It once was thought that only humans made and used tools, however, Jane Goodall's observations in November 1960 of a chimpanzee named David Greybeard using a tool to fish out termites changed this anthropocentric view. We now know that birds use tools, as do many other animals, including dingoes and dogs (a thorough review of this area can be found in Animal Tool Behavior: The Use and Manufacture of Tools by Animals).
What about the recent observation of crocodiles and alligators (crocodilians) using sticks to lure prey by balancing the stick on their head? (Crocodilians include crocodiles, alligators, and caimans.) I found these observations to be fascinating and they show that these animals are capable of rather sophisticated behavior. For example, Vladimir Dinets, an assistant professor of psychology at the University of Tennessee, who co-authored a recent study of this behavior called "Crocodilians use tools for hunting" that appeared in the professional journal Ethology Ecology & Evolution noted, "Alligators living beneath bird rookeries used them, while others didn't" and "the alligators only used twigs as bait during the time of year that the wading birds were busy collecting twigs for their nests, from late March through early June."
Are crafty crocodilians really tool users?
But is this really tool use? Some experts aren't convinced just yet because the crocodiles didn't make the tools. For example, Nathan Emery, who conducts research at Queen Mary University of London who has extensively studied tool use in birds, notes that the if the animals "had detached the sticks from trees themselves, this would be considered true tool use." Of course, more experimentation is needed, but this study shows just how crafty other animals can be and how surprising and fascinating results emerge from careful observations of animals in the wild.
Jason Goldman who reported on these observations notes, "The new study adds to evidence suggesting that alligators, crocodiles and other reptiles are highly social, clever animals, not the plodding dullards of their image. They care for their young and have sophisticated mating rituals, and they might hunt cooperatively." He's right on the mark.
It's not happening at the National Zoo once again
Once again the National Zoo in Washington, D. C. finds itself being investigated for serious neglect of its residents. This is not the first time that this zoo finds itself in the spotlight for issues of serious animal neglect. I wrote about this in 2004 (see also) and despite these charges the zoo was re-accredited by the AZA. Sadly, there are still some major problems.
This is just a heads up about an ongoing investigation of which people should be aware of about which the zoo has remained far too silent. In the video accompanying this CBS report a spokesperson, when pushed about going public with the results of their investigation, says the zoo needs to release the information "in a thorough and process oriented way that makes sense". They have had the time to do so and this excuse seems to be a delaying tactic. They are now focusing on some young tigers who will likely draw visitors. Cruelty can't stand the spotlight and it's essential and urgent that the zoo talks openly about what has and has not been happening there.
The teaser image ("A mugger crocodile balances twigs on its nose to tempt birds collecting small branches to build nests with, at Madras Crocodile Bank in India") can be seen here.
V. Dinets, J.C. Brueggen, J.D. Brueggen. Crocodilians use tools for hunting. Ethology Ecology & Evolution, 2013; : 1 DOI: 10.1080/03949370.2013.858276