Pella Chronicle

Community News Network

December 10, 2013

Crocodiles and alligators may be smarter than they look

It's springtime at Louisiana's Lake Martin. The air is filled with the chattering of wading birds in the trees that ring the shoreline as they build their nests and prepare to lay eggs. An alligator lies submerged, its body just barely breaching the surface. A snowy egret spots a good-looking stick floating on the water. It would make a fine addition to her nest, so she swoops down to snatch it up. Bad idea. The stick was perfectly perched on the alligator's snout, just inches from his razor-sharp teeth. With one well-timed snap of his jaws, the alligator makes quick work of the bird and enjoys his lunch, beak and feathers and all.

Jane Goodall first described chimpanzees using sticks as tools in 1964. Prior to that, it was had been thought that tool use was exclusive to our species. In the decades since, the club of tool users has expanded to include other big-brained mammals such as apes, elephants and dolphins, such clever birds as crows, ravens and jays, and even the octopus. Now it turns out that crocodilians, animals once thought of as stupid, may use tools, too.

Vladimir Dinets, an assistant professor of psychology at the University of Tennessee and an author of a new study describing this hunting technique, first saw a hint that crocodilians - which include crocodiles, alligators, and caimans - might use sticks as a lure in 2007. Doing research in India, he watched as a mugger crocodile lay motionless in shallow water with an array of sticks and twigs laid across its snout. When an egret flew by to grab the stick, the crocodile snapped and the bird narrowly escaped. Dinets had heard stories of similar crafty behavior by animals at Florida's St. Augustine Alligator Farm Zoo.

But these were just isolated anecdotes, not subject to the rigors of scientific observation. "We needed to prove convincingly that the use of sticks was intentional," Dinets said. He started spending his weekends at two Louisiana lakes and discovered that the use of sticks as bait by wild alligators there was not haphazard. Alligators living beneath bird rookeries used them, while others didn't. Because the trees near the lakes don't regularly shed branches or twigs, this suggests that the gators were intentionally searching out sticks to use.

More significant, 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.

This is the first report of a predator synchronizing the use of hunting lures to the seasonal behavior of its prey. And if tool use is rare in the animal kingdom, the use of objects as bait is even more rare. Until now, it has only ever been seen in capuchin monkeys, a few bird species and one insect.

Nathan Emery, a bird cognition researcher at Queen Mary University of London, isn't quite convinced. If the alligators "had detached the sticks from trees themselves, this would be considered true tool use," he says. "They need to do some experimental manipulation to go further in explaining what's driving this." For example, if the alligators were purposely choosing the best sticks and discarding others, that might be sufficient to qualify as true tool use.

Given that tool use might now occur in crocodilians and birds, both of which descend from dinosaurs, might dinosaurs themselves have used tools? According to Dinets, it is "very likely that at least some of the thousands of non-avian dinosaur species used tools as well," but he admits that this is at best an educated guess.

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. "I do think that we have vastly underestimated the abilities of reptiles," Emery says. "but I don't think we've really got into their heads in the same way that we've been able to with birds and mammals."

          

1
Text Only
Community News Network
  • Victimized by the 'marriage penalty'

    In a few short months, I'll pass the milestone that every little girl dreams of: the day she swears - before family and God, in sickness and in health, all in the name of love - that she's willing to pay a much higher tax rate.

    April 15, 2014

  • Allergies are the real midlife crisis

    One of the biggest mysteries is why the disease comes and goes, and then comes and goes again. People tend to experience intense allergies between the ages of 5 and 16, then get a couple of decades off before the symptoms return in the 30s, only to diminish around retirement age.

    April 15, 2014

  • treadmill-very-fast.jpg Tax deduction for a gym membership?

    April marks another tax season when millions of Americans will deduct expenses related to home ownership, children and education from their annual tax bill. These deductions exist because of their perceived value to society; they encourage behaviors that keep the wheels of the economy turning. So why shouldn't the tax code be revised to reward preventive health?

    April 15, 2014 1 Photo

  • bomb1 VIDEO: A year after marathon bombing, Boston remains strong

    The City of Boston came together Tuesday to honor those who were injured and lost their lives at the Boston Marathon on the one-year anniversary of the bombing. While the day was sure to be emotional, those affected by last year's race are showing they won't let the tragedy keep them down.

    April 15, 2014 1 Photo

  • Google acquires drone maker Titan Aerospace to spread Internet

    Google is adding drones to its fleets of robots and driverless cars.
    The Internet search company said it acquired Titan Aerospace, the maker of high-altitude, solar-powered satellites that provides customer access to data services around the world. Terms of the deal weren't disclosed.

    April 14, 2014

  • E-Cigarettes target youth with festivals, lawmakers say

    The findings, in a survey released Monday by members of Congress, should prod U.S. regulators to curb the industry, the lawmakers said. While e-cigarettes currently are unregulated, the Food and Drug Administration is working on a plan that would extend its tobacco oversight to the products.

    April 14, 2014

  • Search teams will send unmanned sub to look for missing Malaysian airliner

    Teams searching for a missing Malaysian airliner are planning for the first time to send an unmanned submarine into the depths of the Indian Ocean to look for wreckage, an Australian official leading the multi-nation search said Monday.

    April 14, 2014

  • Why Facebook is getting into the banking game

    Who would want to use Facebook as a bank? That's the question that immediately arises from news that the social network intends to get into the electronic money business.

    April 14, 2014

  • Screen shot 2014-04-11 at 4.49.09 PM.png Train, entertain your pets with these 3 smartphone apps

    While they may not have thumbs to use the phone, pets can benefit from smartphone apps designed specifically for them.

    April 11, 2014 1 Photo

  • Stepping forward: The real Colbert

    Letterman changed the late-night TV game between his run on NBC's "Late Night" and starting the "Late Show" franchise in 1993. And while it's tough to replace a pop-culture icon, Colbert, in terms of pedigree and sense of humor, makes the most sense.

    April 11, 2014

Features
Facebook
AP Video
Tributes Mark Boston Bombing Anniversary Raw: Kan. Shooting Suspect Faces Judge US Supports Ukraine's Efforts to Calm Tensions Suspect in Kansas Shootings Faces Murder Charges Ukraine: Military Recaptures Eastern Airport Raw: Storm Topples RVs Near Miss. Gulf Coast NASA Showcases Lunar Eclipse Pistorius Cries During Final Cross-Examination The Boston Marathon Bombing: One Year Later Michael Phelps Set to Come Out of Retirement First Women Move to Army Platoon Artillery Jobs Sex Offenders Charged in Serial Killings Police: Woman Stored Dead Babies in Garage OC Serial Murder Suspects May Have More Victims Family: 2 Shot in Head at Kan. Jewish Center Raw: Horse Jumping Inspires 'Bunny Hop' After Attack, Officials Kill 5 Bears in Florida Popular Science Honors Year's Top Inventions ND Oil Boom Attracting Drug Traffickers
Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Obituaries