Review of mugger Crocodylus palustris Lesson, 1831 mortality by vehicle collisions in Gujarat state, India

Railway lines, roadways, canals, and electricity cable networks pose serious problems to wildlife, fragmenting habitats worldwide. These infrastructures are well-recognized as linear intrusions. Today they represent a threat to wildlife, including to the mugger or marsh crocodile (Crocodylus palustris Lesson, 1831). The current study documents 15 crocodile–vehicle collisions (CVCs) recorded in 2 years (2021 and 2022); 11 were on roads, and 4 were on railway tracks. Sex was determined for eleven individuals (five males, six females) and four were of undeterminable sex due to crushing. A total of thirteen individuals were found dead at the various sites of collision, and two juvenile individuals were found injured and one of them was treated successfully and returned to the wild. The highest number of CVCs (nine) occurred in Central Gujarat, followed by three CVCs in Saurashtra, two in the Kutch region, and one in North Gujarat. Mitigation measures required for the collision situations in Gujarat are discussed. A literature survey showed that a total of 75 CVCs were recorded within the last 18 years due to the state s road (n= 51, 68%) and railway (n= 24, 32%) networks, with the highest number of CVCs (56) observed in Central Gujarat and the lowest numbers of CVCs noted in North Gujarat (2) and South Gujarat (no CVCs). There was a high number of subadult and juvenile mugger CVC victims. The CVC site location in the different regions of Gujarat state positively corresponds to crocodile populations. However, the mugger crocodile (C. palustris) is nationally protected under the Indian Wildlife Act as a Schedule I species, and the IUCN criteria is ‘Vulnerable’ and it is an Appendix 1 (CITES) species; therefore, conservation measures are required. CVC incidences were recorded widely in the entire species distribution range, from Iran, India, and Sri Lanka, and can be considered as an emerging threat to mugger crocodiles.