Assessment of chlorinated pesticide exposure to white-rumped vulture Gyps bengalensis in India.

Populations of the critically endangered white-rumped vulture (WRV) Gyps bengalensis have declined drastically due to the use of diclofenac for veterinary purposes in Indian subcontinent. Thirty-two dead WRVs collected from three states, namely Gujarat, Assam and Tamil Nadu in India between 2011 and 2014 were investigated to understand the role of diclofenac in the death, and the results were published. Furthermore, since organochlorine pesticides have been linked to long-term impact on populations in many species of birds across the globe, available tissues of 21 WRVs were tested also for six organochlorine pesticides (DDT, HCH, endosulfan, heptachlor, dieldrin and dicofol) and chlorpyrifos. All vultures were found to have had one or more detectable levels of pesticides in their tissues except one. Similarly, all the pesticides included in the study were detected in at least one of the vultures analysed. DDT (95.2%) was the most frequently detected pesticide followed by HCH (90.5%), and DDT (73.6%) contributed the most to the total pesticide load. Total pesticide load ranged between below detection limit (BDL) and 8753.4 ng/g. High levels of total pesticide load recorded in gut contents showed recent exposure to these legacy pesticides even long after their ban. However, it is perceived that studied pesticides' exposure to birds and their presence in the environment is in decreasing trend in India. Although, varying levels of pesticides were detected, all of which were below the levels reported to be toxic, and also reported earlier in the same species in India. Recorded levels may not create a problem to vultures unlike diclofenac; nevertheless, as continued exposure to the pesticides studied may lead to sub lethal effects in birds, it is prudent to monitor these pesticides along with new generation pesticides and NSAIDs in the critically endangered white-rumped vulture in India, towards its conservation.

Nimesulide poisoning in white-rumped vulture Gyps bengalensis in Gujarat, India.

Population of white-rumped vulture has not recovered in India to a desired level even after diclofenac was banned in 2006. During 2019, there were two known separate incidents of white-rumped vulture mortality involving four white-rumped vultures in Gujarat. After post-mortem examinations, tissues of all four vultures were received for toxicological investigation at the National Centre for Avian Ecotoxicology, SACON. Tissues were screened for a set of toxic pesticides, and none of them was at detectable level. Subsequently, the tissues were analysed for thirteen NSAIDs and paracetamol. Of all the drugs tested, only nimesulide was detected in all the tissues (17-1395 ng/g) indicative of exposure. Visceral gout was also observed in all the four vultures during post-mortem. Residues of nimesulide in tissues with symptoms of gout indicated that the vultures died due to nimesulide poisoning. Although, other than diclofenac, many NSAIDs are suspected to be toxic to white-rumped vultures, only nimesulide is reported in the recent past with clear symptom of gout in wild dead white-rumped vultures similar to diclofenac. Since, nimesulide appears to act similar to diclofenac in exerting toxic effects, if veterinary use of nimesulide continues, white-rumped vulture are bound to suffer. Hence, it is recommended that nimesulide should be banned by the government to conserve white-rumped vulture in the Indian subcontinent. Further, an effective system is recommended to be put in place to collect the tissues of dead vultures for toxicological investigations and eventual conservation of the critically endangered species.

A Comparison of Respiratory Variables in a Wild Population of Ventilated and Nonventilated Black Kites (Milvus migrans govinda).

Black kites (Milvus migrans govinda) often become injured due to kite-string injuries obtained during the International Kite Flying Festival that takes place during the celebration of Uttarayan, in Ahmedabad, India. The purpose of this study was to compare respiratory variables in ventilated and nonventilated black kites, to facilitate an evidence-based decision on whether to ventilate injured birds. A total of 56 juvenile and adult black kites of unknown sex were anesthetized and divided into a ventilated group (VG) and a nonventilated group (NVG). The variables recorded were end tidal carbon dioxide (ETCO2), peripheral capillary oxygen saturation, heart rate, respiratory rate, and maintenance percentage of isoflurane (%ISO). The ETCO2 values were higher in the NVG compared to the VG (72.9 ± 19.8 mm Hg compared to 16.0 ± 5.6 mm Hg, P < .01). The %ISO required to maintain adequate depth of anesthesia was higher in NVG compared to VG (3.5% ± 0.5% compared to 2.2% ± 0.4%, P < .001). Peripheral capillary oxygen saturation was not statistically different between groups (NVG 96.3% ± 3.5% compared to the VG 96.0% ± 5.1%, P = .867). Ventilation under anesthesia appears to lower the ETCO2 and the %ISO flow rate used to maintain a surgical plane of anesthesia. These findings should provide information that will be helpful in the anesthetic management of black kites and may apply to other avian species as well.