Featured Research

from universities, journals, and other organizations

Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey

Date:
December 4, 2013
Source:
University of Tennessee at Knoxville
Summary:
Biologists have observed two crocodilian species -- muggers and American alligators -- using twigs and sticks to lure birds, particularly during nest-building time.

A mugger crocodile balances twigs on its nose to tempt birds collecting small branches to build nests with, at Madras Crocodile Bank, Tamil Nadu in India.
Credit: Vladimir Dinets

Turns out the crocodile can be a shrewd hunter himself. A University of Tennessee, Knoxville, researcher has found that some crocodiles use lures to hunt their prey.

Related Articles


Vladimir Dinets, a research assistant professor in the Department of Psychology, is the first to observe two crocodilian species -- muggers and American alligators -- using twigs and sticks to lure birds, particularly during nest-building time.

The research is published in the current edition of Ethology, Ecology and Evolution. Dinets' research is the first report of tool use by any reptiles, and also the first known case of predators timing the use of lures to a seasonal behavior of the prey -- nest-building.

Dinets first observed the behavior in 2007 when he spotted crocodiles lying in shallow water along the edge of a pond in India with small sticks or twigs positioned across their snouts. The behavior potentially fooled nest-building birds wading in the water for sticks into thinking the sticks were floating on the water. The crocodiles remained still for hours and if a bird neared the stick, they would lunge.

To see if the stick-displaying was a form of clever predation, Dinets and his colleagues performed systematic observations of the reptiles for one year at four sites in Louisiana, including two rookery and two nonrookery sites. A rookery is a bird breeding ground. The researchers observed a significant increase in alligators displaying sticks on their snouts from March to May, the time birds were building nests. Specifically, the reptiles in rookeries had sticks on their snouts during and after the nest-building season. At non-rookery sites, the reptiles used lures during the nest-building season.

"This study changes the way crocodiles have historically been viewed," said Dinets. "They are typically seen as lethargic, stupid and boring but now they are known to exhibit flexible multimodal signaling, advanced parental care and highly coordinated group hunting tactics."

The observations could mean the behavior is more widespread within the reptilian group and could also shed light on how crocodiles' extinct relatives -- dinosaurs -- behaved.

"Our research provides a surprising insight into previously unrecognized complexity of extinct reptile behavior," said Dinets. "These discoveries are interesting not just because they show how easy it is to underestimate the intelligence of even relatively familiar animals, but also because crocodilians are a sister taxon of dinosaurs and flying reptiles."

Dinets collaborated with J.C and J.D. Brueggen from the St. Augustine Alligator Farm Zoological Park in St. Augustine, Fla. More of his crocodile research can be found in his book "Dragon Songs."


Story Source:

The above story is based on materials provided by University of Tennessee at Knoxville. Note: Materials may be edited for content and length.


Journal Reference:

  1. V. Dinets, J.C. Brueggen, J.D. Brueggen. Crocodilians use tools for hunting. Ethology Ecology & Evolution, 2013; 1 DOI: 10.1080/03949370.2013.858276

Cite This Page:

University of Tennessee at Knoxville. "Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey." ScienceDaily. ScienceDaily, 4 December 2013. <www.sciencedaily.com/releases/2013/12/131204182433.htm>.
University of Tennessee at Knoxville. (2013, December 4). Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2013/12/131204182433.htm
University of Tennessee at Knoxville. "Crocodiles are cleverer than previously thought: Some crocodiles use lures to hunt their prey." ScienceDaily. www.sciencedaily.com/releases/2013/12/131204182433.htm (accessed October 25, 2014).

Share This



More Plants & Animals News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins