Corvus brachyrhynchos or Corvus caurinus. Image: Wikipedia. Citation: Research shows crows comparable to humans when it comes to waiting (2011, September 15) retrieved 18 August 2019 from https://phys.org/news/2011-09-crows-humans.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Crows demonstrate their cleverness with tools (w/ Video) Explore further The researchers, led by Dr. Valerie Dufour from the Universite de Strasbourg, began their study by training 12 birds to exchange tokens for food. They gave each bird a piece of food. Keeping their giving hand closed, they showed the birds the reward in their other hand. After a waiting period, the researchers opened their giving hand again. The birds then received the reward if they gave back the initial piece of food.The maximum waiting period the researchers used was five minutes and the quality of the reward varied in each exchange. What the birds did during the waiting period varied with some birds leaving the food on the ground or hiding it and checking on it during the time period.This study shows that the crows are able to wait before making a decision and that this behavior is not limited to only humans and apes. While the researchers believed that the birds would be able to wait a few seconds, they were surprised that the birds were able to wait as long as they did.The destructive behavior, such as hiding the food and checking on it, enabled the crows to wait a longer period of time. Those birds with the longest waiting times all displayed this particular destructive behavior. © 2011 PhysOrg.com More information: Corvids can decide if a future exchange is worth waiting for, Biol. Lett. Published online before print September 14, 2011, doi: 10.1098/rsbl.2011.0726AbstractEvidence for time-dependent calculations about future rewards is scarce in non-human animals. In non-human primates, only great apes are comparable with humans. Still, some species wait for several minutes to obtain a better reward in delayed exchange tasks. Corvids have been shown to match with non-human primates in some time-related tasks. Here, we investigate a delay of gratification in two corvid species, the carrion crow (Corvus corone) and the common raven (Corvus corax), in an exchange task. Results show that corvids success decreases quickly as delay increases, with a maximal delay of up to 320 s (more than 5 min). The decision to wait rests both on the quality of the prospective reward and the time required to obtain it. Corvids also apply tactics (placing the reward on the ground or caching it) that probably alleviate costs of waiting and distract their attention during waiting. These findings contrast previous results on delayed gratification in birds and indicate that some species may perform comparably to primates.via ABC (PhysOrg.com) — In a new study published in Royal Society’s Biology Letters, researchers have discovered that crows and raven birds show the same ability to complete delayed exchange tasks as monkeys and humans do.
Kolkata: For the first time in the state, Voter Verifiable Paper Audit Trails (VVPATs) will be used in all polling booths along with the EVM machines, Sunil Arora, Chief Election Commissioner (CEC) said on Friday.He said that the EVM and VVPAT machines are secure and have proved effective on all parameters. He ruled out the possibility of reintroduction of ballot papers and said for the past two decades EVMs have been used and have been every effective. Also Read – Speeding Jaguar crashes into Mercedes car in Kolkata, 2 pedestrians killedIt may be mentioned that the Opposition leaders, while addressing the United India rally, had demanded reintroduction of ballot papers as EVMs can be tampered with very easily. Arora said: “Tampering and malfunctioning have different meanings but the words have been used in ways as if they are synonymous.” A full team of ECI led by the Chief Election Commissioner and Election Commissioner Ashok Lavasa, paid a visit to review the poll preparedness of the state government. The bench held meetings will leaders of the political parties, District Magistrates, Superintendents of Police, nodal officers of Income Tax, Excise and Commercial tax departments and representatives of civil society groups. Also Read – Bose & Gandhi: More similar than apart, says Sugata BoseThe Commission met state Chief Secretary Malay De, Home Secretary Atri Bhattacharya and DGP Virendra and took stock of the law and order situation. Arora said that the Commission will seek an explanation from Rajeev Kumar, Commissioner of Kolkata Police, who did not attend the meeting on Thursday. The Commission has asked all the District Magistrates and police officers to ensure speedy execution of Non-Bailable Warrants (NBWs) and speedy disposal of pending cases of electoral offences from the last election. The Commission also directed effective use of IT applications Samadhan, Suvidha and Sugam. The CEC said the Central forces will be under police observers and assured a free and fair election. Special security arrangements will be made in the sensitive areas. Adequate CCTV coverage and webcasting in polling stations will be there in sensitive areas. Asked whether the ECI will be able to stop intimidation of voters, Arora assured that election will be free and fair and that the state government has been instructed to take up the law and order issue seriously. He said to ensure impartial monitoring of the election, accessibility observers will be appointed for the first time. The Commission will appoint general observers, police observers, expenditure observers and micro observers. The CEC said representatives of the political parties had requested to deploy Central forces one month before the election and they should carry out route march in the sensitive areas. Some parties had demanded that district officials be instructed to ensure verification of licensed arms and to take effective action against unlicensed arms.
Hear from Polar Explorers, ultra marathoners, authors, artists and a range of other unique personalities to better understand the traits that make excellence possible. How Success Happens September 6, 2007 2 min read Brought to you by PCWorld Just when you think that color-laser printer prices can’t get any lower, they do. Dell’s new Color Laser Printer 1320c debuts at the top of our chart this month, with a killer price and competent overall performance. Its most notable achievement: surprisingly smooth photo quality for a low-end laser. Its major drawback: tiny, pricey toner cartridges. Replacing all four of them at once could cost almost as much as the printer itself (though that’s not an unusual phenomenon; many inexpensive color lasers’ toner sets cost as much as or even more than the printer itself).You’ll get a better cost per page out of the other new arrival, the fourth-place Brother HL-4040CN; it also boasts supercrisp text quality (a bit better than the Dell’s). Neither printer is particularly expandable, but that’s the price you pay for the price you pay.Find the Very Latest Printer ChartsClick on the links below for the latest online printer rankings or a comprehensive list of all printers we’ve tested.Most current Top Inkjet Printers chartMost current Top Multifunction Printers chartMost current Top Monochrome Laser Printers chartMost current Top Color Laser Printers chartAll Printers Listen Now