Farmers' perception of arboreal vertebrate pests in mixed home-garden agroforestry systems and adoption of non-lethal deterrent practices

Abstract:

Across the East African highlands, mixed home-garden agroforestry systems that combine fruit trees, timber species and annual crops within a single landholding face persistent pressure from arboreal vertebrate pests, yet the farmers who manage these gardens have seldom been asked what they actually see, lose and do about the problem. This research documented farmers' perceptions of arboreal vertebrate pest damage, estimated yield losses attributed to four pest guilds, and assessed the adoption and perceived effectiveness of non-lethal deterrent practices in Embu County, central Kenya. A cross-sectional survey was administered to 186 smallholder farmers managing home gardens of 0.2–1.5 hectares between August 2022 and July 2023. Four arboreal pest guilds were identified by respondents: primates (mainly vervet monkeys, Chlorocebus pygerythrus), tree squirrels (Paraxerus ochraceus), straw-coloured fruit bats (Eidolon helvum) and large frugivorous birds (hornbills, turacos). Primates were ranked the most damaging guild by 64.5% of farmers, followed by fruit bats (18.8%), squirrels (10.2%) and birds (6.5%). Self-reported annual crop loss averaged 23.7% of total fruit harvest value. Eight non-lethal deterrent methods were in use; guard dogs (72.3% perceived effective) and chilli-grease fencing (68.1%) ranked highest, while traditional scarecrows (35.6%) and drumming (22.4%) ranked lowest. Adoption of newer methods netting, noise devices, reflective tape increased from 2018 to 2023, coinciding with extension-service outreach. The results inform targeted pest-management advisory by identifying which deterrents farmers trust, which they have abandoned, and which gaps remain for wildlife-friendly crop protection in agroforestry landscapes.