Hi Matthew, 

This question has actually been already answered, I am just trying to think where.  Mark Bekoff certainly worked on this topic, but again, don't know exactly where. I found an article that you might find interesting (link attached), but I am sure there's a more recent review on the topic somewhere. 

Sorry I could not be of further assistance!

http://www.jstor.org/discover/10.2307/2096947?sid=21105927259731&uid=4&uid=2

That is a great help! Thank you!

Matthew

I have a strong suspicion that the amount of danger and/or the difficulty in handling of prey would drive socialization.  For example, if a species preys on another that is particularly dangerous (and the danger can be ameliorated by additional predators), then strong selective pressures are likely to exist towards developing sociality among the predators.

Thank you Todd. 

Regarding Crocodilia then, I know that the majority are big and they are obvious ambush predators, but why would they not form hunting "packs". Could it purely be because ambush is harder with multiple animals, or is it possible that size/danger of prey (for example) is mitigated by the ambush etc. Or because generally a croc will try to grab the nearest part of the animal to the water - generally face or neck - and this should avert the majority of dangers maybe? Obviously only after speculation here rather than gospel, but it is all very much appreciated

Thank you very much everyone. I have some very interesting things to look at now! 

See also Craig Packer's paper in Am Nat titled Why lions form groups: food is not enough. Tim Caro published something similar on cheetahs also. 

Thanks very much Matt! Will do

In regards to crocodiles, I would imagine the readily available small prey such as crustaceans and fish may prevent a group effort pressure. Although certain species rely more on larger prey, I wonder if the abundance of smaller prey counteract a pressure towards group hunting. Also, the pack hunters that come to mind: wild dogs, wolves, hyenas, army ants, have an alpha male and female  (except for the ants who have a queen). Basically there is a somewhat set social dynamic and less competition for breeding which may play into it? Also, many pack hunters are related and willing to give up breeding due to security reasons and kin selection. I'm not too familiar with crocodile sociality and whether or not they disperse from natal sites or stick around with their family members. I would imagine if they stuck around near family helping may be more of a possibility?

A very good point regarding the size of the prey, thank you. Regarding the alpha males/females...whilst the hierarchy is arguably not quite so regimental as in ants/lions/etc, there is an "alpha" but this creature is generally the bull due to his size (and his volume), rather than prowess in formal contest etc. To my knowledge, contests do happen but not to the same degree as in the canids or felidae carnivores.

Rather interesting point regarding a familial link between the members of the packs and your point about being willing to give up breeding for kin selection - the principle akin to Haldine's famous joke. Some fantastic points, and hopefully the papers above will allow me to answer your point about the dispersal - which, from my own knowledge, I do think occurs however not principally depending on location. I think it generally occurs best where the crocs can travel purely through the water systems. 

Thank you again, very much appreciate your points!

In the social insect literature it's been noted that social retrieval permits the subduing of larger prey.  And, although there's there's been less attention given to this, it probably reduces the efficacy of some prey defenses. 

Hi Matt, 

I would think that the environment also plays a role on becoming social. Tigers, for example, which is the species I am more familiarized with, are ambush/stalk predators who usually use the ecotone between forest and clearings to perform kills. This type of environment does not really allow for pack hunting. Tigers don't chase prey, they manage to get within 12-15 m from prey and then attack in a fast rush, one or two leaps to get a hold of the prey. If further than that, the tiger won't try to make the kill. This has been reported in the literature and I also have witnessed it myself. I doubt that this would be possible if more than one individual were involved (i.e. getting in such proximity of prey without being noticed... 12-15 m is really quite close). As far as I understand, same apply to other forest felids, such as lynx or leopard. 

Just a thought...

There is an enormous body of literature out there on the evolution of sociality. Kin selection theory appears to be especially useful, but in the case of predators becoming pack hunters, have a look at some of the papers by Craig Packer (Univ Minnesota); I'm sure you'll find some useful info there.

Thank you for your answers - and sorry for my late reply! 

Maria a very interesting observation! Thank you for sharing! The European lynx certainly works like that - one of the major points for release into Britain was that it is an ambush predator and won't chase a prey animal for more than a few metres. Therefore farmers just need to keep a small stretch of land between their sheep etc and the forests. Good point about the environment shaping the hunting style of individuals, leading to a need for sociality, or not. Thanks!

And an interesting point about the prey's defences being the obstacle Sylvio. Would certainly be a determinant in group size. Thank you! 

And thank you for the papers René! Will get having a look. 

Thank you everyone!

The role of a dominance hierarchy to organize large social groups and how individuals interact in that hierarchy is addressed in a paper on wolf vs dog aggression in social interactions among members with different status within the social system. Interestingly dogs (and humans?) have a much steeper dominance hierarchy than the big bad wolf! Maybe small groups can better afford dissent among its class levels, maybe larger social groups like dogs/humans enforce steeper dominance hierarchies with intolerance of insubordination/dissent for individuals to hold power longer. Maybe you need a stronger hierarchy in larger groups to "get things done?" VERY INTERESTING. It goes to show that old biases about "predators" still prevent a better understanding not only of solitary predators vs species social beyond the family group, but also of ourselves. Humans societies are hierarchical and humans engage variously in social aggression and dissent oppression. We are more like dogs than cats as a species? REFERENCE http://dx.doi.org/10.1098/rspb.2015.0220Testing the myth: tolerant dogs and aggressive wolves

Friederike Range1,2, Caroline Ritter2 and Zso´fia Vira´nyi1,2

1Comparative Cognition, Messerli Research Institute, University of Veterinary Medicine, Vienna, Medical

University of Vienna, University of Vienna, Veterinaerplatz 1, 1210 Vienna, Austria

2Wolf Science Centre, Do¨rfles 48, 2115 Ernstbrunn, Austria

Interesting discussion - from my view some important fact not mentioned yet is the necessarity to learn hunting strategies during ontogeny: crocodiles are able to feed on theirselves from the beginning of their life (I am aware of the mother's activities to give their offspring some shelter for the first days, but I do not know about crocodile mothers to carry prey or food to their youngsters). So the young go on their own over the long period of growing just adjusting their strategy to their actual size and ability to catch food. According to this, there is no evident need for social organizing into (coordinated!) hunting groups.

There is a huge literature on this from wolves, lions, African wild dogs, cheetahs, badgers and red foxes. It was especially well studied in the 1980's and 1990's with countless papers and books on the subject!

Some interesting papers on the advantages of asociality have also been published for leopards (by Stander) and pumas (by Pierce)