The chirp-and-wave recruitment maneuver set off mini-stampedes of mole-rat recruits, and the biologists were ready. They had constructed their plastic labyrinth with several alternative food sources -- in addition to the ones the scouts had discovered -- to learn how recruits find their way to the new food sources without the scouts to guide them.
More often than not, the recruits ignored the alternative food sources and followed routes to the roots their scouts had found. The recruits may be following the scouts' signature scents, which are left in the tunnels or they may be following "map directions" provided by the scouts. To test that hypothesis, the biologists switched the tunnel through which the scouts had traveled to the other side of the maze. They found that recruits followed the scouts' trails but not their directions. When tunnels through which scouts had traveled were replaced with clean tunnels, the recruits were confused.
Recruitment behaviors to share newly discovered food sources are well known in the animal kingdom, Sherman said, pointing to honey bees, ants and some bird and primate species. "Very different species have evolved similar communication signals to ensure survival, " he said. "In the case of the mole-rats and social insects, if the foragers don't share their knowledge, the rest of the colony may starve -- and fail to pass on their nearly identical genes. Food recruitment is a way for individuals to enhance what evolutionary biologists call 'inclusive fitness.' "
Apparently naked mole-rats do not "dance" to give directions behaviorally, as do honey
bees, but lay down chemical trails, as do some ants and tent catepillars. However, the
Cornell study did earn nake
'"/>
Contact: Roger Segelken
hrs2@cornell.edu
607-255-9736
Cornell University News Service
22-Nov-1996