Insect intelligence: paper wasps display strong long-term memory
Jeremy Hance, mongabay.com
November 30, 2008
A recent study in Current Biology finds that paper wasps are capable of remembering rivals a week after initially meeting. As a highly social insect, the discovery proves that the paper wasps’ social interactions are based on applied memory rather than simple instinct. The finding overturns many ideas about the intelligence of insects.
An important part of the finding is the longevity of the paper wasp’s memory. Michael Sheehan, a graduate student who worked on the study, notes that honeybees remember where they have found nectar in the past, “but those memories are pretty fleeting.”
Not so for the paper wasp. To test their memory Sheenan and Elizabeth Tibbets, assistant professor of ecology and evolutionary biology, videotaped reactions of wasp queens as they met for their first time and again one week later.
Studying the footage, it became clear that the wasps were much more aggressive toward each other the first time they met. The second meeting a week later was a different story: "instead of trying to bite each other and really have a rough-and-tumble encounter, they just sort of hung out next to each other," Sheehan said.
To ensure that the wasps were truly employing individual memories of past meetings, the scientists introduced the wasp to more strangers in-between the first and second encounter. Every encounter with a stranger was characterized by high aggression.
"The interesting aspect of this work is not just that the wasps have a good memory, but that it's social memory," Sheehan commented. "It seems that their specific social history with particular individuals is something they're keeping track of and that it matters to their lives."
Female paper wasps share nests, therefore the ability to remember past encounters with others allows them to not waste energy in aggressive action with individuals whom it has already settled its differences.
Intelligence and applied memory are not terms often associated with insects, even highly social ones. Scientists have long believed that being able to form memories and apply them belonged only to species with large brains. Yet the wasps’ brain is less than a millionth size of our own and can still form important and long-term memories. Such a finding has implications on our concepts of animal intelligence, social cognition, and brain evolution.
Micheal J. Sheehan, Elizabeth A. Tibbetts. Robust long-term social memories in a paper wasp. Current Biology, September 23rd, 2008.
Future threats to the Amazon rainforest
(7/31/2008) Between June 2000 and June 2008, more than 150,000 square kilometers of rainforest were cleared in the Brazilian Amazon. While deforestation rates have slowed since 2004, forest loss is expected to continue for the foreseeable future. This is a look at past, current and potential future drivers of deforestation in the Brazilian Amazon.
Brazil charges 81 with illegal Amazon deforestation
(11/2/2008) Brazil will file charges against 81 people accused of being the biggest destroyers of the Amazon rainforest, reports the Associated Press.
Wal-mart mulling contribution to Brazil’s Amazon rainforest fund
(10/26/2008) Wal-mart may contribute to Brazil’s fund for conserving the Amazon rainforest, said Brazilian Environment Minister Carlos Minc.
Brazil to have high resolution imagery for 86% of the Amazon by year end
(10/15/2008) Brazil will have high resolution imagery for 86 percent of its Amazon territory by the end of the year, according to Reuters. The images will help the country protect the Amazon rainforest and prosecute alleged environmental crimes, including illegal logging and agricultural expansion.
Slowing global economy will reduce Amazon deforestation
(10/8/2008) The global financial crisis will likely slow forest clearing in the Amazon rainforest, said Brazil’s environment minister. Falling commodity prices combined with tighter credit and increased aversion to risk will undermine the economics of activities — including logging and agricultural expansion — that are key drivers of deforestation in the Brazilian Amazon. Forest clearing in the region has shown an increasingly tight correlation to beef and soy prices in recent years. Both products are produced on cleared rainforest lands.
Brazilian government is biggest destroyer of the Amazon rainforest
(9/30/2008) A Brazilian government agency changed with land distribution to the poor is the largest driver of deforestation since 2005, according to the country's environmental ministry.
Brazil plans to cut Amazon deforestation to zero by 2015
(9/26/2008) Brazil aims to cut net deforestation to zero by 2015 according to a plan that will be released by the government next week.
Brazil suspends Amazon road project until protected areas established
(9/26/2008) Brazil has temporarily suspended the paving of a major Amazon road pending demarcation of 13 neighboring protected areas, reports the Associated Press.
Brazil to establish oil palm plantations on degraded Amazon rainforest lands
(8/20/2008) Brazil will allow the establishment of oil palm plantations on degraded lands in the Amazon rainforest under a agreement signed between Brazil’s ministers of agriculture and the environment, reports Folha de S. Paulo.
Deforestation in the Brazilian Amazon won’t increase significantly for 2008
(8/15/2008) Brazilian Environment Minister Carlos Minc said Thursday that Amazon deforestation for the 2007-2008 year will likely be comparable to the prior year. The announcement marks an abrupt turn-around for the Brazilian government which in April said that forest destruction was expected to increase for the first time since 2004.
Climate change to hurt Brazil’s farm exports by 2020
(8/11/2008) Climate change could have a significant impact on thye value of Brazil’s agricultural exports according to a study presented Monday at an agribusiness conference in Sao Paulo, reports the Financial Times.
Brazil to send more police into the Amazon to fight illegal logging
(7/23/2008) Brazilian President Luiz Inacio Lula da Silva signed two decrees Tuesday to rein in illegal forest clearing in the Amazon, reports the Associated Press (AP).
Amazon timber industry declares ban on illegal logging
(7/18/2008) The Brazilian state of Pará today announced a ban on the sales of illegally logged timber from the Amazon rainforests.