Behavior brief

Like-minded parents, healthier babies

Image: Wikimedia commons, Liza Gross

Zebra finch pairs that share personality traits like high aggression and an interest in exploration tend to raise healthier, more well fed offspring than pairs who differ, suggesting that parents with similar personalities may cooperate better when caring for their young.W. Schuett et al., "Pairs of zebra finches with similar 'personalities' make better parents," linkurl:Animal Behaviour,;http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W9W-51YB0FF-1&_user=10&_coverDate=01%2F15%2F2011&_alid=1622354788&_rdoc=5&_fmt=high&_orig=search&_origin=search&_zone=rslt_list_item&_cdi=6693&_sort=d&_docanchor=&view=c&_ct=702&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=869cbc839f40ed9803f25454c2d2c6e7&searchtype=a AOP, doi:10.1016/j.anbehav.2010.12.006, 2011.Trading sex for smartsButterflies that learn to recognize red host plants, in addition to the green plants they find by instinct, can lay their eggs in a wider range of environments, but also tend to reproduce less in their lifetime and enter adulthood with fewer developed eggs, suggesting that a trade-off exists between learning and reproduction.E.C. Snell-Rood et al., "Reproductive tradeoffs of learning in a butterfly," linkurl:Behavioral Ecology,;http://beheco.oxfordjournals.org/content/early/2011/01/20/beheco.arq169.full AOP, doi: 10.1093/beheco/arq169, 2011.

Image: Wikimedia commons, Nevil Lazarus

Flirtation via fear?Male splendid fairy-wrens, small promiscuous birds in Australia, tend to call for mates when they hear the calls of their predators, possibly because females are more alert when predators are nearby. Alternatively, the added risk of predation associated with singing around predators may serve as a signal of bravery or physical fitness to females or nearby competitors.

E.I. Greig & S. Pruett-Jones, "Danger may enhance communication: predator calls alert female to male displays," linkurl:Behavioral Ecology,;http://beheco.oxfordjournals.org/content/21/6/1360.abstract?sid=bedf9158-2737-4c1c-886f-6db199ec05b2 21:1360-1366, 2011.Dogs don't get logicDogs always find food regardless of whether they are given an "irrational" direction (a pointing to food with an extended leg when the researcher's hands could have been used) or a "rational" direction (pointing to food with an extended leg when their hands were occupied), suggesting that dogs cannot distinguish between rationality and irrationality -- challenging previous research. J. Kaminski et al., "Do dogs distinguish rational from irrational acts?" linkurl:Animal Behaviour,;http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W9W-51CHMC0-1&_user=10&_coverDate=01%2F31%2F2011&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=ad105ff6c280566e73dfcfd4a5630ab5&searchtype=a 81: 195-203, 2011.Optimistic rats

Image: Wikimedia commons, AlexK100

Rats housed with toys like cardboard tubes and wooden blocks tend to have more positive expectations than their peers -- after being trained to associate more or less food with two different cues, rats in these enriched environments are more likely to anticipate a higher food reward when presented with ambiguous stimuli.N.M. Brydges et al., "Environmental enrichment induces optimistic cognitive bias in rats," linkurl:Animal Behaviour,;http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W9W-51J17KJ-1&_user=10&_coverDate=01%2F31%2F2011&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=a59b3cc475ae235489a81384b387ff2b&searchtype=a 81:169-175, 2011.Parasites deter predatorsNematodes cause their insect larvae hosts to become bio-luminescent and change to a bright pink-red color, seemingly to deter predators and avoid certain death when their host is eaten. A. Fenton et al., "Parasite-induced warning coloration: a novel form of host manipulation," linkurl:Animal Behaviour,;http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W9W-51PR0K9-3&_user=10&_coverDate=02%2F28%2F2011&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b2f044025e4c2cb687e77f2a414c0d5f&searchtype=a 81:417-422, 2011.

Image: Wikimedia commons, Boivie

Swapping shelter for poopOn the southeast Asian island of Borneo, an unusual mutualistic relationship exists between the common woolly bat and a carnivorous pitcher plant. The plant's pitcher provides a safe haven for the bat to roost, and the bat, in turn, defecates in the pitcher, providing the plant with much needed nitrogen.T.U. Grafe et al., "A novel resource-service mutualism between bats and pitcher plants," Royal Society Biology Letters, AOP, linkurl:doi:10.1098/rsbl.2010.1141,;http://rsbl.royalsocietypublishing.org/lookup/doi/10.1098/rsbl.2010.1141 2011.Skill in numbers Mosquitofish make decisions more accurately and quickly when housed in larger groups -- a benefit that may have facilitated the evolution of socialization in a diverse array of animals, including humans.A. Ward et al., "Fast and accurate decisions through collective vigilance," linkurl:PNAS,;http://www.pnas.org/content/early/2011/01/14/1007102108.abstract AOP, doi: 10.1073/pnas.1007102108, 2011.Old clothes

Image: linkurl:Wikimedia commons;http://commons.wikimedia.org/wiki/File:Rhodesian_Men.jp

By tracking the evolution of human head lice, researchers have discovered that humans began wearing clothes about 170,000 years ago -- nearly 70,000 years before previously thought, but still well after they began to lose body hair around 1 million years ago. M.A. Toups et al., "Origin of Clothing Lice Indicates Early Clothing Use by Anatomically Modern Humans in Africa," linkurl:Molecular Biology and Evolution,;http://mbe.oxfordjournals.org/content/28/1/29.abstract?sid=3a3be093-c83e-4159-818a-e674af1e3865 28:29-32, 2011.
**__Related stories:__***linkurl:Behavior brief;http://www.the-scientist.com/news/display/57909/
[6th January 2011] *linkurl:Behavior brief;http://www.the-scientist.com/news/display/57813/
[18th November 2010]