Data from: Tadpole begging reveals high quality

Parents can benefit from allocating limited resources non-randomly among
offspring, and offspring solicitation (i.e., begging) is often
hypothesized to evolve because it contains information valuable to choosy
parents. We tested the diagnostic predictions of three ‘honest begging’
hypotheses –Signal of Need, Signal of Quality, and Signal of Hunger – in
the tadpoles of a terrestrial frog (Oophaga pumilio). In this frog,
mothers provision tadpoles with trophic eggs, and when mothers visit,
tadpoles perform a putative begging signal by stiffening their bodies and
vibrating rapidly. We assessed the information content of intense tadpole
begging with an experimental manipulation of tadpole condition
(need/quality) and food-deprivation (hunger). This experiment revealed
patterns consistent with the Signal of Quality hypothesis and directly
counter to predictions of Signal of Need and Signal of Hunger. Begging
effort and performance were higher in more developed and higher condition
tadpoles and declined with food-deprivation. Free-living mothers were
unlikely to feed tadpoles of a non-begging species experimentally
cross-fostered with their own, and allocated larger meals to more
developed tadpoles and those that vibrated at higher speed. Mother O.
pumilio favour their high quality young, and because their concurrent
offspring are reared in separate nurseries, must do so by making active
allocation decisions. Our results suggest that these maternal choices are
based at least in part on offspring signals, indicating that offspring
solicitation can evolve to signal high quality.