Repellents derived from animals include for instance secretions, blood-based, urin-based, or bone-based substances.
The blood-based repellent Plantskydd® was tested at two sites in Madagascar for its effectiveness in reducing Pteropodid bats (Pteropus rufus) damage on lychee fruits. The relative risk of bat damage was RR = 0.08 in one site, and in the other site damage was reduced by 82 % (Raharimihaja et al. 2016). Plantskydd ® was also evaluated by Johnson et al. (2014) for its potential to reduce mule deer (Odocoileus hemionus) and Rocky Mountain elk (Cervus elaphus nelsoni) damage on sunflower plants in Colorado, USA. The study lasted over two years, and damage was 5 % lower in treatment plots in the first year, and 47 % lower in treatment plots in the second year.
To prevent gnawing damage from woodchucks on apple trees, Swihart (1991) used bobcat urine with or without capillary tubes. Without tubes, gnawing damage was 98 % less in treated orchards, and when the urine was in capillary tubes the gnawing damage was 35 % less in treated orchards.
Hygnstrom and Craven (1988) evaluated a bone-tar oil (Magic Circle, a formulation including 93.8% bone tar oil, State Coll. Labs, Reading, Pa) for its potential to reduce deer (Odicoileus spp.) damage to corn in Wisconsin, USA. The bone tar oil did not manage to reduce damage as yield loss was 15 % higher in treatment fields. A solution including castor oil (Ecodon, contains Ricinolic acid, castor oil) on jute rope eliminated wild boar (Sus scrofa) damage on sorghum in an in Indian study (Sakthivel et al. 2013). The effect lasted for 1 – 30 days, and although a damage reduction was observed in control plots damage was only eliminated in treatment plots (RR = 0.0).
