

Unsustainable hunting to supply wildlife markets is a global threat to bird species and a key driver of biodiversity declines across Africa. Despite well-documented negative impacts of wildlife trade on many bird species, such as Asian hornbills and African vultures, its consequences for African hornbills remain poorly understood. Here, we use data from both online trade and interviews with hunters in Cameroon to investigate the implications of foreign demand for African hornbills, using a twofold approach. First, we explored factors associated with the prices of hornbill skulls, the most heavily traded and expensive hornbill products, in online markets. Second, we examined the relationship between hunting pressure and market demand using semi-structured interviews with hornbill hunters and traders in Cameroon. In our online sales analysis, we considered factors including numbers of sales, species conservation status, Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) listing, body size, sex, and skull length (including bill and casque). In addition, we considered the number of sound recordings available for focal species, as this factor is highly correlated with species range size and may serve as a proxy for detectability in the field. We then used generalized linear mixed-effects models (GLMM) to identify variables closely associated with the prices of hornbill skulls online. Generalized linear models (GLM) were used to examine the relationship between hunting pressure and the local and foreign demands in Cameroon. We found that online trade included skulls and other products from 20 African and five Asian hornbill species, the latter of which were all CITES-listed. The median online price for a hornbill skull was £117. Nearly half (nine out of 20) of the African hornbill species found in online trade were native to Cameroon. The three most heavily traded species—Yellow-casqued Hornbill (Ceratogymna elata), Black-casqued Hornbill (C. atrata), and White-thighed Hornbill (Bycanistes albotibialis)—accounted for 66% of online hornbill products. Larger-bodied hornbill species classified as threatened, subject to CITES regulations, and species with higher numbers of sound recordings available tended to command higher prices online and thus likely face higher hunting pressure. We also found that foreign demand has a significant impact on hornbill hunting pressure, particularly among younger hunters. Approximately 73% of Cameroonian hunters interviewed targeted hornbills, with 91% of these motivated to acquire hornbill heads for trade, and 98% intending to sell their products to foreign buyers. Our findings highlight the urgent need to address the negative impacts of international wildlife trade and implement measures to protect African hornbill populations from increasing threats of overexploitation.