HERITABILITY OF SELECTIVELY ADVANTAGEOUS FORAGING BEHAVIOR IN A SMALLPASSERINE

I measured the heritability of foraging patch choice in a laboratory p opulation of zebra finches (Taeniopygia guttata). Mothers and offsprin g were tested for their ability to discriminate between four foraging patches which provided four different rates of energy gain. Use of a f oraging patch with a high rate of energy gain has been shown to confer a selective advantage on zebra finches in a similar experimental syst em. In this population of zebra finches there was a large amount of va riation in foraging patch choice behaviour both within and among indiv iduals. I determined that foraging patch choice was a phenotypically l abile trait with a degree of stereotypy or repeatability, much lower t han those typically recorded for morphological traits. The mating beha viour of zebra finches required that heritability be determined from a mother-offspring regression, which showed that narrow sense heritabil ity of foraging patch choice was approximately 0.346. This heritabilit y was significantly different than zero, as was heritability when it w as limited by repeatability to 0.246. Foraging patch choice, a behavio ur that has a demonstrated fitness consequence, had a heritable compon ent in this laboratory population of zebra finches.