Crocodile and Big cats Interaction

[TheSmok]

(10-18-2020, 03:19 PM)Shadow Wrote: I posted that same source last August. So this same case comes up once a year then. I think, that this has been many times here too in different threads so in that way not so interesting to old posters maybe. But what makes it interesting is, that even though this is over a decade old case, it seems to be only really confirmed case known in which a saltwater crocodile has killed a tiger. Naturally environment is what it is, so quite difficult to know how many crocodiles tigers kill there and how many vice versa.

Naturally from Africa it´s well known, that lions kill crocodiles every now and then and some lions are even crocodile killer specialists. If anything can be concluded based on it, I would assume that tigers kill crocodiles too more often than some rare reports tell. Difficult to imagine, that tigress Machli would be only tiger noticing reliable easy prey, especially when on land or shallow water. This is what I think after trying to find out a bit more about interactions between big cats and crocodiles. For sure crocodiles have their moments, but known cases seem to back up more it, that more often big cats are the ones having a meal.

It is not surprising that the interaction between tigers and saltwater crocodiles in Sundarban is rare nowadays. There are only about 140 crocodiles in Bangladesh Sundarbans - http://www.zsbd.org.bd/pdf_journal/04_Dr_Aziz_USA.pdf and about 88 tigers - https://thelogicalindian.com/environment/tigers-sundarbans-96-21005, which makes their population density extremely low (about 0.023 and 0.015 individuals per square kilometer, respectively, if the Bangladesh Sundarban forest area is 6000 square kilometerss). However, tigers exhibit avoidance behavior towards basking areas of crocodiles, which may mean that even with low population density crocodiles pose a real threat to tigers in the mangrove habitat, where big cats are frequently forced to swim. There are numerous reports of interactions between crocodiles and tigers in Sundarbans, published before the foundation of Sundarbans National Park (e.g. accounts, described by Robert Quinton). They should be taken with some scientific skepticism, but at least show that with the larger population density, interactions between crocodiles and tigers were probably more common.

I highly doubt that some lions actually become "specialized crocodile killers". At least this has not been confirmed by any dietary study. In the only study where Nile crocodiles were recorded in the diet of lions, they had a low Jacobs index (https://academic.oup.com/jmammal/article/91/5/1280/903109). But it's not surprising to me if lions kill Nile crocodiles more often than vice versa, just because smaller crocodiles often leave the water for various reasons (to scavenge lion kills, due to drought, being displaced by larger dominant crocodiles, etc.), while lions are relatively rare enter the water. Even larger crocodiles can be vulnerable if they are completely isolated from water, although I still do not know any cases of lions killing crocodiles over ~3.5 meters long, I heard a report that a clan of spotted hyenas killied a very large Nile crocodile when it was left without water for several months during a severe drought.
Perhaps the same should be observed in the case with tigers and muggers (although tigers, unlike lions, always attack crocodiles alone, and therefore tigers are likely to usually take smaller crocs). Machli was not the only tiger known to attack some wandering muggers during droughts, at least her son Jhumaroo also eat some crocs along with Machli in 2004, 2005 and 2008. Also, there is one good video with detailed information about the legendary Machli's fight with 12-foot mugger (there are english subtitles):

It is highly unlikely that this was a predatory attack.

However, these assumptions do not have strong scientific statistical evidence, as they are based only on some fragmentary observations. It should be noted that big cat kills are much easier to find than crocodile kills (which are often stored underwater), which can create some bias. In addition, big cats (especially lions and tigers), are among the most frequently filmed and well-studied large carnivores in the world, as opposed to crocodiles. For example, we have almost no data on population structure, feeding ecology, spatial organization and etc for mugger crocodiles, while there are dozens of similar studies for tigers and leopards from the same areas. In any case, interactions between crocodiles and big cats are unlikely to play any important ecological role for both sides, with the exception of jaguars and caimans, where there are stable predator-prey reslonships. But caimans are ecologically very different from macropredatory crocodiles as well. Reply