Featured Research

from universities, journals, and other organizations

A Little Larceny Comes Naturally To Northwestern Crows

Date:
December 12, 2001
Source:
University Of Washington
Summary:
Crows and ravens are depicted as being clever and tricky animals in countless American Indian stories and legends. Those characterizations apparently are right on the mark, according to a pair of University of Washington researchers who have found a species of crow that is constantly looking for opportunities to steal food from other members of its flock.

Crows and ravens are depicted as being clever and tricky animals in countless American Indian stories and legends. Those characterizations apparently are right on the mark, according to a pair of University of Washington researchers who have found a species of crow that is constantly looking for opportunities to steal food from other members of its flock.

Related Articles


In fact, the behavior is so prevalent among Northwestern crows (Corvus caurinus) that it shatters the long-held belief of some animal behaviorists that the birds primarily are looking for predators when they scan their surroundings, report Renee Robinette Ha, a UW lecturer in psychology, and James Ha, a research associate professor of psychology.

Their findings were recently published in the journal Animal Behaviour.

"Crows and other corvids (ravens, jays and magpies) are highly intelligent," said Renee Ha. "Among birds, only parrots match them in intelligence. Crows are social, highly cognitive birds whose intelligence is up there with dogs."

"Crow vigilance is based on the opportunity to steal food," said James Ha. "The over-riding factor in their vigilance behavior is 'who's got food I can steal,' not 'is there a predator lurking around.' It has been dogma that crows are vigilant for predators, but they really are vigilant about each other."

To observe crows, the Has needed an open, non-wooded site where the birds' behavior could be readily seen. They found it in Meadowdale Park, a suburban site along Puget Sound in Snohomish County, north of Seattle. The park is relatively undeveloped with light human and dog traffic, which might have disturbed the birds.

The researchers observed crows for 290 hours over 18 months, watching a randomly selected bird for five minutes. All observed birds, which were in groups ranging between five and 50 individuals, were within one meter of the exposed tidal zone where food was available. The birds were observed through binoculars from a distance of 30 to 50 meters.

Among the available prey were sand lances, silvery fish the size of sardines that burrow into the sand. Other food sources include invertebrates such as clams, worms, shore crabs and snails. Larger prey such as sand lances, clams and crabs cannot be quickly consumed, and crows that catch them often become the targets of their thieving neighbors.

"Finding that chance to steal food is a very uniform strategy among these birds," said Renee Ha. "They are not like the crows in the city that forage for food in dumpsters."

As for predators, the researchers witnessed several bald eagle attacks while they were observing the crows. The researchers previously documented some eagle predation on crows, but they did not observe a bald eagle killing a crow during this study. Typically, when an eagle flew over the beach, the crows flew up and mobbed the eagle until it left the area.

"If you have a varied environment like a forest, crows can only be intermittently observed," said James Ha. "But on an open beach we have a stable system to study, and we've been able to open a door on crow behavior because we can see what they are doing all the time, what they are feeding on and how they are using their cognitive behavior in the wild. We also can band birds and watch them year after year."

The Has are continuing their research, using DNA to focus on what they describe as a "very complex family system" to further understand the crows' behavior.

The Animal Behavior Society; Sigma XI, a scientific honor society; and the UW Graduate School funded the vigilance study.


Story Source:

The above story is based on materials provided by University Of Washington. Note: Materials may be edited for content and length.


Cite This Page:

University Of Washington. "A Little Larceny Comes Naturally To Northwestern Crows." ScienceDaily. ScienceDaily, 12 December 2001. <www.sciencedaily.com/releases/2001/12/011210163210.htm>.
University Of Washington. (2001, December 12). A Little Larceny Comes Naturally To Northwestern Crows. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2001/12/011210163210.htm
University Of Washington. "A Little Larceny Comes Naturally To Northwestern Crows." ScienceDaily. www.sciencedaily.com/releases/2001/12/011210163210.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Kids Die While Under Protective Services

Kids Die While Under Protective Services

AP (Dec. 18, 2014) As part of a six-month investigation of child maltreatment deaths, the AP found that hundreds of deaths from horrific abuse and neglect could have been prevented. AP's Haven Daley reports. (Dec. 18) Video provided by AP
Powered by NewsLook.com
When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
The Hottest Food Trends for 2015

The Hottest Food Trends for 2015

Buzz60 (Dec. 17, 2014) Urbanspoon predicts whicg food trends will dominate the culinary scene in 2015. Mara Montalbano (@maramontalbano) has the story. Video provided by Buzz60
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