Tuesday, April 21, 2015

Crocodilians use tools for hunting


When people think of complex tools, they often associate them with humans and possibly monkeys. Using objects to trick other organisms is extremely rare among the animal kingdom. However, there have been some unreliable records of crocodilians using objects as temptation. Saltwater crocodiles have been rumored to use leftover fish in order to entice birds and Mugger crocodiles have been said to place sticks across their snout and wait for birds to approach. It remains unclear if these reports of tool use among crocodilians are accidental or intentional.

Researchers observed four different areas in Louisiana for one year a few hours after sunrise.
            Site 1: Lake with Egrets
            Site 2: Same lake; 2 km from Egrets
            Site 3: Lake with Egrets, Spoonbills, Ibis
            Site 4: Same lake; 1 km from birds

Researchers compared the prevalence of alligators with sticks on their snouts between the nest building season and the following six-week period for Sites One and Three. They also compared the differences between the sites with birds and without birds during the nest-building season.

The stick-displaying behavior was only recorded during the birds’ breeding season, more specifically during the nest-building season. During this time, the alligators at Sites 1 and 3 (near the birds) were much more likely to display this behavior than the alligators living away from the birds.

This paper is very significant because this is the first claim that any reptile 1) uses complex tools 2) exploits the seasonal behavior of  prey. Although researchers do not know any details regarding the factors that stimulate the stick-displaying behavior, this is a huge step for herpetology. Historically, herps have been looked at in a negative light. However, this discovery shows how advanced reptiles truly are. It will be interesting to uncover the methods crocodilians use once more research is conducted. This discovery could have interesting implications for dinosaurs since crocodilians are a sister taxon.


Dinets, V., Brueggan, J.C., Brueggan, J.D. (2015). Crocodilians use tools for hunting. Ethology Ecology & Evolution. http://www.tandfonline.com.nuncio.cofc.edu/doi/pdf/10.1080/03949370.2013.858276

2 comments:

Allison Welch said...

Amazing! Thanks for sharing this!

Anonymous said...

What an interesting article! The animal kingdom never ceases to amaze me with how advanced animals really are. It is so cool to see crocodiles using their environment to attract prey. This is definitely a topic that scientists should further explore because it might lead to a better understanding of behaviors in not only herps, but also dinosaurs as you point out.