Resource preferences and the emergence of individual niche
specialization within populations
Abstract
Growing evidence that individuals of many generalist animals behave as
resource specialists has attracted research interest for its ecological
and evolutionary implications. Although variation in resource
preferences is critical for developing a general theory of individual
specialization, it remains to be shown whether diverging preferences can
arise among individuals sharing a similar environment and whether these
are stable enough to be ecologically relevant. We addressed these issues
by means of common garden experiments in feral pigeons (Columba livia),
a species known to exhibit resource specialization in the wild.
Food-choice experiments on wild-caught pigeons and their captive-bred
descendants showed that variation in food preferences can easily arise
within a population and that this variation may represent a substantial
fraction of the population niche. However, a cross-fostering experiment
revealed that the genetic and early common-environment components of
food preferences were low, reducing their stability and eroding niche
variation in the long-term.