Helpers: Effects of Experimental Removal on Reproductive Success

Science  22 Jan 1982:
Vol. 215, Issue 4531, pp. 421-422
DOI: 10.1126/science.215.4531.421


Experimental removal of helpers from a communal bird population decreased the reproductive success of the reduced units. By controlling for variables that are potentially correlated with both reproductive success and unit size, this experiment establishes that helpers-contribute significantly to their indirect fitness.