Abstract

Carbofuran is a very toxic carbamate insecticide commonly used in agriculture to control insects, mites, and nematodes. Although it works well against pests, non-target creatures such as birds, animals, and aquatic life are at serious risk due to its high acute toxicity, which can have detrimental physiological and behavioral impacts even at low exposure levels. This study investigated the toxicological effects of carbofuran exposure on populations of Great Coucals (Centropus sinensis) in Pakistan's Lodhran and Bahawalpur areas. The study evaluated both wild and captive-reared birds by examining carbofuran residues in tissues, eggs, and prey items, as well as by assessing hematological and biochemical responses. Across all seasons, dietary analysis showed a strong preference for animal-based components, with fruits, vegetables, and caterpillars all ranking highly. The highest residue amounts were found in eggs (0.68 mg/kg), leg muscle (0.14 mg/kg), liver (0.21 mg/kg), stomach contents (5.28 mg/kg) and blood (2.71 mg/kg) of captive-reared birds subjected to 5 mg/kg carbofuran. Hematological indices such red blood cells count, hemoglobin (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were significantly reduced in birds treated with dose-dependent incremental carbofuran. Dose-dependent mortality rates were 30% at 0.5 mg/kg, 65% at 2.5 mg/kg, and 85% at 5 mg/kg. A sharp drop in probability of survival for birds subjected to 0.5 mg/kg and 2.5 mg/kg carbofuran recorded between 10 and 20 weeks. These results reveal the serious physiological and pathological effects of carbofuran exposure in Great Coucals, underscoring the possible harm to ecosystem health and bird populations.