Observations on cooperative fishing, use of bait for hunting, propensity for marigold flowers and sentient behaviour in Mugger Crocodiles Crocodylus palustris (Lesson, 1831) of river Savitri at Mahad, Maharashtra, India

Abstract

As far as animal cognition is concerned, in comparison with mammals and birds, reptiles have been underestimated and research in reptilian cognition hasn’t progressed much due to this bias. Though crocodiles are generally stereotyped as lethargic and lacking social interactions except for territoriality, parental care and prey ambush, they demonstrate discrete behavioural repertoire in a variety of situations suggestive of refined cognition. The observations presented here were recorded during a long-term study on Muggers Crocodylus palustris of Savitri River in Maharashtra, and indicate social behaviour of remarkable acuity among Muggers to optimize foraging, which clearly hints at cooperative fishing. Also, on many occasions here, the Muggers were seen to have sticks on their snouts or lay still in the vicinity of floating twigs presumably to lure birds that desperately scouted for nesting material; though only on one occasion the unsuspecting bird was ambushed successfully. Flight initiation distances (FID) of birds that forage and nest in crocodilian habitat have been measured to assess their wariness towards crocodile’s presence. We report the attraction of free ranging Muggers here to the yellow Marigold Tagetes erecta flowers. We also remark on apparent sentience involving a dog that was chased into the river by a pack of feral dogs, the ‘aquatic refugee’ having been seemingly nudged and escorted to safety of the bank by crocodiles. All these behaviours are discussed in the light of previous reports involving other crocodilian species elsewhere, to assess the cognitive faculty of this species.