Behavior brief

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,;http://www.cell.com/current-biology/abstract/S0960-9822%2810%2901449-1 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 et al., "Whistling in caterpillars (Amorpha juglandis, Bombycoidea): sound-producing mechanism and function," linkurl:Journal of Experimental Biology,;http://jeb.biologists.org/cgi/content/abstract/214/1/30?ijkey=2f77babd09f2a13b1f57af5b0c947dc48f9d2767&keytype2=tf_ipsecsha 214:30-37, 2011.

Bait use in birdsAfter reviewing the literature, researchers concluded bait fishing by certain species of herons is a real and distinct behavior. Bait fishing is characterized by a bird placing an attractive, buoyant object on the water within striking distance, and waiting for their prey to swim up -- a behavior some consider tool use. Graeme D. Ruxton and Michael H. Hansell, "Fishing with a Bait or Lure: A Brief Review of the Cognitive Issues," linkurl:Ethology,;http://onlinelibrary.wiley.com/doi/10.1111/j.1439-0310.2010.01848.x/abstract 117:1-9, 2011.

Seasonal cuisine for cougars

Cougar, Puma concolor
Wikimedia Commons/Malcom

Cougars change their predation patterns by season, according to what prey is vulnerable at a given time of year, new research suggests. Cougars hunt mostly juvenile ungulates in the summer when they are plentiful, females in the spring when they are weak from pregnancy, and males in autumn, during the rut, when they are exhausted from fighting. Kyle H. Knopff et al., "Cougar Kill Rate and Prey Composition in a Multiprey System," linkurl:Journal of Wildlife Management,;http://www2.allenpress.com/pdf/WILD-74-07_1435_1447.pdf 74:1435?1447; 2010.Smell and sight distinguishes sexFlies use sight and smell to distinguish sex. When faced with flies free of pheromones, males attack other males but not females. When females are doused in male pheromones, however, males attack them as if they are males, indicating that pheromonal cues can override visual cues.M.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,;http://www.plosbiology.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000541;jsessionid=7D06B6FE921E9C631E323937C6E11E33.ambra01 2010.Dull but not defunctWhen their sharp mandibles get dull, leaf-cutter ants switch jobs and join the delivery workers, carrying the bits of leaf cut from the foraging site to the colony, suggesting that displaced workers can still be useful within the community. Robert 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,;http://www.springerlink.com/content/n0u117221888kv68/ 2010.

Eavesdropping to gain trustSong sparrows can eavesdrop on interactions between others in the population to gain information about whether or not certain individuals should be trusted, a behavior researchers call indirect reciprocity. Çaǧlar Akçay et al., "Indirect reciprocity: song sparrows distrust aggressive neighbours based on eavesdropping," linkurl:Animal Behaviour,;http://faculty.washington.edu/beecher/Akcay%20etal%20AB%202010.pdf 80:1041-1047, 2010.
**__Related stories:__***linkurl:Behavior brief;http://www.the-scientist.com/news/display/57813/
[18th November 2010] *linkurl:Chimp's gestures share language roots;http://www.the-scientist.com/blog/display/54388/
[28th February 2008] *linkurl:Fly sex peptide flips behavior;http://www.the-scientist.com/news/display/53981/
[10th December 2007]