Chimps carry dolls
Chimpanzee, Pan troglodytes
Wikimedia Commons/Kallgan
Both male and female young chimpanzees play with sticks, but females do so more often and occasionally carry them like mother chimpanzees carry their offspring. These findings suggest that the tendency for girls to play more with dolls more than boys is not just a result of sex-stereotyped socialization, but rather comes, at least in part, from biological preferences.Sonya M. Kahlenberg and Richard W. Wrangham, "Sex differences in chimpanzees' use of sticks as play objects resemble those of children," Current Biology, AOP, linkurl:doi:10.1016/j.cub.2010.11.024,; 2010.Whistling warnings to predatorsWalnut sphinx caterpillars blow air out of a small hole on their abdomen called a spiracle, making a whistling sound that is audible to birds and humans. Lasting up to four seconds, the whistle appears to ward off predators, such as hungry birds, which fly away upon hearing the sound.Veronica L. Bura...
Bait use in birdsGraeme D. Ruxton and Michael H. Hansell, "Fishing with a Bait or Lure: A Brief Review of the Cognitive Issues," linkurl:Ethology,; 117:1-9, 2011.Seasonal cuisine for cougars
Cougar, Puma concolor
Wikimedia Commons/Malcom
Kyle H. Knopff et al., "Cougar Kill Rate and Prey Composition in a Multiprey System," linkurl:Journal of Wildlife Management,; 74:1435?1447; 2010.Smell and sight distinguishes sexM.P. Fernandez et al., "Pheromonal and Behavioral Cues Trigger Male-to-Female Aggression in Drosophila," PLoS Biology, AOP, linkurl:doi:10.1371/journal.pbio.1000541,;;jsessionid=7D06B6FE921E9C631E323937C6E11E33.ambra01 2010.Dull but not defunctRobert M. S. Schofield et al., "Leaf-cutter ants with worn mandibles cut half as fast, spend twice the energy, and tend to carry instead of cut," Behavioral Ecology and Sociobiology, AOP, linkurl:doi: 10.1007/s00265-010-1098-6,; 2010.Eavesdropping to gain trust Çaǧlar Akçay et al., "Indirect reciprocity: song sparrows distrust aggressive neighbours based on eavesdropping," linkurl:Animal Behaviour,; 80:1041-1047, 2010.

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