Peafowl (Pavo cristatus) and crane damage to establishing seedlings is a widely reported constraint on smallholder cucurbit production across Tamil Nadu, yet few field-level trials document the efficacy of low-cost, farmer-assembled deterrent combinations under commercial intercropping conditions. This study reports a case-controlled field trial conducted on a 1.5-acre watermelon (Citrullus lanatus) crop intercropped with mature coconut (Cocos nucifera) at Karegoundapalayam, Coimbatore district, Tamil Nadu. During the first sowing cycle, 2,710 seeds were sown; sustained foraging by an estimated 15 peafowl and 5 cranes destroyed 1,500 seedlings by the fifteenth day after sowing, and only 64 plants (2.4% of seeds sown) survived to establishment by day 25, corresponding to a reported yield loss of up to 80%. In response, an integrated deterrent package was deployed, combining zigzag 6 mm nylon rope strung between coconut palms fitted with reflective ribbon and compact-disc (CD) flash strips, perimeter reflective spiral deterrents and wind spinners, four human-effigy scarers, and scheduled early-morning pyrotechnic (cracker) sound bursts, with rope geometry rotated fortnightly and scarer positions rotated every four days to counter habituation. Bird visitation ceased within three days of deployment. A second sowing of 2,750 seeds under the maintained deterrent regime achieved 2,720 germinated seedlings (98.9% germination), with the entire stand reaching the fruiting stage at the time of reporting. These results indicate that a rotated, multi-modal (visual + physical + auditory) deterrent system can rapidly and durably suppress peafowl- and crane-mediated seedling loss in open-field cucurbit–coconut intercropping without recourse to lethal or chemical control, offering a replicable, low-cost model for smallholder farms in peafowl-dense agro-ecosystems of peninsular India.